Abstract

A hybrid trigger circuit suitable for a thyristor, comprising a hardware method trigger circuit and a software method trigger circuit, wherein the hardware method trigger circuit is connected to the software method trigger circuit in parallel through a gate line and a cathode line, so as to trigger the thyristor. The software method trigger circuit triggers the thyristor through a logical judgement, both the trigger pulse width and the continuous trigger time being able to be set by software, and has relatively high electrical isolation. The hardware method trigger circuit can bear a relatively high overvoltage value, and can continuously trigger the thyristor. The hybrid trigger circuit has a simple structure and low costs and is realized easily.

IPC Classes  ?

• H03K 17/72 - Bipolar semiconductor devices with more than two PN junctions, e.g. thyristors, programmable unijunction transistors, or with more than three electrodes, e.g. silicon controlled switches, or with more than one electrode connected to the same conductivity region, e.g. unijunction transistors
• H02M 1/06 - Circuits specially adapted for rendering non-conductive gas discharge tubes or equivalent semiconductor devices, e.g. thyratrons, thyristors

Abstract

A direct current breaker bridge module, comprising an IGBT press-fitting unit (2), a capacitor bank (3), a laminated busbar (4), a control unit, an energy supply unit (7) and a support frame (8); the capacitor bank is electrically connected to the IGBT press-fitting unit via the laminated busbar; the capacitor bank is connected to the control unit and the energy supply unit; and the IGBT press-fitting unit, the capacitor bank, the laminated busbar, the control unit and the energy supply unit are located on the support frame. The direct current breaker bridge module eliminates a potential explosion risk of a traditional welded module in a failure state, improves integration of the module, reduces a total volume of the module, lowers voltage spike of the module when a large current is cut off, and also provides a larger heat dissipation area for the control unit.

IPC Classes  ?

• H01H 71/00 - Details of the protective switches or relays covered by groups

Abstract

A breaking testing device for a high-voltage direct-current circuit breaker, and a testing method therefor. A reactor L of the device and a high-voltage direct-current circuit breaker are serially connected and then respectively connected in parallel to a high-voltage circuit and a low-voltage circuit. Two ends of the high-voltage direct-current circuit breaker are connected in parallel to bypass switches. Two ends of a full-bridge module in a mechanical switch-full-bridge module branch are connected in parallel to protective thyristors. In the testing method, a low-voltage large-current source injects a rated current to a circuit breaker through an isolating thyristor valve; a high-voltage small-current source is used to charge a capacitor, an initial testing voltage is established, a high-voltage circuit is triggered by a spark gap, a testing current is adjusted by the reactor and is then injected into the circuit breaker, the isolating thyristor valve is turned off, the breaking is implemented when an expected breaking current or a maximum breaking time is reached, and the circuit breaker tolerates a transient-state recovery overvoltage and a high-voltage circuit capacitor residual-voltage. By means of the device and the method, a current, a voltage and a heat stress of a high-voltage direct-current circuit breaker in actual operation can be reproduced, and testing equivalence is high, thereby providing a capability of reliably detecting the breaking performance of the circuit breaker.

IPC Classes  ?

• G01R 31/327 - Testing of circuit interrupters, switches or circuit-breakers
• H02H 3/00 - Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition, with or without subsequent reconnection

Abstract

A direct current voltage conversion device and a bridge arm control method therefor. The device is a structure having a single phase, two phases or more than two phases, each phase consisting of a basic function module, the basic function module comprising device cascade structures (S1, S4) connected in series and a sub-module cascade structure. Via combination of the device series connection structures and the sub-module cascade structure, voltage conversion may be implemented without a transformer, soft switching of series connection devices may be implemented, and investment and space may be reduced.

IPC Classes  ?

• H02M 3/10 - Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
• H02M 3/155 - Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only

Abstract

A direct current voltage compensation method for a parallel mixed-type multi-level converter. The converter is a three-phase power transmission structure, the three-phase power transmission structure consisting of a parallel-type single-phase structure series connection. A parallel-type single-phase structure consists of an H bridge full-control device structure (2) and a sub-module cascade structure (1) connected in parallel, the H bridge full-control device structure consisting of a cascade structure having four full-control devices (S1-S4), the sub-module cascade structure consisting of a half-bridge sub-module series connection. The compensation method comprises: an isolation time is added during a converter normal operating mode, the sub-module cascade structures are freely controlled in the isolation time, a required compensation voltage is thereby outputted, compensation of a direct current voltage shortfall is implemented, and a compensation ratio in the three-phase power transmission structure adjusts a three-phase distribution ratio according to requirements. The compensation method effectively implements direct voltage fluctuation compensation of a parallel-type mixed new topology, and is particularly suitable for voltage compensation in the case of an alternating current system fault.

IPC Classes  ?

• H02M 7/17 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only arranged for operation in parallel

Abstract

The present invention relates to a testing apparatus and method of a direct-current power transmission converter valve, and particularly to a synthesis loop-based testing apparatus and method for a forward recovery characteristic of a thyristor. The testing apparatus comprises a constant-current voltage source, a sample thyristor T, a diode D, an adjustable capacitor C, an adjustable saturable reactor L, a heating loop, an impulse generator and a damping loop. The testing method adopts two sets of power supply systems respectively used for providing a charging voltage and a forward high voltage for the sample thyristor, and during testing, the current output by the constant-current source and the voltage output by the impulse voltage generator are exerted on a tested thyristor alternately. The testing apparatus and method can meet the requirement of the forward recovery characteristic testing of a high-power semiconductor device under different voltages, different frequencies, different trigger signals, different junction temperatures, different current peak values, and different di/dt conditions. The testing method is simple and can be implemented easily. The needed device capacity is small and the apparatus cost is low.

IPC Classes  ?

• G01R 31/327 - Testing of circuit interrupters, switches or circuit-breakers

Abstract

A modular multi-level flexible direct-current topology circuit suitable for fault ride-through, comprising a module cascading circuit, a voltage conversion circuit and a compensation circuit, wherein after being connected to the voltage conversion circuit in parallel, the module cascading circuit is connected to the compensation circuit in series. The direct-current topology circuit can achieve alternating-current and direct-current fault ride-through simply and effectively, thereby being suitable for application in the field of high-voltage high-capacity direct-current overhead lines.

IPC Classes  ?

• H02J 3/12 - Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
• H02J 1/02 - Arrangements for reducing harmonics or ripples

Abstract

A DC fault ride-through control method of a hybrid modular multilevel converter. The control method dynamically configures the number of added half-bridge submodules (HBSMs) and full-bridge submodules (FBSMs) within the same leg by controlling the addition and removal of HBSMs and FBSMs (3, 4)in the leg and tracking the average of capacitance and voltage of the HBSMs and FBSMs and monitoring the DC side fault state based on the effectively operated HBSMs and FBSMs, thus realizing the balance of capacitance and voltage of the HBSMs and FBSMs in the steady state, and achieving effective control of AC/DC current and voltage during a transient state DC fault. The method ensures continuous operation of a converter and prevents shutdown of the converter due to a fault.

IPC Classes  ?

• H02M 7/483 - Converters with outputs that each can have more than two voltage levels

Abstract

A method for coordinating and controlling a multi-terminal flexible direct current transmission system, the method comprising the following steps: (1) a sagging slope control regulated by direct current is added to a constant direct current voltage station in a multi-terminal flexible direct current transmission system; (2) the sagging slope control regulating direct current voltage is added to a constant active power station; (3) when interstation communication does not exist, two constant current voltage stations in a multi-terminal system are set as constant direct current voltage control stations, and the constant direct current voltage control stations serve as balancing nodes in a direct current network. When the system operation condition is out of the range adjusted by the direct current voltage sagging slope control, the method optimally adjusts the system direct current voltage and the power of each station, such that the direct current network can maintain the optimal voltage level after experiencing a major failure.

IPC Classes  ?

• H02J 3/36 - Arrangements for transfer of electric power between ac networks via a high-tension dc link

Abstract

A bidirectional transmission convertor suitable for a high voltage and a high power, comprising a power module. The power module comprises a high-frequency transformer and modules of a full-bridge topological structure which are respectively connected to each phase of the primary side and the secondary side of the high-frequency transformer, wherein the modules of the full-bridge topological structure which are respectively connected to each phase of the primary side and the secondary side respectively comprise four modules SMp and four modules SMs, each bridge arm of the modules of the full-bridge topological structure which are connected to each phase of the primary side is respectively provided with one module SMp, and each bridge arm of the modules of the full-bridge topological structure which are connected to each phase of the secondary side is respectively provided with one module SMs. The convertor reduces the switching frequency and the switching loss of a power tube, reduces the electrical stress borne by a single tube, and improves the waveform quality of an alternating current link.

IPC Classes  ?

• H02M 3/335 - Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only

Abstract

A single-phase inverter test circuit for a modular multi-level convertor and a test method therefor. The method comprises: constructing a single-phase test circuit by using two modular multi-level bridge arms; connecting a passive resistance-inductance load; by means of the open-loop passive inversion algorithm and capacitive balancing algorithm, outputting a sine voltage and a sine current; and simulating the normal operation of a modular multi-level convertor, thereby completing the test of the electrical and capacitive balancing algorithms of the modular multi-level convertor. In the test circuit, a direct-current side is supported by a voltage source, so that in the control algorithm, there is no need to control a direct-current voltage, thereby simplifying the controller algorithm of the test. In the test circuit, a direct-current voltage source at the direct-current side is connected to a capacitor in parallel, so that bidirectional currents can flow in a direct-current bus and bridge arms, thereby solving the problem that a sub-module can be charged only, but cannot discharge when the direct-current voltage source is tested separately.

IPC Classes  ?

• G01R 31/00 - Arrangements for testing electric propertiesArrangements for locating electric faultsArrangements for electrical testing characterised by what is being tested not provided for elsewhere
• G01R 31/02 - Testing of electric apparatus, lines, or components for short-circuits, discontinuities, leakage, or incorrect line connection

Abstract

A valve monitor system ("VM system" for short) applicable to high-capacity MMC flexible high-voltage direct-current transmission, comprising: an event generation unit, an event transmitting unit and an upper computer background PC. The valve monitor system adopts the principle that parallel events of unit cases are subjected to parallel processing and centralized processed by unifying platforms finally is adopted, and GPS timing marks are applied to an event processing base layer at the same time. Through a unified status detection mechanism, event source levels are eliminated, the timing marks are unified, an event transfer path is simplified, cache capacity of a large number of instantaneous events is enhanced, capacities of storage query and real-time display of the upper computer background are improved, and a standard interface with the background is established. Valve and VBC body events can be generally guaranteed, to be accurately generated, timely reported, reliably stored and conveniently inquired. Therefore, multiple problems of event missing, sequence disordering and the like occurring in above projects are solved.

IPC Classes  ?

• G05B 19/418 - Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM]

Abstract

A device and method for testing the steady-state operation of an MMC flexible direct current sub-module. The exchange of reactive power between a sub-module to be tested and an energy-storage reactor is controlled through a test control system, and voltage stress and current stress of the sub-module operated in the work condition of a flexible direct current transmission system are simulated. Whether a power device of the sub-module is qualified and whether assembly is correct are tested through a long-time steady-state operation. Active loss is reduced and electric power is saved through the method for testing the exchange of reactive power. Certain amount of line loss exists in the process of the exchange of reactive power and an energy supplement device is needed for supplementing energy for the lost electric power.

IPC Classes  ?

• G01R 31/00 - Arrangements for testing electric propertiesArrangements for locating electric faultsArrangements for electrical testing characterised by what is being tested not provided for elsewhere

Abstract

A loss determination method for a flexible direct-current converter based on the modular multi-level technology. The method comprises the following steps: step 1: determining a current of a single-phase voltage source converter; step 2: determining the conduction loss of the voltage source converter; step 3: determining the switch loss of the voltage source converter; and step 4: determining the total three-phase loss of the voltage source converter. The method effectively calculates the average current and the effective current of an insulated gate bipolar transistor (IGBT) of an upper-half bridge arm/a free-wheeling diode (FWD) of a lower-half bridge arm of a converter sub-module, or a free-wheeling diode (FWD) of the upper-half bridge arm/an insulated gate bipolar transistor (IGBT) of the lower-half bridge arm, so that a relationship between the loss of the insulated gate bipolar transistor (IGBT) and the free-wheeling diode (FWD) in the sub-module, and a modulation factor, a power factor, an active transmission power and the like of a flexible direct current power transmission system can be reflected, thereby visualizing complex problems.

IPC Classes  ?

• H02M 7/797 - Conversion of AC power input into DC power outputConversion of DC power input into AC power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only

Abstract

A control system of a multi-terminal flexible direct-current power transmission system, and a control method therefor. The method comprises: according to the power requirement of an alternating-current side of a converter station and the constraint conditions of a converter and a direct-current line, with the goal that the loss of the operating power of the entire multi-terminal system is minimum, calculating the optimal power flow of a direct-current network, and determining a common reference voltage of the direct-current system, a power instruction of each convertor station and a droop coefficient required by slope control. The N-1 check of the convertor station of the multi-terminal direct-current power transmission system is achieved by using same to calculate the power flow of the multi-terminal direct-current network, performing analysis, and establishing a control protection policy. The N-1 check of the direct-current line of the multi-terminal direct-current power transmission system is achieved by using same to calculate the power flow of the multi-terminal direct-current network, performing analysis, and establishing a control protection policy in advance. The control system and the control method therefor can conduct flexible and safe control on the power flow and the direct-current voltage in the multi-terminal direct-current network.

IPC Classes  ?

• H02J 3/36 - Arrangements for transfer of electric power between ac networks via a high-tension dc link

Abstract

Disclosed is a sub-module capacitor voltage balancing optimization method for a modular multilevel converter. The system used in the method is a modular multilevel converter system, and a flexible direct current power transmission system valve based control system architecture using a distributed parallel processing mode as the architecture is established. The method comprises the following steps: (1) determining the objective of sub-module capacitior voltage balancing control; (2) establishing a sub-module state decision optimization model; (3) performing sub-module capacitor voltage balancing optimization; and (4) verifying the sub-module capacitior voltage balancing optimization. The adoption of the distributed computation architecture results in a great improvement of processing capability, and also guarantees the application of complex algorithm strategies in high-voltage large-capacity flexible direct current power transmission system.

IPC Classes  ?

• H02M 7/483 - Converters with outputs that each can have more than two voltage levels

Abstract

A protection method for a modular multilevel converter during a bridge arm short circuit fault includes the following steps: 1) setting a fault detection time interval △t of the protection switches connected in parallel with the bridge arms of the modular multilevel converter; 2) setting a fault action threshold value Q; 3) setting voltage threshold values Ulim.ac and Ulim.arm; 4) detecting the voltage Uac(t) between the alternating-current terminal of the modular multilevel converter and the ground, and computing Q1=abs(aveage(U ac(△t)))-U lim.ac; 5) detecting the bridge arm voltage Uarm(t) of the modular converter, and computing Q2=abs(aveage(U arm(△t)))-U lim.arm; 6) a bridge arm short circuit fault occurring if Q2 x Q1 > Q; and 7) trigging the protection switch connected in parallel with the bridge arm of a normal phase when it is determined that the modular multilevel converter has occurred the bridge arm short circuit fault. According to the method, by employing the protection switches connected in parallel with the bridge arms, the bridge arm short circuit fault time duration of the modular multilevel converter is shortened, such that the direct-current bias voltage withstood by a transformer and the overvoltage withstood by the converter bridge arms are reduced, the device requirement and cost thereof are lowered, and the economical efficiency and security are improved.

IPC Classes  ?

• H02H 7/10 - Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for convertersEmergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for rectifiers
• H02M 1/32 - Means for protecting converters other than by automatic disconnection

Abstract

A commutation apparatus based on a controllable commutation inductor (3), and an implementation method therefor. The commutation apparatus uses a three-phase half-bridge structure. The three-phase half-bridge structure consists of serially connected commutation units. Each of the commutation units comprises a converter transformer and a converter inverter (2). A commutation inductor is serially connected between the valve side of the converter transformer and the converter inverter. A controllable inductor in the commutation inductor is used together with a control protection system in a converter station. When the converter station normally operates, a switch is turned off, and the controllable inductor is comprised in the commutation inductor; when the control protection system in the converter station detects a commutation failure, the switch is turned on, so that a leakage inductance value of the commutation inductor is lowered, the commutation angle is reduced, and the turn-off angle is increased. The commutation apparatus improves a commutation feature of a converter valve on an inverter side when a commutation failure occurs, and the commutation apparatus has the advantages of requiring less elements, is easy to implement, and requiring low cost.

IPC Classes  ?

• H02J 3/36 - Arrangements for transfer of electric power between ac networks via a high-tension dc link

Abstract

Provided are an extra-valve cooling system for a direct current converter valve and operating method thereof. The system comprises a main pump, an air cooler and a closed cooling tower; the main pump, the air cooler and the closed cooling tower are orderly connected in series via a pipeline, and the series pipeline is connected with a converter valve to form a closed loop; a three-way valve is arranged between the air cooler and the closed cooling tower, and the three-way valve is connected with a bypass pipeline in parallel and then connected with the converter valve; the temperature of a cooling medium in the loop can be decreased to reach a preset temperature by adjusting the working state of the air cooler and the working state of the closed cooling tower according to environment temperature change; the extra-valve cooling system for the direct current converter valve has high cooling capacity, excellent environmental adaptability and good energy/water saving performances.

IPC Classes  ?

• H05K 7/20 - Modifications to facilitate cooling, ventilating, or heating

Abstract

A serial water-cooled heat sink based on a damping resistor, the heat sink comprising a heat sink body, a thyristor and a resistor. The heat sink body comprises an aluminum panel, a heat sink cavity comprising a water channel and water channel wall, a water inlet and a water outlet; the thyristor conforms to the surface of the aluminum panel; the water inlet and water outlet are respectively disposed on the top and bottom of the heat sink body; two heat sink cavities are disposed inside the aluminum panel; and the resistor is disposed inside the water channel wall.

IPC Classes  ?

• H01C 1/082 - Cooling, heating or ventilating arrangements using forced fluid flow

Abstract

A lamination busbar of a voltage source-type convertor unit suitable for an IGBT. The lamination busbar comprises a compound insulation busbar, and a U-shaped short-circuit busbar adapted to the compound insulation busbar, wherein two electrodes of the U-shaped short-circuit busbar are respectively connected to a corresponding end of one IGBT so as to realize the short circuit of two IGBTs. Two ends of the compound insulation busbar are respectively connected to corresponding ends of a capacitor terminal and the IGBT. The installation of the U-shaped short circuit busbar is more convenient, so that not only a bolt connection process is minimized, but also the distributed inductance of the busbar is reduced. Combined with the compound insulation busbar, the distributed inductance in a loop is further reduced.

IPC Classes  ?

• H01B 5/02 - Single bars, rods, wires or stripsBus-bars
• H01B 7/02 - Disposition of insulation
• H02M 1/00 - Details of apparatus for conversion

Abstract

A module flow balancing water channel used for a direct-current converter valve. The water channel comprises a water inlet pipe, a water outlet pipe, a saturable reactor, a thyristor radiator, a damping resistor, and a water distribution connection pipeline. A water channel circuit consists of a thyristor radiator and damping resistor branch circuit and saturable reactor branch circuits, and the thyristor radiator and damping resistor branch circuit and the saturable reactor branch circuits are disposed in a mode with parallel connection and series connection mixed. The water inlet pipe and the water outlet pipe are disposed in parallel, and a diagonal water inlet and outlet method is used. The thyristor radiator and the damping resistor are connected in series to form a branch circuit and are connected in parallel between the water inlet pipe and the water outlet pipe. The saturable reactor branch circuits are disposed between the head end of the water inlet pipe and the tail end of the water outlet pipe and between the tail end of the water inlet pipe and the head end of the water outlet pipe separately. Compared with the prior art, the module flow balancing water channel used for the direct-current converter valve has the advantages that flow distribution is even, temperature distribution of thyristors is even, no flow dead zone exists in the water channel, and local discharging caused by deposition of air and impurities is avoided.

IPC Classes  ?

• H01L 23/473 - Arrangements for cooling, heating, ventilating or temperature compensation involving the transfer of heat by flowing fluids by flowing liquids

Abstract

The present invention provides a cold-accumulation external cooling system for a direct current converter valve, and an operation method thereof. The system comprises an air cooler (2), a plate-type heat exchanger (3), a water chilling unit, a fixed-frequency cooling pump (6), a buffer tank (7), a thermocline cold-accumulation groove (8), a variable-frequency cooling pump (9), and a cooling water pump (10). The plate-type heat exchanger (3) has a hot side and a cold side, and an improvement thereof is that, the hot side of the plate-type heat exchanger (3) is connected in series with a cooling device (1), the air cooler (2), the plate-type heat exchanger (3), and the cooling water pump (10) to form a circulation loop; and the cold side of the plate-type heat exchanger (3) is connected in series with the thermocline cold-accumulation groove (8) and the variable-frequency cooling pump (9) to form a cold supply loop for a cold-accumulation tank; the water chilling unit, the fixed-frequency cooling pump (6), and the buffer tank (7) are connected in series to form a cold supply loop for the water chilling unit. Compared with the prior art, the cold-accumulation external cooling system for a direct current converter valve and the operation method thereof have a wide range of a cold-accumulation temperature difference; therefore, the system is high-temperature resistant in summer, and is anti-freezing in winter by accumulating heat.

IPC Classes  ?

• H05K 7/20 - Modifications to facilitate cooling, ventilating, or heating

Abstract

A valve base control device and method for a modular multi-level convertor (4). The modular multi-level convertor (4) is provided with a bridge arm comprising a plurality of cascaded submodules. The valve base control device comprises the following components constructed in a hierarchical control architecture: a current control unit which is used for realizing the current control of a convertor and the real-time generation of the input number of bridge arm submodules, acquiring the current direction of the bridge arm, and sending number information and current direction information; a bridge arm collection control unit which is used for determining submodules to be input or cut out according to the received state of each submodule and the number information and the current direction information which are received from the current control unit, and sending a determination result; and a bridge arm subsection control unit which is used for realizing the input or cut out of each submodule according to the determination result received from the bridge arm collection control unit, and acquiring the state of each submodule and sending same to the bridge arm collection control unit. The above-mentioned hierarchical control architecture disperses the functions of the valve base control device for a convertor to a plurality of hardware devices, so as to reduce the load of a single hardware device.

IPC Classes  ?

• H02J 3/36 - Arrangements for transfer of electric power between ac networks via a high-tension dc link
• H02M 1/08 - Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters

Abstract

An integrated heat-dissipation thyristor (1) comprises a thyristor base (5) and a thyristor cover, a chip with a protection layer being provided between the thyristor base and the thyristor cover, the end at which the thyristor base is connected to the protection layer being provided with a circulating flow channel (8) along the axial direction, and the other end of the thyristor base being connected to a heat sink (2). A cooling water channel (9) disposed inside the heat sink is connected to the head and the tail of the circulating flow channel in the thyristor base by a pipe (7) disposed vertically at the head and the tail of the cooling water channel, so that a connected water channel is formed between the heat sink and the thyristor, and in addition, a micro-channel is disposed in the water channel, thereby improving the heat dissipation efficiency of the thyristor, retarding the temperature rising, increasing the transmission capacity and operational reliability of a direct current power transmission thyristor valve, and prolonging the service life.

IPC Classes  ?

• H01L 29/74 - Thyristor-type devices, e.g. having four-zone regenerative action
• H01L 23/473 - Arrangements for cooling, heating, ventilating or temperature compensation involving the transfer of heat by flowing fluids by flowing liquids
• H01L 23/367 - Cooling facilitated by shape of device

Abstract

A high-power thyristor. The thyristor comprises a thyristor base (1), a ceramic circular shell, a protective layer (2), a chip (3) and a thyristor cover (4) which are arranged in sequence in an axial direction, wherein a rubber sleeve is wrapped around the outer edge of the chip (3); the protective layer (2) and the chip (3) are buckled into the ceramic circular shell in sequence; and a temperature sensor is arranged in the axial direction of the thyristor. By additionally installing a precise temperature sensor on the chip of the thyristor, the real-time monitoring of the temperature of the chip of the thyristor is realized, and the temperature measurement deviation can be reduced, forming intuitive real-time temperature data, and providing reliable conditions for junction temperature protection and other intellectualized functions of a direct-current converter valve.

IPC Classes  ?

• H01L 29/74 - Thyristor-type devices, e.g. having four-zone regenerative action
• H01L 23/367 - Cooling facilitated by shape of device
• G01K 11/32 - Measuring temperature based on physical or chemical changes not covered by group , , , or using changes in transmittance, scattering or luminescence in optical fibres
• H05K 7/20 - Modifications to facilitate cooling, ventilating, or heating

Abstract

A joint regulator test device for a magnetically controlled shunt reactor which is applicable to an ultra-high/extremely-high voltage power transmission system, comprising a single-phase body of the magnetically controlled shunt reactor, a test power source, a rectifying device, a filtering device and a shunt capacitor, wherein the single-phase body of the magnetically controlled shunt reactor comprises a network-side winding, a control-side winding and a compensation-side winding; the test power source, the rectifying device and the filtering device are respectively correspondingly connected to the network-side winding, the control-side winding and the compensation-side winding; and the shunt capacitor is connected to the network-side winding in parallel. The test device uses a shunt capacitor of a general laboratory to simulate the on-site actual working conditions, so as to complete the overall performance test of the device before it leaves the factory.

IPC Classes  ?

• G01R 31/00 - Arrangements for testing electric propertiesArrangements for locating electric faultsArrangements for electrical testing characterised by what is being tested not provided for elsewhere

Abstract

A method for controlling capacitance balance of legs of a three-phase full-bridge Modular Multilevel Converter (MMC). Based on an on/off state of a current sub-module, a leg current, and a sub-module inputting instruction to determine sub-modules that are to be input in positive or negative direction at the next time point, the balance of the capacitances and the voltages of the sub-modules inside the legs is controlled. By the on/off state of the full-bridge sub-module, the control method implements consistent on/off frequencies of devices in the sub-module, and reduces the on/off frequencies of the devices. The control method is applicable to control of operation of the DC-side converter in a normal state or in a failing state, and control handover is not required.

IPC Classes  ?

• H02M 7/483 - Converters with outputs that each can have more than two voltage levels

Abstract

A triggering and monitoring unit for a converter valve thyristor comprises a central processing unit I, an auxiliary circuit I connected to the central processing unit I, a central processing unit II, and an auxiliary circuit II connected to the central processing unit II. An electronic-to-optical converting circuit of the auxiliary circuit I communicates with the central processing unit II. A control and protection system sends a triggering command and junction temperature information of the thyristor to a valve-based electronic device. The valve-based electronic device generates a triggering pulse according to the received triggering command and the junction temperature information of the thyristor, and sends the triggering pulse to a thyristor triggering and monitoring unit. The thyristor triggering and monitoring unit generates and sends a triggering pulse to a thyristor gate pole. The triggering and monitoring unit actively monitors a thyristor by using a twin pulse code, improves the reliability of the method for triggering and monitoring a converter valve, and has a junction temperature protection function.

IPC Classes  ?

• H02J 13/00 - Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the networkCircuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network

Abstract

An implementation method for a forward direction slope control policy of a direct current transmission system. A direct current transmission system used in the implementation method comprises a rectification side power supply, a thyristor valve, a smoothing reactor (Ld), a circuit resistor (R), a circuit inductor (L), a circuit ground capacitor (C), an equivalent commutating resistor (dxr) and an equivalent commutating resistor (dxi), the thyristor valve, the smoothing reactor (Ld), the circuit resistor (R) and the circuit inductor (L) being serially connected sequentially. The method comprises the following steps: A, determining a constraint function of a direct current transmission system; B, establishing a forward direction slope curve volt-ampere characteristic; C, calculating a voltage fluctuation caused by current deviation; D, establishing a relationship between a turn-off angle and an electric current increment; E, establishing a linear function relationship of a turn-off angle increment and the electric current increment; and F, normalizing the constraint function. By means of the method, the problem is solved that a stable operation point does not exist between current regulators at two ends and thus a direct current oscillates in a reciprocating mode between two definite values, so that the direct current transmission system can operate stably, thereby avoiding the impact of power fluctuation on a power grid.

IPC Classes  ?

• H02J 1/00 - Circuit arrangements for dc mains or dc distribution networks

Abstract

A direct-current circuit breaker and an implementation method therefor. The direct-current circuit breaker comprises a converter circuit, a cutout circuit, and an energy absorption circuit (Z) which are connected in parallel, wherein the cutout circuit comprises a cutout inductor (L2) and a cutout unit which are connected in series; and the converter circuit comprises a converter inductor (L1), a converter unit and a mechanical switch (K) which are connected in series, and the converter unit has a smaller turn-on resistance than the cutout unit. The direct-current circuit breaker is novel in topology structure, and simple in control. The current is cut off by a power semiconductor switch module, and a capacitor contained in the module is capable of limiting the current. The converter circuit and the cutout circuit can achieve shunting through a full-bridge structure, thereby reducing a current stress of power electronic devices.

IPC Classes  ?

• H02H 3/08 - Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition, with or without subsequent reconnection responsive to excess current

Abstract

A submodule unit of a voltage-source converter based on a full-controlled device. The voltage-source converter is of a three-phase six-bridge-arm structure. Each bridge arm comprises N submodule units connected in series. The submodule unit comprises an electric power component mainly composed of a capacitor (C) and an IGBT module of a half-bridge structure, a main support structure (5), a support plate (8), a connecting waterpipe (9) and radiators (10). The main support structure is used for supporting the electric power component, the support plate, the connecting waterpipe and the radiators of the submodule unit. The support plate is arranged perpendicular to a base of the main support structure. Two symmetrically arranged radiators are provided on the support plate, and the radiators are connected by the connecting waterpipe. Two IGBT modules of each submodule unit are respectively placed on the two radiators. The bottom of the capacitor of each submodule unit is fixed to the base of the main support structure by bolts. The submodule unit is independent in structure, and is convenient in installation and transportation.

IPC Classes  ?

• H02M 1/00 - Details of apparatus for conversion
• H02M 7/00 - Conversion of AC power input into DC power outputConversion of DC power input into AC power output

Abstract

An anti-corrosion water-cooling damping resistance wire body comprises: a resistance element (1) and a resistance wire provided outside the resistance element (1), a protrusion (2) vertical to the axial direction being provided along the axial direction of the resistance element (1), a groove (3) for receiving the resistance wire (5) being provided at the resistance element periphery parallel with the axial direction of the resistance element (1), and the two ends of the resistance wire (5) being anti-corrosion ends. The anti-corrosion water-cooling damping resistance wire body increases the contact area of the resistance wire and the cooling water, reduces the resistance of the cooling water, and achieves a desirable cooling effect.

IPC Classes  ?

• H01C 1/082 - Cooling, heating or ventilating arrangements using forced fluid flow
• H01C 1/024 - HousingEnclosingEmbeddingFilling the housing or enclosure the housing or enclosure being hermetically sealed
• H01C 3/20 - Non-adjustable metal resistors made of wire or ribbon, e.g. coiled, woven, or formed as grids the resistive element being formed in two or more coils or loops continuously wound as a spiral, helical, or toroidal winding wound on cylindrical or prismatic base

Abstract

An adjustment method and system for a flexible direct current power transmission coupling transformer on-load tap changer. Said adjustment method adjusts the coupling transformer transformation ratio of an on-load tap changer installed on the network side or the valve side of a coupling transformer, and includes the following steps: separately calculating a relationship table for the grid voltage fluctuation and the coupling transformer tap position of the on-load tap changer installed on the network side or the valve side of the coupling transformer; adjusting the coupling transformer transformation ratio. Said adjustment system comprises a coupling transformer, an alternating current system, and a voltage source converter; the coupling transformer is connected between the alternating current system and the voltage source converter. The present adjustment method and system can, in the presence of grid voltage fluctuation, ensure that the ratio of the coupling transformer valve-side voltage to the coupling transformer direct current voltage remains unchanged, thus maximally utilizing the reactive power output capacity of the converter and ensuring that the modulation ratio of the converter is within its optimal range.

IPC Classes  ?

• H02P 13/00 - Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output