并网输电逆变换器电能稳定性优化控制仿真

Simulation of Optimal Control for Power Stability of Grid-Connected Inverter

针对光伏并网输电逆变换器输出电能稳定性的优化控制问题,为降低逆变器的开关损耗和并网电流的谐波畸变率,实现对网侧电流的实时跟踪,提高输出电能质量,提出变环宽滞环控制和模糊控制相结合的逆变器电流内环控制方法。环宽采用预置的正弦函数模型,通过模糊推理在线整定正弦函数模型中的环宽系数,实现降低开关损耗和电流环的实时跟踪控制,利用逆变器的多功能特性,抑制逆变器输出电流波形畸变,提高输出电能质量。采用Matlab软件对上述控制策略进行了仿真分析,结果表明,改进后的控制方法可以有效地降低逆变器的开关损耗,改善并网电流波形,提高输出电能稳定性。

In order to optimize the control of output power of inverter, reduce the switching loss and harmonic distortion rate of current, simultaneously, achieve real-time tracking inverter network side of current, a new control method of inverter is proposed, which has the advantages of variable - loop band hysteresis controller and fuzzy con- troller. The method adopted that preset sine function replacing the expression of hysteresis loop band. In addition, fuzzy reasoning is used in the variable loop band hysteresis current control system to tune the coefficient of hysteresis loop band. Finally, the purpose of lower switching loss and well control effect is achieved. By using the multifunc- tional characteristic of inverter, the waveform distortion output current is suppressed and the stability of the control strategy is improved. The switching frequency and output current harmonic distortion are calculated and compared. The simulation results in Matlab show that the above advanced control method can effectively reduce switching loss and improve grid current waveform of inverter, thereby, the power stability of inverter will be optimized.