1. A method of a wireless router, comprising:accessing, by the wireless router, default credentials, wherein the default credentials include a birth certificate, wherein the birth certificate was issued by a manufacturer of the wireless router;
checking, by the wireless router, access to a backhaul link to an upstream network;
authenticating, by the wireless router, using the default credentials;
procuring, by the wireless router, from a CA (Certificate Authority) server, a customer certificate of a customer comprising the wireless router procuring digital certificates issued by the customer for a certificate validity time using a standard protocol;
replacing, by the wireless router, the birth certificate with the customer certificate;
authenticating, by the wireless router, with an authentication server using the customer certificate;
procuring, by the wireless router, from a management server, a customer specific wireless mesh configuration after being authenticated by the authentication server, comprising the wireless router connecting to the management server using the customer certificate, and once authenticated, the management server downloading the customer specific wireless mesh configuration to allow the wireless router to operate within the wireless mesh network, wherein the customer specific wireless mesh configuration comprises at least a mesh ID, a radio channel number, and IP addresses of the wireless router;
rebooting, by the wireless router, using the customer specific wireless mesh configuration, thereby allowing the wireless router to operate within a wireless mesh network, wherein the rebooting is triggered upon obtaining the customer specific wireless mesh configuration; and
broadcasting, by the wireless router, service set identifiers (SSIDs) derived from the default credentials.

1. A galvanic separating apparatus, comprisinga printed circuit board, the printed circuit board comprising a first soldering pad, a second soldering pad and a recess, whereby the pads are arranged on a lower side of the printed circuit board thereby defining a clearance and/or creepage distance between the pads, and the recess is arranged between the pads,
a bobbin arranged on an upper side of the printed circuit board, the bobbin comprising an axle and a pair of flanges,
a primary insulated winding layer connected to the first soldering pad and a second insulated winding layer connected to the second soldering part, whereby the winding layers are arranged on the upper side of the printed circuit board and are wound about the axle of the bobbin within the pair of flanges, and
an insulating layer, whereby the insulating layer extends from the upper side through the recess and protrudes on the lower side beyond the printed circuit board thereby increasing the clearance and/or creepage distance, whereby
a portion of the insulating layer is arranged within the bobbin between the pair of flanges, and
the clearance and/or creepage distance is ?1.2 a distance between the pads on the lower side of the printed circuit board.

1. An electrical device comprisingan electrical apparatus including a gas insulation, the electrical apparatus is one of a gas-insulated transformer or gas-insulated reactor, comprising a housing enclosing an interior space, at least a portion of which interior space defining an insulation space containing a dielectric insulation fluid comprising an organofluorine compound, and an electrical component being arranged in the insulation space and being surrounded by the insulation fluid, said electrical component comprising at least one winding, the electrical device further comprising
an electrical connector for bringing the electrical apparatus from a non-operational state to an operational state by connecting one or more of the at least one winding to a power grid,
wherein the device further comprises an auxiliary power source which is connectable to one or more of the at least one winding when the electrical apparatus is in the non-operational state,
wherein the auxiliary power source is an auxiliary alternating-current power source, and
wherein the auxiliary alternating-current power source has an electrical power rating comparable to rated load losses of the electrical apparatus.

1. A system comprising:an apparatus including a housing configured to contain a fluid;
a multi-layer coating applied to the housing;
wherein the multi-layer coating includes:
a layer of a primer coating;
a layer of a mid coating including mechanical and chemical properties capable of at least partially closing a hole in the housing; and
a layer of a top coating including properties that resist ultraviolet radiation from passing therethrough.

1. A control system for monitoring and control of a micro-grid, the micro-grid comprising a plurality of power generating sources capable of being connected and disconnected from a plurality of electrical loads in the micro-grid and a rotating electrical machine electrically connectable to an electrical bus of the micro-grid as one of a power generating source and an electrical load, the control system comprising:a plurality of controllers for controlling the plurality of power generation sources and the plurality of loads, wherein the plurality of controllers are communicatively connected to each other over a communication bus, the plurality of controllers comprising:
a first controller for controlling at least one of a power generation source and an electrical load, from the plurality of power generation sources and from the plurality of electrical loads respectively; and
a second controller for controlling the rotating electrical machine, wherein the second controller operates a clutch for at least one of coupling and decoupling a shaft of the rotating electrical machine to a shaft of a prime mover and ensures electrical synchronization between the rotating electrical machine and the micro-grid prior to connecting the rotating electrical machine to the electrical bus of the micro-grid;
wherein the first controller is configured to detect a power variation event in the associated at least one of the power generation source and the electrical load, controlled by the first controller; and
wherein the second controller is configured to operate the rotating electrical machine by operating the clutch for at least one of (i) coupling the shaft of the rotating electrical machine to the shaft of the prime mover for supplying electrical power to the electrical bus of the micro-grid and (ii) de-coupling the shaft of the rotating electrical machine from the shaft of the prime mover, based on a communication indicative of the power variation event on the communication bus.

1. A method of monitoring switching by an on-load tap changer, OLTC, from a first contact to a second contact of a transformer winding during a switching time period, the method comprising:measuring (M1) a phase voltage of the transformer over time;
measuring (M2) a temperature of the OLTC over time;
based on the measured voltage and temperature, determining (M3) that the switching from the first contact to the second contact has not been successful;
wherein the determining (M3) includes determining that the measured voltage has changed during the switching time period and that the change is above a predetermined threshold; and
wherein the determining (M3) includes determining that the measured temperature continues to rise after the end of the switching time period.

1. A fast earthing switch device for High Voltage applications comprising:a gas-tight casing, a movable contact connectable to and unconnectable from a fixed contact, said movable contact being linearly movable along a direction of movement between an open position in which said movable contact is spaced apart from said fixed contact and a closed position in which said movable contact is connected to said fixed contact, and vice-versa,
an operating mechanism for said movable contact, said operating mechanism comprises an actuating spring actuating a closing operation of said movable contact from said open position to said closed position, at least a driving lever mounted on an operating shaft actuating an opening operation of said movable contact from said closed position to said open position, said driving lever also partially reloading said actuating spring during said opening operation, and
coupling means operatively coupling said driving lever to said movable contact,
wherein said closing operation comprises a first phase in which said driving lever is engaged with said coupling means and moves said movable contact so that said movable contact is further spaced apart from said fixed contact while said actuating spring is further loaded, and a second phase in which said driving lever disengages from said coupling means and the movable contact is free to fast move under an action of said actuating spring into said closed position.

1. A gas-insulated high-voltage switching device, comprising:an arcing contact arrangement comprising a first arcing zone member and a second arcing zone member, wherein the first arcing zone member and the second arcing zone member are movable relative to one another along an axis (B),
wherein the first arcing zone member comprises a first arcing contact unit; and
wherein the second arcing zone member comprises:
a second arcing contact unit configured to receive the first arcing contact unit;
an auxiliary nozzle surrounding at least a part of the second arcing contact unit and having an auxiliary nozzle throat which has an axial extension and allows passage at least of an end of the first arcing contact unit,
a main nozzle surrounding at least a part of the auxiliary nozzle, and having a main nozzle throat, which has an axial extension sideways of the auxiliary nozzle throat and allows passage at least of the end of the first arcing contact unit,
a cross-sectional area of the main nozzle throat is decreasing in an axial direction away from the auxiliary nozzle throat so as to form a converging flow duct for a flow of an arc-extinguishing gas wherein
the converging flow duct of the main nozzle throat has a length L in the axial direction in a range of 15 mm to 80 mm, and
the main nozzle throat has an aperture angle ? in a range from more than 0° to at most 15° and a shape of the main nozzle throat is frusto-conical.

1. A transformer system, comprising:a transformer;
a transformer tank housing the transformer in a bath of a coolant;
a ballistic impact detection system having a controller and at least one ballistic impact sensor communicatively coupled to the controller, wherein the ballistic impact detection system is operative to determine an occurrence of a ballistic impact on the transformer system based on an output of the at least one ballistic impact sensor; and
a plurality of radiator systems operative to transfer heat from the coolant, each radiator system of the plurality of radiator systems having a top actuated valve communicatively coupled to the controller and fluidly coupling the top of the each radiator system to the transformer tank; a bottom actuated valve communicatively coupled to the controller and fluidly coupling the bottom of the each radiator system to the transformer tank; and a float level sensor communicatively coupled to the controller and operative to detect a level of the coolant in each radiator system of the plurality of radiator systems;
wherein upon a determination of the occurrence of the ballistic impact, the controller is operative to direct each top actuated valve and each bottom actuated valve to close, and
wherein the controller is operative to determine, after each top actuated valve and each bottom actuated valve are closed, whether any of the radiator systems of the plurality of radiator systems are leaking coolant based on an output of the float level sensors.

1. A phase shifting transformer for poly-phase alternating current (AC) with source side terminals and with load side terminals, the phase shifting transformer comprising:an exciting unit comprising a first transformer with primary coils connected between pairs of the source side terminals and with secondary coils to provide quadrature voltages; and
a series unit comprising a second transformer with primary coils connected in series between the source side terminals and the load side terminals and with secondary coils to receive the quadrature voltages, thus providing a voltage phase displacement between the source side terminals and the load side terminals;
wherein the exciting unit comprises further coils that are magnetically coupled to the primary coils and to the secondary coils of the exciting unit to provide further voltages, with the further coils connected in series between the source side terminals and the series unit, so that the voltages at the load terminals are combinations of the quadrature voltages and the further voltages with the source voltages, thus modifying the voltage phase displacement between the source side terminals and the load side terminals.

1. A magnetic shunt assembly for magnetic shielding of a power device, comprising:a plurality of joined ferromagnetic sheets in the form of strips wound in a spiral arrangement, each of the plurality of joined ferromagnetic sheets having a same width and each made from a same grain-oriented ferromagnetic material, and a plurality of bonding layers for bonding subsequent sheets of said plurality of ferromagnetic sheets to form an integral assembly, wherein each of the plurality of ferromagnetic sheets is bonded to an adjacent one of the plurality of ferromagnetic sheets via a respective one of the plurality of bonding layers, wherein the ferromagnetic sheets and the bonding layers are aligned, said bonding layers being one of:
obtained from a thermosetting resin;
formed from an adhesive system comprising an epoxy adhesive and a curing agent;
formed from an adhesive system comprising an epoxy adhesive curable by heat;
formed from an adhesive system comprising an acrylic adhesive and a curing agent;
wherein the plurality of joined ferromagnetic sheets form outermost layers of the magnetic shunt assembly; and
means for coupling the magnetic shunt assembly externally of the power device.

1. A transformer system, comprising:a transformer;
a transformer tank housing the transformer in a bath of a dielectric fluid;
a controller; and
a fiber optic pressure sensor communicatively coupled to the controller, the fiber optic pressure sensor including a fiber optics bundle disposed and submerged in the dielectric fluid in the transformer tank and operative to provide an output that varies with a pressure of the dielectric fluid,
wherein the controller is operative to determine the pressure of the dielectric fluid based on the output of the fiber optic pressure sensor;
wherein the controller is operative to determine an occurrence of a ballistic impact on the transformer tank by determining a level of the dielectric fluid based on the output of the fiber optic pressure sensor and comparing the level of the dielectric fluid to a prior level of the dielectric fluid or to a threshold level of the dielectric fluid, and
wherein the controller is operative to determine an occurrence of a ballistic impact on the transformer tank by determining, based on the output of the fiber optic pressure sensor, a rate of change of the level of the dielectric fluid in the transformer tank.

1. A method for travelling wave protection of a transmission line, the method comprising:performing high-pass filtering of a current and/or voltage measurement of a transmission line so as to detect fault-caused high-frequency components of said current and/or voltage measurement, wherein the high-pass filtering has a cut-off frequency which is higher than the highest frequency of harmonics of the current and/or voltage measurement; and
providing a result of said high-pass filtering as input to a trip decision maker performing travelling wave protection.

9. A device for calculating winding currents at a delta side for a transformer comprising two or more windings connected with two or more lines, with at least a first winding of the two or more windings being a delta connected winding, the device comprising:an input interface configured to obtain line currents measured with measurement equipment associated with the two or more lines;
a current calculator configured to:
calculate zero sequence currents for at least a second winding of the two or more windings of the transformer, from the line currents measured at a corresponding line connected with at least the second winding;
calculate zero sequence currents for the first winding based on (i) the zero sequence currents calculated for at least the second winding, (ii) a phase displacement between the two or more windings, and (iii) a turns ratio associated with the two or more windings of the transformer; and
calculate winding currents for the first winding from the zero sequence currents calculated for the first winding and from the line currents measured at a corresponding line connected with the first winding; and
an output interface configured to render the calculated winding currents for one or more monitoring, protection, and control operations associated with the transformer.

1. A modular multilevel voltage source converter comprising:a number of phase legs, each of the phase legs comprising an upper and a lower phase arm comprising cells with energy storage elements; and
a control unit operative to:
model a circulating current in one of the phase legs using a first expression (?VPR1, ?Vcap-PR1), a second expression (?VR2N, ?Vcap-R2N) and at least one modulation signal (mR, mcm), where the first expression comprises the sum of cell voltages measured in the upper phase arm ?Vcap-PR1 and the second expression comprises the sum of cell voltages measured in the lower phase arm ?Vcap-R2N;
determine a circulating current control signal (ER1?ER2+2VCM) for the one of the phase legs through the circulating current modelling without measuring the circulating current in the one of the phase legs; and
combine the circulating current control signal as a feed forward signal with a modulation signal used for one phase arm of the phase arms thereby obtaining a modified modulation signal controlling the one phase arm of the phase arms to reduce or introduce a circulating current while a waveshape is formed, wherein the at least one modulation signal comprises the modulation signal used for the one phase arm of the phase arms.

1. A method for operating a microgrid network comprising a first microgrid and a second microgrid, the method comprising:synchronizing the first microgrid operating at a first voltage and a first frequency with the second microgrid operating at a second voltage and a second frequency by
determining a first voltage range and a first frequency range for operating the first microgrid;
determining a second voltage range and a second frequency range for operating the second microgrid;
determining an overlapping voltage range included within both the first voltage range of the first microgrid and the second voltage range of the second microgrid;
determining an overlapping frequency range included within both the first frequency range of the first microgrid and the second frequency range of the second microgrid;
selecting a third voltage within the overlapping voltage range;
selecting a third frequency within the overlapping frequency range;
controlling the first microgrid to change from the first voltage and the first frequency to the third voltage and the third frequency;
controlling the second microgrid to change from the second voltage and the second frequency to the third voltage and the third frequency; and
connecting the first microgrid with the second microgrid by closing a switch connecting the first microgrid to the second microgrid.

15. A system comprising:a historian data repository configured to:
acquire historical sensor data yielded from one or more sensors operably coupled to power system equipment, the historical sensor data indicative of one or more sensor measurements; and
acquire historical field test data yielded from one or more field tests performed on the power system equipment, the historical field test data indicative of one or more field test measurements; and
a data analyzer component configured to:
analyze the historical sensor data and the historical field test data to identify a design flaw of a component of the power system equipment;
determine a redesign cost to redesign the component;
determine a failure impact corresponding to a failure of the power system equipment due to the component failing from the design flaw; and
perform one of (i) a redesign of the component in response to the failure impact exceeding the redesign cost, or (ii) a redesign of a second component of the power system equipment in response to the redesign cost exceeding the failure impact.

1. A microgrid control system for a power microgrid configured to be connected to a power distribution grid via at least one point of common coupling, PCC, the microgrid comprising a plurality of assets in the form of distributed generators, DGs, loads and/or energy storages, the control system comprising:a microgrid controller arrangement; and
a network controller arrangement;
wherein the network controller arrangement is distributed and comprises a plurality of network controllers each being configured to:
be associated with an interface to a segment of the microgrid and perform measurements on the microgrid, including measuring a power flow over the interface,
send information to at least one other of the plurality of network controllers based on the performed measurements, and
send information to the microgrid controller arrangement based on the performed measurements, including frequency and voltage differentials, the information relating to assets of the plurality of assets which are comprised in the segment of the microgrid with which segment the network controller is associated;
wherein the microgrid controller arrangement is configured to, based on the information from the plurality of network controllers, calculate power and voltage references for each of the plurality of assets and control the plurality of assets by instructing respective converter controller of each of the plurality of assets.

1. An on-load tap changer, comprising:an actuator-configured to adjust a turn ratio of a transformer; and
a processing unit configured to control the actuator and to communicate with a control device via a digital signal connection, the processing unit being further configured to receive a status detected by a sensor, wherein the processing unit is configured to communicate at least one of a control command or the status with the control device, the processing unit being configured to control the actuator based on the control command; and
a panel connected to the processing unit and configured to indicate the status and receive the control command for controlling the actuator.

1. A system for in-situ inspection comprising: a remotely operated submersible having a ballast system which includes a pump, a pressure vessel reservoir, and an inflatable bladder, the pressure vessel reservoir in fluid communication via the pump with the inflatable bladder, the pump circulating a fluid to the pressure vessel reservoir from the inflatable bladder to achieve variable buoyancy, wherein movement of the fluid out of the pressure vessel reservoir alters a density of the pressure vessel reservoir to provide a buoyant force for the remotely operated submersible; wherein the fluid is transferred from the pressure vessel reservoir to the inflatable bladder by a pressure of the fluid in the pressure vessel reservoir; and wherein the fluid is transferred back from the inflatable bladder to the pressure vessel reservoir by pumping the fluid with the pump.

1. A system comprising:a three phase power transmission system including a first conductor line, a second conductor line and a third conductor line;
one or more sensors configured to detect traveling waves in each of the first second and third conductors;
a controller operable for receiving data transmitted by the one or more sensors and determining which of the traveling modal waves is a first metallic mode wave, a second metallic mode wave and/or a ground mode wave; and
wherein the controller is operable to determine which of the conductor lines are faulted based on detection of one or more of first metallic mode waves, second metallic mode waves and/or ground mode waves.

1. An on-load tap changer, comprising:an actuator-configured to adjust a turn ratio of a transformer; and
a processing unit configured to control the actuator and to communicate with a control device via a digital signal connection, the processing unit being further configured to receive a status detected by a sensor, wherein the processing unit is configured to communicate at least one of a control command or the status with the control device, the processing unit being configured to control the actuator based on the control command; and
a panel connected to the processing unit and configured to indicate the status and receive the control command for controlling the actuator.

1. A transformer, comprising:a first yoke formed of a plurality of first yoke laminations oriented parallel to a first plane, the plurality of first yoke laminations includes a first subset of laminations positioned adjacent an outer region thereof and a second subset of laminations positioned inward of and adjacent to the outer region, the first subset having a first length dimension and the second subset having a second length dimension shorter than the first length dimension;
a second yoke formed of a plurality of second yoke laminations oriented parallel to the first plane;
a center leg formed of a plurality of center leg laminations oriented parallel to a second plane that is oriented at an angle relative to the first plane, wherein the angle is less than 90 degrees, wherein the center leg includes a first end, and wherein the first yoke and the second yoke are in direct contact with the center leg at the first end;
a coil disposed around the center leg;
a butt joint between the first end of the center leg and at least one of the first yoke and the second yoke;
an outer leg formed of a plurality of outer leg laminations, wherein the outer leg and the first yoke are in direct contact; and
a mitered joint between the first yoke and the outer leg.

1. A surge arrester, comprising:a preassembled active part extending in a longitudinal direction; and
a separately produced flexible housing defining a bore in the longitudinal direction and having an opening at an end surface of the flexible housing,
the flexible housing being arranged surrounding the active part via the bore and in contact with the active part, the contact causing a deformation of the flexible housing in a circumferential direction, the deformation generating a pressure applied on the active part along a radial direction,
wherein the flexible housing comprises a thermoplastic or thermoset supporting member including a plurality of supporting pieces extending in the longitudinal direction, the supporting pieces being arranged along the circumferential direction in contact with a lateral surface of the active part,
wherein the flexible housing comprises an external insulation made of a flexible material and injected, casted or extruded at the supporting member.

1. A fluid-insulated electrical apparatus, comprising:a housing enclosing an interior space, in which interior space an electrical component comprising at least one winding is arranged, at least a portion of the interior space defining an insulation space;
an insulation fluid disposed within the insulation space and electrically insulating at least a part of the electrical component from the housing, the insulation fluid comprising a first organofluorine compound and a background gas, wherein the first organofluorine compound is selected from the group consisting of fluoroethers, fluoroketones, fluoroolefins, fluoronitriles, and mixtures thereof;
a cooling element comprising a condenser, an evaporator and a cooling fluid to be circulated between the condenser and the evaporator, the evaporator being configured such that at least a part of the electrical component is immersed in the cooling fluid in its liquid state, thus being in direct contact with the cooling fluid, the cooling fluid consisting of second organofluorine compound selected from the group consisting of fluoroethers, fluoroketones, fluoroolefins, fluoronitriles, and mixtures thereof, wherein the cooling fluid is devoid of a background gas,
wherein the insulation fluid has a first condensation temperature and the cooling fluid has a second condensation temperature lower than the first condensation temperature.

1. A particle extraction system comprising:a support bay configured to hold an electrical interrupter;
an actuator system operable for cycling the electrical interrupter to release particles;
a fluid source in fluid communication with internal flowpaths formed within the electrical interrupter, wherein flowing fluid from the fluid source is operable to entrain released particles therewith; and
a vacuum slot operable for receiving the flowing fluid and the entrained particles egressed from the electrical interrupter.

1. A monitoring arrangement for monitoring a surge arrester which is connected to a live wire of a power network at a connection point on the live wire in order to protect an electrical apparatus of the power network against incoming surges, the monitoring arrangement comprising:a conductor element, which is configured to be electrically connected to ground and to the surge arrester so that electric current impulses passing through the surge arrester will pass through this conductor element;
an analogue measuring circuit for sensing current impulses passing through the conductor element and producing analogue measuring signals representing such current impulses;
an analog-to-digital converter connected to the analogue measuring circuit and configured to sample the analogue measuring signals from the analogue measuring circuit in order to convert these analogue measuring signals into digital signals; and
an electronic processing device for receiving said digital signals from the analog-to-digital converter and producing monitoring data based on these digital signals;
wherein:
that the electronic processing device is configured to establish, based on digital signals produced by the analog-to-digital converter for a current impulse through the surge arrester caused by an incoming surge in the live wire, a voltage peak value representing the highest voltage at said connection point during the incoming surge; and
that the electronic processing device is configured to establish, based on said voltage peak value and by means of a calculation model or look-up table, a maximum-voltage value representing an estimated maximum voltage across the electrical apparatus during the incoming surge in question.

1. A high voltage winding for a single electrical phase of a high voltage electromagnetic induction device, wherein the high voltage winding comprises:a first winding part, and
a second winding part,
wherein the first winding part includes:
a first conductor,
a first solid electrical insulator circumferentially enclosing the first conductor, and
a first semi-conductive sheath circumferentially enclosing the first solid electrical insulator, wherein the first semi-conductive sheath is earthed or connected to an electric potential that is lower than a rated voltage of the high voltage winding, and
wherein the second winding part includes:
a second conductor, and
a second solid electrical insulator circumferentially enclosing the second conductor and forming an outermost layer of the second winding part.

1. A longitudinal voltage regulator, comprising:a voltage source configured to generate an additional voltage; and
a transformer configured to couple the additional voltage into an input voltage of the longitudinal voltage regulator,
wherein the transformer comprises the voltage source and is configured both to generate the additional voltage using the voltage source and to couple the additional voltage into the input voltage of the longitudinal voltage regulator,
wherein the transformer has a number of taps connected to output terminals of a step switch of the longitudinal voltage regulator; and
wherein positions of the taps are non-linearly distributed over a number of turns of a primary winding of the transformer such that a change in a selection of a tap of the number of taps enables a linear change in the additional voltage.

1. A method for controlling operation of an electrical power distribution network including a plurality of distributed energy resources (DERs), the method comprising:providing a distribution system controller at a transmission substation which couples the electrical power distribution network to an electrical power transmission grid;
providing a plurality of subnetwork controllers at a respective plurality of distribution substations serviced by the transmission substation and servicing a respective plurality of subnetworks of the distribution network, each of the subnetwork controllers configured to bi-directionally communicate with the distribution system controller and to bi-directionally communicate with a respective plurality of distributed energy resource controllers (DER controllers), each of the DER controllers configured to control operation of one or more of the plurality of DERs, one or more of the DER controllers being configured to control operation of two or more DERs which are located in different subnetworks of the distribution network;
in a first control process iteration, performing an ex-ante energy service control variable simulation in which:
(a) the subnetwork controllers determine and transmit to the distribution system controller initial aggregate energy service price forecasts for their respective subnetworks based upon initial DER energy service price forecasts provided by the respective plurality of DER controllers in each subnetwork,
(b) the distribution system controller determines and transmits to each of the subnetwork controllers an initial network-wide energy service price determined in response to the initial aggregate energy service price forecasts and without use of a power flow optimization for the distribution network, and
(c) the subnetwork controllers determine and transmit to their respective DER controllers initial DER controller-specific energy service prices determined in response to the initial network-wide energy service price;
in a second control process iteration after the first iteration, performing an ex-ante energy service control variable determination and energy service request operation in which:
(a) the subnetwork controllers determine and transmit to the distribution system controller updated aggregate energy service prices for their respective subnetworks determined based upon updated DER energy service prices provided by the respective plurality of DER controllers in each subnetwork,
(b) the distribution system controller determines and transmits to each of the subnetwork controllers respective subnetwork controller-specific energy service prices determined in response to the updated aggregate energy service prices and the power flow optimization for the distribution network, and
(c) the subnetwork controllers determine and transmit to their respective DER controllers respective updated DER controller-specific energy service prices and energy service requests for energy services determined in response to the respective subnetwork controller-specific energy service prices; and
in response to the transmission of the DER controller-specific energy service prices and the energy service requests, receiving at the distribution substations at least a portion of the energy services requested of the DER controllers and receiving at the transmission substation at least a portion of the energy services requested by the subnetwork controllers.

1. A method to improve operation of a transformer cooling system, wherein the transformer cooling system comprises a central controller, a transformer, a plurality of motor-fan chains to cool down said transformer, a shared variable frequency drive (VFD) bus fed by a VFD, and an alternating current (AC) bus fed by an AC power source, both of the VFD bus and the AC bus being controlled by said central controller, and both of the VFD bus and the AC bus being shared by motor-fan chains, the method comprising:preprocessing an initial data input by a user;
collecting an on-line data corresponding to a transformer loss associated with driving at least one motor-fan chain of the plurality of motor fan chains with at least one of the VFD bus or the AC bus;
calculating a control command of the transformer cooling system to meet a requirement of a transformer loss by computing a control objective based on initial data and the on-line data, wherein the control command includes an instruction to selectively drive, based at least in part on the transformer loss, at least one motor-fan chain of the plurality of motor fan chains with at least one of the VFD bus or the AC bus; and
executing control actions associated with the control command by selectively driving, based at least in part on the transformer loss, the at least one motor-fan chain with at least one of the VFD bus or the AC bus.

1. A dry type cast-coil transformer having a voltage rating of 1 kV and above, comprising:at least one coil with a plurality of conductor turns;
a cast comprising a polymeric resin, encompassing the coil and having a cast surface;
a ferromagnetic core on which the coil with the encompassing cast is mounted;
an insulated cable termination connected to the coil, wherein a connection point between the insulated cable termination and the coil is within the cast, and wherein a first part of the insulated cable termination extends from the connection point through a portion of the cast to the cast surface,
a second part of the insulated cable termination forms a flexible portion of the insulated cable termination which further extends from the cast surface outwards,
wherein the insulated cable termination comprises a plurality of sheds provided around the flexible portion of the insulated cable termination for at least a part of a length of the insulated cable termination outwards from the cast surface, and
wherein the flexible portion and the plurality of sheds provided around the flexible portion form a flexible section extending from the cast surface outward.

1. A generator switch, comprisingan encapsulation which is at ground potential during operation of the generator switch,
an electrical conductor which is arranged in an electrically insulated fashion inside the encapsulation and is at high-voltage potential during operation of the generator switch, a gravity-driven cooling device having an evaporator and a condenser arranged above the evaporator and further having a coolant, wherein the evaporator is thermally conductively connected to the electrical conductor and is therefore at high-voltage potential during operation of the generator switch, and wherein the condenser is connected to the encapsulation and is therefore at ground potential during operation of the generator switch,
wherein the evaporator is connected to the condenser by means of a line system having an insulator, so that during operation of the generator switch coolant vapor can be conveyed from the evaporator to the condenser and liquid coolant can be conveyed from the condenser to the evaporator,
wherein the insulator has an insulating section with an upper end,
wherein the line system has a coolant line, which connects a coolant outlet of the condenser to a coolant inlet of the evaporator, and furthermore has a coolant vapor line which connects a coolant vapor outlet of the evaporator to a coolant vapor inlet of the condenser, in such a way that a closed loop-type circuit is formed,
in that, during operation of the generator switch, a level of the liquid coolant in the line system with the cooling device in a static condition is at least as high as the upper end of the insulating section in the insulator,
wherein the insulator has a portion of the coolant line configured as a first insulating channel and a portion of the coolant vapor line configured as a second insulating channel, and
wherein the insulator has an insulating body that receives the two insulating channels, and, for each insulating channel, a first connecting piece connected to the electrical conductor and a second connecting piece connected to the condenser.

1. A method for controlling operation of an electrical power distribution network including a plurality of distributed energy resources (DERs), the method comprising:providing a distribution system controller at a transmission substation which couples the electrical power distribution network to an electrical power transmission grid;
providing a plurality of subnetwork controllers at a respective plurality of distribution substations serviced by the transmission substation and servicing a respective plurality of subnetworks of the distribution network, each of the subnetwork controllers configured to bi-directionally communicate with the distribution system controller and to bi-directionally communicate with a respective plurality of distributed energy resource controllers (DER controllers), each of the DER controllers configured to control operation of one or more of the plurality of DERs, one or more of the DER controllers being configured to control operation of two or more DERs which are located in different subnetworks of the distribution network;
in a first control process iteration, performing an ex-ante energy service control variable simulation in which:
(a) the subnetwork controllers determine and transmit to the distribution system controller initial aggregate energy service price forecasts for their respective subnetworks based upon initial DER energy service price forecasts provided by the respective plurality of DER controllers in each subnetwork,
(b) the distribution system controller determines and transmits to each of the subnetwork controllers an initial network-wide energy service price determined in response to the initial aggregate energy service price forecasts and without use of a power flow optimization for the distribution network, and
(c) the subnetwork controllers determine and transmit to their respective DER controllers initial DER controller-specific energy service prices determined in response to the initial network-wide energy service price;
in a second control process iteration after the first iteration, performing an ex-ante energy service control variable determination and energy service request operation in which:
(a) the subnetwork controllers determine and transmit to the distribution system controller updated aggregate energy service prices for their respective subnetworks determined based upon updated DER energy service prices provided by the respective plurality of DER controllers in each subnetwork,
(b) the distribution system controller determines and transmits to each of the subnetwork controllers respective subnetwork controller-specific energy service prices determined in response to the updated aggregate energy service prices and the power flow optimization for the distribution network, and
(c) the subnetwork controllers determine and transmit to their respective DER controllers respective updated DER controller-specific energy service prices and energy service requests for energy services determined in response to the respective subnetwork controller-specific energy service prices; and
in response to the transmission of the DER controller-specific energy service prices and the energy service requests, receiving at the distribution substations at least a portion of the energy services requested of the DER controllers and receiving at the transmission substation at least a portion of the energy services requested by the subnetwork controllers.

1. A system for monitoring the travel curve of a moving part of a circuit breaker, the system comprising:a device for optically monitoring the travel path of a moving part of a circuit breaker, the device comprising:
a light source,
a light detection device,
an optical element having a plurality of zones with different optical properties which are alternately arranged, wherein the optical element is adapted to be provided on a moving part of a circuit breaker to be monitored, and wherein the light source emits light to the optical element which is intensity-modulated by the optical element and received by the light detection device during operation of the circuit breaker,
an accelerometer adapted for mounting it to the circuit breaker to be monitored, wherein the accelerometer is attached to the moving part of the circuit breaker,
a control unit for receiving signals from the light detection device and from the accelerometer, the control unit being configured to determine a travel curve of the moving part of the circuit breaker based on the detected modulated light and on the detected vibration signal, wherein the vibration signal is employed to identify a change of direction of movement of the moving part of the circuit breaker.

1. A method for discovery of semantic data of a plurality of agents in a distributed networked system, the method comprising:sending a semantic profile with associated data for each of the plurality of agents to one or more receiving agents that are in direct communication with one or more of sending agents;
receiving, at each of the one or more receiving agents, the semantic profile and associated data from the respective one or more sending agents;
in response to determining at the one or more receiving agents that the received semantic profile includes an unknown semantic profile and associated data for an unknown agent, updating the semantic profile of the one or more receiving agents to include the unknown semantic profile and associated data for the unknown agent; and
after updating the semantic profile of the one or more receiving agents, iteratively sending, receiving and updating the semantic profiles of the plurality of agents until none of the one or more receiving agents receive any semantic profile and associated data that includes any unknown semantic profile and associated data for any unknown agent.

1. A semiconductor switching device comprising:a semiconductor element having a cathode side and an anode side opposite to the cathode side; and
a housing, wherein the housing comprises:
a cathode pole piece arranged on the semiconductor element on the cathode side;
an anode pole piece is arranged on the semiconductor element on the anode side, wherein the cathode pole piece and the anode pole piece laterally project beyond the semiconductor element; and
a spring system laterally surrounding the semiconductor element for clamping the semiconductor element between the cathode pole piece and anode pole piece, wherein the spring system comprises a ring-shaped washer laterally surrounding the semiconductor element, the washer having a first side and second side opposite to the first side;
wherein the washer is made of a material that keeps its shape reproducibly under deformation at least up to a spring deflection;
wherein the washer is deflectable between the cathode pole piece and the anode pole piece by a first deflection element that comprises a plurality of first protruding elements that contact the washer in a first contact area of the washer on the first side, and by a second deflection element that comprises a plurality of second protruding elements that contact the washer in a second contact area of the washer on the second side;
wherein the first protruding elements are spaced from each other and wherein the second protruding elements are spaced from each other and offset from the first protruding elements so that the first contact area is laterally displaced to the second contact area and the first contact area and the second contact area are arranged lateral to each other in a plane parallel to the cathode side; and
wherein the first deflection element and the second deflection element are adapted to deflect the washer during clamping by a strain distance that is less or equal to the spring deflection, wherein the strain distance is sufficiently large that in a clamped condition an electrical contact is achievable between the cathode pole piece, the semiconductor element and the anode pole piece.

1. A fiber-optic current sensor comprisinga light source generating light with a coherence length Lc,
a first beam splitter splitting the light from said light source into a first and a second branch,
a second beam splitter combining the light from said first and second branches,
a polarization-maintaining connecting fiber adapted to carry light in first and second, mutually orthogonal polarization modes and receiving light from said second beam splitter for a first passage through said connecting fiber,
a sensor head, wherein said sensor head is adapted and structured to receive light waves from said first and said second polarization mode of said connecting fiber, to generate a current-dependent phase shift between said light waves, and to reflect said light waves back into said connecting fiber with switched polarizations for a second passage through said connecting fiber,
a detector located to detect a light intensity resulting from the interference of said waves after their second passage through said connecting fiber,
a first releasable connector in said first branch, and
a second releasable connector in said second branch,
wherein said first branch is adapted to carry light in a first and a second polarization mode between said first connector and a select one of said first or said second beam splitters, and
wherein said second branch is adapted to carry light in a first and a second polarization mode between said second connector and said select beam splitter,
wherein without angular misalignment of said connectors, light traveling towards the sensor head is in the first polarization modes of the first and second branches.

1. A fiber optic sensor comprising:a light source;
a polarizing element;
a detector;
a polarization maintaining (PM) fiber;
a sensing element; and
a cross-coupling element in an optical path between the polarizing element and the sensing element,
wherein the cross-coupling element is configured to generate a defined cross-coupling between the two orthogonal polarizations of the fundamental mode in the PM fiber,
wherein the cross-coupling element and the sensing element are separated along the optical path, and
wherein a quadratically temperature-dependent contribution from the cross-coupling element to a sensor signal of the fiber optic sensor is configured to counteract a quadratically temperature-dependent contribution from at least one other element of the fiber optic sensor to the sensor signal.

1. A high power flash battery system for flash charging of an onboard battery, comprising:a wayside flash battery; and
a half-bridge cell comprising:
a first switch and a second switch configured to work in complementary mode to provide a voltage compensation mode and a bypass mode, respectively; and
a capacitor, a supercapacitor, or a battery, connected in series between the wayside flash battery through the first switch and a load,
wherein the half-bridge cell has a voltage polarity opposite to that of the wayside flash battery,
wherein the half-bridge cell is configured to be in the voltage compensation mode when the system is unloaded, and to be switched to the bypass mode when a voltage drop occurs due to the system being loaded.

1. An on-load tap changer for making tap changes in a transformer winding, the tap changer comprising:a tap change module configured to be connected to the transformer winding and comprising a bypass switch assembly, a vacuum interrupter assembly and a selector switch assembly;
a motor connected to rotate at least one shaft, wherein the at least one shaft is connected to the tap change module and is operable upon rotation to cause the tap change module to perform a sequence of operations that effectuate a tap change, the operations comprising actuating the bypass switch assembly, actuating the vacuum interrupter assembly and actuating the selector switch assembly;
a multi-turn absolute encoder connected to the at least one shaft and operable to determine a position of the at least one shaft; and
a monitoring system connected to the encoder to receive the position of the at least one shaft and operable to monitor a tap change by determining from the position of the at least one shaft where the tap change module is in the sequence of operations.

1. A two-stage valve arrangement for the hydraulic actuation of a piston in a cylinder of a high voltage or medium voltage power switch, the two-stage valve arrangement comprising:a main stage with a first main valve configured as a 2/2-way valve and a second main valve configured as a 2/2-way valve, a high pressure line configured to conduct a fluid under high pressure being connected directly to an inlet-side valve connector of the first main valve, and a low pressure line configured to conduct a fluid under low pressure being connected directly to an inlet-side valve connector of the second main valve, an outlet-side valve connector of the first main valve and an outlet-side valve connector of the second main valve being connected hydraulically to one another and to a space situated on one side of the piston, and
a pilot control stage with at least one pilot control valve having two connectors on the inlet side, one of the two connectors being connected to the high pressure line and the other of the two connectors being connected to the low pressure line, a hydraulic pilot control outlet of the pilot control stage being connected both to a first control face of the first main valve, to act in an opening manner, and to a first control face of the second main valve, to act in a closing manner,
wherein the pilot control stage is configured to establish a connection between the high pressure line and the hydraulic pilot control outlet in a first position of the at least one pilot control valve, such that the high pressure acts on the first control face of the first main valve and on the first control face of the second main valve to cause an opening of the first main valve and a closing of the second main valve, with the result that fluid under high pressure is fed to the space which is situated on the one side of the piston
wherein the pilot control stage is configured to establish a connection between the low pressure line and the hydraulic pilot control outlet in a second position of the at least one pilot control valve, such that the low pressure acts on the first control face of the first main valve and on the first control face of the second main valve to cause a closing of the first main valve and an opening of the second main valve, with the result that fluid is discharged in a direction of the low pressure line from the space which is situated on the one side of the piston,
wherein the first main valve further comprises a second control face configured to act in a closing manner, a third control face configured to act in a closing manner, and a fourth control face configured to act in an opening manner, the second control face of the first main valve being connected to the high pressure line, the third control face of the first main valve being connected to the low pressure line, and the fourth control face of the first main valve being connected to the outlet-side valve connector of the first main valve, and
wherein a size ratio of the first and fourth control faces of the first main valve with respect to the second and third control faces of the first main valve is configured such that a resulting force which acts in an opening manner remains in force in an open state of the first main valve.

1. Apparatus for the generation, the distribution and/or the usage of electrical energy, said apparatus comprising:a housing enclosing an insulating space and an electrically conductive part arranged in the insulating space, said insulating space containing a dielectric insulation medium, at least a portion of which being in the form of an insulation gas comprising an organofluorine compound,
wherein at least some components of the apparatus that are directly exposed to the insulation gas have a surface and are made of a material which remains unaltered during exposure to the insulation gas for a period of more than 5 years at operational conditions, and at least a portion of the surface is devoid of any nucleophilic group reactive towards the organofluorine compound and/or reactive towards any degradation product of the organofluorine compound at operational conditions,
wherein a compound contained on the surface of the at least some components and forming an integral part of the material and/or a compound bound to the surface is or are devoid of a nucleophilic group, and the nucleophilic group is any chemical group that is able to donate in a chemical reaction an electron pair to an electrophile, with the electrophile being the organofluorine compound or its degradation product(s) and the organofluorine compound being selected from the group consisting of: fluoroethers, fluoroketones, fluoroolefins, fluoronitriles, and mixtures thereof, and
wherein the compound comprises a coating compound.

1. A semiconductor power module comprising:an electrically and thermally conductive base plate,
a semiconductor chip,
a first layer of graphene between the semiconductor chip and the electrically and thermally conductive base plate, where the first layer of graphene is in electrical and thermal contact with a first side of the electrically and thermally conductive base plate,
a first metallic layer with a first low melting point on the first side of the semiconductor chip between the semiconductor chip and first layer of graphene,
a second metallic layer with a second low melting point on a second side of the semiconductor chip opposite the first side of the semiconductor chip, the first and second metallic layers being provided for obtaining a short-circuit failure mode of the semiconductor chip creating an electrically conducting alloy with the semiconductor chip,
an upper base plate on top of the second metallic layer, and
a top electrode on top of the upper base plate.

1. A remotely operated submersible comprising:a plurality of signal receivers each structured to receive a control transmission through a liquid environment from a remote control station, the control transmission including a command, and wherein each of the plurality of signal receivers use a different communication pathway; and
a controller structured to, upon detection of a detectable heartbeat in the control transmission received by one of the plurality of signal receivers, use the command from the control transmission having the detectable heartbeat to manipulate a system on the remotely operated submersible, the controller being further adapted to generate a command to activate a ballast of the remotely operated submersible in response to a lack of detection of the detectable heartbeat in the control transmission received by each of the plurality of signal receivers.

1. A method for condition monitoring of a wireless network in an industrial plant, the wireless network comprising one or more wired gateways and a plurality of access nodes connected wirelessly with at least one of the one or more wired gateways, each access node being associated with at least one field device of a plurality of field devices, the method comprising:periodically receiving information associated with packet transfer, channel access, and communication links from one or more of the one or more wired gateways and the plurality of access nodes;
estimating from the received information one or more parameters associated with each access node of the plurality of access nodes, the one or more parameters being estimated based on one or more of (i) a number of packets transmitted from the access node to a corresponding gateway, and a corresponding number of responses received from the corresponding gateway, (ii) a number of packets transmitted from the corresponding gateway to the access node, and a corresponding number of responses received from the access node, (iii) wireless communication channels used by the access node and one of a neighboring access node or the corresponding gateway, or (iv) a number of and identity of other access nodes and wired gateways connected with the access node, the one or more parameters comprising one or more of:
a channel error for each access node, the channel error for a first respective access node being determined based on a difference in the wireless communication channels used by the first respective access node and one of the neighboring access node or the corresponding gateway; or
a stability factor for each access node, the stability factor for a second respective access node being determined based on a difference in one or more of the number of or the identity of the other access nodes and wired gateways connected with the second respective access node;
determining a connectivity status of each field device of the plurality of field devices based on the one or more parameters estimated for each access node; and
rendering the connectivity status of each field device of the plurality of field devices on a user interface associated.

1. A first voltage source converter having a direct current (DC) side for connection to a DC system and having an alternating current (AC) side for connection to an AC system and for interconnection with an AC side of a second voltage source converter, said second voltage source converter having a DC side connected to the DC system and the first voltage source converter comprising:a number of converter valve pairs, each pair being connected to a corresponding AC phase of the AC system; and
a control unit operative to control the converter valve pairs to generate at least one voltage waveform and the control unit when reducing oscillations is configured to create a virtual resistance around a resonance frequency formed between the first voltage source converter and the second voltage source converter,
wherein the control unit when forming the virtual resistance is operative to multiply a phase current with a proportional gain for obtaining an oscillations damping control signal, reducing oscillations between the first voltage source converter and the second voltage source converter by combining the oscillations damping control signal with a converter reference voltage.