永磁型风机海上风电送出系统甩负荷故障暂时过电压影响因素分析

Analysis on Influence Factors of Temporary Overvoltage of Load Rejection Fault of Offshore Wind Power Transmission System of Permanent Magnet Synchronous Generator

为评估永磁型风机风电送出线路发生甩负荷情况下系统暂时过电压水平,需明确故障发生后系统暂时过电压特性及其影响因素。通过对永磁型风机控制保护策略的数学分析,得知风电机组直流母线电压额定值、网侧变流器调制比、直流母线过电压保护定值和风电机组过电压保护定值及其动作策略为系统暂时过电压主要影响因素。另外,送出系统无功补偿类型、配置方式等也是系统暂时过电压影响因素。采用电磁暂态仿真软件PSCAD/EMTDC对上述影响因素进行了验证,结果表明,风电机组设计中应考虑其对系统暂时过电压的影响,系统暂时过电压计算中需要重点考虑风机的相关控制保护策略。

In order to evaluate the temporary overvoltage level of the wind power transmission system based on permanent magnet synchronous generator(PMSG)in case of load rejection,it is necessary to clarify the temporary overvoltage characteristics and its influencing factors after the fault.According to the mathematical analysis of the control and protection strategies of PMSG-based wind turbine,it was known that the DC bus rated voltage of the wind turbine,the modulation ratio of the grid side converter(GSC),the DC bus overvoltage protection setting,the wind turbine overvoltage protection setting and its action strategy were the main factors affecting the temporary overvoltage of the system.In addition,the type of reactive power compensation and configuration were also the factors influencing the temporary overvoltage of the system.PSCAD/EMTDC was used to verify the above factors.The results show that the relative control and protection strategies of PMSG-based wind turbine should be considered in wind turbine design and the calculation of the temporary overvoltage for wind farm.