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This paper presents a feasibility investigation of a zero-voltage switching (ZVS) pulsewidth modulation (PWM) dc-dc converter with secondary-side phase-shifting power control scheme. The ZVS-PWM dc-dc converter treated here can achieve soft commutation in all the power devices under the wide range of output power variation. By the phase-shifting control that is based on the secondary-side rectifier linked with a high-frequency planar transformer, the effective reduction of idling power in the primary-side inverter as well as snubber-less rectifications in the secondary-side rectifier can be actually attained. The essential experimental data obtained from a 100-kHz/2.5-kW prototype are described herein to validate the soft-switching circuit and control scheme, and then the effectiveness of the dc-dc converter is discussed and evaluated from a practical point of view. [ABSTRACT FROM AUTHOR]

A novel soft-switching PWM utility frequency AC to high-frequency AC power conversion circuit, incorporating boost-half-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications, is presented. The operating principle and the operation modes are described using equivalent circuits with the operating voltage and current waveforms. The operating performances are illustrated and evaluated, including the power regulation and power conversion efficiency against duty cycle characteristics based on the power dissipation as compared with those of the previously developed high-frequency inverter. The practical effectiveness of the power converter is substantially proved, based on experimental results from a practical design example. [ABSTRACT FROM AUTHOR]

A hybrid excitation system is presented, consisting of a capacitor bank with a small-scale active power filter (APF), to regulate the output voltage of the stand-alone induction generator (IG) by controlling its reactive current component and to filter the harmonic currents generated by a nonlinear diode rectifier load. A deadbeat current control structure for pulse-width modulation APF connected to a stand-alone IG working with variable speed and different types of loads is proposed to enhance the operating performance of the stand-alone IG. Sensorless control of the IG, meaning current vector control without voltage sensor and mechanical shaft sensor, is considered and the fixed command control for the IG line-to-line voltage is achieved with high accuracy. In the proposed system a new design of phase-locked-loop circuit is used to determine the stator voltage vector position of the IG. A 2.2 kW laboratory prototype has been built to confirm the feasibility of the proposed method. The measurement results validate the proposed power generating system with the deadbeat current controller as a good application for the IG to reduce the total system cost. [ABSTRACT FROM AUTHOR]

This paper presents a novel circuit topology of the voltage source type zero voltage softswitching (ZVS) full bridge DC-DC power converter with an isolated high-frequency transformer, which incorporates zero-current soft-switching (ZCS) phase-shifted (PS)-PWM active power switches in series with diodes of two bridge arms of a full-bridge rectifier on the high-frequency transformer secondary side. This high-frequency linked DC-DC power converter can achieve ZVS for noncontrolled active power switches on the primary side of the transformer and ZCS for PSPWM active switches on the secondary side of the transformer under wide load variations as well as a wide PS-PWM regulation range. The switching power losses and conduction power losses of the active devices of the proposed DC-DC converter can be considerably reduced. The proposed DC-DC converter blocks circulating current flowing through the semiconductor switching devices on the transformer primary side as compared to the lossless snubbing capacitor and transformer leakage and magnetising inductor-assisted soft-switching full-bridge DC-DC converter with ZVS PS-PWM scheme on the transformer primary side. The steady-state operating principles of the proposed DC-DC converter are evaluated and discussed, based on the simulation and experimental results obtained from a 2 kW-40 kHz breadboard set-up using IGBTs. [ABSTRACT FROM AUTHOR]

A double two-switch forward type high-frequency transformer linked zero-voltage and zero-current mode soft-switching (ZVZCS) pulse width modulation (PWM) DC-DC power converter using IGBTs is presented. A new circuit configuration of the isolated type PWM softswitching converter is proposed to reduce idling and circulating currents in the main circuit without using complex additional active auxiliary resonant snubber circuits and power semiconductor devices, and to decrease the peak voltage across power devices, and their peak current stresses. This soft-switching PWM DC DC power converter has the unique advantages of less power circuit components and power semiconductor devices, high power conversion efficiency, constant frequency duty cycle control scheme, cost-effective and stable soft-switching operating range under wide load variations for high power applications. The basic operating principle of the softswitching power converter treated here is illustrated using periodic steady-state circuit analysis for each mode equivalent circuit. The effectiveness of the proposed soft-switching DC-DC power converter built and tested as a 500 W-100 kHz breadboard setup using IGBTs is verified and evaluated on the basis of simulation and theoretical circuit analysis. [ABSTRACT FROM AUTHOR]

A novel zero current soft-switching (ZCS) pulse-width modulation (PWM) bidirectional dc-dc converter (BDC) with non-inverting polarity multi-mode voltage regulations is presented. In the proposed BDC, all the power devices commutate in ZCS with the aid of single-auxiliary switch-based edge-resonant cells; accordingly the switching power losses can be minimised. The effectiveness of the proposed BDC and its steady-state characteristics are verified in experiments with a 500 W-50 kHz prototype. [ABSTRACT FROM AUTHOR]