基于减载控制的光伏电站主动频率响应方法

Active frequency response method of photovoltaic power plant based on load shedding control

传统光伏发电系统通常运行在最大功率点,不对电网频率改变进行响应,不能为抑制电网频率变化提供有功功率,随着光伏渗透率的提升,对电网的安全稳定运行产生影响,因此光伏等新能源设备应具有响应系统频率变化的能力。文章采用减载控制,在不改变主电路结构、逆变器并网策略,不增设储能设备的情况下实现系统频率的响应。首先通过设置主从阵列得到当前最大功率运行点,实现减载控制;然后针对频率改变,通过设置频率-减载率对应关系,实现有功功率输出的改变,对系统进行有功支撑;最后通过半实物仿真平台进行仿真,验证了结果的有效性。

The traditional photovoltaic power generation system usually operates at the maximum power operation point,does not respond to the change of grid frequency,and cannot provide active power to suppress the change of grid frequency.With the increase of photovoltaic permeability,the safe and stable operation of the grid will be affected.In this paper,load shedding control is adopted to realize the response to system frequency without changing the main circuit structure,grid connection strategy of inverter and adding energy storage equipment.First,the current maximum power operation point is obtained by setting the master-slave array to achieve load shedding control.By setting the corresponding relationship between frequency and load shedding rate,the change of active power output for frequency change is achieved,and the system is provided with active power support.Finally,the effectiveness of the results is verified through simulation on the hardware in the loop simulation platform.