直驱永磁风电机组的改进附加惯性控制方法

An Improved Additional Inertia Control Method for D-PMSG

风电并网容量的增加将导致系统惯性降低,不利于电网安全稳定运行。针对附加惯性控制与最大功率跟踪控制之间存在相互影响的问题,提出改进附加惯性控制方法。该控制方法不仅可以利用附加惯性控制的辅助功率对系统频率提供支撑,还可以根据系统频率变化调节转速,补偿最大功率跟踪控制的有功参考,从而避免了2种控制在动态调节过程中的相互影响,使得机组的输出功率更好地响应系统频率的变化。仿真分析验证了在改进的控制方法下,直驱永磁风电机组不仅减小了负荷扰动初期的频率变化率,还缩短了系统频率调节时间,调频效果得到改善。

The increase of wind power capacity causes the decrease of system inertia and therefore threatens the grid security. In view of the mutual influence between additional inertia control and maximum power point tracking （MPPT） control, an improved additional inertia control method is pro- posed in this paper. The proposed method utilizes the auxiliary power of additional inertial control to support system frequency, and can compensate the active power reference of MPPT control by adjusting the rotor speed according to the system frequency variation, so as to avoid the mutual influence of the two control methods in the dynamic regulation process, and make the output power of wind turbine better respond to the change of system frequency. The simulation results show that with the proposed control scheme, directly-driven wind turbine with permanent magnet synchronous generator（D-PMSG） can reduce the system frequency change rate in the initial period, and shorten the system frequency regulation time, while improves the system frequency regulation results.