Push–pull converter

Abstract: A new design of an efficient batteryless pumping system powered from photovoltaic panels, comprising a push-pull converter and an induction motor, is presented. Detailed evaluation of the energy processing cycle has allowed the formulation of a set of design principles and the optimization of a sensorless induction motor drive system. The resulting performance enhancement is demonstrated experimentally.

Abstract: A single stage high frequency push-pull converter with input power factor correction. The boost converter for input power factor correction and the high-frequency push-pull DC/AC inverter are combined into a single stage converter thereby reducing the number of circuit components while at the same time reducing the voltage stress on the high frequency switching transistors of the converter.

Abstract: In this paper, a soft-switching single-inductor push-pull converter is proposed A push-pull converter is suitable for low-voltage photovoltaic ac module systems, because the step-up ratio of the high-frequency transformer is high, and the number of primary-side switches is relatively small However, the conventional push-pull converter does not have high efficiency because of high-switching losses due to hard switching and transformer losses (copper and iron losses) as a result of the high turn ratio of the transformer In the proposed converter, primary-side switches are turned ON at the zero-voltage switching condition and turned OFF at the zero-current switching condition through parallel resonance between the secondary leakage inductance of the transformer and a resonant capacitor The proposed push-pull converter decreases the switching loss using soft switching of the primary switches In addition, the turn ratio of the transformer can be reduced by half using a voltage-doubler of secondary side The theoretical analysis of the proposed converter is verified by simulation and experimental results

Abstract: Isolated boost converter is desirable in the low-to-high dc/dc application where isolation is required or a large step up is in a need. The challenge of designing such a converter for high power applications is how to handle the high current at the input and high voltage at the output. An effective way is to parallel the inputs and series the outputs of the isolated boost converters. Based on this concept, a new interleaved and isolated boost converter is proposed in this paper that has two inductors in parallel at the input to share the current and two capacitors in series at the output to share the voltage. The current stresses and voltage stresses of the converter are both alleviated. The two boost converter cells realize demagnetizing by helping each other, which simplifies the transformer structures. With interleaved operation, the current ripple is smaller; therefore, it is possible to use smaller capacitors at the input and output of the converter. All these features make the new interleaved isolated boost converter desirable for high power low-to-high dc/dc applications. The proposed interleaved isolated boost converter is presented based on the basic isolated boost converter, but the interleaved structure is applicable to other isolated boost converters including the full-bridge converter, the push-pull converter, and the L-type half-bridge converter. The theoretical analysis is verified by a 200W prototype.