With the continuous improvement of the manufacturing level of power electronic elements and the increasing demand of power quality by the people,the static synchronous compensator(STATCOM)based on the voltage re-injection converter has a fast dynamic response speed,does not require filtering devices and outputs low voltage harmonic contents and is suitable for high-voltage and high-power transmission systems.The main circuit re-injection topological structure of the DC voltage re-injection type STATCOM consists of two three-phase full bridges in series and an additional re-injection branch,and the re-injection branch adopts a cascaded H-bridge structure.The zero-crossing interval generated by the re-injection voltage can achieve the zero-voltage on-off of the three-phase full-bridge switch.The construction method of the re-injection branch pulse sequence is designed and an improved cycle logic trigger sequence is proposed.The simulation shows that the re-injection branch can effectively suppress the capacitor voltage unbalance in the re-injection cascaded H-bridge under the specific cyclic trigger pulse.The advantages of the converter in terms of zero-crossing turn-off and harmonic elimination are verified by the simulation platform.The reactive current is taken as a direct control command,a closed-loop control system is set up to verify that the STATCOM can effectively reduce the harmonic content and switching frequency in high-voltage and high-power systems,improve the operation reliability of devices and systems,and is especially suitable for high-voltage and high-power environments.
关键词
无功补偿/STATCOM/电压源型变换器/电压重注/高压大容量
Key words
reactive power compensation/STATCOM/voltage source converter/voltage re-injection/high voltage and large capacity
维普
万方数据