A mathematical model of grid voltage and power is established in αβ coordinate system for single-phase PWM rectifier.According to the differential flatness theory,the state variables,outputs and intermediate variables of the control system are chosen,presenting that the differential flatness based direct power control for single-phase PWM rectifier.The controller consists of feed-forward control and nonlinear error feedback compensation.Feed-forward control plans control state variables' reference trajectories according to the desired outputs and nonlinear error feedback compensation adjusts flat outputs of control system to eliminate errors between desired and actual outputs.Simulation results show that the DC voltage can keep a good stability as its grid voltage amplitude and phase change and follow the active and reactive power's reference trajectories to make a rapid power response.The system has strong anti-interference ability and good robustness.%在αβ坐标系下建立了单相PWM整流器交流侧电压和功率的数学模型.根据微分平坦理论,选取了系统的状态变量、输出量和中间变量,提出了单相PWM整流器直接功率平坦控制策略.依据微分平坦设计的控制器分为前馈控制和非线性误差反馈补偿两部分.前馈控制用系统输出量的期望值来规划状态变量的运行轨迹;非线性误差反馈补偿校正控制系统平坦输出,消除了输出量期望值和实际值误差.仿真结果表明,在系统网侧电压的幅值和相位突变时,直流侧电压能保持较好的稳定性,且直流电压跟随有功功率和无功功率参考值的轨迹能快速作出响应,系统抗干扰能力强、鲁棒性好.
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