功率前馈的准Z源光伏并网逆变器Quasi-PR控制

Quasi-PR Control Strategy for Quasi-Z Source PV Grid-connected Inverter Based on Power Feed-forward

为了加快准Z源光伏并网逆变器的动态响应,避免电网电压矢量定向控制策略需解耦控制和多次坐标变换的不足,同时提高并网电流控制器对电网频率偏移的适应范围,将功率前馈及准比例谐振控制引入准Z源光伏并网系统中。在两相静止坐标下,将功率前馈、准比例谐振控制与直通分段空间矢量脉宽调制(SVPWM)相结合,设计了并网系统的完整控制策略。在Matlab/Simulink中搭建了系统仿真模型,并与传统控制进行对比分析。仿真结果表明:当外界环境发生变化时,采用功率前馈的准比例谐振控制策略能使系统较快地过渡到另一个稳态,且可实现对给定值的无静差跟踪控制,抗电网频率偏移能力强。

In order to speed up the dynamic response of quasi-Z source photovoltaic grid-connected inverter,and to avoid the shortcomings of grid voltage vector-oriented control strategy which have to adopt decoupling control and multiple coordinate transformation,and to improve the adaptive range of grid connected current controller to grid frequency deviation,we introduced power feed-forward and quasi-PR control to the quasi-Z source grid-connected photovoltaic system.The complete control strategy of the grid connected system was designed by combining the power feed-forward,quasi-proportional resonant control strategy,and the shoot through segment SVPWM.Moreover,a simulation model of system was established and compared with the traditional control in Matlab/Simulink software.The simulation results show that the quasi-PR control strategy with power feed-forward can make the system transfer to another steady state quickly when the external environment changes and achieve no-static-error tracking of a given value in the stationary coordinate,meanwhile,the system is capable of resisting network frequency deviation.