UHVDC闭锁引发风电场暂态过电压分析及HVRT协调控制

Transient overvoltage analysis of wind farm with UHVDC block andHVRT coordinated control

针对特高压直流(UHVDC)闭锁引发送端风电场高电压穿越(HVRT)问题,建立了UHVDC输电送端风电系统数学模型,研究了UHVDC闭锁对送端风电场过电压的影响,分析了过电压对永磁直驱风电机组的影响及机组功率可控域。提出了基于机组可控域划分的风电机组和静止同步补偿器相协调的风电场HVRT控制策略,在机组可控域内,风电机组利用其动态无功补偿实现HVRT,当超出机组可控域时,风电场集中无功补偿装置与风电机组协调控制实现HVRT。最后,在PSCAD/EMTDC中建立系统仿真模型,验证了理论分析与控制策略的准确性与有效性,直流闭锁引发风电机组高电压脱网的风险得到降低。

For HVRT(High Voltage Ride Through)problem of sending wind farm caused by UHVDC(Ultra High Voltage Direct Current)block,the mathematical model of the wind farm at the sending end of UHVDC transmission is established,the influence of UHVDC blocking fault on the overvoltage of the wind farm at the sending end is studied,and the influence of overvoltage on the direct drive permanent magnet synchronous generator wind turbine and the power controllable domain of wind turbine are analyzed.The control strategy of HVRT is proposed based on the coordination of wind turbine with division of controllable domain and static synchronous compensator.In the controllable domain of wind turbine,the wind turbine uses its dynamic reactive power compensation to achieve HVRT.When beyond the controllable domain of wind turbine,the centralized reactive power compensation device of the wind farm coordinates with the wind turbine to achieve HVRT.Finally,the system simulation model is established in PSCAD/EMTDC to verify the accuracy and effectiveness of theoretical analysis and control strategy,and the risk of high voltage offgrid of wind turbines during UHVDC blocking fault is reduced.