基于模糊自适应PI策略的并网逆变器死区补偿

Grid-Connected Inverter Dead-Time Compensation Based on Fuzzy-Adaptive PI Strategy

IGBT死区效应的存在使三相并网逆变器输出电流不能准确跟踪参考电流,导致系统控制性能较差,而传统的死区补偿方法在相电流过零时存在电流极性判断不准确的问题。针对以上问题,提出一种基于模糊自适应PI策略的三相并网逆变器死区补偿方法。该方案将扰动观测器应用到电流双环模糊自适应PI控制系统中,将死区效应引起的电压误差视为外部扰动,经过扰动观测器估算后,反馈到输入端用以抵消死区效应的影响。模糊自适应PI电流双环控制策略可以解决实际系统响应速度慢、动态特性差的问题。通过MATLAB/Simulink仿真和试验验证了所提方案能够有效降低死区效应的影响,提高系统动态响应。

The existence of IGBT dead-time effect made the output current of three-phase grid-connected inverters unable to track the reference current accurately,which led to poor control performance.However,the traditional dead-time compensation method had the problem of inaccurate current polarity judgment when the phase current was zero.Based on the above problems,a dead-time compensation method for three-phase grid-connected inverter based on fuzzy-adaptive PI strategy was proposed.The disturbance observer was applied to the current double-loop fuzzy-adaptive PI control system.The voltage error caused by dead-time effect was regarded as an external disturbance.After the estimation of the disturbance observer,the voltage error was fed back to the input to counteract the dead-time effect.Fuzzy-adaptive PI current double-loop control strategy could solve the problems of slow response and poor dynamic characteristics of the actual system.The simulation of MATLAB/Simulink and experiment showed that the method could effectively reduce the influence of dead-time effect and improve the dynamic response of the system.