Monitoring system and test system suitable for electromagnetic immunity test of converter valve submodule

Abstract

The invention relates to a monitoring system and a testing system suitable for a converter valve sub-module electromagnetic immunity test, and belongs to the field of converter valve sub-module testing. The system comprises a control unit, and a sub-module interface unit, an EMC signal interface unit, a power supply control acquisition interface unit and a wave recording unit which are respectively connected with the control unit, the sub-module interface unit is used for issuing a control instruction to a tested sub-module and collecting data sent by the tested sub-module; the EMC signal interface unit is used for sending a control instruction to EMC test equipment and collecting an EMC test signal; the power supply control acquisition interface unit is used for issuing a power supply control instruction to a sub-module power supply system and acquiring sub-module power supply voltage; the wave recording unit is used for recording interaction data of each interface unit and generating a wave recording file; and the control unit is used for issuing a control instruction through each interface unit and controlling the wave recording unit to carry out data wave recording. According to the invention, a user can conveniently check the operation states of the sub-module in different electromagnetic environments and analyze and position the fault reason of the sub-module.

Description

Technical Field

[0001] The invention belongs to the field of converter valve submodule testing, and relates to a monitoring system and a test system suitable for an electromagnetic immunity test of a converter valve submodule. Background Art

[0002] In recent years, the proportion of high-voltage flexible DC transmission projects in the field of DC transmission has increased year by year, and flexible DC transmission technology has become an important part of my country's power grid architecture. At present, it is widely used in DC power electronic engineering fields such as UHV DC transmission converter valves, DC distribution networks, low-frequency transmission and static VAR compensators. The flexible DC converter valve based on modular multilevel converter (MMC) is composed of a large number of cascaded sub-modules with the same structure. It is the core component of the DC project, and its operating status is related to the reliability of the entire DC project. The flexible DC converter valve realizes level modulation by continuously switching on and off the sub-modules, causing a sharp change in voltage and current in the system, which will generate strong electromagnetic interference. As the core component of the MMC system, the sub-module has been working in a high-voltage and high-power working environment for a long time, making it one of the components most prone to electromagnetic interference.

[0003] In addition, the flexible direct current system based on MMC converter valve has a relatively short development time, and the relevant theories and technologies on electromagnetic compatibility (EMC) for flexible direct current are not mature. In the early construction of flexible direct current transmission demonstration projects, the submodules had insufficient electromagnetic interference protection capabilities, resulting in submodule failures. In the most serious cases, the converter station system was shut down, which directly affected the safe operation of the high-voltage direct current transmission system. Therefore, in order to ensure the safe, reliable and stable operation of the flexible direct current project, the flexible transmission converter valve submodule must have sufficient ability to resist electromagnetic interference.

[0004] At present, it is difficult to predict and simulate multi-path electromagnetic interference such as conduction and radiation coupling of flexible power transmission converter valves, and it is still difficult to establish accurate conduction interference and space radiation models. The Chinese invention patent application with publication number CN111562449A discloses an anti-electromagnetic interference test device for converter valves, which includes an online monitoring system. After applying an electromagnetic interference test signal to the converter valve, the online monitoring system monitors the working state of the converter valve before and after power supply to determine whether the anti-electromagnetic interference test has passed. The Chinese invention patent application with publication number CN112240962A discloses a hybrid electromagnetic interference application device for flexible DC converter valve submodules, which includes a monitoring circuit. When a hybrid electromagnetic interference test is performed on a normally working converter valve submodule, the monitoring circuit determines whether the converter valve submodule is working under the hybrid electromagnetic interference signal. Although a monitoring device is set up in the above test device, this is a "black box" assessment method. Designers or testers can only assess the EMC performance of the submodule based on whether the submodule works normally during and after the interference application process. It is impossible to view the operating status of the submodule in different electromagnetic environments through EMC test phenomena or test results. In particular, if a fault occurs during EMC testing, this method cannot accurately locate the real cause of the submodule failure, which is very inconvenient when finding the problem. Summary of the invention

[0005] The purpose of the present invention is to provide a monitoring system and a test system suitable for electromagnetic immunity test of a converter valve submodule, so as to solve the problem that the existing monitoring circuit cannot check the operating status of the submodule in different electromagnetic environments and analyze and locate the cause of the submodule failure.

[0006] The monitoring system for electromagnetic immunity test of converter valve submodule provided by the present invention to solve the above technical problems includes a monitoring device, which includes a control unit and a submodule interface unit, an EMC signal interface unit, a power control acquisition interface unit and a recording unit respectively connected to the control unit; the submodule interface unit is used to connect the submodule under test, send control instructions to the submodule under test and collect data sent by the submodule under test; the EMC signal interface unit is used to connect the EMC test equipment, send control instructions to the EMC test equipment and collect EMC test signals; the power control acquisition interface unit is used to send power control instructions to the submodule power supply system and collect the submodule power supply voltage; the recording unit is used to record the interactive data of the submodule interface unit, the EMC signal interface unit and the power control acquisition interface unit, and generate a recording file; the control unit is used to send control instructions through each interface unit and control the recording unit to record data.

[0007] Furthermore, the system also includes an on-site auxiliary unit, which includes an acquisition communication module, which is connected to the power control acquisition interface unit. The acquisition communication module is used to collect and process the electrical signals of the sub-module under test, and convert the electrical signals into optical signals and then send them to the monitoring device.

[0008] Furthermore, the acquisition communication module is also used to forward the power control instruction sent by the power control acquisition interface unit to the sub-module power supply system, and collect the sub-module power supply voltage and send it to the monitoring device.

[0009] Furthermore, the on-site auxiliary unit also includes a decoupling and discharge module, which is used to be connected between the submodule power supply system and the submodule under test, decouple the interference signal of the submodule power supply system during the test, and discharge the test voltage when the power supply voltage of the submodule under test is cut off.

[0010] Furthermore, the acquisition and communication module includes a filtering circuit, an acquisition circuit, a photoelectric converter and a communication circuit.

[0011] Furthermore, the on-site auxiliary unit also includes a power supply module for supplying power to the acquisition and communication module, and the power supply module is a dry cell battery.

[0012] Furthermore, the system also includes a human-computer interaction unit, which is connected to the control unit and is used to achieve human-computer interaction and communication with the background.

[0013] Furthermore, the data sent by the submodule under test includes the communication status of the submodule, the fault status of the submodule, the electrical signal detected by the submodule and the switch status of the electronic switch device of the submodule.

[0014] Furthermore, the EMC test signal includes the starting time of applying the test signal, the frequency point of the test signal, and the voltage and current waveform information.

[0015] The electromagnetic immunity test system of the converter valve submodule provided by the present invention to solve the above-mentioned technical problems includes EMC testing equipment and a submodule power supply system. The test system also includes the monitoring system suitable for the electromagnetic immunity test of the converter valve submodule as described above. The EMC signal interface unit in the monitoring system is connected to the EMC testing equipment, and the monitoring system is connected to the submodule power supply system.

[0016] The monitoring system and the test system of the present invention have the beneficial effects of collecting and recording the input voltage of the power submodule, the control instructions of the power submodule, the EMC test signals, the operating status information and the electrical signals of the power submodule in the electromagnetic interference environment during the EMC test, so as to facilitate the test personnel to view the operating status of the submodule under test in different electromagnetic environments, and when the submodule under test fails, the recording file can be called to quickly locate the cause of the failure during the EMC test of the submodule, and the margin between a certain electrical signal of the power submodule and the set threshold value when being interfered in the electromagnetic interference environment can be viewed, thereby providing an effective monitoring means for the electromagnetic compatibility design and testing of the submodule. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural block diagram of a monitoring device applicable to electromagnetic immunity test of a converter valve submodule according to an embodiment of the present invention; Figure 2 is a structural block diagram of an on-site auxiliary unit according to an embodiment of the present invention; Figure 3 It is a structural block diagram of an electromagnetic immunity test system applicable to a converter valve submodule according to an embodiment of the present invention; Figure 4 It is a schematic diagram of the structure of an existing half-bridge IGBT flexible direct current power submodule. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0019] The basic idea of ​​the present invention is that during the electromagnetic immunity test of the power submodule of the converter valve, the operating status, electrical quantity parameters, and EMC interference information of the power submodule in different electromagnetic environments can be monitored and recorded, so that the operating status of the power submodule can be observed and the cause of the power submodule failure can be analyzed and located through the recording file combined with the EMC interference information, thereby providing an effective and safe monitoring means for the electromagnetic compatibility design and test of the power submodule of the converter valve.

[0020] A monitoring system embodiment suitable for electromagnetic immunity test of converter valve submodule Based on the above basic ideas, Figure 1 As shown, the monitoring system of this embodiment includes a monitoring device, which includes a control unit, a wave recording unit, a submodule interface unit, a power control and acquisition interface unit, and an EMC signal interface unit.

[0021] The control unit is mainly responsible for data processing, data transmission and algorithm implementation, and specifically implements the following functions: 1) Control and discharge of the input voltage of the power submodule under test: send power control instructions to the power supply of the power submodule under test, control the power supply system of the power submodule to output according to the set power supply voltage, and control the submodule to quickly discharge the test voltage after cutting off the power supply of the submodule. 2) Generation of power submodule control instructions, setting of fault trigger conditions and generation of EMC test control instructions, and control of the corresponding unit to send control instructions.

[0022] When the power submodule needs to be tested for EMC, the control unit will generate power submodule control instructions, EMC test equipment control instructions, and power system control instructions after receiving the test instructions, and send the power submodule control instructions to the tested power submodule through the submodule interface unit, send the power control instructions to the power supply of the power submodule through the power control acquisition interface unit, and send the EMC test control instructions to the EMC test equipment through the EMC signal interface unit. When it is determined that the power submodule fails under the current test environment, a power cut-off control instruction is sent to the power submodule power supply system, thereby cutting off the submodule input voltage, and at the same time controlling the discharge circuit to discharge the test voltage to ensure the safety of the test.

[0023] The submodule interface unit communicates with the converter valve power submodule through optical fiber, and is mainly responsible for issuing control instructions to the power submodule and collecting the submodule operating status and electrical quantity parameters.

[0024] The power control acquisition interface unit is used to connect to the submodule power supply system, and is responsible for sending submodule power supply voltage control instructions, power cut-off control instructions and test voltage discharge control instructions to the submodule power supply system, as well as collecting submodule input voltage signals.

[0025] The EMC signal interface unit is used for optical fiber communication with the EMC test equipment. It is mainly responsible for the control of the EMC test equipment and the collection of EMC test signal frequency, output voltage and current waveforms, including issuing control instructions to the EMC test equipment and collecting EMC test signal frequency, output voltage and current waveform information.

[0026] The recording unit is responsible for recording data information such as power submodule control instructions, power submodule operating status and electrical quantity parameters, EMC test signals, and generating recording files.

[0027] Based on the above monitoring system of this embodiment, when conducting EMC test, it is possible to collect the input voltage of the power submodule, the control instructions of the power submodule, the EMC test signal, the operating status information and electrical quantity parameters of the power submodule in the electromagnetic interference environment in real time, and summarize the collected data information to form a recording file. If the submodule does not fail at the end of the test, the submodule passes the EMC test and has good electromagnetic interference resistance; if the submodule fails, by checking the recording file and combining the EMC interference (such as frequency point, voltage amplitude, field strength) information to analyze the flexible direct current power submodule operating instructions, electrical quantity parameters, optical signal feedback status, etc., the cause of the fault can be quickly located.

[0028] Preferably, the monitoring system of this embodiment further includes a human-computer interaction unit, which is connected to the control unit and is responsible for human-computer interaction and background communication.

[0029] Preferably, the power submodule data collected by the submodule interface unit of this embodiment includes information such as submodule communication status, submodule fault status, electrical signals detected by the submodule, switch status of submodule electronic switch devices, etc. The EMC test signal collected by the monitoring device includes the start time of the test signal application, the frequency point of the signal, and the voltage and current waveforms.

[0030] Preferably, the monitoring device can adopt a chassis-type structural design, and the control unit, human-computer interaction unit, recording unit, submodule interface unit, power control acquisition interface unit and EMC signal interface unit are integrated and packaged in the chassis.

[0031] As a preferred implementation mode, in order to further accurately locate the cause of the submodule failure, the monitoring system of the present invention also includes an on-site auxiliary unit, such as Figure 2 As shown, the local auxiliary unit includes a collection and communication module, which is responsible for collecting and processing the electrical signals of the power sub-module.

[0032] Preferably, the acquisition communication module mainly includes a filtering circuit, an acquisition circuit, a photoelectric converter and a communication module. The acquisition communication module is connected to the submodule under test, collects the electrical signal of the submodule under test, and converts the electrical signal into an optical signal, and sends the optical signal to the monitoring device through an optical fiber connected to the power control acquisition interface unit. When the submodule under test fails, under the influence of electromagnetic interference, the data information sent to the submodule interface unit from the control board of the submodule under test may be incomplete or inaccurate, while the acquisition communication module directly collects the electrical signal of the peripheral circuit of the control board of the submodule under test, which is not affected by the performance of the submodule control board. The monitoring device can more accurately locate the cause of the failure of the submodule by comparing and analyzing the electrical quantity parameters of the submodule collected by the submodule interface unit and the electrical signal of the submodule transmitted by the power control acquisition interface unit.

[0033] Preferably, the on-site auxiliary unit also includes a decoupling discharge module. The decoupling discharge module is arranged between the power submodule and the submodule power supply system, and is used to perform interference signal decoupling processing on the voltage signal output by the submodule power supply system, filter out the interference signal during the test, improve the stability of the programmable power supply, and protect the power supply of the power submodule. The decoupling discharge module is also connected to the acquisition communication module, and when receiving the discharge control instruction, the discharge circuit in the decoupling discharge module is opened to quickly discharge the submodule test voltage, thereby improving the stability and safety of the test.

[0034] Preferably, the on-site auxiliary unit is also provided with a power supply module for providing power to the acquisition communication module. The power supply module is powered by dry batteries, thereby avoiding electromagnetic interference signals transmitted by space and external power supply systems and improving the stability of the power supply voltage.

[0035] Preferably, the acquisition and communication module, power supply module and decoupling discharge module of the on-site auxiliary unit are placed in a shielding box to shield the electromagnetic interference signals in the space, improve the anti-interference capability of the monitoring system, and effectively improve the reliability and accuracy of the on-site auxiliary unit.

[0036] An embodiment of a converter valve submodule electromagnetic immunity test system The test system includes a monitoring system, EMC test equipment and a submodule power supply system. The specific structure of the monitoring system can be found in the above monitoring system embodiment, which will not be described in detail here. Figure 3 As shown, the EMC signal interface unit and the EMC test equipment in the monitoring system are connected via optical fiber communication; when the monitoring system does not include an on-site auxiliary unit, the power control acquisition interface unit is connected to the sub-module power supply system; when the monitoring system includes an on-site auxiliary unit, the power control acquisition interface unit is connected to the acquisition communication module of the on-site auxiliary unit, and the acquisition communication module is connected to the sub-module power supply system.

[0037] Preferably, the submodule power supply system in this embodiment is a programmable power supply.

[0038] The flexible direct current power submodule generally adopts a half-bridge or full-bridge topology. This embodiment takes a half-bridge IGBT flexible direct current power submodule as an example to illustrate the working principle of the test system of the present invention. Figure 4As shown in the figure, the half-bridge flexible DC power submodule mainly consists of two parts: power hardware and submodule controller. The power hardware part mainly includes power devices such as IGBT, DC capacitor C, thyristor T, bypass switch K and voltage equalization resistor R. The submodule controller mainly includes three parts: energy source, IGBT driver board and control board (SCE). The control board contains small signal control protection judgment logic circuits. These circuits are the parts with low working voltage level and are most easily interfered with, and need to be monitored. In addition, the interface between the control board and the energy source, IGBT driver board, capacitor, bypass switch, and thyristor is an electrical signal, which is also easily interfered with and needs to be monitored. When the flexible DC power submodule is running, the energy source status feedback signal, bypass switch status feedback signal, IGBT driver board control and feedback signal are summarized in the control board through optical signals, which also need to be monitored.

[0039] When performing EMC testing on the flexible direct current power submodule, the submodule interface unit of the monitoring device is connected to the power submodule under test through optical fiber, the EMC signal interface unit communicates with the EMC test equipment through optical fiber, and the power control acquisition interface unit communicates with the acquisition communication module of the local auxiliary unit through optical fiber. The acquisition communication module of the local auxiliary unit is connected to the power submodule under test, and the acquisition communication module is also connected to the submodule power supply system. The submodule power supply system is connected to the submodule under test through the decoupling discharge module.

[0040] When the system is connected, the test instructions are sent through the human-computer interaction unit of the monitoring device, and the monitoring device sends power control instructions to the submodule power supply system through the power control acquisition interface unit, so that the submodule power supply system outputs the corresponding power supply voltage to the submodule under test, and sends EMC test control instructions to the EMC test equipment through the EMC signal interface unit, so that the EMC test equipment applies the corresponding electromagnetic interference signal, and sends submodule control instructions to the submodule under test through the submodule interface unit to control the submodule under test to start working. When the test system is running normally, the monitoring device synchronously collects the input voltage of the flexible direct power submodule, the power submodule control instructions, the EMC test signals, the operating status information and electrical signals of the power submodule in the electromagnetic interference environment, and summarizes the collected data information to form a recording file. If the submodule does not fail at the end of the test, the submodule passes the EMC test and has good electromagnetic interference resistance performance; if the submodule fails, by viewing the recording file, combining the EMC interference (such as frequency point, voltage amplitude, field strength) information to analyze the flexible direct power submodule operation instructions, electrical signal information, optical signal feedback status, etc., the cause of the fault can be quickly located.

[0041] During the EMC test, the local auxiliary unit further decouples the power supply interference signal through the decoupling discharge module, thereby improving the stability of the programmable power supply. When a power submodule fails, the monitoring device controls the cutting off of the submodule power supply voltage, and at the same time controls the decoupling discharge module to open the discharge circuit to ensure the safety of the test. By retrieving the corresponding recording file, the transient process of the flexible direct current power submodule fault is analyzed, and the cause of the failure during the EMC test of the flexible direct current power submodule is quickly located.

[0042] In summary, the present invention can automatically apply and discharge the supply voltage of the flexible direct current power submodule, record the operating status and electrical parameters of the tested flexible direct current power submodule during EMC testing, and present the data processing results in multiple ways. Compared with the prior art, the present invention can quickly locate the cause of the failure during the EMC test of the submodule, check the margin between a certain electrical signal of the power submodule and the set threshold when it is interfered in the electromagnetic interference environment, and provide an effective monitoring means for the electromagnetic compatibility design and testing of the submodule.

Claims

1. A monitoring system suitable for electromagnetic immunity test of converter valve submodule, characterized in that ,The system includes a monitoring device, which includes a control unit and a submodule interface unit, an EMC signal interface unit, a power control acquisition interface unit and a wave recording unit respectively connected to the control unit; the submodule interface unit is used to connect the submodule under test, send control instructions to the submodule under test and collect data sent by the submodule under test; the EMC signal interface unit is used to connect the EMC test equipment, send control instructions to the EMC test equipment and collect EMC test signals; The power control and acquisition interface unit is used to send power control instructions to the sub-module power supply system and collect the sub-module power supply voltage; the recording unit is used to record the interaction data between the sub-module interface unit, the EMC signal interface unit and the power control and acquisition interface unit, and generate a recording file; the control unit is used to send control instructions through each interface unit and control the recording unit to perform data recording.

2. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 1 is characterized in that: The system also includes an on-site auxiliary unit, which includes a collection and communication module. The collection and communication module is connected to the power control collection interface unit. The collection and communication module is used to collect and process the electrical signals of the sub-module under test, and convert the electrical signals into optical signals and then send them to the monitoring device.

3. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 2 is characterized in that: The acquisition communication module is also used to forward the power control instruction sent by the power control acquisition interface unit to the submodule power supply system, and collect the submodule power supply voltage and send it to the monitoring device.

4. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 3 is characterized in that: The on-site auxiliary unit also includes a decoupling and discharging module, which is used to be connected between the submodule power supply system and the submodule under test, decouple the interference signal of the submodule power supply system during the test, and discharge the test voltage when the power supply voltage of the submodule under test is cut off.

5. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 3 is characterized in that: The acquisition and communication module includes a filtering circuit, an acquisition circuit, a photoelectric converter and a communication circuit.

6. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 3 is characterized in that: The on-site auxiliary unit also includes a power supply module for supplying power to the acquisition and communication module, and the power supply module is a dry cell.

7. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 1, characterized in that: The system also includes a human-computer interaction unit, which is connected to the control unit and is used to realize human-computer interaction and communication with the background.

8. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 1 is characterized in that: The data sent by the submodule under test includes the communication status of the submodule, the fault status of the submodule, the electrical signal detected by the submodule and the switch status of the electronic switch device of the submodule.

9. The monitoring system for electromagnetic immunity test of converter valve submodule according to claim 1, characterized in that: The EMC test signal includes the starting time of applying the test signal, the frequency point of the test signal, and the voltage and current waveform information.

10. A converter valve submodule electromagnetic immunity test system, the test system includes EMC test equipment and a submodule power supply system, characterized in that: The test system also includes a monitoring system suitable for electromagnetic immunity testing of a converter valve submodule as described in any one of claims 1 to 9, wherein the EMC signal interface unit in the monitoring system is connected to the EMC test equipment, and the monitoring system is connected to the submodule power supply system.

Images