超级电容储能和卸荷电路协调控制的永磁同步风电机组低电压穿越策略

Low⁃voltage Ride⁃through Control Strategy of Permanent Magnetic Synchronous Wind Turbine with Coordination of Super Capacitor Energy Storage and Chopper Circuit

针对永磁同步风力发电机组的低电压穿越问题,结合超级电容储能与卸荷电路的优点,提出了一种超级电容储能和卸荷电路协调控制的低电压穿越策略。当低电压故障发生时,在机组变流器的直流侧同时投入卸荷电阻和超级电容储能系统共同吸收故障期间的不平衡功率。在故障清除后,超级电容储能系统根据网侧变流器的运行状态将故障期间吸收的能量回馈电网。仿真结果表明,所提协调控制策略能在保证机组可靠实现故障穿越的同时,降低超级电容的设计容量和成本,并提高风能的利用率。

In view of the low⁃voltage ride⁃through problem of permanent magnet synchronous wind turbine,a kind of low⁃voltage ride⁃through control strategy with the coordination of super capacitor energy storage and chopper circuit,combing with the advantages of both super capacitor energy storage and chopper circuit,is proposed.In case of fault of low voltage,the chopper resistor and super capacitor energy storage system are put into operation simultaneously at the DC link of the back⁃to⁃back converter to absorb jointly the unbalanced power due to the fault.After clearance of the fault,the super capacitor energy storage system feeds back the energy absorbed during the fault to the grid in ac⁃cordance with the operation state of the grid side converter.The simulation results show that the proposed coordinat⁃ed control strategy can,at the time of assuring to achieve reliably fault ride⁃through of the wind turbine,reduce the design capacity and cost of super capacitor and improve the utilization rate of wind energy.