储能型直驱式风电场联合STATCOM的多模式无功协调控制

Multi Mode Reactive Power Coordination Control of Storage-based Direct-driven Wind Farm Combined with STATCOM

直驱永磁风机由于具备无功调节能力强、运行效率高等优势,在大功率风电市场拥有广阔前景。为解决电网故障时直驱式风电场的无功支撑问题,本文在分析直驱永磁风机无功调节能力的基础上,重新设计了风机网侧变流器控制策略,并提出一种静止同步补偿器(STATCOM)与风机间的无功协调控制策略。当并网点电压变化幅度小于设定阈值时,仅启用STATCOM进行无功支撑,网侧变流器工作在单位功率因数模式;当超过设定阈值时则切换风机的工作状态,将无功需求在二者之间协调分配且优先利用风机的无功调节能力,结合网侧变流器无功可调容量选择不同无功通道进行快速无功支撑。直流侧储能系统将风机直流电压始终控制在允许范围内。提升了并网点电压稳定性和风电场无功裕度,仿真结果验证了控制策略的有效性。

Direct-driven permanent magnet wind generator has broad prospects in the high power wind power market thanks to such advantages as strong reactive power regulation capacity and high operating efficiency.For solving the problem of reactive power support for direct-driven wind farms in power grid fault,in this paper the control strategy of GSC on the basis of analyzing the reactive power regulation capability of wind generator is designed,and a reactive power coordinated control strategy between STATCOM and wind generator is proposed.When the voltage variation amplitude is less than the set threshold,only STATCOM is used for reactive power support and the converter of the grid side operates in the unit power factor mode.In case of exceeding the set threshold,the operation status of thewind generator is switched so to coordinate and distribute the reactive need between them and the reactive power adjustment ability of the wind generator is in priority use.The different reactive power channel is selected with combining the reactive power adjustable capacity of inverter of the grid side for the fast reactive power support.The energy storage system on DC side controls the DC voltage in allowable range.The control strategy improves the voltage stability of PCC and reactive power margin of wind farm and the results shows that the control strategy is effective.