Generalized analysis of current ripple in a pulsewidth modulation H-bridge converter with unipolar-bipolar switching

The aim of this letter is to describe a generalized analysis of the current ripple occurring in an H-bridge with pulsewidth modulation (PWM) technique. The general equation of the current ripple is obtained. By means of this equation, it is shown that the two strategies commonly used for the bridge control (unipolar and bipolar) are two limit cases of a general method. The control condition with minimum ripple is found. Finally, experimental results of a typical example are shown (applied to a DC drive) in different conditions, thus confirming the theoretical results.