WO2015161610A1

WO2015161610A1 - Direct-current fault isolation type subunit and bridge arm topology structure for flexible direct-current power transmission converter station

Info

Publication number: WO2015161610A1
Application number: PCT/CN2014/086070
Authority: WO
Inventors: 朱晋; 韦统振; 霍群海; 吴理心; 韩立博; 张桐硕
Original assignee: 中国科学院电工研究所
Priority date: 2014-04-25
Filing date: 2014-09-05
Publication date: 2015-10-29

Abstract

A direct-current fault isolation type subunit topology for a flexible direct-current power transmission converter station, comprising at least one capacitor group, at least two fully-controlled semiconductor devices, and a fault isolation combinational circuit. The at least two fully-controlled semiconductor devices are connected to the at least one capacitor group to form a half-bridge subunit form. A plurality of leading-out terminals of the fault isolation combinational circuit are connected to a positive electrode and a negative electrode of the at least one capacitor group, and connection points of the at least two fully-controlled semiconductor devices respectively.

Description

Sub-unit and bridge arm topology of DC fault isolation flexible DC transmission converter station

Technical field

The invention relates to a sub-unit and bridge arm topology structure of a DC fault isolation type flexible direct current power transmission converter station.

Background technique

Due to the unique advantages of DC transmission based on voltage source conversion, it has broad application prospects in the fields of clean new energy integration, urban transmission and distribution capacity expansion, and offshore isolated load transmission. Modular multilevel converter (MMC) is based on the cascading of half-bridge sub-modules. It has the requirements of consistent dynamic voltage equalization for the device, good scalability, high output voltage waveform quality, and switching frequency. Low, low operating losses and many other advantages have become the mainstream trend of current converter selection. However, this structure has inherent defects that cannot effectively handle DC faults. When the DC side fails, the anti-parallel diode of the fully-controlled switching device is easy to form an energy feeding loop that directly connects the fault point with the AC system, and cannot simply rely on the converter action to complete the DC side fault current clearing. At present, most of the VSC-HVDC projects that have been put into operation use cable laying lines to reduce the probability of DC faults, but the cost is high and the economic benefits are poor.

The self-clearing of the DC-side fault is realized by the converter's own control, and the system does not need to be operated, so the system recovers quickly. This technology has been widely used in the traditional DC transmission technology, that is, the arc current is quickly eliminated by forced phase shift. Finding a new type of converter with DC fault ride-through capability is a hot research topic in academia and industry. In 2010, ALSTOM proposed a variety of hybrid converters combining the characteristics of traditional two-level inverters and MMC structures at the International Power Grid Conference, in which the bridge arms alternately conduct multi-level inverters and hybrid cascades. Level converters have DC fault ride-through capability. However, the control is more complicated, and it is more difficult to balance the voltage of the sub-unit capacitors. Although the full bridge sub-module (FBSM) also has DC blocking capability, the loss during normal operation is large, and the cost of the converter station is significantly increased.

Summary of the invention

The object of the present invention is to overcome the deficiencies of the prior art and propose a new DC fault isolation type flexible direct current power transmission converter subunit topology. The invention can make the entire converter station have the DC side fault processing capability, reduce the loss as much as possible during normal operation, and can reduce the construction cost of the converter station.

According to the present invention, there is provided a DC fault isolation type flexible direct current power transmission converter station subunit, which may include at least one capacitor bank, at least two fully controlled semiconductor devices, and a fault isolation combination circuit for isolating a DC fault. The at least two fully controlled semiconductor devices are connected to the at least one capacitor bank in the form of a half bridge subunit. The plurality of lead terminals of the fault isolation combination circuit are respectively connected to the connection points of the positive electrode and the negative electrode of the at least one capacitor group and the at least two fully-controlled semiconductor devices.

According to the first aspect of the present invention, the DC fault isolation type flexible DC power transmission converter subunit of the first embodiment is composed of a first capacitor group, a second capacitor group, four fully controlled semiconductor devices, and a fault isolation combination. The circuit consists of the following connections:

The anode of the first capacitor group is connected to the collector of the first fully-controlled semiconductor device; the emitter of the first fully-controlled semiconductor device is connected to the collector of the second fully-controlled semiconductor device, and is connected as the first fully-controlled device Point; the emitter of the second fully controlled semiconductor device is connected to the negative electrode of the first capacitor group; the anode of the second capacitor group is connected to the collector of the third fully controlled semiconductor device; and the emitter of the third fully controlled semiconductor device Connected to the collector of the fourth fully-controlled semiconductor device as a second fully-controlled device connection point; the emitter of the fourth fully-controlled semiconductor device is connected to the cathode of the second capacitor group.

The first terminal of the fault isolation combination circuit is connected to the anode of the first capacitor group, the second terminal of the fault isolation combination circuit is connected to the cathode of the first capacitor group, and the third terminal of the fault isolation combination circuit and the second capacitor group The positive terminal is connected, the fourth lead terminal of the fault isolation combination circuit is connected to the negative pole of the second capacitor group, and the fifth lead terminal of the fault isolation combination circuit is connected with the connection point of the first full control type device, and the fifth lead of the fault isolation combination circuit is connected. The terminal is connected to the connection point of the second full control device. The seventh terminal of the fault isolation combined circuit is used as the first terminal of the DC fault isolation type flexible DC transmission converter subunit, and the eighth terminal of the fault isolation combined circuit is used as the subunit of the DC fault isolation flexible DC transmission converter subunit Second lead terminal.

When the subunit is in normal operation, when the first fully controlled semiconductor device is turned off, the second The fully controlled semiconductor device is turned on, the third fully controlled semiconductor device is turned on, and when the fourth fully controlled semiconductor device is turned off, the voltage between the first lead terminal and the second lead terminal of the subunit is 0, and the first capacitor The group and the second capacitor group are not connected to the circuit.

When the first fully controlled semiconductor device is turned off, the second fully controlled semiconductor device is turned on, the third fully controlled semiconductor device is turned off, and when the fourth fully controlled semiconductor device is turned on, the first terminal of the subunit is connected with The voltage between the second terminals is the voltage across the second capacitor group; the first capacitor group is not connected to the circuit.

When the first fully controlled semiconductor device is turned on, the second fully controlled semiconductor device is turned off, the third fully controlled semiconductor device is turned off, and when the fourth fully controlled semiconductor device is turned on, the first terminal of the subunit is connected with The voltage between the second terminals is the voltage across the first capacitor group; the second capacitor group is not connected to the circuit.

When the first fully controlled semiconductor device is turned on, the second fully controlled semiconductor device is turned off, the third fully controlled semiconductor device is turned on, and the fourth fully controlled semiconductor device is turned off, the first lead terminal of the subunit is The voltage between the second terminals is the sum of the voltages across the first capacitor group and the second capacitor group.

When the subunits are locked, the working principle is different according to the structure of the fault isolation combined circuit.

The fault isolation combination circuit may be composed of a combination of a first diode module and a sixth full control type semiconductor device, or may be composed of a combination of a second diode module and a fifth full control type semiconductor device, or may be composed of The diode module and the fifth full control type semiconductor device are combined, and may also be composed of a combination of the second diode module and the sixth full control type semiconductor device, or may be composed of the first diode module and the second diode The tube module, the fifth full control type semiconductor device and the sixth full control type semiconductor device are combined.

When the fault isolation combined circuit is composed of a first diode module, a second diode module, a fifth full control type semiconductor device, and a sixth full control type semiconductor device, the cathode of the first diode module is The first terminal of the fault isolation combination circuit is connected, the anode of the first diode module is connected to the collector of the fifth full control type semiconductor device, and the second terminal of the emitter and fault isolation combination circuit of the fifth full control type semiconductor device Connecting, the collector of the sixth full control type semiconductor device is connected to the third terminal of the fault isolation combination circuit, the emitter of the sixth full control type semiconductor device is connected to the cathode of the second diode module, and the second diode module Anode Connected to the fourth terminal of the fault isolation combination circuit. The emitter of the sixth fully controlled semiconductor device is connected to the collector of the fifth fully controlled semiconductor device. The fifth terminal of the fault isolation combination circuit is connected to the seventh terminal of the fault isolation combination circuit, and the sixth terminal of the fault isolation combination circuit is connected with the eighth terminal. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-unit, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the second The sum of the voltages across the capacitor bank forms a counter electromotive force that blocks the inflow current. When a current flows from the second terminal of the subunit, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the voltage across the second capacitor group form a reverse The electromotive force blocks the inflow current.

When the fault isolation combination circuit is composed of a combination of the first diode module and the sixth full control type semiconductor device, the emitter of the sixth full control type semiconductor device is connected to the fifth terminal of the fault isolation combination circuit, and the sixth The collector of the fully controlled semiconductor device is connected to the third terminal of the fault isolation combination circuit. The cathode of the first diode module is coupled to the first terminal of the fault isolation combination circuit, and the anode of the first diode module is coupled to the fourth terminal of the fault isolation combination circuit. In this connection mode, the first terminal of the fault isolation combination circuit is connected to the seventh terminal of the fault isolation combination circuit, and the sixth terminal of the fault isolation combination circuit is connected to the eighth terminal. The second terminal of the fault isolation combination circuit is vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-unit, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the second The sum of the voltages across the capacitor bank forms a counter electromotive force that blocks the inflow current. When a current flows from the second terminal of the subunit, the first capacitor group and the second capacitor group are connected in series to the forward circuit, the first capacitor group is bypassed, the second capacitor group is forwardly connected to the circuit, and the second The voltage across the capacitor bank forms a counter electromotive force that blocks the inflow current.

When the fault isolation combined circuit is composed of a fifth full control type semiconductor device and a second diode module. The emitter of the fifth fully controlled semiconductor device is connected to the second terminal of the fault isolation combination circuit, and the collector of the fifth full control type semiconductor device is connected to the third terminal of the fault isolation combination circuit. The cathode of the second diode module is coupled to the first terminal of the fault isolation combination circuit, and the anode of the first diode module is coupled to the fourth terminal of the fault isolation combination circuit. The fifth terminal of the fault isolation combination circuit is connected to the seventh terminal of the fault isolation combination circuit, and the fourth terminal of the fault isolation combination circuit is connected with the eighth terminal. Fault isolation combination The third terminal of the road is vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-unit, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the second The sum of the voltages across the capacitor bank forms a counter electromotive force that blocks the inflow current. When a current flows from the second terminal of the subunit, the second capacitor group is bypassed, and the first capacitor group is forwardly connected to the circuit, and the voltage across the first capacitor group forms a counter electromotive force to block the inflow current.

The DC fault isolation type flexible DC transmission converter subunit topology may also be composed only of the first capacitor group, the first fully controlled semiconductor device, the second fully controlled semiconductor device and the fault isolation circuit; the first capacitor group The positive electrode is connected to the collector of the first fully controlled semiconductor device; the emitter of the first fully controlled semiconductor device (T1) is connected to the collector of the second fully controlled semiconductor device as a first fully controlled device connection point; The emitter of the second fully controlled semiconductor device is connected to the cathode of the first capacitor group.

a first lead terminal of the fault isolation combination circuit is connected to a positive pole of the first capacitor group, a second lead terminal of the fault isolation combination circuit is connected to a cathode of the first capacitor group, and a fifth lead terminal of the fault isolation combination circuit is first The connection terminal of the full control device is connected, and the seventh terminal of the fault isolation combination circuit is used as the first terminal of the subunit of the DC fault isolation type flexible DC transmission converter station, and the eighth terminal of the fault isolation combination circuit is used as the DC fault isolation type flexible DC The second lead-out terminal of the power transmission converter subunit.

The fault isolation combination circuit is composed of a first diode and a fifth full control type semiconductor device; a cathode of the first diode is connected to a first terminal of the fault isolation combination circuit, and an anode and a fifth of the first diode The collector connection of the fully controlled semiconductor device, the emitter of the fifth fully controlled semiconductor device is connected to the second terminal of the fault isolation combination circuit.

The fifth terminal of the fault isolation combination circuit is connected to the seventh terminal of the fault isolation combination circuit, and the eighth terminal of the fault isolation combination circuit is connected to the collector of the fifth full control type semiconductor device; the third terminal of the fault isolation combination circuit The fourth terminal and the sixth terminal are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-unit, the first capacitor group is forwardly connected to the circuit, and the voltage across the first capacitor group forms a counter electromotive force to block the inflow current. When a current flows from the second terminal of the subunit, the first capacitor group is forwardly connected to the circuit, and the voltage across the first capacitor group forms a counter electromotive force to block the inflow current.

The DC fault isolation type flexible DC transmission converter subunit topology may also be composed only of the second capacitor group, the third full control type semiconductor device, the fourth full control type semiconductor device and the fault isolation circuit; the second capacitor group The positive electrode is connected to the collector of the third fully controlled semiconductor device; the emitter of the third fully controlled semiconductor device is connected to the collector of the fourth fully controlled semiconductor device as a connection point of the second fully controlled device; The emitter of the control semiconductor device is connected to the cathode of the second capacitor group.

The third lead terminal of the fault isolation combination circuit is connected with the anode of the second capacitor group, the fourth terminal of the fault isolation combination circuit is connected with the cathode of the second capacitor group, and the fifth terminal of the fault isolation combination circuit and the second full control The device is connected at the connection point; the seventh terminal of the fault isolation combination circuit is used as the first terminal of the DC fault isolation type flexible DC transmission converter subunit, and the eighth terminal of the fault isolation combination circuit is used as the DC fault isolation type flexible DC transmission. The second terminal of the stream station subunit.

The fault isolation circuit is composed of a sixth full control type semiconductor device and a second diode module; the collector of the sixth full control type semiconductor device is connected with the third terminal of the fault isolation combination circuit, and the emission of the sixth full control type semiconductor device The pole is connected to the cathode of the second diode, and the anode of the second diode is connected to the fourth terminal of the fault isolation combination circuit.

The sixth terminal of the fault isolation combination circuit is connected to the eighth terminal of the fault isolation combination circuit, and the seventh terminal of the fault isolation combination circuit is connected to the emitter of the sixth full control type semiconductor device; the first terminal of the fault isolation combination circuit The second terminal and the fifth terminal are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-unit, the second capacitor group is forwardly connected to the circuit, and the voltage across the second capacitor group forms a counter electromotive force to block the inflow current. When a current flows from the second terminal of the subunit, the second capacitor group is forwardly connected to the circuit, and the voltage across the second capacitor group forms a counter electromotive force to block the inflow current.

Each of the first diode module and the second diode module in the fault isolation combination circuit may be composed of a diode and b resistors, and c capacitors, and d inductors are connected in series, a is An integer greater than or equal to 1, and b, c, and d are integers greater than or equal to zero.

Under normal operating conditions, current does not flow through the diode due to the reverse blocking characteristics of the diode. When a fault occurs, if the current flows from the anode of the diode in the first diode module or the second diode module to the cathode, the first diode module or the second diode The inductors, resistors, and capacitors in the module are connected to the circuit. The resistor can be used to dissipate the fault energy. The inductor can be used to suppress the rate of rise of the fault current. The capacitor is charged by the fault current, which increases the equivalent capacitor voltage that is connected to the circuit, thereby helping to block the fault current.

The six fully-controlled semiconductor devices are composed of at least one IGBT connected in series, or may be composed of at least one other type of fully-controlled devices with anti-parallel diodes connected in series, such as GTO, IGCT, and the like.

The first capacitor group and the second capacitor group may be composed of one or more capacitors connected in series or in parallel. The capacitor group may be provided with an additional circuit unit such as a bleeder resistor, a precharge circuit, or the like.

According to a second aspect of the present invention, the DC fault isolation type flexible direct current power transmission converter subunit of the second embodiment comprises a first capacitor group, a second capacitor group, five fully controlled semiconductor devices, and a fault isolation combination. Circuit composition. The connection method is as follows:

The anode of the first capacitor group is coupled to the collector of the first fully controlled semiconductor device. The emitter of the first fully-controlled semiconductor device is connected to the collector of the second fully-controlled semiconductor device as the first terminal of the sub-unit topology of the DC fault isolation type flexible DC transmission converter station. The emitter of the second fully-controlled semiconductor device is connected to the emitter of the fifth fully-controlled semiconductor device and then to the cathode of the first capacitor group. The collector of the fifth fully controlled semiconductor device is connected to the anode of the second capacitor group and then to the collector of the third fully controlled semiconductor device. The emitter of the third fully controlled semiconductor device is connected to the collector of the fourth fully controlled semiconductor device as a second terminal of the sub-unit topology of the DC fault isolation type flexible DC power converter station. The emitter of the fourth fully controlled semiconductor device is connected to the cathode of the second capacitor group.

The first terminal of the fault isolation combination circuit is connected to the anode of the first capacitor group, and the second terminal of the fault isolation combination circuit is connected with the first terminal of the topology of the DC fault isolation flexible DC transmission converter subunit, and the fault is isolated. The third lead-out terminal of the combined circuit is connected to the second lead-out terminal of the DC fault isolation type flexible DC power transmission converter sub-unit topology, and the fourth lead-out terminal of the fault isolation combination circuit is connected to the cathode of the second capacitor group. The fifth terminal of the fault isolation combination circuit is connected to the cathode of the first capacitor group, and the sixth terminal of the fault isolation combination circuit is connected to the anode of the second capacitor group.

When the subunit topology is working normally, the fifth fully controlled semiconductor device is turned on, when The first fully controlled semiconductor device is turned off, the second fully controlled semiconductor device is turned on, the third fully controlled semiconductor device is turned on, and the fourth fully controlled semiconductor device is turned off, the first lead terminal of the subunit topology is The voltage between the second lead terminals is 0, and the first capacitor group C1 and the second capacitor group C2 are not connected to the circuit;

When the first fully-controlled semiconductor device is turned off, the second fully-controlled semiconductor device is turned on, the third fully-controlled semiconductor device is turned off, and the fourth fully-controlled semiconductor device is turned on, the sub-cell topology first lead-out terminal The voltage between the second terminal and the second terminal is the voltage across the second capacitor group C2; the first capacitor group C1 is not connected to the circuit;

When the first fully-controlled semiconductor device is turned on, the second fully-controlled semiconductor device is turned off, the third fully-controlled semiconductor device is turned on, and the fourth fully-controlled semiconductor device is turned off, the sub-cell topology first lead-out terminal The voltage between the second terminal and the second terminal is the voltage across the first capacitor group C1; the second capacitor group C2 is not connected to the circuit;

When the first fully-controlled semiconductor device is turned on, the second fully-controlled semiconductor device is turned off, the third fully-controlled semiconductor device is turned off, and the fourth fully-controlled semiconductor device is turned on, the sub-cell topology first lead-out terminal The voltage between the second extraction terminal and the second extraction terminal is the sum of the voltages across the first capacitor group C1 and the second capacitor group C2;

When the subunit topology is locked, the working principle is different according to the structure of the fault isolation combined circuit.

The fault isolation combination circuit may be composed only of the fifth diode module, or may be composed only of the first diode module, or may be composed only of the second diode module, or may be composed of the first diode. The module and the second diode module are combined, and may also be composed only of the third diode module, or may be composed only of the fourth diode, or may be composed of the third diode module and the fourth diode module. Combination composition.

When the fault isolation combined circuit is composed only of the fifth diode module, the cathode of the fifth diode module is connected to the first lead terminal of the fault isolation combination circuit, and the anode of the fifth diode module is isolated from the fault. The fourth lead terminal of the combination circuit is connected, the third lead terminal of the fault isolation combination circuit, the second lead terminal of the fault isolation combination circuit, the fifth lead terminal of the fault isolation combination circuit, and the sixth lead terminal of the fault isolation combination circuit are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-cell topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the first capacitor The sum of the voltage across the group C1 and the voltage across the second capacitor group forms a counter electromotive force that blocks the inflow current.

When a current flows from the second terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the voltage across the second capacitor group form a sum of voltages Back electromotive force blocks the inflow current.

When the fault isolation combination circuit is composed of the first diode module and the second diode module, the connection form of the fault isolation combination circuit 1 is as follows: the cathode of the first diode module and the fault isolation combination circuit The second lead terminal is connected, and the anode of the first diode module is connected to the fourth lead terminal of the fault isolation combination circuit. The cathode of the second diode module is connected to the first lead terminal of the fault isolation combination circuit, and the anode of the second diode module is connected to the third lead terminal of the fault isolation combination circuit. The fifth lead terminal of the fault isolation combination circuit and the sixth lead terminal of the fault isolation combination circuit are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-cell topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the first capacitor group The sum of the voltages across the two capacitor banks forms a counter electromotive force that blocks the inflow current. When a current flows from the second lead terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in parallel to the forward access circuit, and the voltages at both ends of the first capacitor group and the second capacitor group are inverted. The electromotive force blocks the inflow current.

When the fault isolation combination circuit is composed only of the first diode module, the connection form of the fault isolation combination circuit is as follows: the cathode of the first diode module is connected to the second extraction terminal of the fault isolation combination circuit, first The anode of the diode module is connected to the fourth terminal of the fault isolation combination circuit. The first lead terminal of the fault isolation combination circuit, the third lead terminal of the fault isolation combination circuit, the fifth lead terminal of the fault isolation combination circuit, and the sixth lead terminal of the fault isolation combination circuit are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-cell topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the first capacitor group The sum of the voltages across the two capacitor banks forms a counter electromotive force that blocks the inflow current. When a current flows from the second lead terminal of the subunit topology, the first capacitor group is bypassed, the second capacitor group is forwardly connected to the circuit, and the voltage across the second capacitor group forms a counter electromotive force to block the inflow current.

When the fault isolation combined circuit is composed only of the second diode module, the fault is separated The connection form of the combination circuit is as follows: the cathode of the second diode module is connected to the first lead terminal of the fault isolation combination circuit, and the anode of the second diode module is connected to the third lead terminal of the fault isolation combination circuit. The second lead-out terminal of the fault isolation combination circuit, the fourth lead-out terminal of the fault isolation combination circuit, the fifth lead-out terminal of the fault isolation combination circuit, and the sixth lead-out terminal of the fault isolation combination circuit are vacant. After all the fully-controlled semiconductor devices are latched, when current flows from the first terminal of the sub-cell topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the first capacitor group The sum of the voltages across the two capacitor banks forms a counter electromotive force that blocks the inflow current. When a current flows from the second terminal of the subunit topology, the second capacitor group is bypassed, and the first capacitor group is forwardly connected to the circuit, and the voltage across the first capacitor group forms a counter electromotive force to block the inflow current.

When the fault isolation combined circuit is composed of a third diode module and a fourth diode module, the cathode of the third diode module is connected to the first lead terminal of the fault isolation combination circuit, and the third diode The anode of the module is connected to the sixth lead terminal of the fault isolation combination circuit; the cathode of the fourth diode module is connected to the fifth lead terminal of the fault isolation combination circuit, and the anode of the fourth diode module is combined with the fault isolation combination circuit The four lead terminals are connected, the second lead terminal of the fault isolation combination circuit, and the third lead terminal of the fault isolation combination circuit are vacant. When a current flows from the first terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the voltage across the second capacitor group form a sum of voltages Back electromotive force blocks the inflow current. When a current flows from the second lead terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in parallel to the forward access circuit, and the voltages at both ends of the first capacitor group and the second capacitor group are connected in parallel. The voltage forms a counter electromotive force that blocks the inflow current.

When the fault isolation combined circuit is composed only of the third diode module, the cathode of the third diode module is connected to the first lead terminal of the fault isolation combination circuit, and the anode of the third diode module is isolated from the fault. a sixth lead terminal of the combination circuit is connected, a second lead terminal of the fault isolation combination circuit, a third lead terminal of the fault isolation combination circuit, a fourth lead terminal of the fault isolation combination circuit, and a fifth lead terminal of the fault isolation combination circuit are vacant; When a current flows from the first lead terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in series to the forward connection circuit, and the voltage across the first capacitor group and the voltage across the second capacitor group are A counter electromotive force is formed to block the inflow current. When current flows from the subunit topology When the second lead terminal flows in, the second capacitor group is bypassed, and the first capacitor group is forwardly connected to the circuit, and the voltage across the first capacitor group forms a counter electromotive force to block the inflow current.

When the fault isolation combination circuit is composed only of the fourth diode module, the cathode of the fourth diode module is connected to the fifth terminal of the fault isolation combination circuit, and the anode of the fourth diode module is isolated from the fault. The fourth lead terminal of the combination circuit is connected, the second lead terminal of the fault isolation combination circuit, the third lead terminal of the fault isolation combination circuit, the sixth lead terminal of the fault isolation combination circuit, and the first lead terminal of the fault isolation combination circuit are vacant. When a current flows from the first terminal of the subunit topology, the first capacitor group and the second capacitor group are connected in series to the forward circuit, and the voltage across the first capacitor group and the voltage across the second capacitor group form a sum of voltages Back electromotive force blocks the inflow current. When a current flows from the second lead terminal of the subunit topology, the first capacitor group is bypassed, the second capacitor group is forwardly connected to the circuit, and the voltage across the second capacitor group forms a counter electromotive force to block the inflow current.

The fifth fully controlled semiconductor device can be replaced by a wire.

After the fifth fully-controlled semiconductor device is replaced by a wire, if the flexible DC transmission converter station composed of such a sub-unit topology needs to retain DC-side fault processing capability, the second fully-controlled semiconductor device and the third full control At least one of the type of semiconductor devices needs to be replaced by a combination of bidirectional turn-off semiconductor devices. The bidirectional turn-off semiconductor device combination has various implementation forms, such as an anti-parallel consisting of two sets of IGBTs, or a combination of four diode modules and one semiconductor device module.

Each of the first diode module, the second diode module, the third diode module, the fourth diode module, and the fifth diode module in the fault isolation combination circuit may be One or more diodes are formed in series with a resistor, capacitor or inductor.

For example, each of the first to fifth diode modules may be composed of a diode and b capacitors, c capacitors, and d inductors in series, where a is an integer greater than or equal to 1, and b, c, and d are both Is an integer greater than or equal to 0.

The five fully-controlled semiconductor devices are composed of at least one IGBT connected in series, or may be composed of at least one other fully-controlled device with anti-parallel diodes connected in series, such as GTO, IGCT, and the like. The first capacitor group and the second capacitor group may be composed of one or more capacitors connected in series or in parallel. The capacitor group may be provided with an additional circuit unit such as a bleeder resistor, a precharge circuit, or the like.

According to a third aspect of the present invention, a flexible DC power transmission converter bridge arm is provided, which is composed of m DC fault isolation type flexible DC power transmission converter subunits and n half bridge types according to the present invention. The subunits are cascaded, m is an integer greater than or equal to 1, and n is an integer greater than or equal to zero.

Advantages of the invention include:

a. Compared with the half-bridge MMC sub-unit, it has DC-side fault processing capability;

b. Compared with the full bridge MMC subunit, the cost is significantly reduced;

c. The loss is significantly reduced compared to the full bridge MMC subunit.

DRAWINGS

The invention will be further described below in conjunction with the drawings and specific embodiments.

1 is a schematic diagram showing the circuit structure of a DC fault isolation type flexible direct current power transmission converter subunit according to a first embodiment of the present invention;

2 is a circuit schematic diagram of Embodiment 1 of a DC fault isolation type flexible DC power transmission converter subunit according to a first embodiment of the present invention;

3 is a circuit schematic diagram of Embodiment 2 of a DC fault isolation type flexible direct current power transmission converter subunit according to a first embodiment of the present invention;

4 is a circuit schematic diagram of Embodiment 3 of a DC fault isolation type flexible DC power transmission converter subunit according to a first embodiment of the present invention;

5 is a circuit schematic diagram of Embodiment 4 of a DC fault isolation type flexible DC power transmission converter subunit according to a first embodiment of the present invention;

6 is a circuit schematic diagram of Embodiment 5 of a DC fault isolation type flexible DC power transmission converter subunit according to a first embodiment of the present invention;

7 is a circuit schematic diagram of Embodiment 6 of a DC fault isolation type flexible DC power transmission converter sub-unit according to a first embodiment of the present invention;

8 is a circuit schematic diagram of Embodiment 7 of a DC fault isolation type flexible direct current power transmission converter subunit according to a first embodiment of the present invention;

9 is a DC fault isolation type flexible DC according to a first embodiment of the present invention. Circuit schematic diagram of Embodiment 8 of the power transmission converter subunit;

10 is a circuit schematic diagram of Embodiment 9 of a DC fault isolation type flexible direct current power transmission converter subunit according to a first embodiment of the present invention;

11 is a circuit diagram showing a circuit structure of a DC fault isolation type flexible direct current power transmission converter subunit according to a second embodiment of the present invention;

12 is a schematic diagram showing the circuit structure of Embodiment 1 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

13 is a schematic diagram showing the circuit structure of Embodiment 2 of a DC fault isolation type flexible DC power transmission converter sub-unit according to a second embodiment of the present invention;

14 is a schematic diagram showing the circuit structure of Embodiment 3 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

15 is a schematic diagram showing the circuit structure of Embodiment 4 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

16 is a schematic diagram showing the circuit structure of Embodiment 5 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

17 is a schematic diagram showing the circuit structure of Embodiment 6 of a DC fault isolation type flexible DC power transmission converter sub-unit according to a second embodiment of the present invention;

18 is a schematic diagram showing the circuit structure of Embodiment 7 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

19 is a schematic diagram showing the circuit structure of Embodiment 8 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

20 is a schematic diagram showing the circuit structure of Embodiment 9 of a DC fault isolation type flexible DC power transmission converter subunit according to a second embodiment of the present invention;

21 is an implementation of a bidirectional turn-off semiconductor device combination of the present invention;

22 is another implementation of the bidirectional turn-off semiconductor device combination of the present invention;

Figure 23 is a schematic illustration of a bridge arm of a flexible direct current transmission converter station in accordance with the present invention.

detailed description

The DC fault isolation type flexible DC power transmission converter subunit according to the present invention may include at least one capacitor group, at least two fully controlled semiconductor devices, and is used for isolating DC Faulty fault isolation combination circuit. The at least two fully controlled semiconductor devices are connected to the at least one capacitor bank in the form of a half bridge subunit. The plurality of lead terminals of the fault isolation combination circuit are respectively connected to the connection points of the positive electrode and the negative electrode of the at least one capacitor group and the at least two fully-controlled semiconductor devices.

Two more specific embodiments of the DC fault isolation type flexible direct current power transmission converter subunit according to the present invention are separately discussed below.

(1) Embodiment 1

As shown in FIG. 1 , the DC fault isolation type flexible DC power transmission converter sub-unit according to the first embodiment of the present invention comprises a first capacitor group C101, a second capacitor group C102, and four fully-controlled semiconductor devices T101 and T102. T103, T104, and fault isolation combining circuit 107 are composed. The connection method is as follows:

The positive electrode 101 of the first capacitor group C1 is connected to the collector of the first fully-controlled semiconductor device T101; the emitter of the first fully-controlled semiconductor device T101 is connected to the collector of the second fully-controlled semiconductor device T102 as the first The full-controlled device connection point 105; the emitter of the second fully-controlled semiconductor device T102 is connected to the negative electrode 102 of the first capacitor group C1011; the positive electrode 103 of the second capacitor group C102 and the collector of the third fully-controlled semiconductor device T103 Connecting; the emitter of the third fully-controlled semiconductor device T103 is connected to the collector of the fourth fully-controlled semiconductor device T104 as the second fully-controlled device connection point 106; the emitter of the fourth fully-controlled semiconductor device T104 is The negative electrode 104 of the second capacitor group C102 is connected.

The first extraction terminal 111 of the fault isolation combination circuit 107 is connected to the anode 101 of the first capacitor group C101, and the second extraction terminal 112 of the fault isolation combination circuit 107 is connected to the cathode 102 of the first capacitor group C101, and the fault isolation combination circuit 107 is connected. The third lead terminal 113 is connected to the positive electrode 103 of the second capacitor group C102, the fourth lead terminal 114 of the fault isolation combining circuit 107 is connected to the negative electrode 104 of the second capacitor group C102, and the fifth lead terminal 115 of the fault isolation combining circuit 107 is connected. The first fully-controlled device connection point 105 is connected, and the sixth extraction terminal 116 of the fault isolation combining circuit 107 is connected to the second full-control device connection point 106. The seventh terminal 117 of the fault isolation combining circuit 107 serves as a first lead terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal 118 of the fault isolation combining circuit 107 serves as a DC fault isolation type flexible DC power transmission converter station. Second of the subunit Lead the terminal.

Example 1

Fig. 2 shows a specific embodiment 1 of the first embodiment of the present invention. As shown in FIG. 2, the DC fault isolation type flexible DC power transmission converter sub-unit of Embodiment 1 of the first embodiment of the present invention includes: a first capacitor group C101, a second capacitor group C102, and four fully-controlled semiconductor devices. T101, T102, T103, T104, and fault isolation combining circuit 107. The connection method is the same as that described with reference to FIG.

The fault isolation combining circuit 107 is composed of a fifth full control type semiconductor device T105, a sixth full control type semiconductor device T106, a first diode module D101, and a second diode module D102. The cathode of the first diode module D101 is connected to the first terminal 111 of the fault isolation combination circuit 107, and the anode of the first diode module D101 is connected to the collector 119 of the fifth fully-controlled semiconductor device T105. The emitter of the semiconductor device T105 is connected to the second terminal 112 of the fault isolation combination circuit 107, and the collector of the sixth full control semiconductor device T106 is connected to the third terminal 113 of the fault isolation combination circuit 107. The sixth fully controlled semiconductor The emitter 120 of the device T106 is coupled to the cathode of the second diode module D102, and the anode of the second diode module D102 is coupled to the fourth terminal 114 of the fault isolation combination circuit 107. The emitter 120 of the sixth full control type semiconductor device T106 is connected to the collector 119 of the fifth full control type semiconductor device T105. The fifth terminal 115 of the fault isolation combining circuit 107 is connected to the seventh terminal 117 of the fault isolation combining circuit 107, and the sixth terminal 116 of the fault isolation combining circuit 107 is connected to the eighth terminal 118.

Example 2

Fig. 3 shows a second embodiment of the first embodiment of the present invention. As shown in FIG. 3, the DC fault isolation type flexible DC power transmission converter sub-unit of Embodiment 2 of the first embodiment of the present invention includes: a first capacitor group C101, a second capacitor group C102, and four fully-controlled semiconductor devices. T101, T102, T103, T104, and fault isolation combining circuit 107. The connection method is the same as that described with reference to FIG.

The fault isolation combining circuit 107 is composed of a sixth full control type semiconductor device T106 and a first diode module D101. The emitter and fault of the sixth fully controlled semiconductor device T106 The fifth terminal 115 of the isolation combining circuit 107 is connected, and the collector of the sixth full control type semiconductor device T106 is connected to the third terminal 113 of the fault isolation combining circuit 107. The cathode of the first diode module D101 is connected to the first terminal 111 of the fault isolation combination circuit 107, and the anode of the first diode module D101 is connected to the fourth terminal 114 of the fault isolation combination circuit 107. The first terminal 111 of the fault isolation combining circuit 107 is connected to the seventh terminal 117 of the fault isolation combining circuit 107, and the sixth terminal 116 of the fault isolation combining circuit 107 is connected to the eighth terminal 118. The second terminal 112 of the fault isolation combining circuit 107 is vacant.

Example 3

Fig. 4 shows a specific embodiment 3 of the first embodiment of the present invention. As shown in FIG. 4, the DC fault isolation type flexible DC power transmission converter sub-unit of Embodiment 3 of the first embodiment of the present invention includes: a first capacitor group C101, a second capacitor group C102, and four fully-controlled semiconductor devices. T101, T102, T103, T104, and fault isolation combining circuit 107. The connection method is the same as that described with reference to FIG.

The fault isolation combining circuit 107 is composed of a fifth full control type semiconductor device T105 and a second diode module D102. The emitter of the fifth full control type semiconductor device T105 is connected to the second terminal 112 of the fault isolation combining circuit 107, and the collector of the fifth full control type semiconductor device T105 is connected to the sixth terminal 116 of the fault isolation combining circuit 107. The cathode of the second diode module D102 is connected to the first terminal 111 of the fault isolation combination circuit 107, and the anode of the second diode module D102 is connected to the fourth terminal 114 of the fault isolation combination circuit 107. The fifth terminal 115 of the fault isolation combining circuit 107 is connected to the seventh terminal 117 of the fault isolation combining circuit 107, and the fourth terminal 114 of the fault isolation combining circuit 107 is connected to the eighth terminal 118. The third terminal 113 of the fault isolation combining circuit 107 is vacant.

Example 4

Fig. 5 shows a specific embodiment 4 of the first embodiment of the present invention. As shown in FIG. 5, the DC fault isolation type flexible DC power transmission converter sub-unit of Embodiment 4 of Embodiment 1 of the present invention includes: a first capacitor group C101, two fully-controlled semiconductor devices T101, T102, and a fault. The combination circuit 107 is isolated. The connection method is as follows:

Current collection of the positive electrode 101 of the first capacitor group C101 and the first fully-controlled semiconductor device T101 The emitter of the first fully-controlled semiconductor device T101 is connected to the collector of the second fully-controlled semiconductor device T102 as the first fully-controlled device connection point 105; the emitter of the second fully-controlled semiconductor device T102 It is connected to the negative electrode 102 of the first capacitor group C101.

The first extraction terminal 111 of the fault isolation combination circuit 107 is connected to the anode 101 of the first capacitor group C101, and the second extraction terminal 112 of the fault isolation combination circuit 107 is connected to the cathode 102 of the first capacitor group C101, and the fault isolation combination circuit 107 is connected. The fifth lead terminal 115 is connected to the first full control type device connection point 105. The seventh terminal 117 of the fault isolation combining circuit 107 serves as a first lead terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal 118 of the fault isolation combining circuit 107 serves as a DC fault isolation type flexible DC power transmission converter station. The second lead terminal of the subunit.

The fault isolation combining circuit 107 is composed of a fifth full control type semiconductor device T105 and a first diode module D101. The cathode of the first diode module D101 is connected to the first terminal 111 of the fault isolation combination circuit 107, and the anode of the first diode module D101 is connected to the collector 119 of the fifth fully-controlled semiconductor device T105. The emitter of the semiconductor device T105 is connected to the second terminal 112 of the fault isolation combining circuit 107. The fifth terminal 115 of the fault isolation combining circuit 107 is connected to the seventh terminal 117 of the fault isolation combining circuit 107, and the eighth terminal 118 of the fault isolation combining circuit 107 is connected to the collector 119 of the fifth full control type semiconductor device T105. The third terminal 113, the fourth terminal 114, and the sixth terminal 116 of the fault isolation combining circuit 107 are vacant.

Example 5

Fig. 6 shows a specific embodiment 5 of the first embodiment of the present invention. As shown in FIG. 6, the DC fault isolation type flexible DC power transmission converter sub-unit of Embodiment 5 of Embodiment 1 of the present invention includes: a second capacitor group C102, two fully-controlled semiconductor devices T103, T104, and a fault. The combination circuit 107 is isolated. The connection method is as follows:

The positive electrode 103 of the second capacitor group C102 is connected to the collector of the third fully-controlled semiconductor device T103; the emitter of the third fully-controlled semiconductor device T103 is connected to the collector of the fourth fully-controlled semiconductor device T104, as the second The full-controlled device connection point 106; the emitter of the fourth fully-controlled semiconductor device T104 is connected to the negative electrode 104 of the second capacitor group C102.

The third lead terminal 113 of the fault isolation combining circuit 107 and the second capacitor group C102 The positive electrode 103 is connected, the fourth extraction terminal 114 of the fault isolation combination circuit 107 is connected to the negative electrode 104 of the second capacitance group C102, and the fifth extraction terminal 116 of the fault isolation combination circuit 107 is connected to the second full control device connection point 106. The seventh terminal 117 of the fault isolation combining circuit 107 serves as a first lead terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal 118 of the fault isolation combining circuit 107 serves as a DC fault isolation type flexible DC power transmission converter station. The second lead terminal of the subunit.

The fault isolation combining circuit 107 is composed of a sixth full control type semiconductor device T106 and a second diode module D102. The collector of the sixth full control type semiconductor device T106 is connected to the third terminal 113 of the fault isolation combining circuit 107, and the emitter 120 of the sixth full control type semiconductor device T106 is connected to the cathode of the second diode module D102, and the second The anode of the diode module D102 is coupled to the fourth terminal 114 of the fault isolation combination circuit 107. The sixth terminal 116 of the fault isolation combining circuit 107 is connected to the eighth terminal 118 of the fault isolation combining circuit 107, and the seventh terminal 117 of the fault isolation combining circuit 107 is connected to the emitter 120 of the sixth full control type semiconductor device T106. The first terminal 111, the second terminal 112, and the fifth terminal 115 of the fault isolation combining circuit 107 are vacant.

Example 6

Fig. 7 is a sixth embodiment of the first embodiment of the present invention, which is a further refinement of the second diode module D102 of the fifth embodiment of Fig. 6. The second diode module D102 in FIG. 7 is composed of a diode 131 connected in series with a capacitor 132.

Example 7

FIG. 8 is a seventh embodiment of the first embodiment of the present invention, which is a further refinement of the second diode module D102 of the fifth embodiment of FIG. 6. The second diode module D102 of FIG. 8 is composed of a diode 131 connected in series with a capacitor 132 and a resistor 133.

Example 8

Fig. 9 is a first embodiment of the first embodiment of the present invention, which is a further refinement of the second diode module D102 of the fifth embodiment of Fig. 6. The second diode module D102 in FIG. 9 is composed of a diode 131 connected in series with a resistor 133.

Example 9

FIG. 10 is a ninth embodiment of the present invention, which is a further refinement of the second diode module D102 of the fifth embodiment of FIG. 6. The second diode module D102 in FIG. 10 is composed of a diode 131 and a capacitor 132 in series with a resistor 133 and an inductor 134.

Although in Embodiments 6-9, the number of diodes 131 is one, and the number of capacitors 132, resistors 133, and inductors 134 are both 0 or 1, it will be understood by those skilled in the art that the second diode The module D102 may be composed of a2 diodes and b2 capacitors, c2 capacitors, and d2 inductors in series, where a2 is an integer greater than or equal to 1, and b2, c2, and d2 are integers greater than or equal to zero.

Moreover, although Embodiments 6-9 are further refinement of the second diode module D102 of Embodiment 5 of FIG. 6, those of ordinary skill in the art will appreciate that the same applies to Embodiments 1, 3 (Figure The second diode module D102 in 2, 4).

Moreover, similarly, for the first diode module D101 in the embodiments 1, 2, 4 (Figs. 2, 3, 5), it can be composed of a1 diodes and b1 capacitors, c1 capacitors, and d1 inductors together. A series composition, where a1 is an integer greater than or equal to 1, and b1, c1, and d1 are integers greater than or equal to zero.

(2) Implementation 2

As shown in FIG. 11, the DC fault isolation type flexible direct current power transmission converter subunit according to the second embodiment of the present invention comprises a first capacitor group, a second capacitor group, five fully controlled semiconductor devices, and a fault isolation combined circuit. composition. The positive electrode 202 of the first capacitor group C201 is connected to the collector of the first fully-controlled semiconductor device T201. The emitter of the first fully-controlled semiconductor device T201 is connected to the collector of the second fully-controlled semiconductor device T202 as the first extraction terminal 204 of the DC fault isolation type flexible DC transmission converter sub-unit. The emitter of the second fully-controlled semiconductor device T202 is connected to the emitter of the fifth fully-controlled semiconductor device T205, and then to the negative electrode 205 of the first capacitor group C201. The collector of the fifth full control type semiconductor device T205 is connected to the anode 206 of the second capacitor group C202, and then connected to the collector of the third full control type semiconductor device T203. The emitter of the third fully controlled semiconductor device T203 is connected to the collector of the fourth fully controlled semiconductor device T204 as a DC fault isolation The second lead-out terminal 207 of the sub-unit topology of the off-type flexible direct current power transmission converter station. The emitter of the fourth fully-controlled semiconductor device T204 is connected to the anode 203 of the second capacitor group C202.

The first extraction terminal 212 of the fault isolation combination circuit 201 is connected to the positive pole 202 of the first capacitor group C201, the second extraction terminal 214 of the fault isolation combination circuit 201 and the first extraction of the DC fault isolation type flexible DC power transmission converter subunit The terminal 204 is connected, and the third lead terminal 217 of the fault isolation combining circuit 201 is connected to the second lead terminal 207 of the DC fault isolation type flexible DC power transmitting converter subunit, and the fourth lead terminal 213 and the second of the fault isolation combining circuit 201 are connected. The negative electrode 203 of the capacitor group C202 is connected. The fifth terminal 215 of the fault isolation combining circuit 201 is connected to the negative electrode 205 of the first capacitor group C201, and the sixth terminal 216 of the fault isolation combining circuit 201 is connected to the positive electrode 206 of the second capacitor group C202.

Example 1

Fig. 12 shows a specific embodiment 1 of the second embodiment of the present invention. As shown in FIG. 12, the DC fault isolation type flexible direct current power transmission converter sub-unit of the first embodiment of the second embodiment of the present invention includes: a first capacitor group C201, a second capacitor group C202, and five fully-controlled semiconductor devices. T201, T202, T203, T204, T205, and fault isolation combining circuit 201. The connection method is the same as that described with reference to FIG.

The fault isolation combining circuit 201 is composed of a combination of a first diode module D201 and a second diode module D202. The connection form of the fault isolation combination circuit 201 is as follows: the cathode of the first diode module D201 is connected to the second extraction terminal 214 of the fault isolation combination circuit 201, and the anode of the first diode module D201 is connected to the fault isolation combination circuit 201. The four lead terminals 213 are connected. The cathode of the second diode module D202 is connected to the first extraction terminal 212 of the fault isolation combination circuit 201, and the anode of the second diode module D202 is connected to the third extraction terminal 217 of the fault isolation combination circuit 201.

In Embodiment 1, the fifth lead terminal 215 and the sixth lead terminal 216 of the fault isolation combining circuit 201 are respectively vacant.

Example 2

Fig. 13 shows a specific embodiment 2 of the second embodiment of the present invention. As shown in Figure 13, The DC fault isolation type flexible DC power transmission converter subunit of Embodiment 2 of the second embodiment includes: a first capacitor group C201, a second capacitor group C202, and five full control type semiconductor devices T201, T202, T203, T204, T205. And the fault isolation combining circuit 201. The connection method is the same as that described with reference to FIG.

The fault isolation combining circuit 201 is composed of a fifth diode module D200. The cathode of the fifth diode module D200 is connected to the anode of the first capacitor group C201, and the anode of the fifth diode module D200 is connected to the fourth terminal 213 of the fault isolation combination circuit 201.

In the second embodiment, the second lead terminal 214, the third lead terminal 217, the fifth lead terminal 215, and the sixth lead terminal 216 of the fault isolation combining circuit 201 are respectively vacant.

Example 3

Fig. 14 shows a specific embodiment 3 of the second embodiment of the present invention. This is different from Embodiment 2 shown in FIG. 13 in that the fifth fully-controlled semiconductor device T205 in Embodiment 2 is replaced by a wire, and the third fully-controlled semiconductor device T203 is replaced by the bidirectional turn-off semiconductor combination 220. The connection method is as follows:

The emitter of the second fully-controlled semiconductor device T202 is connected to the anode 205 of the first capacitor group C201, then to the anode 206 of the second capacitor group C202, and then to one end of the bidirectional shutdown semiconductor combination 220. The other end of the bidirectional turn-off semiconductor combination 220 is connected to the collector of the fourth full control type semiconductor device T204 as the second lead terminal 207 of the DC fault isolation type flexible DC power converter station subunit.

Here, although the bidirectional turn-off semiconductor combination 220 replaces the third fully-controlled semiconductor device T203, those skilled in the art will appreciate that the second fully-controlled semiconductor device T202 can also be replaced by the bidirectional turn-off semiconductor combination 220.

In addition, it should be noted here that although the embodiment is made on the basis of the embodiment 2, those skilled in the art should understand that the fifth full can also be used for the embodiment described before or after the embodiment. The control semiconductor device T205 is replaced by a wire, and the second or third fully-controlled semiconductor device T202 or T203 is replaced by a bidirectional turn-off semiconductor combination 220.

Example 4

Fig. 15 shows a specific embodiment 4 of the second embodiment of the present invention. The difference from the embodiment 3 shown in FIG. 14 is that:

The fault isolation combining circuit 201 is composed of a first diode module D201. The cathode of the first diode module D201 is connected to the first lead terminal 204 of the DC fault isolation type flexible DC power transmission converter subunit, and the anode of the first diode module D201 and the cathode of the second capacitor group C202 203 connection.

In the fourth embodiment, the first extraction terminal 212, the third extraction terminal 217, the fifth extraction terminal 215, and the sixth extraction terminal 216 of the fault isolation combining circuit 201 are respectively vacant.

It will be understood by those skilled in the art that the configuration of the fault isolation combining circuit 201 in Embodiment 4 is also applicable to Embodiment 1.

Example 5

Fig. 16 shows a specific embodiment 5 of the second embodiment of the present invention. The difference from the embodiment 2 shown in FIG. 13 is that:

The fault isolation combining circuit 201 is composed of a second diode module D202. The cathode of the second diode module D202 is connected to the anode 202 of the first capacitor group C201, the anode of the second diode module D201 and the second terminal of the DC fault isolation type flexible DC power transmission converter subunit 207 connection.

In the fifth embodiment, the second lead terminal 214, the fourth lead terminal 213, the fifth lead terminal 215, and the sixth lead terminal 216 of the fault isolation combining circuit 201 are respectively vacant.

Those of ordinary skill in the art will appreciate that the configuration of the fault isolation combining circuit 201 in Embodiment 5 is equally applicable to Embodiment 3 or 4.

Example 6

Fig. 17 shows a specific embodiment 6 of the second embodiment of the present invention. The difference from the embodiment 1 shown in FIG. 12 is that, as shown in FIG. 17, when the fault isolation combining circuit 201 is composed of the third diode module D203 and the fourth diode module D204, the third The cathode of the diode module D203 is connected to the anode 202 of the first capacitor group C201, the anode of the third diode module D203 is connected to the anode 206 of the second capacitor group C202, and the cathode of the fourth diode module D204 is first. The anode 205 of the capacitor group C201 is connected, and the anode of the fourth diode module D204 is The negative electrode 203 of the second capacitor group C202 is connected.

In the sixth embodiment, the second lead terminal 214 and the third lead terminal 217 of the fault isolation combining circuit 201 are respectively vacant.

Example 7

Fig. 18 shows a specific embodiment 7 of the second embodiment of the present invention. The difference from the embodiment 6 shown in FIG. 17 is that, as shown in FIG. 18, when the fault isolation combining circuit 201 is composed only of the third diode module D203, the cathode of the third diode module D203 Connected to the positive electrode 206 of the first capacitor group C201, the anode of the third diode module D203 is connected to the positive electrode 202 of the second capacitor group C202.

In the seventh embodiment, the second lead terminal 214, the third lead terminal 217, the fourth lead terminal 213, and the fifth lead terminal 215 of the fault isolation combining circuit 201 are respectively vacant.

Example 8

Fig. 19 shows a specific embodiment 8 of the second embodiment of the present invention. The difference from the embodiment 6 shown in FIG. 17 is that, as shown in FIG. 19, when the fault isolation combining circuit 201 is composed only of the fourth diode module D204, the cathode of the fourth diode module D204 Connected to the negative electrode 205 of the first capacitor group C201, the anode of the fourth diode module D204 is connected to the negative electrode 203 of the second capacitor group C202.

In the seventh embodiment, the first extraction terminal 212, the second extraction terminal 214, the third extraction terminal 217, and the sixth extraction terminal 216 of the fault isolation combining circuit 201 are respectively vacant.

Example 9

Fig. 20 shows a specific embodiment 9 of the second embodiment of the present invention. The difference from the embodiment 1 shown in FIG. 12 is that, as shown in FIG. 20, the first diode module D201 and the second diode module D202 in the fault isolation combining circuit 201 are both composed of a diode and A resistor is composed in series.

A diode module in all embodiments of the second embodiment of the present invention, such as the first diode module D201, the second diode module D202, the third diode module D203, and the fourth, should be understood by those skilled in the art. Diode module D204, fifth diode module D200 It can be composed of one or more diodes connected in series with a resistor, capacitor or inductor.

The first diode module D201 may be composed of a1 diodes and b1 capacitors, c1 capacitors, and d1 inductors in series, where a1 is an integer greater than or equal to 1, and b1, c1, and d1 are integers greater than or equal to zero.

The second diode module D202 may be composed of a2 diodes and b2 capacitors, c2 capacitors, and d2 inductors in series, where a2 is an integer greater than or equal to 1, and b2, c2, and d2 are integers greater than or equal to zero.

The third diode module D203 may be composed of a3 diodes and b3 capacitors, c3 capacitors, and d3 inductors in series, wherein a3 is an integer greater than or equal to 1, and b3, c3, and d3 are integers greater than or equal to zero.

The fourth diode module D204 may be composed of a4 diodes and b4 capacitors, c4 capacitors, and d4 inductors in series, wherein a4 is an integer greater than or equal to 1, and b4, c4, and d4 are integers greater than or equal to zero.

The fifth diode module D200 may be composed of a5 diodes and b5 capacitors, c5 capacitors, and d5 inductors in series, wherein a5 is an integer greater than or equal to 1, and b5, c5, and d5 are integers greater than or equal to zero.

About bidirectional turn-off semiconductor device combinations

21 and 22 are two implementations of the bidirectional turn-off semiconductor device combination 220 of the present invention, respectively.

As shown in FIG. 21, the emitter of the sixth full control type semiconductor device 221 is connected to the emitter of the seventh full control type semiconductor device 222, and the collector of the sixth full control type semiconductor device 221 is connected to the seventh full control type semiconductor device. The collector of 222 is taken up as both ends of such a bidirectional turn-off semiconductor device combination 220.

As shown in FIG. 22, the cathode of the sixth diode module 223, the cathode of the eighth diode module 225 are connected to the collector of the fully-controlled semiconductor device 227, and the anode of the seventh diode module 224 is ninth. The anode of the pole tube module 226 is connected to the emitter of the eighth full control type semiconductor device 227, and the anode of the sixth diode module 223 is connected to the cathode of the seventh diode module 224 as such a bidirectional turn-off semiconductor device combination. One end of 220 is taken out, and the anode of the eighth diode module 225 is connected to the cathode of the ninth diode module 226 as such a bidirectional turn-off semiconductor The other end of the body device combination 220 is taken.

Although in the embodiments 3 and 4, the bidirectional turn-off semiconductor device combination 220 is constituted by the configuration as shown in FIG. 22, it will be understood by those skilled in the art that the bidirectional turn-off semiconductor device combination 220 can be replaced by the following figure. The configuration shown in Fig. 21.

(III) Topological structure of bridge arm of flexible DC transmission converter station

Figure 23 is a schematic illustration of a bridge arm of a flexible direct current transmission converter station in accordance with the present invention. As shown in FIG. 23, the bridge arm of the present invention comprises m DC fault isolation type flexible direct current power transmission converter subunits ISM1, ISM2, ..., ISMm and n half bridge subunits SM1, SM2. ,...,SMn cascaded. The first lead-out terminal of the first DC fault-isolated flexible DC power transmission converter sub-unit ISM1 serves as the first lead-out terminal of the bridge arm, and the second lead-out of the first DC fault-isolated flexible DC power transmission converter sub-unit ISM1 The terminal is connected to the first lead terminal of the second DC fault isolation flexible DC power transmission converter subunit ISM2, and so on, the second lead terminal of the mth DC fault isolation type flexible DC power transmission converter subunit ISMm The first lead terminals of the half bridge type subunit SM1 are connected, the second lead terminals of the first half bridge type subunit SM1 are connected to the first lead terminals of the second half bridge type subunit SM2, and the remaining half bridge type subunits are connected. By way of example, the second terminal of the n-th half-bridge sub-unit SMn is connected to one end of the inductor L, and the other end of the inductor L serves as a second terminal of the bridge arm. Where m is an integer greater than or equal to 1, and n is an integer greater than or equal to zero.

Claims

A DC fault isolation type flexible direct current power transmission converter subunit includes:

At least one capacitor bank,

At least two fully controlled semiconductor devices, and

Fault isolation combination circuit for isolating DC faults,

Wherein the at least two fully-controlled semiconductor devices are connected to the at least one capacitor group in the form of a half bridge subunit, and

The plurality of lead terminals of the fault isolation combination circuit are respectively connected to the connection points of the positive electrode and the negative electrode of the at least one capacitor group and the at least two fully-controlled semiconductor devices.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 1, wherein the DC fault isolation type flexible direct current power transmission converter subunit comprises a first capacitor group (C101) and a second unit. Capacitor bank (C102), four fully controlled semiconductor devices (T101, T102, T103, T104), and fault isolation combination circuit (107); positive pole (101) of the first capacitor bank (C101) and the first full control a collector connection of a semiconductor device (T101); an emitter of the first fully-controlled semiconductor device (T101) is connected to a collector of the second fully-controlled semiconductor device (T102) as a first fully-controlled device connection point ( 105); the emitter of the second fully controlled semiconductor device (T102) is connected to the cathode (102) of the first capacitor group (C101); the anode (103) of the second capacitor group (C102) and the third fully controlled semiconductor a collector connection of the device (T103); an emitter of the third fully-controlled semiconductor device (T103) is connected to a collector of the fourth fully-controlled semiconductor device (T104) as a second fully-controlled device connection point (106) The emitter of the fourth fully controlled semiconductor device (T104) and the cathode of the second capacitor group (C102) (10) 4) connection;

The first lead terminal (111) of the fault isolation combining circuit (107) is connected to the anode (101) of the first capacitor group (C101), and the second lead terminal (112) of the fault isolation combining circuit (107) is first. The cathode (102) of the capacitor group (C101) is connected, the third terminal (113) of the fault isolation combination circuit (107) is connected to the anode (103) of the second capacitor group (C102), and the fault isolation combination circuit (107) is connected. The fourth lead terminal (114) is connected to the negative pole (104) of the second capacitor group (C102), and the fault isolation combined circuit (107) The fifth terminal (115) is connected to the first fully-controlled device connection point (105), and the sixth terminal (116) of the fault isolation combination circuit (107) is connected to the second full-control device connection point (106). The seventh terminal (117) of the fault isolation combination circuit (107) serves as a first terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal (118) of the fault isolation combination circuit (107) serves as a DC The second lead-out terminal of the fault isolation type flexible direct current power transmission converter subunit.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 2, wherein said fault isolation combining circuit (107) is controlled by a fifth full control type semiconductor device (T105) and a sixth full control a semiconductor device (T106), a first diode module (D101), and a second diode module (D102); a cathode of the first diode module (D101) and a fault isolation combination circuit (107) One terminal (111) is connected, the anode of the first diode module (D101) is connected to the collector (119) of the fifth fully-controlled semiconductor device (T105), and the emitter of the fifth fully-controlled semiconductor device (T105) Connected to the second terminal (112) of the fault isolation combination circuit (107), the collector of the sixth full control type semiconductor device (T106) is connected to the third terminal (113) of the fault isolation combination circuit (107), the sixth full The emitter (120) of the control semiconductor device (T106) is connected to the cathode of the second diode module (D102), and the fourth terminal of the anode and fault isolation combination circuit (107) of the second diode module (D102) (114) connection; the emitter (120) of the sixth fully controlled semiconductor device (T106) and the fifth fully controlled semiconductor device (T1) The collector (119) of 05) is connected; the fifth terminal (115) of the fault isolation combining circuit (107) is connected to the seventh terminal (117) of the fault isolation combining circuit (107), and the fault isolation combining circuit (107) The six terminals (116) are connected to the eighth terminal (118).
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 2, wherein said fault isolation combining circuit (107) is composed of a sixth full control type semiconductor device (T106) and a first diode The tube module (D101) is composed; the emitter of the sixth full control type semiconductor device (T106) is connected to the fifth terminal (115) of the fault isolation combination circuit (107), and the collector of the sixth full control type semiconductor device (T106) Connected to the third terminal (113) of the fault isolation combination circuit (107); the cathode of the first diode module (D101) is isolated from the fault The first terminal (111) of the combination circuit (107) is connected, the anode of the first diode module (D101) is connected to the fourth terminal (114) of the fault isolation combination circuit (107); and the fault isolation combination circuit (107) The first terminal (111) is connected to the seventh terminal (117) of the fault isolation combination circuit (107), and the sixth terminal (116) of the fault isolation combination circuit (107) is connected to the eighth terminal (118); the fault isolation combination circuit The second terminal (112) of (107) is vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 2, wherein said fault isolation combining circuit (107) is composed of a fifth full control type semiconductor device (T105) and a second diode The tube module (D102) is composed; the emitter of the fifth full control type semiconductor device (T105) is connected to the second terminal (112) of the fault isolation combination circuit (107), and the collector of the fifth full control type semiconductor device (T106) Connected to the third terminal (113) of the fault isolation combination circuit (107); the cathode of the second diode module (D102) is connected to the first terminal (111) of the fault isolation combination circuit (107), and the second diode The anode of the module (D102) is connected to the fourth terminal (114) of the fault isolation combination circuit (107); the fifth terminal (115) of the fault isolation combination circuit (107) and the seventh terminal of the fault isolation combination circuit (107) ( 117) The fourth terminal (114) of the fault isolation combining circuit (107) is connected to the eighth terminal (118); the third terminal (113) of the fault isolation combining circuit (107) is vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 1, wherein the DC fault isolation type flexible direct current power transmission converter subunit comprises a first capacitor group (C101), first The fully controlled semiconductor device (T101), the second fully controlled semiconductor device (T102) and the fault isolation circuit (107); the positive electrode (101) of the first capacitor group (C101) and the first fully controlled semiconductor device (T101) a collector connection; an emitter of the first fully-controlled semiconductor device (T101) is connected to a collector of the second fully-controlled semiconductor device (T102) as a first fully-controlled device connection point (105); The emitter of the fully controlled semiconductor device (T102) is connected to the negative electrode (102) of the first capacitor group (C101);

The first extraction terminal (111) of the fault isolation combining circuit (107) is connected to the anode (101) of the first capacitor group (C101), and the second of the fault isolation combining circuit (107) The lead terminal (112) is connected to the negative pole (102) of the first capacitor group (C101), and the fifth lead terminal (115) of the fault isolation combining circuit (107) is connected to the first full control type device connecting point (105), and the fault occurs. The seventh terminal (117) of the isolation combining circuit (107) serves as a first terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal (118) of the fault isolation combining circuit (107) serves as a DC fault isolation. a second lead-out terminal of the flexible DC power transmission converter subunit;

The fault isolation combining circuit (107) is composed of a first diode module (D101) and a fifth full control type semiconductor device (T105); a cathode and fault isolation combination circuit of the first diode module (D101) (107) The first terminal (111) is connected, the anode of the first diode module (D101) is connected to the collector (119) of the fifth fully-controlled semiconductor device (T105), and the fifth fully-controlled semiconductor device (T105) The emitter is connected to the second terminal (112) of the fault isolation combination circuit (107);

The fifth terminal (115) of the fault isolation combining circuit (107) is connected to the seventh terminal (117) of the fault isolation combining circuit (107), and the eighth terminal (118) and the fifth of the fault isolation combining circuit (107) The collector (119) of the fully-controlled semiconductor device (T105) is connected; the third terminal (113), the fourth terminal (114), and the sixth terminal (116) of the fault isolation combining circuit (107) are vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 1, wherein the DC fault isolation type flexible direct current power transmission converter subunit comprises a second capacitor group (C102) and a third unit. A fully-controlled semiconductor device (T103), a fourth fully-controlled semiconductor device (T104), and a fault isolation circuit (107); a positive electrode (103) of the second capacitor group (C102) and a third fully-controlled semiconductor device (T103) a collector connection; the emitter of the third fully-controlled semiconductor device (T103) is connected to the collector of the fourth fully-controlled semiconductor device (T104) as a second fully-controlled device connection point (106); The emitter of the fully controlled semiconductor device (T104) is connected to the cathode (104) of the second capacitor group (C102);

The third lead terminal (113) of the fault isolation combining circuit (107) is connected to the anode (103) of the second capacitor group (C102), and the fourth terminal (114) and the second capacitor group of the fault isolation combining circuit (107) are connected. The cathode (104) of (C102) is connected, and the fifth terminal (116) of the fault isolation combination circuit (107) is connected to the second full control device (106). The seventh terminal (117) of the fault isolation combining circuit (107) serves as a first terminal of the DC fault isolation type flexible DC power transmission converter subunit, and the eighth terminal (118) of the fault isolation combining circuit (107) is a second lead terminal of the DC fault isolation type flexible DC power transmission converter subunit;

The fault isolation circuit (107) is composed of a sixth full control type semiconductor device (T106) and a second diode module (D102); a collector and fault isolation combination circuit of the sixth full control type semiconductor device (T106) (107) The third terminal (113) is connected, the emitter (120) of the sixth full control type semiconductor device (T106) is connected to the cathode of the second diode module (D102), and the anode of the second diode module (D102) Connected to a fourth terminal (114) of the fault isolation combination circuit (107);

The sixth terminal (116) of the fault isolation combining circuit (107) is connected to the eighth terminal (118) of the fault isolation combining circuit (107), and the seventh terminal (117) and the sixth terminal of the fault isolation combining circuit (107) The emitter (120) of the fully-controlled semiconductor device (T106) is connected; the first terminal (111), the second terminal (112), and the fifth terminal (115) of the fault isolation combining circuit (107) are vacant.
A DC fault isolation type flexible direct current power transmission converter station subunit according to any one of claims 3, 4 and 6, characterized by: a first diode module in said fault isolation combining circuit (107) (D101) is composed of a1 diodes and b1 resistors, and c1 capacitors, and d1 inductors in series, a1 is an integer greater than or equal to 1, and b1, c1, and d1 are integers greater than or equal to zero.
A DC fault isolation type flexible direct current power transmission converter station subunit according to any one of claims 3, 5 and 7, characterized by: a second diode module in said fault isolation combining circuit (107) (D102) is composed of a2 diodes and b2 resistors, and c2 capacitors, and d2 inductors in series, a2 is an integer greater than or equal to 1, and b2, c2, and d2 are integers greater than or equal to zero.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 1, wherein: said DC fault isolation type flexible direct current power transmission converter station The unit is composed of a first capacitor group (C201), a second capacitor group (C202), five fully-controlled semiconductor devices (T201, T202, T203, T204, T205), and a fault isolation combination circuit (201); The positive electrode (202) of the group (C201) is connected to the collector of the first fully controlled semiconductor device (T201); the emitter of the first fully controlled semiconductor device (T201) and the second fully controlled semiconductor device (T202) Collector connection, as the first lead terminal (204) of the DC fault isolation type flexible DC power transmission converter subunit topology; the emitter of the second fully controlled type semiconductor device (T202) and the fifth full control type semiconductor device (T205 The emitter is connected, and then connected to the negative electrode (205) of the first capacitor group (C201); the collector of the fifth fully-controlled semiconductor device (T205) is connected to the anode (206) of the second capacitor group (C202), And then connected to the collector of the third fully controlled semiconductor device (T203); the emitter of the third fully controlled semiconductor device (T203) is connected to the collector of the fourth fully controlled semiconductor device (T204) as a DC fault isolation Second lead terminal of the sub-unit topology of the flexible DC transmission converter station (207); The emitter of the four fully controlled semiconductor device (T204) is connected to the negative electrode (203) of the second capacitor group (C202);

The first lead terminal (212) of the fault isolation combining circuit (201) is connected to the anode (202) of the first capacitor group (C201), and the second lead terminal (214) of the fault isolation combining circuit (201) is isolated from the DC fault type. The first lead terminal (204) of the flexible DC power transmission converter subunit is connected, the third lead terminal (217) of the fault isolation combination circuit (201) and the second lead of the DC fault isolation type flexible DC power converter station subunit The terminal (207) is connected, the fourth lead terminal (213) of the fault isolation combining circuit (201) is connected to the negative pole (203) of the second capacitor group; and the fifth lead terminal (215) of the fault isolation combining circuit (201) is connected A cathode (205) of a capacitor bank is connected, and a sixth terminal (216) of the fault isolation combining circuit (201) is connected to the anode (206) of the second capacitor group.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) is composed of a fifth diode module (D200); and a fifth diode The cathode of the tube module (D200) is connected to the first lead terminal (212) of the fault isolation combination circuit (201), and the fourth lead terminal of the anode of the fifth diode module (D200) and the fault isolation combination circuit (201) ( 213) connection, third isolation terminal (217) of fault isolation combination circuit (201), fault isolation combination circuit The second lead terminal (214) of (201), the fifth lead terminal (215) of the fault isolation combining circuit (201), and the sixth lead terminal (216) of the fault isolation combining circuit (201) are vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) comprises a first diode module (D201) and a second diode The module (D202) is composed; the cathode of the first diode module (D201) is connected to the second lead terminal (214) of the fault isolation combination circuit (201), and the anode of the first diode module (D201) is combined with the fault isolation. The fourth lead terminal (213) of the circuit (201) is connected; the cathode of the second diode module (D202) is connected to the first lead terminal (212) of the fault isolation combination circuit (201), and the second diode module ( The anode of D202) is connected to the third lead terminal (217) of the fault isolation combination circuit (201), the fifth lead terminal (215) of the fault isolation combination circuit (201), and the sixth lead terminal of the fault isolation combination circuit (201). (216) Vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) is composed of a first diode module (D201); The cathode of the tube module (D201) is connected to the second lead terminal (214) of the fault isolation combination circuit (201), and the anode of the first diode module (D201) and the fourth lead terminal of the fault isolation combination circuit (201) ( 213) connection; the first lead terminal (212) of the fault isolation combining circuit (201), the third lead terminal (217) of the fault isolation combining circuit (201), and the fifth lead terminal of the fault isolation combining circuit (201) (215) The sixth lead terminal (216) of the fault isolation combining circuit (201) is vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) is composed of a second diode module (D202); and the second diode The cathode of the tube module (D202) is connected to the first extraction terminal (212) of the fault isolation combination circuit (201), and the anode of the second diode module (D202) and the third extraction terminal of the fault isolation combination circuit (201) ( 217) connection; second extraction terminal (214) of fault isolation combination circuit (201), fault isolation combination circuit (201) The fourth lead terminal (213), the fifth lead terminal (215) of the fault isolation combining circuit (201), and the sixth lead terminal (216) of the fault isolation combining circuit (201) are vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) comprises a third diode module (D203) and a fourth diode The module (D204) is composed; the cathode of the third diode module (D203) is connected to the first lead terminal (212) of the fault isolation combination circuit (201), and the anode of the third diode module (D203) is combined with the fault isolation. The sixth lead terminal (216) of the circuit (201) is connected; the cathode of the fourth diode module (D204) is connected to the fifth lead terminal (215) of the fault isolation combination circuit (201), and the fourth diode module ( The anode of D204) is connected to the fourth lead terminal (213) of the fault isolation combination circuit (201), the second lead terminal (214) of the fault isolation combination circuit (201), and the third lead terminal of the fault isolation combination circuit (201) (217) Vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) is composed of a third diode module (D203); and a third diode The cathode of the tube module (D203) is connected to the first lead terminal (212) of the fault isolation combination circuit (201), and the anode of the third diode module (D203) and the sixth lead terminal of the fault isolation combination circuit (201) ( 216) a second lead terminal (214) of the fault isolation combining circuit (201), a third lead terminal (217) of the fault isolation combining circuit (201), and a fourth lead terminal of the fault isolation combining circuit (201) (213) The fifth terminal (215) of the fault isolation combining circuit (201) is vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fault isolation combining circuit (201) is composed of a fourth diode module (D204), and a fourth diode The cathode of the tube module (D204) is connected to the fifth lead terminal (215) of the fault isolation combination circuit (201), and the fourth lead terminal of the anode of the fourth diode module (D204) and the fault isolation combination circuit (201) ( 213) a second lead terminal (214) of the fault isolation combining circuit (201), a third lead terminal (217) of the fault isolation combining circuit (201), and a sixth lead terminal of the fault isolation combining circuit (201) (216) The first lead terminal (212) of the fault isolation combining circuit (201) is vacant.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 12 or 13, wherein the first diode module (D201) in the fault isolation combining circuit (201) is composed of a1 The diode is composed of b1 resistors, c1 capacitors, and d1 inductors in series, a1 is an integer greater than or equal to 1, and b1, c1, and d1 are integers greater than or equal to zero.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 12 or 14, wherein the second diode module (D202) in the fault isolation combining circuit (201) is composed of a2 The diode is composed of b2 resistors, c2 capacitors, and d2 inductors in series, a2 is an integer greater than or equal to 1, and b2, c2, and d2 are integers greater than or equal to zero.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 15 or 16, wherein the third diode module (D203) in the fault isolation combining circuit (201) is composed of a3 The diode is composed of b3 resistors, c3 capacitors, and d3 inductors in series, a3 is an integer greater than or equal to 1, and b3, c3, and d3 are integers greater than or equal to zero.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 15 or 17, wherein the fourth diode module (D204) in the fault isolation combining circuit (201) is composed of a4 The diode is composed of b4 resistors, c4 capacitors, and d4 inductors in series, a4 is an integer greater than or equal to 1, and b4, c4, and d4 are integers greater than or equal to zero.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 11, wherein the fifth diode module (D200) in the fault isolation combining circuit (201) is composed of a5 diodes and B5 resistors, and c5 capacitors, and d5 inductors are connected in series, a5 is an integer greater than or equal to 1, b5, c5, d5 are greater than, etc. An integer of 0.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fifth full control type semiconductor device (T205) is replaced by a wire, and the second fully controlled type semiconductor device (T202) ) is replaced by a combination of bidirectional turn-off semiconductor devices.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein said fifth full control type semiconductor device (T205) is replaced by a wire, and the third fully controlled type semiconductor device (T203) ) is replaced by a combination of bidirectional turn-off semiconductor devices.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 10, wherein one of said first to fifth full control type semiconductor devices (T201, T202, T203, T204, T205) Replaced by at least one semiconductor device in series.
A DC fault isolation type flexible direct current power transmission converter station subunit according to claim 23 or 24, wherein said bidirectional turn-off semiconductor device combination is composed of a sixth full control type semiconductor device (221) and a seventh full The control semiconductor device (222) is configured, wherein an emitter of the sixth full control type semiconductor device (221) is connected to an emitter of the seventh full control type semiconductor device (222), and a sixth full control type semiconductor device (221) The collector and the collector of the seventh fully-controlled semiconductor device (222) are taken out as both ends of the bidirectional turn-off semiconductor device combination.
The DC fault isolation type flexible direct current power transmission converter station subunit according to claim 23 or 24, wherein the bidirectional turn-off semiconductor device combination is composed of a sixth diode module (223) and a seventh diode a tube module (224), an eighth diode module (225), a ninth diode module (226), and an eighth fully-controlled semiconductor device (227), wherein the sixth diode module (223) The cathode of the cathode, the eighth diode module (225) is connected to the collector of the fully controlled semiconductor device (227), and the cathode of the seventh diode module (224) The anode of the pole, the ninth diode module (226) is connected to the emitter of the eighth fully controlled semiconductor device (227), and the anode of the sixth diode module (223) and the seventh diode module (224) a cathode connection is taken as one end of the bidirectional turn-off semiconductor device combination, and an anode of the eighth diode module (225) is connected to a cathode of the ninth diode module (226) as the bidirectional turn-off semiconductor device The other end of the combination is taken.
A flexible DC transmission converter station arm, the bridge arm comprising m DC fault isolation type flexible DC transmission converter station sub-unit and n half bridge type according to any one of claims 1-27 A unit cascaded composition, where m is an integer greater than or equal to 1, and n is an integer greater than or equal to zero.