Robust current control method with disturbance voltage observer for voltage source PWM inverter

The voltage source PWM (pulse width modulated) inverter is used for power supply in the field of motor control, UPS (uninterruptible power supply), power conditioner, and so on. Current tracking control for the PWM inverter is very important, since current control ability affects control performance of plant. In this paper, the robust current control method with a disturbance voltage observer for a voltage source PWM inverter is presented; current is controlled to be exactly equal to the reference current under variations of load parameters and operating conditions. Also, the influence of estimation error is restrained by time-varying feedback gain based on Lyapunov´s direct method. The feedback gain is calculated on-line to ensure the system´s stability with various disturbances