Control system for improving bypass safety and reliability of MMC power module

Abstract

The invention discloses a control system for improving the bypass safety and reliability of an MMC power module. The control system comprises a power module unit control board, a power device drivingboard and a bypass switch driving board, a trigger switch, an energy storage capacitor and a bypass switch-on driving coil are arranged on the bypass switch driving board, the trigger switch, the energy storage capacitor and the bypass switch-on driving coil are connected in sequence to form a bypass switch driving circuit, the bypass switch driving circuit further comprises a high-speed photoelectric device, the high-speed photoelectric device is in communication connection with the power device driving board, and when the bypass switch driving circuit is turned on, the high-speed photoelectric device is started to send a locking IGBT signal to the power device driving board. The control system disclosed by the invention can eliminate the potential risk of turning on the bypass switch ina turn-on state of the IGBT of the power module, thereby avoiding large economic loss problems such as serious damage to the power device and other equipment, and ensuring a safe and reliable bypass of a fault module.

Description

Technical field [0001] The invention relates to flexible direct current transmission technology, in particular to a control system for improving the safety and reliability of bypass of MMC power modules. Background technique [0002] Compared with conventional DC transmission technology, flexible DC transmission technology does not require reactive power compensation, has no commutation failure problem, convenient active and reactive power adjustment, low harmonic level, and is suitable for forming a multi-terminal DC system. It makes flexible DC transmission related technology It has been developed rapidly, and the construction of flexible DC transmission projects is in full swing. Among them, the flexible DC transmission system based on MMC (modular multilevel converter) topology is the most representative and technical advantage. [0003] Such as figure 1 As shown, the MMC is composed of six bridge arms, each of which is composed of N power modules (also called sub-modules) casc...

AI Technical Summary

Problems solved by technology

[0012] In order to solve the problem that the bypass switch of the power module is closed when the power module is switched on, causing the power module capacitor to be short-circuited and discharged, causing serious damage to the power device IGBT and other equipment in the circuit, the present invention provides a method for improving the safety and reliability of the MMC power module bypass The control system improves the drive circuit of the bypass switch and the control structure of the power module to ensure that the IGBT can be locked before the bypass switch is closed regardless of the triggering of the drive circuit of the bypass switch for any reason, ensuring the safe and reliable bypass of the power module. road, avoiding large economic losses caused by damage to expensive equipment such as IGBTs

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