Soft-switching high quality rectifier employing a novel control scheme

Among the high quality rectifier (HQR) topologies proposed in the literature, the boost one has demonstrated to be as simple, powerful and cost-effective to become the most widely used in practical applications. In conventional designs, a boost HQR working in continuous conduction mode (CCM) needs to be input-current controlled besides being output-voltage regulated. This paper addresses the aim of an improvement of the boost HQR in terms of higher power density and simpler control stage, by a novel approach employing a quasi-resonant switching technique. In particular, zero voltage switching (ZVS) and zero current switching (ZCS) techniques have been investigated as a means to obtain resistor emulator behaviour of the boost power converter in CCM by using a new sort of automatic current shaping capability, which means that no current control loop is required. The ZCS technique offers a practical way to reach this goal. Correspondingly, a new control strategy has emerged which employs a voltage control loop only, maintaining all the input-side features of CCM and allowing higher power conversion frequencies. The characteristics of the novel HQR scheme are discussed in detail and analysis, simulation as well as experimental results are provided