DC Bus Current Analysis Considering AC Current Ripple in Three-phase Voltage Source Converters

DC current is an important parameter for the three-phase voltage source converter (VSC). It determines the thermal and reliability status of DC-link capacitor or battery. Analysis and prediction of DC current is associated with three-phase AC current and its ripple, together with the pulse-width-modulation (PWM) method. Based on the AC current ripple prediction method, this paper gives a general DC bus current prediction method with consideration of the AC current ripple. Comparison with simulation results shows the benefits of the method for DC bus current prediction. Experimental results are also provided to validate the prediction result. The predicted DC current ripple can match well with the experimental result.