基于Sugeno-Mamdani模糊模型的电流跟踪型光伏并网逆变器

Photovoltaic grid connected inverter with current tracking control based on Sugeno-Mamdani fuzzy model

针对并网光伏逆变器对于输入量变化大、控制算法复杂,开关频率大而导致逆变器发热的问题,提出一种分段控制策略.利用模糊控制算法对输入变化不敏感的特点,设计一种输出PWM控制信号变化较小的逆变器,从而减小开关器件的负荷达到提高逆变效率的目的.设计采用分段控制当输出误差很大的时候使用sugeno模型,当输出误差较小时使用mamdani模型,该文中以单相全桥逆变电路为例,给出详细的仿真分析,仿真结果表明,设计的逆变器与传统控制方法相比,具有稳定性好、抗扰动型强、开关频率低等优势,输出电流的总谐波失真(THD)为1.73%,能够与并网电压达到同频,输出功率因素非常接近1,达到了系统并网发电要求.

A piecewise control strategy was proposed,aimed at the grid connected photovoltaic inverter to the input quantity changes,the complex control algorithm and the inverter heat problem caused by quick switching frequency. by using fuzzy control algorithm. A PWM output control signal changes smaller inverter was designed by using the characteristics of input and less sensitive to changes so as to reduce the load and improve the switching device the purpose of the inverter efficiency. Piecewise control method was used in this design,when output error was big the Sugeno model was selected,when output error was smaller the Mamdani model was selected. Based on the single- phase full bridge inverter circuit example,this paper has gived a detailed analysis of simulation. The simulation results show that,compared with the traditional design of the inverter control method,the newly designed inverter has the advantages of good stability,strong anti disturbance,lowly switching frequency and so on. The output current total harmonic distortion（ THD） is 1. 73%,and the grid voltage can reach the same frequency,the output power factor was very close to 1,which has reached the power requirements of the grid connected system.