Enhanced Control Technique of PWM Converter Under Harmonically Distorted Voltage Conditions

Based on the instantaneous active and reactive power mathematic model of PWM converter under the 5th and 7th harmonically distorted grid voltage,two different control strategy were proposed to reduce the input current harmonic components or power ripple to enhance the operation performance of PWM converter,in which the current reference of the fundamental frequency and the harmonic frequency for the different control target was deduced.Consequently,based on the fundamental frequency and harmonic frequency synchronous rotating reference frames of the grid voltage,a multiple PI current control scheme was proposed to implement the accurate control of the fundamental frequency and harmonic frequency current.The feasibility of the proposed algorithms and control strategy were validated by experimental studies on a 1 kW PWM converter system.