Bypass thyristor false triggering protection system and method

Abstract

The invention provides a bypass thyristor false triggering protection system and method. The bypass thyristor false triggering protection system comprises a valve layer controller, a current measuring device, a bypass thyristor and a current converter. The bypass thyristor is connected in parallel with the outlet end of the current converter and is used for bypassing the current converter; a branch where the bypass thyristor is located is connected to a current measuring device. The valve layer controller is connected with the current measuring device, the bypass thyristor and the current converter, and the valve layer controller is used for receiving current signals collected by the current measuring device and controlling a bypass of the bypass thyristor and a switching device of the current converter. A current measuring device is connected to a branch of a bypass thyristor, a valve layer controller is adopted to obtain current information detected by the current measuring device in real time, false triggering detection of the bypass thyristor is achieved, locking of a converter switching device is controlled to achieve false triggering protection, and the method is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly to a protection system and method for mis-triggering of bypass thyristors. Background Art

[0002] Compared with traditional mechanical switches, bypass thyristors have the characteristics of large current and fast conduction bypass, and are widely used in flexible AC and DC transmission converter valve equipment. During transient faults in the power system or faults of the converter itself, the bypass thyristor can quickly bypass converter modules such as H-bridges and MMCs to protect the switching devices of the converter.

[0003] In practical engineering applications, due to factors such as interference to the bypass thyristor trigger board and unreasonable design of the drive circuit, the bypass thyristor has the problem of being mis-triggered. When the converter module is normally unlocked and operating, if the bypass thyristor is mis-triggered, it will cause the DC capacitor in the converter module to be directly short-circuited, and the IGBT switching device will flow through a short-circuit current exceeding its tolerance, which will easily burn out the IGBT switching device.

[0004] Existing research on the problem of mis-triggering of bypass thyristors pays more attention to how to avoid the mis-triggering of bypass thyristors. For example, "CN202320562751.7 Thyristor drive circuit for improving the anti-interference ability of MMC sub-module bypass switches" improves its anti-interference ability by optimizing the thyristor drive circuit to avoid mis-triggering of the thyristor; "CN208754258U A thyristor for preventing mis-triggering" prevents mis-triggering of the thyristor by optimizing the structure of the thyristor body. Therefore, it can be concluded that most existing research focuses on the optimization of bypass thyristors and their external drive circuits to reduce the possibility of their mis-triggering, and rarely involves the detection method after the thyristor is mis-triggered, especially after the bypass thyristor of the converter is mis-triggered, and the protection of the converter after detecting the mis-triggering of the bypass thyristor. Summary of the Invention

[0005] To overcome the deficiencies of the above-mentioned prior art, the present invention proposes a protection system for mis-triggering of bypass thyristors, including: a valve layer controller, a current measuring device, a bypass thyristor, and a converter;

[0006] The bypass thyristor is connected in parallel to the outlet end of the converter for bypassing the converter;

[0007] The branch where the bypass thyristor is located is connected to the current measuring device;

[0008] The valve layer controller is respectively connected to the current measuring device, the bypass thyristor, and the converter, and the valve layer controller is used to obtain the current signal collected by the current measuring device, trigger the bypass thyristor, and control the converter switch.

[0009] Optionally, a current analog signal acquisition terminal, a high-speed analog-to-digital converter chip, a bypass thyristor mis-trigger protection pressure plate, and a control protection module are provided inside the valve layer controller;

[0010] The current analog signal terminal is connected to the high-speed analog-to-digital converter and is used to transmit the collected current signal of the bypass thyristor to the high-speed analog-to-digital converter chip;

[0011] The high-speed analog-to-digital converter chip is used to convert the current signal into a digital signal;

[0012] The bypass thyristor mis-trigger protection pressure plate is used to determine whether the bypass thyristor mis-trigger protection system is operating;

[0013] The control protection module is used to control the converter switch according to the digital signal when the bypass thyristor mis-trigger protection pressure plate is put into operation.

[0014] Optionally, the bypass thyristor is a bidirectional optically triggered thyristor.

[0015] Optionally, the current measuring device includes a current transformer, a Hall current sensor, or an optical fiber current sensor.

[0016] Optionally, the converter is an H-bridge converter.

[0017] Optionally, the switching device of the converter is an IGBT.

[0018] Based on the same inventive concept, the present invention proposes a method for protecting against mis-triggering of a bypass thyristor, including:

[0019] Using a valve layer controller to receive the branch current of the bypass thyristor detected by a current measuring device;

[0020] If there is no trigger instruction for the bypass thyristor in the valve layer controller and the branch current is greater than the current threshold within a continuous T period, use the valve layer controller to block the switching device of the converter.

[0021] Optionally, when using the valve layer controller to block the switching device of the converter, it also includes using the valve layer controller to report a protection event to an external monitoring system.

[0022] Based on the same inventive concept, the present invention also provides a computer device, including: one or more processors;

[0023] A memory for storing one or more programs;

[0024] When the one or more programs are executed by the one or more processors, the method for protecting against mis-triggering of a bypass thyristor as described above is implemented.

[0025] Based on the same inventive concept, the present invention also provides a computer-readable storage medium with a computer program stored thereon. When the computer program is executed, it implements a method for protecting against mis-triggering of a bypass thyristor as described above.

[0026] Compared with the closest prior art, the beneficial effects of the present invention are as follows:

[0027] A bypass thyristor mis-triggering protection system and method provided by the present invention include: a valve layer controller, a current measuring device, a bypass thyristor, and a converter; the bypass thyristor is connected in parallel to the outlet end of the converter for bypassing the converter; the branch where the bypass thyristor is located is connected to the current measuring device; the valve layer controller is respectively connected to the current measuring device, the bypass thyristor, and the converter. The valve layer controller is used to receive the current signal collected by the current measuring device, control the bypass of the bypass thyristor, and control the switch of the converter. In this application, without affecting the normal triggering of the bypass thyristor, only a current measuring device needs to be connected to the branch of the bypass thyristor. The valve layer controller is used to obtain the current information detected by the current measuring device in real time, implement the detection of mis-triggering of the bypass thyristor, and control the locking of the switching device of the converter to achieve mis-triggering protection, which is simple and reliable; the present invention can be used as a backup solution for various existing optimization schemes for preventing mis-triggering of bypass thyristors. In the case where various anti-mis-triggering optimization schemes fail, it can effectively detect the mis-triggering fault of the bypass thyristor of the converter and perform protection. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the circuit topology of a bypass thyristor mis-triggering protection system provided by the present invention;

[0029] Figure 2 It is a schematic diagram of the flow of a bypass thyristor mis-triggering protection method provided by the present invention;

[0030] Figure 3 It is a logical diagram of a bypass thyristor mis-triggering protection method provided by the present invention. Detailed Description of the Embodiment

[0031] A bypass thyristor mis-triggering protection system and method provided by the present invention can be used in power electronic converter and commutation valve devices such as flexible AC transmission FACTS and flexible DC transmission VSC-HVDC. The present invention adds a current detection device to the branch of the bypass thyristor to detect the current of the bypass thyristor branch in real time, quickly identify the abnormal triggering of the bypass thyristor, and timely lock the IGBT device of the converter to protect the safety of the IGBT device of the converter.

[0032] The following further describes the specific embodiments of the present invention in detail with reference to the drawings.

[0033] Embodiment 1

[0034] Taking the mis-trigger protection of the bypass thyristor of the H-bridge converter in the flexible AC transmission device as an example, the mis-trigger protection system will be described according to Figure 1 the circuit topology diagram of a bypass thyristor mis-trigger protection system shown in

[0035] A bypass thyristor mis-trigger protection system provided by the present invention, as Figure 1 shown, includes: a valve layer controller, a current measurement device, a bypass thyristor, and a converter;

[0036] The bypass thyristor is connected in parallel to the outlet end of the converter for bypassing the converter;

[0037] The branch where the bypass thyristor is located is connected to the current measurement device;

[0038] The valve layer controller is respectively connected to the current measurement device, the bypass thyristor, and the converter. The valve layer controller is used to obtain the current signal collected by the current measurement device, trigger the bypass thyristor, and control the converter switch.

[0039] Optionally, the current measurement device includes a current transformer, a Hall current sensor, or an optical fiber current sensor. In this embodiment, the current measurement device selects a current transformer CT. The current transformer CT selects an electromagnetic current transformer with a rated current of 1000A. The electromagnetic current transformer is connected to the branch of the bypass thyristor for real-time detection of the current signal of the bypass thyristor branch;

[0040] The secondary winding of the electromagnetic current transformer is connected to the valve layer controller for transmitting the current signal to the valve layer controller.

[0041] The valve layer controller is used to control the converter and the bypass thyristor triggering function; among them, the valve layer controller controls the on-off and unlocking and locking of the switching devices in the converter, and executes the protection function of the converter. The valve layer controller locks the switching devices of the converter and triggers the bypass thyristor when the converter fails.

[0042] In this embodiment, the valve layer controller selects a large-capacity programmable gate array FPGA to achieve the fast control of the converter switching device and the bypass thyristor triggering by the valve layer controller.

[0043] The valve layer controller is provided with a current analog signal acquisition terminal, a high-speed analog-to-digital converter chip, a bypass thyristor mis-trigger protection pressure plate, and a control and protection module;

[0044] The current analog signal terminal is connected to a high-speed analog-to-digital converter, and is used to transmit the collected current signal of the bypass thyristor to the high-speed analog-to-digital converter chip. Among them, the secondary winding of the electromagnetic current transformer is connected to the current analog signal terminal.

[0045] The high-speed analog-to-digital converter chip (high-speed AD sampling chip) is used to convert the current signal into a digital signal; the high-speed AD sampling chip selected in the valve layer controller of this embodiment can achieve a sampling period of the order of 10 us, and is used to quickly obtain the current signal and convert it into a digital signal, so that the valve layer controller can quickly identify the abnormal current in the bypass thyristor branch.

[0046] The bypass thyristor mis-trigger protection pressure plate is used to determine whether the bypass thyristor mis-trigger protection system is operating.

[0047] Specifically, when the bypass thyristor mis-trigger protection pressure plate is put into operation, the enable signal of the protection pressure plate is in an effective state, and the valve layer controller will detect in real time whether the current is abnormal. If the current is abnormal, the converter will be blocked; if the bypass thyristor mis-trigger protection pressure plate is not put in, the valve layer controller will not perform current detection and the switching device for blocking the converter.

[0048] The control and protection module is used to control the converter switch according to the digital signal when the bypass thyristor mis-trigger protection pressure plate is put into operation.

[0049] In this embodiment, the converter is an H-bridge converter, and the switching device of the converter is an IGBT, which is used to realize power conversion. The IGBT is selected from the Infineon brand.

[0050] Optionally, the bypass thyristor is a bidirectional optically triggered thyristor of Zhuzhou CRRC Times brand. The bidirectional optically triggered thyristor is connected in parallel at the outlet end of the H-bridge converter. When there is an instantaneous fault in the power system or a converter fault, when the valve layer controller blocks the IGBT, it quickly triggers the bypass thyristor TBS to bypass the H-bridge converter to protect the IGBT module from damage.

[0051] Without affecting the normal triggering of the bypass thyristor, the present invention only needs to connect a current measuring device to the branch of the bypass thyristor, adopt the conventional analog signal acquisition circuit of the valve layer controller, obtain the current information detected by the current measuring device in real time, realize the mis-trigger detection of the bypass thyristor, and control the blocking of the converter IGBT to realize mis-trigger protection, which is simple and reliable; the present invention can be used as a backup solution for various existing anti-mis-trigger optimization schemes of bypass thyristors. When various anti-mis-trigger optimization schemes fail, the protection system is used to effectively detect the abnormal triggering fault of the converter bypass thyristor, block the IGBT in time, and realize the reliable protection of the IGBT device of the converter module.

[0052] Embodiment 2

[0053] Based on the same inventive concept, the present invention also provides a method for protecting against mis-triggering of a bypass thyristor, as Figure 2 shown, including:

[0054] S1. Use the valve layer controller to receive the branch current of the bypass thyristor detected by the current measuring device;

[0055] S2. If there is no trigger instruction for the bypass thyristor in the valve layer controller and the branch current is greater than the current threshold within a continuous T period, use the valve layer controller to block the switching devices of the converter.

[0056] Combined Figure 3 with the logic schematic diagram of a method for protecting against mis-triggering of a bypass thyristor, this method will be specifically described.

[0057] In step S1, when the bypass thyristor mis-trigger protection system is in an operating state (i.e., when the bypass thyristor mis-trigger protection pressure plate of the valve layer controller is put into operation), use the current analog signal acquisition terminal of the valve layer controller to receive the branch current of the bypass thyristor detected by the current measuring device. The current analog signal acquisition terminal transmits the current signal of the branch current to the high-speed AD sampling chip to be converted into a digital signal for subsequent mis-trigger detection and protection.

[0058] If the bypass thyristor mis-trigger protection pressure plate is not put into operation, that is, the bypass thyristor mis-trigger protection system is not operating, then the branch current detection and subsequent mis-trigger detection and protection are not performed.

[0059] In step S2, if there is no trigger instruction for the bypass thyristor in the valve layer controller and the branch current is greater than the current threshold within a continuous T period, use the valve layer controller to block the switching devices of the converter, specifically including:

[0060] When the bypass thyristor mis-trigger protection pressure plate is put into operation, if there is no protection action state, that is, when there is no trigger instruction for the bypass thyristor in the valve layer controller, when the branch current of the bypass thyristor obtained by the valve layer controller is greater than the set current threshold Iset and exceeds the T period, it is determined that the bypass thyristor is mis-triggered, and the valve layer controller immediately blocks the IGBT devices of the converter; in this embodiment, the current threshold Iset is set to 100 A according to the actual situation, and T is set to 5 sampling points.

[0061] When using the valve layer controller to block the switching devices of the converter, it also includes using the valve layer controller to report a protection event to the external monitoring system.

[0062] A method for protecting against mis-triggering of a bypass thyristor provided by this application can be used as a backup solution for various existing optimization solutions for preventing mis-triggering of bypass thyristors. When various anti-mis-triggering optimization solutions fail, it can effectively detect the abnormal triggering fault of the bypass thyristor of the converter, promptly block the IGBT, and achieve reliable protection for the IGBT device of the converter module.

[0063] Embodiment 3

[0064] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a method for protecting against mis-triggering of a bypass thyristor in the above embodiment.

[0065] Embodiment 4

[0066] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by the processor are stored in this storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the steps of a method for protecting against mis-triggering of a bypass thyristor in the above-mentioned embodiments.

[0067] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0068] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one or more of these flows Figure 1 or a combination of multiple flows and / or blocks

[0069] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the specified functions in Figure 1 one or more of these flows Figure 1The functions specified in one or more boxes.

[0070] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in one Figure 1 one process or more processes and / or boxes Figure 1 step of the functions specified in one or more boxes.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent replacements to the specific implementation manners of the application. However, these changes, modifications or equivalent replacements are all within the protection scope of the claims pending for approval of the application.

Claims

1. A bypass thyristor mis-trigger protection system, characterized in that, it includes: a valve layer controller, a current measuring device, a bypass thyristor, and a converter; the bypass thyristor is connected in parallel to the outlet end of the converter for bypassing the converter; a current measuring device is connected to the branch where the bypass thyristor is located; the valve layer controller is respectively connected to the current measuring device, the bypass thyristor, and the converter, and the valve layer controller is used to obtain the current signal collected by the current measuring device, trigger the bypass thyristor, and control the converter switch.

2. The bypass thyristor mis-trigger protection system according to claim 1, characterized in that, the valve layer controller is provided with a current analog signal acquisition terminal, a high-speed analog-to-digital converter chip, a bypass thyristor mis-trigger protection pressure plate, and a control protection module; the current analog signal terminal is connected to the high-speed analog-to-digital converter for transmitting the collected current signal of the bypass thyristor to the high-speed analog-to-digital converter chip; the high-speed analog-to-digital converter chip is used to convert the current signal into a digital signal; the bypass thyristor mis-trigger protection pressure plate is used to determine whether the bypass thyristor mis-trigger protection system is operating; the control protection module is used to control the converter switch according to the digital signal when the bypass thyristor mis-trigger protection pressure plate is put into operation.

3. The bypass thyristor mis-trigger protection system according to claim 1, characterized in that, the bypass thyristor is a bidirectional optically triggered thyristor.

4. The bypass thyristor mis-trigger protection system according to claim 1, characterized in that, the current measuring device includes a current transformer, a Hall current sensor, or an optical fiber current sensor.

5. The bypass thyristor mis-trigger protection system according to claim 1, characterized in that, the converter is an H-bridge converter.

6. The bypass thyristor mis-trigger protection system according to claim 1, characterized in that, the switching device of the converter is an IGBT.

7. A bypass thyristor mis-trigger protection method, characterized in that, it includes: using the valve layer controller to receive the branch current of the bypass thyristor detected by the current measuring device; if there is no trigger instruction for the bypass thyristor in the valve layer controller and the branch current is greater than the current threshold within a continuous T period, then use the valve layer controller to block the switching device of the converter.

8. The bypass thyristor mis-trigger protection method according to claim 7, characterized in that, while using the valve layer controller to block the switching device of the converter, it also includes using the valve layer controller to report a protection event to an external monitoring system.

9. A computer device, characterized in that, it includes: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, it implements a bypass thyristor mis-trigger protection method according to any one of claims 7 to 8.

10. A computer-readable storage medium, characterized in that, it stores a computer program, and when the computer program is executed, it implements a bypass thyristor mis-trigger protection method according to any one of claims 7 to 8.

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