Valve control over-voltage-over-current cooperative protection method and system for flexible direct current converter valve

A flexible DC and overvoltage protection technology, which is used in protection against overvoltage, emergency protection devices with automatic disconnection, emergency protection circuit devices, etc. It can solve fault ride-through failure, increased investment, and does not involve flexible DC It solves the problems of valve-controlled overpressure-overcurrent synergistic protection method, etc., to achieve the effect of improving fault ride-through capability, reducing capacitance value, and enhancing system reliability.

Active Publication Date: 2022-08-02
STATE GRID ECONOMIC TECH RES INST CO +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, when the AC and DC systems fail, it is easy to block due to the overvoltage and overcurrent of the flexible DC converter valve reaching its protection setting value, resulting in the failure of fault ride through
[0004] In order to solve the above problems, the existing technology usually connects more sub-modules in series to reduce the voltage of a single module, but this will cause an increase in investment
At present, the body overvoltage protection and the body overcurrent protection of the converter valve are completely independent and will not cooperate with each other, that is, the overvoltage protection only monitors the overvoltage of the module, and the overcurrent protection only monitors the overcurrent of the bridge arm. When the overvoltage protection setting value is set , it is assumed that when the bridge arm current is the maximum value (that is, 2 times the rated current), the maximum voltage that can be unlocked and operated is the maximum capacity of the equipment. None of the prior art involves the valve-controlled overvoltage-overcurrent cooperative protection method of the flexible DC converter valve.

Method used

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  • Valve control over-voltage-over-current cooperative protection method and system for flexible direct current converter valve
  • Valve control over-voltage-over-current cooperative protection method and system for flexible direct current converter valve
  • Valve control over-voltage-over-current cooperative protection method and system for flexible direct current converter valve

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Experimental program
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Effect test

Embodiment 1

[0048] Embodiment 1: The valve-controlled overvoltage-overcurrent coordinated protection method for a flexible DC converter valve provided in this embodiment includes the following steps:

[0049] S1, such as figure 1 As shown, for the IGBT device used in the flexible DC converter valve, the turn-off peak voltage test under different turn-off currents was carried out, and the maximum capacitor voltage when the turn-off peak voltage did not exceed the rated voltage of the device when different currents were turned off was recorded, and plotted. The neutron module of the flexible DC converter valve unlocks the operating voltage-current operating capability curve, and the specific process includes:

[0050] S11. Build a double-pulse test platform based on the adopted IGBT device, set the initial value of the test current to 0pu, adjust the test current to the initial value, and set the current step size to carry out the double-pulse test. Preferably, the step size can be selected...

Embodiment 2

[0066] Embodiment 2: The above Embodiment 1 provides a valve-controlled overpressure-overcurrent cooperative protection method for a flexible DC converter valve. Correspondingly, this embodiment provides a valve-controlled overpressure-overcurrent protection method for a flexible DC converter valve. Overcurrent cooperative protection system. The system provided in this embodiment may implement the valve-controlled overvoltage-overcurrent cooperative protection method of the flexible DC converter valve of the first embodiment, and the system may be implemented by software, hardware, or a combination of software and hardware. For the convenience of description, when describing this embodiment, the functions are divided into various units and described respectively. Of course, during implementation, the functions of each unit may be implemented in one or more software and / or hardware. For example, the system may include integrated or separate functional modules or functional uni...

Embodiment 3

[0090] Embodiment 3: This embodiment provides an electronic device corresponding to the valve-controlled overvoltage-overcurrent cooperative protection method of the flexible DC converter valve provided in the first embodiment. The electronic device may be an electronic device used for a client. For example, a mobile phone, a notebook computer, a tablet computer, a desktop computer, etc., are used to execute the method of the first embodiment.

[0091] like Figure 5 As shown, the electronic device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The bus can be an Industry Standard Architecture (ISA, IndustryStandard Architecture) bus, a Peripheral Device Interconnect (PCI, Peripheral Component) bus or an Extended Industry Standard Architecture (EISA, Extended Industry Standard Component) bus and the like. A computer program that ca...

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PUM

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Abstract

The invention relates to a valve control overvoltage-overcurrent cooperative protection method and system for a flexible direct current converter valve, and relates to the field of direct current transmission, and the method comprises the steps: obtaining a voltage-current operation capability curve of a sub-module in the flexible direct current converter valve during unlocking operation; obtaining the maximum voltage of each current unlocking operation based on the voltage-current operation capability curve, and calculating a voltage-current protection constant value curve of a sub-module in the flexible DC converter valve based on the maximum voltage of each current unlocking operation; and each sub-module controller performs overvoltage protection by using a dynamic overvoltage protection constant value according to the real-time operation current of the bridge arm and the voltage-current protection constant value curve of the sub-module. The constant value of overvoltage protection is dynamically adjusted according to the magnitude of the current in the operation process, the constant value of overvoltage protection is high when the current is small, the constant value of overvoltage protection is low when the current is large, the risk of overvoltage protection action locking of the converter valve under the alternating-current and direct-current fault of the system can be reduced, and the fault ride-through capacity is improved.

Description

technical field [0001] The invention relates to a valve-controlled overvoltage-overcurrent cooperative protection method and system for a flexible DC converter valve, and relates to the field of DC power transmission. Background technique [0002] The flexible DC adopts fully-controlled IGBT devices, which are voltage source converters. In principle, it gets rid of the dependence on the AC power grid. It has no commutation failure, black start capability, independent decoupling control of active and reactive power, and flexible operation mode. Moreover, it can realize important technical advantages such as large-scale power flow regulation and control, and is widely used in application scenarios such as asynchronous grid interconnection and new energy transmission. [0003] At present, the main bottleneck in the development of flexible DC is that its device body is weak in withstand transient voltage and current. Taking a 4.5kV / 3kA IGBT device as an example, the maximum cur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/122H02H7/125H02H3/10H02H3/20G01R31/40H02J3/36
CPCH02H7/122H02H7/125H02H3/006H02H3/10H02H3/202G01R31/40H02J3/36Y02E60/60
Inventor 赵峥李明李探张涛田园园郭铭群王绍武马为民卢亚军熊凌飞张进郑宽祝全乐黄曹炜罗舒翰
Owner STATE GRID ECONOMIC TECH RES INST CO
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