阅读说明：本技术 换流阀桥臂阻尼模块的取能电路及其控制方法 (Energy taking circuit of converter valve bridge arm damping module and control method thereof ) 是由 谢晔源 张中锋 王宇 朱铭炼 卢宇 田杰 李海英 于 2020-06-29 设计创作，主要内容包括：本申请提供换流阀桥臂阻尼模块的取能电路及其控制方法。所述换流阀桥臂阻尼模块的取能电路中,阻尼模块包括并联连接的阻尼电阻、功率半导体开关和旁路开关,所述换流阀还包括正常子模块,所述正常子模块包括功率电容、功率半导体单元和功率旁路开关,所述阻尼模块和所述正常子模块串联连接,其特征在于,所述阻尼模块还包括取能电容、第一阻断二极管、电源单元和控制单元,所述电源单元从所述取能电容取得电能,为所述控制单元供电；所述第一阻断二极管的阳极连接相邻正常子模块功率电容的正极,所述取能电容的正极连接所述第一阻断二极管的阴极,所述取能电容的负极连接所述阻尼模块阻尼电阻的一端。(The application provides an energy taking circuit of a converter valve bridge arm damping module and a control method thereof. In an energy taking circuit of the converter valve bridge arm damping module, the damping module comprises a damping resistor, a power semiconductor switch and a bypass switch which are connected in parallel, the converter valve further comprises a normal submodule, the normal submodule comprises a power capacitor, a power semiconductor unit and a power bypass switch, and the damping module is connected with the normal submodule in series; the anode of the first blocking diode is connected with the anode of the power capacitor of the adjacent normal sub-module, the anode of the energy taking capacitor is connected with the cathode of the first blocking diode, and the cathode of the energy taking capacitor is connected with one end of the damping resistor of the damping module.)

1. An energy-taking circuit of a damping module of a bridge arm of a converter valve, wherein the damping module comprises a damping resistor, a power semiconductor switch and a bypass switch which are connected in parallel, the converter valve further comprises a normal submodule which comprises a power capacitor, a power semiconductor unit and a power bypass switch, the damping module and the normal submodule are connected in series, and the energy-taking circuit is characterized in that,

the damping module further comprises an energy taking capacitor, a first blocking diode, a power supply unit and a control unit, wherein the power supply unit obtains electric energy from the energy taking capacitor and supplies power to the control unit; the anode of the first blocking diode is connected with the anode of the power capacitor of the adjacent normal sub-module, the anode of the energy taking capacitor is connected with the cathode of the first blocking diode, and the cathode of the energy taking capacitor is connected with one end of the damping resistor of the damping module.

2. The energy harvesting circuit of the converter valve bridge arm damping module of claim 1, wherein the normal sub-modules comprise a high potential sub-module and a low potential sub-module.

3. The energy extraction circuit of the converter valve bridge arm damping module of claim 1, further comprising:

and the cathode of the second blocking diode is connected with the anode of the energy taking capacitor, and the anode of the second blocking diode is connected with the anode of the power capacitor of the adjacent normal sub-module on the other side.

4. The energy extraction circuit of a converter valve bridge arm damping module according to any one of claims 1 to 3, further comprising:

and the current-limiting resistor is connected in series between the anode of the energy taking capacitor and the cathode of the first blocking diode or/and the cathode of the second blocking diode.

5. The energy extraction circuit of the converter valve bridge arm damping module of claim 3, further comprising:

the cathode of the first blocking diode is connected with the first current limiting resistor in series and then is connected with the anode of the energy taking capacitor;

and the cathode of the second blocking diode is connected with the anode of the energy taking capacitor after being connected with the second current limiting resistor in series.

6. The energy extraction circuit of the converter valve bridge arm damping module of claim 1, further comprising:

and the divider resistor is connected with the energy taking capacitor in parallel.

7. The energy obtaining circuit of the converter valve bridge arm damping module of claim 5, wherein when the values of the first current limiting resistor and the second current limiting resistor are different, the charging voltage value of the energy obtaining capacitor is determined according to the smaller value of the first current limiting resistor and the second current limiting resistor.

8. The energy extraction circuit of a converter valve bridge arm damping module according to any one of claims 1 to 3, wherein the normal submodules connected to the anode of the first blocking diode or the anode of the second blocking diode are distributed in the same bridge arm or different bridge arms of the converter valve.

9. A method for controlling the start-up of a converter valve bridge arm damping module energy-taking circuit according to any one of claims 2 to 8, when only the first blocking diode connected to the high-potential submodule is present, the method comprising:

charging a normal sub-module, wherein an energy taking capacitor of the damping module is charged from the high-potential sub-module power capacitor through the connected first blocking diode;

when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit starts to work to supply power to the control unit, and communication between the control unit of the damping module and an upper-layer control system is established;

and unlocking the converter valve, and starting unlocking the normal sub-module and the damping module.

10. A method for controlling the start-up of an energy-taking circuit of a damping module of a bridge arm of a converter valve according to any one of claims 2 to 8, when only a first blocking diode connected to a low-potential submodule is present, the method comprising:

charging the normal submodule;

the normal sub-module is unlocked, and the energy-taking capacitor of the damping module is charged from the low-potential sub-module power capacitor through a first blocking diode connected with the low-potential sub-module power capacitor;

when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit of the damping module starts to work and supplies power to the control unit, and the control unit of the damping module establishes communication with an upper-layer control system;

and unlocking the damping module, enabling the normal sub-module to work, and completing the starting of the converter valve.

11. A method for controlling the start-up of a converter valve bridge arm damping module energy-taking circuit according to any one of claims 2 to 8, when a first blocking diode connected to a high-potential submodule and a second blocking diode connected to a low-potential submodule are simultaneously present, the method comprising:

the normal sub-module starts charging, and the energy-taking capacitor of the damping module is charged from the high-potential sub-module power capacitor through the connected first blocking diode;

when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit of the damping module starts to work and supplies power to the control unit, and communication between the control unit of the damping module and an upper-layer control system is established;

unlocking the converter valve, and starting the normal sub-module and the damping module to work;

and if the resistance value of a first current-limiting resistor connected with the high-potential submodule is larger than the resistance value of a second current-limiting resistor connected with the low-potential submodule, the energy-taking capacitor of the damping module is continuously charged by the capacitor of the low-potential module.

12. A method of fault control of a converter valve bridge arm damping module energy extraction circuit according to any one of claims 1 to 8, comprising:

when the voltage of the energy taking capacitor is abnormal, the control unit sends a bypass command;

and when the inside of the damping module is in fault, the control unit sends out a bypass command.

Technical Field

The application relates to the field of power electronics, in particular to an energy taking circuit of a converter valve bridge arm damping module and a control method thereof.

Background

The damping module is added in the bridge arm of the converter valve, after the direct current side of the system breaks down, the switch tube in the damping module is quickly locked, and the damping resistor is put into the damping module, so that the rising rate of direct current short-circuit current can be effectively inhibited, the quick attenuation of the fault current after the circuit breaker on the alternating current side is tripped is accelerated, and the quick fault recovery of the flexible direct current system can be further realized.

Because the damping module is not provided with a power capacitor for storing energy, energy must be taken from the power capacitor of an adjacent normal sub-module, and designing an energy taking circuit with high reliability and low cost is a very important application requirement.

Disclosure of Invention

The embodiment of the application provides an energy obtaining circuit of a damping module of a bridge arm of a converter valve, wherein the damping module comprises a damping resistor, a power semiconductor switch and a bypass switch which are connected in parallel, the converter valve further comprises a normal submodule which comprises a power capacitor, a power semiconductor unit and a power bypass switch, and the damping module is connected with the normal submodule in series; the anode of the first blocking diode is connected with the anode of the power capacitor of the adjacent normal sub-module, the anode of the energy taking capacitor is connected with the cathode of the first blocking diode, and the cathode of the energy taking capacitor is connected with one end of the damping resistor of the damping module.

Further, the normal sub-modules include a high potential sub-module and a low potential sub-module.

Furthermore, the energy taking circuit of the converter valve bridge arm damping module further comprises a second blocking diode, the cathode of the second blocking diode is connected with the anode of the energy taking capacitor, and the anode of the second blocking diode is connected with the anode of the power capacitor of the adjacent normal sub-module on the other side.

Furthermore, the energy taking circuit of the converter valve bridge arm damping module further comprises a current limiting resistor, and the current limiting resistor is connected in series between the anode of the energy taking capacitor and the cathode of the first blocking diode or/and the cathode of the second blocking diode.

Furthermore, the energy taking circuit of the converter valve bridge arm damping module further comprises a first current limiting resistor and a second current limiting resistor, and a cathode of the first blocking diode is connected with the anode of the energy taking capacitor after being connected with the first current limiting resistor in series; and the cathode of the second blocking diode is connected with the anode of the energy taking capacitor after being connected with the second current limiting resistor in series.

Furthermore, the energy obtaining circuit of the converter valve bridge arm damping module further comprises a divider resistor, and the divider resistor is connected with the energy obtaining capacitor in parallel.

Further, when the values of the first current limiting resistor and the second current limiting resistor are different, the charging voltage value of the energy taking capacitor is determined according to the smaller value of the first current limiting resistor and the second current limiting resistor.

Further, the normal submodules connected with the anode of the first blocking diode or the anode of the second blocking diode are distributed on the same bridge arm or different bridge arms of the converter valve.

The embodiment of the application also provides a starting control method of the converter valve bridge arm damping module energy obtaining circuit, and when only a first blocking diode connected with the high-potential submodule exists, the method comprises the following steps: charging a normal sub-module, wherein an energy taking capacitor of the damping module is charged from the high-potential sub-module power capacitor through the connected first blocking diode; when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit starts to work to supply power to the control unit, and communication between the control unit of the damping module and an upper-layer control system is established; and unlocking the converter valve, and starting unlocking the normal sub-module and the damping module.

The embodiment of the application also provides a starting control method of the converter valve bridge arm damping module energy taking circuit, and when only a first blocking diode connected with a low potential submodule exists, the method comprises the following steps: charging the normal submodule; the normal sub-module is unlocked, and the energy-taking capacitor of the damping module is charged from the low-potential sub-module power capacitor through a first blocking diode connected with the low-potential sub-module power capacitor; when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit of the damping module starts to work and supplies power to the control unit, and the control unit of the damping module establishes communication with an upper-layer control system; and unlocking the damping module, enabling the normal sub-module to work, and completing the starting of the converter valve.

The embodiment of the application also provides a starting control method of the converter valve bridge arm damping module energy taking circuit, and when a first blocking diode connected with a high-potential submodule and a second blocking diode connected with a low-potential submodule exist at the same time, the method comprises the following steps: the normal sub-module starts charging, and the energy-taking capacitor of the damping module is charged from the high-potential sub-module power capacitor through the connected first blocking diode; when the energy-taking capacitor voltage of the damping module is charged to the starting voltage threshold value of the power supply unit of the damping module, the power supply unit of the damping module starts to work and supplies power to the control unit, and communication between the control unit of the damping module and an upper-layer control system is established; unlocking the converter valve, and starting the normal sub-module and the damping module to work; and if the resistance value of a first current-limiting resistor connected with the high-potential submodule is larger than the resistance value of a second current-limiting resistor connected with the low-potential submodule, the energy-taking capacitor of the damping module is continuously charged by the capacitor of the low-potential module.

The embodiment of the application further provides a fault control method for the converter valve bridge arm damping module energy obtaining circuit, which comprises the following steps: when the voltage of the energy taking capacitor is abnormal, the control unit sends a bypass command; and when the inside of the damping module is in fault, the control unit sends out a bypass command.

According to the technical scheme provided by the embodiment of the application, high-reliability energy taking of double-path redundant input is realized, but high-voltage isolation power supplies configured by two adjacent normal sub-modules are reduced, the problem that high-voltage insulation needs to be endured between the primary side-secondary side winding and the secondary side-secondary side winding of the two high-voltage isolation power supplies in the normal sub-modules in the prior art is solved, and the high-voltage isolation power supply has higher reliability and better economical efficiency. The energy-taking capacitor in the damping module can form a resistance-capacitance voltage-dividing unit with the voltage-dividing resistor and the current-limiting resistor, so that the voltage of the energy-taking capacitor can be reduced, the differential mode voltage input by the damping module power system is reduced, the reliability of the power system is further improved, and the insulation cost is reduced. An independent isolation power supply unit is configured, and the problem of electromagnetic interference caused by the fact that high-voltage power supplies of two adjacent sub-modules are connected in parallel and are grounded in the prior art is solved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is one of schematic diagrams of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

Fig. 2 is a second schematic diagram of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

Fig. 3 is a third schematic diagram of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

Fig. 4 is a flowchart of a start control method of a converter valve bridge arm damping module according to an embodiment of the present application.

Fig. 5 is a second flowchart of a start control method of an energy obtaining circuit of a bridge arm damping module of a converter valve according to an embodiment of the present application.

Fig. 6 is a third flowchart of a start control method of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

Fig. 7 is a flowchart of a fault control method of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be understood that the terms "first", "second", etc. in the claims, description, and drawings of the present application are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this application, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Fig. 1 is one of schematic diagrams of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

In an energy obtaining circuit of the converter valve bridge arm damping module, a damping module ZN comprises a damping resistor Rz, a power semiconductor switch Tz and a bypass switch Kz which are connected in parallel. The converter valve further comprises a normal submodule, the normal submodule comprises a high-potential submodule and a low-potential submodule, and the normal submodule comprises a power capacitor, a power semiconductor unit and a power bypass switch. The damping module ZN and the normal sub-modules are connected in series.

The damping module ZN further comprises an energy-taking capacitor C, a first blocking diode D1, a power supply unit and a control unit, wherein the power supply unit takes electric energy from the energy-taking capacitor C and supplies power to the control unit. The anode of the first blocking diode D1 is connected with the anode of the adjacent normal sub-module power capacitor C1, the anode of the energy-taking capacitor C is connected with the cathode of the first blocking diode D1, and the cathode of the energy-taking capacitor C is connected with one end of the damping resistor Rz of the damping module.

Optionally, a current limiting resistor R1 is connected in series between the anode of the energy extracting capacitor C and the cathode of the first blocking diode D1.

Optionally, two ends of the energy-taking capacitor C are connected in parallel with the voltage-dividing resistor R2.

The charging voltage value of the energy-taking capacitor C is determined by the small resistor in the current-limiting resistor R1 and the voltage-dividing resistor R2.

And normal submodules connected with the anodes of the first blocking diodes of the damping modules are distributed on the same bridge arm or different bridge arms of the converter valve.

Fig. 2 is a second schematic diagram of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

In an energy obtaining circuit of the converter valve bridge arm damping module, a damping module ZN comprises a damping resistor Rz, a power semiconductor switch Tz and a bypass switch Kz which are connected in parallel. The converter valve further comprises a normal submodule, the normal submodule comprises a high-potential submodule and a low-potential submodule, and the normal submodule comprises a power capacitor, a power semiconductor unit and a power bypass switch. The damping module ZN and the normal sub-modules are connected in series.

The damping module ZN further comprises an energy-taking capacitor C, a first blocking diode D1, a power supply unit and a control unit, wherein the power supply unit takes electric energy from the energy-taking capacitor C and supplies power to the control unit. The anode of the first blocking diode D1 is connected with the anode of the power capacitor C1 of the adjacent normal submodule (i.e. high potential submodule), the anode of the energy-taking capacitor C is connected with the cathode of the first blocking diode D1, and the cathode of the energy-taking capacitor C is connected with one end of the damping resistor Rz of the damping module.

The anode of the energy-taking capacitor C is also connected with the cathode of a second blocking diode D2, and the anode of the second blocking diode D2 is connected with the anode of the power capacitor of the adjacent normal submodule (i.e. low potential submodule) on the other side.

Optionally, a current-limiting resistor R1 is connected in series between the anode of the energy-extracting capacitor C and the cathode of the first blocking diode D1 or the cathode of the second blocking diode D2, or the first blocking diode D1 and the second blocking diode D2 are connected in series with the first current-limiting resistor and the second current-limiting resistor, respectively, and then connected with the anode of the energy-extracting capacitor C.

Optionally, a voltage dividing resistor R2 is connected in parallel across the energy-taking capacitor.

The charging voltage value of the energy-taking capacitor C is determined by the small resistance values of the current-limiting resistor R1 and the voltage-dividing resistor R2.

And the normal submodules connected with the anodes of the first blocking diode or the second blocking diode of the damping module are distributed on the same bridge arm or different bridge arms of the converter valve.

Fig. 3 is a third schematic diagram of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application.

As shown in fig. 3, the damping module ZN and the normal sub-module are distributed on different bridge arms of the converter valve, and the connection mode and the energy-taking working principle of the energy-taking circuit of the damping module and the normal sub-module are the same as those of the embodiment shown in fig. 1 and 2, and are not described again.

Fig. 4 is a flowchart of a start control method of a converter valve bridge arm damping module according to an embodiment of the present application, and illustrates a start control method of a damping module when only the first blocking diode D1 connected to the high potential submodule SM1 exists.

In S110, the normal sub-module is charged, and the damping module energy-taking capacitor C is charged from the high potential sub-module SM1 power capacitor C1 through the connected first blocking diode D1.

In S120, when the voltage of the energy-obtaining capacitor C of the damping module ZN is charged to the starting voltage threshold of the damping module power supply unit, the damping module power supply unit starts to operate to supply power to the control unit, and communication between the damping module control unit and the upper control system is established.

In S130, the converter valve is unlocked, and the normal sub-module and the damping module start to unlock.

Fig. 5 is a second flowchart of a start control method for a converter valve bridge arm damping module according to an embodiment of the present application, and illustrates a start control method for a damping module when only a first blocking diode connected to a low potential submodule SM2 exists.

In S210, the normal sub-module starts charging.

In S220, the normal sub-module is unlocked and the damping module energy extraction capacitor C is charged from the low potential sub-module SM2 power capacitor through the connected first blocking diode D1.

In S230, when the voltage of the damping module energy-taking capacitor C is charged to the starting voltage threshold of the damping module power supply unit, the damping module power supply unit starts to operate to supply power to the control unit, and the damping module control unit establishes communication with the upper control system.

In S240, the damping module is unlocked, the normal sub-module works, and the converter valve is started.

Fig. 6 is a third flowchart of a start-up control method for a bridge arm damping module of a converter valve according to an embodiment of the present disclosure, and illustrates a start-up control method for the damping module ZN when a first blocking diode D1 connected to a high-potential submodule SM1 and a second blocking diode D2 connected to a low-potential submodule SM2 exist at the same time.

In S310, the normal submodule starts charging, and the damping module energy-taking capacitor C is charged from the high potential submodule SM1 power capacitor through the connected first blocking diode D1.

In S320, when the voltage of the energy-taking capacitor C of the damping module is charged to the starting voltage threshold of the power supply unit of the damping module, the power supply unit of the damping module starts to supply power to the control unit, and communication between the control unit of the damping module and the upper control system is established.

In S330, the converter valve is unlocked, and the normal sub-module and the damping module start to work;

in S340, if the first current limiting resistor connected to the high-potential sub-module is greater than the second current limiting resistor connected to the low-potential sub-module, the damping module energy-taking capacitor C will be continuously charged by the low-potential sub-module SM2 power capacitor.

Fig. 7 is a flowchart of a fault control method of an energy obtaining circuit of a converter valve bridge arm damping module according to an embodiment of the present application, and includes the following steps.

In S410, it is determined whether the voltage of the energy-extracting capacitor C is normal.

In S420, if no, the damping module control unit issues a bypass command to close the bypass switch Kz.

In S430, if yes, it is continuously determined whether an internal fault of the damping module ZN occurs.

If so, the damping module control unit issues a bypass command to close the bypass switch Kz, as in S420. If not, the damping module continues to work normally.

And repeating the steps to judge the fault control.

According to the technical scheme provided by the embodiment of the application, high-reliability energy taking of double-path redundant input is realized, but high-voltage isolation power supplies configured by two adjacent normal sub-modules are reduced, the problem that high-voltage insulation is required to be endured between the primary side-secondary side winding and the secondary side-secondary side winding of the two high-voltage isolation power supplies in the normal sub-modules in the prior art is solved, and the high-voltage isolation power supply has higher reliability and better economical efficiency; the energy-taking capacitor in the damping module can form a resistance-capacitance voltage-dividing unit with the voltage-dividing resistor and the current-limiting resistor, so that the voltage of the energy-taking capacitor can be reduced, the differential mode voltage input by the damping module power supply system is further reduced, the reliability of the power supply system is further improved, and the insulation cost is reduced; an independent isolation power supply unit is configured, and the problem of electromagnetic interference caused by the fact that high-voltage power supplies of two adjacent sub-modules are connected in parallel and are grounded in the prior art is solved.

The foregoing detailed description of the embodiments of the present application has been presented to illustrate the principles and implementations of the present application, and the description of the embodiments is only intended to facilitate the understanding of the methods and their core concepts of the present application. Meanwhile, a person skilled in the art should, according to the idea of the present application, change or modify the embodiments and applications of the present application based on the scope of the present application. In view of the above, the description should not be taken as limiting the application.