基于周期性最大功率点检测的风电机组功率备用控制方法

Power reserve control method of wind turbine units based on periodic maximum power point measurement

风电机组通常运行于最大功率输出模式,无法为受扰电网提供紧急功率支撑。稳态时预留部分出力可提高风电机组主动电网支撑能力,为此提出一种基于周期性最大功率点(MPP)检测的风电机组功率备用控制(PRC)方法。通过周期性执行最大功率点跟踪程序检测风电机组实时MPP,一旦检测到MPP即可确定PRC模式参考值并切换为直接功率控制。设置伪单调转速-机械功率曲线使风电机组稳定运行在超速功率备用点,并通过储能装置平抑MPP检测产生的峰值功率波动。仿真结果表明提出的控制方法在定风速和变风速情况下均可以准确控制检测风电机组MPP并实现PRC,并且使得风电机组一次调频效果优于传统PRC。

The wind turbine units usually operate in the maximum power output mode and cannot provide emergency power support for the disturbed power grid.Reserving part of the output power in the steady state can improve the support capability of the wind turbine units in the active network.Therefore,a power reserve control(PRC)method for wind turbine units based on periodic maximum power point(MPP)measurement is proposed.The real-time MPP of the wind turbine units is detected by periodically executing the maximum power point tracking(MPPT)program.Once the MPP is measured,the PRC mode reference value can be determined and switched to direct power control.The pseudo monotonic rotating speed-mechanical power curve is set to make the wind turbine units operate stably at the overspeed power reserve point,and the energy storage device is applied to suppress the peak power fluctuation introduced by the MPP measurement.The simulative results show that the proposed control method can accurately measure the MPP of the wind turbine units and realize PRC under the conditions of constant and variable wind speeds.Moreover,the primary frequency regulation performance of the wind turbine units with the proposed method is better than that of the traditional PRC.