采用扰动观测器的并网逆变器死区补偿方法

Dead-time compensation of grid-connected inverter based on disturbance observer

为解决传统死区补偿方法在相电流过零点附近电流极性检测不准的问题,提出一种新的死区补偿方法。根据扰动观测器的控制原理,设计了相应的观测器,将其作为补偿器引入到传统双环PI控制系统中,此系统无需检测电流极性,将死区效应引起的电压误差视为系统扰动,利用扰动观测器对其进行在线估算,并将估算值作为补偿信号反馈到输入端以抵消电压误差对系统的影响。通过仿真与实验比较可知,该方法能够克服传统方案的弊端,可以降低各种扰动对输出电流的稳态误差,不仅提高了死区补偿效果,还提高了系统的稳定性和抗扰性能。

In order to solve the dead-time compensation method in phase current near zero polarity detection uncertainty,a kind of new dead-time compensation method was presented.Based on disturbance observer control principle,the corresponding observer which was designed as compensator was introduced into the traditional double-loop PI control system.The system need not detect current polarity,caused the dead voltage error by factors such as dead-time effect as the disturbance of the system,using disturbance observer for on-line estimation,then the estimate value as a compensation signal feedback to the input end to offset voltage error influence on the system.The simulation and experiment show that the proposed method overcomes the disadvantages of the traditional method,reduces all kinds of disturbances on the output current of the steady state error,improves the compensation effect,and improves system stability and anti-interference capability.