The main advantage of the resonant power conversion technique is its ability to eliminate turn on or turn off loss on semiconductor power devices, so that the converter can operate efficiently at multi-MHz switching frequency and yield higher power density compared to the Pulse-Width-Modulated (PWM) technique. However, the main disadvantage of most resonant power conversion techniques is lack of ability to remove the technical conflict of high voltage and current stresses. Moreover, the resonant converter with multiphase configuration for low voltage and high current application poses severe technical challenges. In this paper, the zero-ripple resonant converters - a new class in resonant power conversion is proposed. The advantages of the zero-ripple-resonant technique such as minimum voltage stress, `zero'-ripple input and output currents and its ability to achieve new multiphase architecture are presented. The simulation results and key operation waveforms are given to support this new concept.