永磁直驱风力机低电压运行储能容量取值研究

Research on Energy Storage Capacity Allocation for Low Voltage Operation of the Permanent Magnetic Synchronous Generator

针对永磁直驱风力机低电压运行时存在的直流侧过电压问题,建立了运用超级电容器储能来解决该问题的方案,提出了超级电容器储能容量取值方法。对故障前后系统能量变化进行分析设计了储能系统充放电控制策略,结合超级电容器等效模型进行数学推导得出储能容量计算表达式。通过模拟不同深度电压跌落故障进行仿真计算,分别得出所需超级电容器储能容量。最后对比储能投入前后直流侧电压变化证明了所提出的储能容量计算方法的正确性以及储能系统控制策略的有效性。

In view of the overvoltage which occurs to the DC side when the permanent magnetic synchronous generator (PMSG)operates at a low voltage,this paper proposes to use the Super Capacitor Energy Storage (SCES),and also the rea-sonable value range of the storage capacity. Firstly,it analyzes the energy change of the system before and after the fault and designs the energy storage system charge/discharge control stra-tegy. The energy storage capacity expression is acquired by means of the mathematical derivation with super capacitor equivalent models. Simultaneously, the different depths of voltage sag faults are simulated and calculated to obtain the storage capacity of the super capacitor energy as required. Finally,comparisons of voltage changes in the DC side before and after the energy storage verify the validity of calculation method about energy storage capacities and the effectiveness of energy storage system control strategy.