A robust controller for multimodule current-mode push-pull converters is presented. First, the small-signal equivalent circuit and the transfer function model of the multimodule converter system are obtained. Then, the selection of slope compensation and the model reduction are performed using the concept of dominant energy mode. Based on the reduced converter model, a PI (proportional plus integral) controller is quantitatively designed according to the prescribed regulating specifications using a systematic design procedure. A robust controller is proposed and augmented to improve the control performance when the parameter variations caused by system configuration change and operating point shift have occurred. The performance of the converter and the effectiveness of the proposed controller are demonstrated by simulation and experimental results. >