Sliding mode based on active-disturbance rejection controller for pulse width modulation rectifier under asymmetrical input voltages

In order to suppress the harmonic power and load disturbance effect to the DC bus voltage under the PWM asymmetrical grid voltage condition, a new voltage control method is proposed based on sliding mode active disturbance rejection theory. Sliding mode active disturbance rejection controller (ADRC) can control positive /negative-sequence current and exactly estimate coupling disturbance in PWM rectifier, then compensate for it, so that system external disturbance can be reduced. Simulation and experimental results show that this method can fast and not overshoot control to the output voltage, and suppress harmonics in power transmission and load changes to system effectively, keep the DC voltage steady and PWM rectifier working without interruption under unbalanced input voltages.