基于反推控制的储能系统并网变流器直接PQ控制策略

Direct PQ Control Strategy for Grid-Connected Inverter of Energy Storage System Based on Backstepping Control

新能源和储能装置的并网变流器功率控制多采用基于PI调节器的电流双闭环来间接实现,存在静态误差和参数整定困难等缺点。为使储能系统更好地参与电网功率调节,在推导并网变流器有功功率和无功功率状态方程的基础上,提出了基于反推控制的直接PQ控制策略,省去了电流转化环节,避免了复杂的有功功率和无功功率解耦过程。进一步,依据控制性能选取了反推控制器参数,使系统在设定时间内进入稳态。仿真结果表明,提出的控制器性能良好,能够快速、准确地跟踪电网功率指令。与基于PI控制的电流双闭环功率控制策略相比,反推控制参数更易整定,且调节时间短,不存在静态误差。

The power control of grid-connected converters for new energy and energy storage devices is realized indirectly by current double closed-loop based on PI regulator,which has some shortcomings such as static error and difficulty in parameter setting.In order to make the energy storage system effectively participate in power regulation of the grid,the direct PQ control strategy based on backstepping control is proposed after deducing the state equation of active power and reactive power of the grid-connected converter,which eliminates current conversion link and avoids the complicated decoupling process of active power and reactive power.Furthermore,according to the control performance,the parameters of the backstepping controller are selected to make the system enter the steady state within the set time.The simulation results show that the controller proposed in this paper has good performance and can track power instructions quickly and accurately.Compared with the current double closed-loop power control strategy based on PI control,the parameters of backstepping controller are easier to set,the adjustment time is short,and there is no static error.