阅读说明：本技术 一种具备自我保护功能的功率模块及其控制方法 (Power module with self-protection function and control method thereof ) 是由 张中锋 袁庆伟 陆翌 黄晓明 李继红 裘鹏 谢晔源 宣晓华 倪晓军 丁超 王柯 于 2019-09-10 设计创作，主要内容包括：本发明提出一种具备自我保护功能的功率模块,所述功率模块包括支撑电容、半桥电路、第三全控型开关器件和功率模块控制回路,第三全控型开关器件并联在功率模块输出端口；功率模块控制回路在功率模块内部半桥电路发生故障时,通过对第三全控型开关器件的开关控制维持系统电流的导通路径,并控制模块支撑电容电压在合理范围内,使得功率模块控制回路的电源供电得到保证,保持整个功率模块处于可控工作状态。(The invention provides a power module with a self-protection function, which comprises a support capacitor, a half-bridge circuit, a third fully-controlled switch device and a power module control loop, wherein the third fully-controlled switch device is connected in parallel with an output port of the power module; when a half-bridge circuit in the power module breaks down, the power module control loop maintains a conduction path of system current through the switch control of the third full-control type switching device, and the control module supports capacitor voltage within a reasonable range, so that power supply of a power supply of the power module control loop is guaranteed, and the whole power module is kept in a controllable working state.)

1. A power module with self-protection function comprises a support capacitor and a half-bridge circuit, and is characterized by further comprising a third fully-controlled switch device and a power module control loop, wherein the third fully-controlled switch device is connected in parallel with an output port of the power module; when a half-bridge circuit in the power module breaks down, the power module control loop maintains a conduction path of system current through the switch control of the third full-control type switching device, and the control module supports capacitor voltage within a reasonable range, so that power supply of a power supply of the power module control loop is guaranteed, and the whole power module is kept in a controllable working state.

2. The self-protection power module of claim 1, wherein the half-bridge circuit comprises a first fully-controlled switching device and a first anti-parallel diode, and a second fully-controlled switching device and a second anti-parallel diode, an emitter of the first fully-controlled switching device is connected to a collector of the second fully-controlled switching device, an anode of the supporting capacitor is connected to the collector of the first fully-controlled switching device, a cathode of the supporting capacitor is connected to an emitter of the second fully-controlled switching device, and an output port of the power module is the emitter and the emitter.

3. The self-protection power module of claim 1, wherein the power supply of the power module control loop is self-powered from a high voltage of a power module support capacitor; when the voltage of the supporting capacitor is larger than the preset value, the power module control loop is in a working state.

4. The self-protection power module of claim 1, wherein the power module control loop comprises a power board, a control board; the power supply board card supplies power to the control board card, and the control board card samples the voltage of the supporting capacitor and controls the on-off of the fully-controlled switch device.

5. The self-protection power module of claim 4, wherein when the half-bridge circuit inside the power module fails, the half-bridge circuit protective latch is turned off, the conducting path of the system current is maintained through the switch control of the third fully-controlled switch device, and the module support capacitor voltage is controlled within a reasonable range, the power board keeps taking power from the support capacitor and then supplies power to the control board, so as to keep the whole power module in a controllable working state.

6. The method according to any one of claims 1 to 4, wherein the method comprises the following steps:

step 11: when the interior of the power module is normal, the third full-control type switching device is always in an off state, and the half-bridge circuit carries out system energy transmission;

step 12: when a power device in the half-bridge circuit fails at a certain moment, the half-bridge circuit is locked and shut down immediately, so that the expansion of a failure range is avoided;

step 13: power module control loop collects voltage value u of direct current support capacitor in real time_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLComparing; when u is_dc＞u_dcHWhen the power module is charged, a switching-on command is issued to the third full-control type switching device, and the power module supporting capacitor is stopped being charged; when u is_dc＜u_dcLAnd when the power module is in a controllable working state, the power module is controlled to be in a controllable working state.

7. The method according to claim 2, wherein the method comprises the steps of:

step 21: when the interior of the power module is normal, the third full-control type switching device is always in a turn-off state, and the full-control switching device in the half-bridge circuit executes an alternate turn-on and turn-off instruction to transmit system energy;

step 22: when a bridge type full-control switching device fault occurs inside the power module at a certain moment, the half-bridge circuit needs to be locked and shut down immediately, and the fault range is prevented from being expanded;

step 23: real-time acquisition direct current support for power module control loopVoltage value u of capacitor_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLComparing; when u is_dc＞u_dcHWhen the power module is in overvoltage damage, a switching-on command is issued to the third fully-controlled switch device, the forward current of the system flows through the third fully-controlled switch device, the reverse current flows through the second anti-parallel diode of the half bridge, and the power module is stopped being charged to the support capacitor of the power module; when u is_dc＜u_dcLAnd when the power module is in a controllable working state, the power module control loop keeps obtaining energy from the supporting capacitor to obtain power supply, and the whole module is in a controllable working state.

Technical Field

The invention belongs to the technical field of high-voltage high-power flexible direct current power transmission and transformation, and particularly relates to a power module with a self-protection function.

Background

The flexible direct current transmission converter valve is a device which converts high-voltage heavy current alternating current into high-voltage heavy current, remotely transmits electric energy to a terminal through an overhead line or a cable, and converts the high-voltage heavy current into the high-voltage alternating current at the terminal. The flexible direct-current transmission converter valve can realize interconnection of a plurality of regional power grids, active power and reactive power transmitted by a system can be quickly controlled, and the flexibility of power transmission is greatly enhanced.

At present, most of power modules in the flexible direct current transmission converter valve adopt a half-bridge sub-module topology structure. When a power module in the system has a fault, in order to enable the system to continue to work normally, the fault power module needs to be bypassed by a mechanical switch, if the mechanical switch is bypassed, the fault module cannot be cut off, and in order to avoid further expansion of a fault range, tripping of the whole system is caused. Therefore, there is a need for a power module with a self-protection function that can solve the above-mentioned problems, and can maintain a system current conduction path when the module half-bridge IGBT is locked due to a fault and the bypass switch is turned off.

Disclosure of Invention

The invention aims to solve the defects of the existing scheme, and provides a power module with a self-protection function and a control method thereof, which are used for solving the problem of system tripping when a bypass switch of the power module is rejected.

In order to achieve the purpose, the specific scheme of the invention is as follows:

a power module with a self-protection function comprises a supporting capacitor, a half-bridge circuit, a third fully-controlled switch device and a power module control loop, wherein the third fully-controlled switch device is connected to an output port of the power module in parallel; when a half-bridge circuit in the power module breaks down, the power module control loop maintains a conduction path of system current through the switch control of the third full-control type switching device, and the control module supports capacitor voltage within a reasonable range, so that power supply of a power supply of the power module control loop is guaranteed, and the whole power module is kept in a controllable working state.

Preferably, the half-bridge circuit includes a first fully-controlled switching device, a first anti-parallel diode, a second fully-controlled switching device, and a second anti-parallel diode, an emitter of the first fully-controlled switching device is connected to a collector of the second fully-controlled switching device, an anode of the support capacitor is connected to the collector of the first fully-controlled switching device, a cathode of the support capacitor is connected to an emitter of the second fully-controlled switching device, and an output port of the power module is the emitter and the emitter.

Preferably, the power supply of the power module control loop is self-powered from the high potential of the power module support capacitor; when the voltage of the supporting capacitor is larger than the preset value, the power module control loop is in a working state.

Preferably, the power module control loop comprises a power board card and a control board card; the power supply board card supplies power to the control board card, and the control board card samples the voltage of the supporting capacitor and controls the on-off of the fully-controlled switch device. When the half-bridge circuit in the power module breaks down, the half-bridge circuit protective locking is switched off, a conduction path of system current is maintained through the switch control of the third full-control type switch device, the voltage of the support capacitor of the control module is in a reasonable range, the power supply board card keeps taking energy from the support capacitor and then supplies power to the control board card, and the whole power module is kept in a controllable working state.

The invention also provides a control method of the power module with the self-protection function, which comprises the following steps:

step 11: when the interior of the power module is normal, the third full-control type switching device is always in an off state, and the half-bridge circuit carries out system energy transmission;

step 12: when a power device in the half-bridge circuit fails at a certain moment, the half-bridge circuit is locked and shut down immediately, so that the expansion of a failure range is avoided;

step 13: power module control loop collects voltage value u of direct current support capacitor in real time_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLComparing; when u is_dc＞u_dcHWhen the power module is charged, a switching-on command is issued to the third full-control type switching device, and the power module supporting capacitor is stopped being charged; when u is_dc＜u_dcLAnd when the power module is in a controllable working state, the power module is controlled to be in a controllable working state.

When the half-bridge circuit adopts a specific structure as follows: the power module comprises a first full-control type switch device, a first anti-parallel diode, a second full-control type switch device and a second anti-parallel diode, wherein an emitting electrode of the first full-control type switch device is connected with a collecting electrode of the second full-control type switch device, an anode of a supporting capacitor is connected with the collecting electrode of the first full-control type switch device, a cathode of the supporting capacitor is connected with the emitting electrode of the second full-control type switch device, and an output port of the power module is the emitting electrode and the emitting electrode. The control method of the power module with the self-protection function comprises the following steps:

step 21: when the interior of the power module is normal, the third full-control type switching device is always in a turn-off state, and the full-control switching device in the half-bridge circuit executes an alternate turn-on and turn-off instruction to transmit system energy;

step 22: when a bridge type full-control switching device fault occurs inside the power module at a certain moment, the half-bridge circuit needs to be locked and shut down immediately, and the fault range is prevented from being expanded;

step 23: power module control loop collects voltage value u of direct current support capacitor in real time_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLComparing; when u is_dc＞u_dcHWhen the power module is in overvoltage damage, a switching-on command is issued to the third fully-controlled switch device, the forward current of the system flows through the third fully-controlled switch device, the reverse current flows through the second anti-parallel diode of the half bridge, and the power module is stopped being charged to the support capacitor of the power module; when u is_dc＜u_dcLAnd when the power module is in a controllable working state, the power module control loop keeps obtaining energy from the supporting capacitor to obtain power supply, and the whole module is in a controllable working state.

The invention has the beneficial effects that:

(1) the power module has a self-protection function, and when the full-control type switching device of the half-bridge circuit is in fault protective locking and turning off, the conduction path of system current can be controlled and maintained through the parallel full-control type switching device of the output port, so that system tripping is avoided.

(2) According to the control method, the voltage of the supporting capacitor of the fault module can be controlled within a reasonable range, the module cannot generate serious overvoltage to cause fault expansion, and the power board cannot lose power, the fault module controls the board to normally take energy and keep normal execution of set logic, so that the fault module and an upper computer are in communication and are in a controllable working state.

Drawings

FIG. 1 is a schematic circuit diagram of a power module with self-protection function according to the present invention;

FIG. 2 is a schematic diagram of the working condition that forward current flows through the protective IGBT bypass under the control method of the invention;

FIG. 3 is a schematic diagram of the working condition of the reverse current flowing through the lower antiparallel diode of the half-bridge under the control method of the present invention;

FIG. 4 is a schematic diagram of a forward current charging energy-compensating working condition loop for a module capacitor under the control method of the present invention.

Detailed Description

The technical scheme of the invention is explained in detail in the following with the accompanying drawings.

The first specific embodiment of the power module with the self-protection function comprises a support capacitor, a half-bridge circuit, a third fully-controlled switch device and a power module control loop, wherein the third fully-controlled switch device is connected in parallel with an output port of the power module; when a half-bridge circuit in the power module breaks down, the power module control loop maintains a conduction path of system current through the switch control of the third full-control type switching device, and the control module supports capacitor voltage within a reasonable range, so that power supply of a power supply of the power module control loop is guaranteed, and the whole power module is kept in a controllable working state.

The half-bridge circuit comprises a first full-control type switch device, a first anti-parallel diode, a second full-control type switch device and a second anti-parallel diode, an emitting electrode of the first full-control type switch device is connected with a collector electrode of the second full-control type switch device, an anode of a supporting capacitor is connected with the collector electrode of the first full-control type switch device, a cathode of the supporting capacitor is connected with an emitting electrode of the second full-control type switch device, and an output port of the power module is the emitting electrode and the emitting electrode.

The power supply of the power module control loop is used for self-extracting energy from the high potential of the power module support capacitor; when the voltage of the supporting capacitor is larger than the preset value, the power module control loop is in a working state.

The power module control loop comprises a power supply board card and a control board card; the power supply board card supplies power to the control board card, and the control board card samples the voltage of the supporting capacitor and controls the on-off of the fully-controlled switch device. When the half-bridge circuit in the power module breaks down, the half-bridge circuit protective locking is switched off, a conduction path of system current is maintained through the switch control of the third full-control type switch device, the voltage of the support capacitor of the control module is in a reasonable range, the power supply board card keeps taking energy from the support capacitor and then supplies power to the control board card, and the whole power module is kept in a controllable working state. As shown in fig. 1, a second embodiment of a power module with self-protection function according to the present invention is shown:

the power module main loop is formed by a support capacitor, a half-bridge circuit and a module output port parallel protection type IGBT, the half-bridge IGBT circuit comprises a first full-control type switching device VT1, an anti-parallel diode VD1, a second full-control type switching device VT2 and an anti-parallel diode VD2, an emitter of the first full-control type switching device VT1 is connected with a collector of a second full-control type switching device VT2, an anode of a direct current support capacitor is connected with a collector of the first full-control type switching device VT1, a direct current support cathode is connected with an emitter of the second full-control type switching device VT2, an output port of the power module is an emitter of the VT1 and an emitter of the VT2, a third full-control type switching device VT3 is connected in parallel at the output port of the power module and used as the protection type IGBT, and the power module control loop comprises a power supply and a control board card. The power supply board card supplies power to the control board card, and the control board card samples capacitor voltage and controls the on and off of the IGBT according to set logic. When the inside half-bridge circuit of power module breaks down, half-bridge circuit IGBT protectiveness shutting-off, through the switch control to the parallelly connected protection type IGBT of output port maintain the conduction path of system's electric current to control module support capacitor voltage is in reasonable scope, and the power integrated circuit board can keep getting the ability and then supplying power to the control integrated circuit board from supporting capacitor, makes whole power module be in controllable operating condition, thereby realizes the self-protection of module when the inside half-bridge circuit of power module breaks down.

The output port parallel protection type device VT3 is a full control type semiconductor power device IGBT.

The power supply board card is used for self-energy taking of high potential of the supporting capacitor of the slave power module. When the voltage of the direct current support capacitor is larger than a certain value, the power panel starts to work to supply power for the control board card; when the voltage of the direct current supporting capacitor is smaller than a certain value, the power supply board card stops working and cannot supply power to the control board card.

The control board card has a communication function with an upper computer, can control the on and off of the half-bridge circuit IGBT and the output port parallel protection type IGBT, can monitor and protect the running state of the IGBT in real time, and can acquire the voltage value u of the direct current support capacitor in real time_dc。

A specific embodiment of the method for controlling a power module with a self-protection function according to the present invention includes the following steps:

s11: when the interior of the power module is normal, the third full-control type switching device is always in an off state, and the half-bridge circuit carries out system energy transmission;

s12: when a power device in the half-bridge circuit fails at a certain moment, the half-bridge circuit is locked and shut down immediately, so that the expansion of a failure range is avoided;

s13: power module control loop collects voltage value u of direct current support capacitor in real time_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLComparing; when u is_dc＞u_dcHWhen the power module is charged, a switching-on command is issued to the third full-control type switching device, and the power module supporting capacitor is stopped being charged; when u is_dc＜u_dcLAnd when the power module is in a controllable working state, the power module is controlled to be in a controllable working state.

Another embodiment of the control method of the power module with self-protection function according to the present invention is described with reference to fig. 1, which includes the following specific steps:

s21: when the interior of the power module is normal, the output port parallel protection type IGBT switching device VT3 is always in a turn-off state, and the half-bridge circuit IGBT executes an alternate turn-on and turn-off instruction to transmit system energy;

s22: when a bridge type IGBT fault occurs inside the power module at a certain moment, the bridge type IGBT needs to be immediately locked and shut off 2 to be disconnected, so that the fault range is prevented from being expanded;

s23: control board card collects voltage value u of direct current support capacitor in real time_dcAnd the upper limit value u of the capacitor voltage_dcHAnd lower limit value u of capacitor voltage_dcLA comparison is made. When u is_dc＞u_dcHWhen the power module works under the bypass working condition, a switching-on command is issued to an outlet parallel protection type IGBT switching device VT3, forward current of the system flows through VT3 as shown in fig. 2, reverse current flows through a half-bridge lower tube antiparallel diode VD2 as shown in fig. 3, and charging of a power module support capacitor is stopped under the bypass working condition, so that overvoltage damage of the power module is avoided; when u is_dc＜u_dcLDuring the process, a turn-off command is issued to the outlet parallel protection type IGBT switching device VT3, as shown in FIG. 4, the forward current of the system flows through a half-bridge upper tube diode VD1 to charge the support capacitor, so that the voltage of the module capacitor cannot further drop, the reverse current still flows through a half-bridge lower tube antiparallel diode VD2, the power supply board card can keep taking energy from the support capacitor and then supply power to the control board card, and the whole module is in a controllable working state.

The above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and various modifications or changes made with reference to the above embodiments are within the scope of the present invention.