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

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.