Soft Switching PWM Inverter Type Research Articles

Optimal Design of a DC-DC Converter for Photovoltaic Generation

This paper presents novel circuit topology of half-bridge soft-switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed, half-bridge high frequency PWM inverter with a high frequency planar transformer link PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode-equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC bus lines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, high switching frequency IGBTs can actually be selected in the frequency range of 40[㎑] under the principle of soft-switching. The performance evaluations of the experimental setup are illustrated practically.

A Novel Prototype of Duty Cycle Controlled Soft-Switching Half-Bridge DC-DC Converter with Input DC Rail Active Quasi Resonant Snubbers Assisted by High Frequency Planar Transformer

This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency planar transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the frequency range of 60 kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of this new converter topology is proved for such low voltage and large current DC-DC power supplies as DC bus feeding from a practical point of view.

A Novel type of High-Frequency Transformer Linked Soft-Switching PWM DC-DC Power Converter for Large Current Applications

This paper presents a new circuit topology of DC busline switch and snubbing capacitor-assisted full-bridge soft-switching PWM inverter type DC-DC power converter with a high frequency link for low voltage large current applications as DC feeding systems, telecommunication power plants, automotive DC bus converters, plasma generator, electro plating plants, fuel cell interfaced power conditioner and arc welding power supplies. The proposed power converter circuit is based upon a voltage source-fed H type full-bridge high frequency PWM inverter with a high frequency transformer link. The conventional type high frequency inverter circuit is modified by adding a single power semiconductor switching device in series with DC rail and snubbing lossless capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge inverter arms and DC busline can achieve ZVS/ZVT turn-off and ZCS turn-on commutation operation. Therefore, the total switching losses at turn-off and turn-on switching transitions of these power semiconductor devices can be reduced even in the high switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules is selected to be 60 kHz. It is proved experimentally by the power loss analysis that the more the switching frequency increases, the more the proposed DC-DC converter can achieve high performance, lighter in weight, lower power losses and miniaturization in size as compared to the conventional hard switching one. The principle of operation, operation modes, practical and inherent effectiveness of this novel DC-DC power converter topology is proved for a low voltage and large current DC-DC power supplies of arc welder applications in industry.

Auxiliary resonant snubber bridge-leg associated soft-switching PWM inverter type DC-DC converter family with bidirectional active switches and voltage clamping diodes

A prototype of voltage-source soft-switching PWM inverter-type auxiliary resonant bridge-leg link snubbers is proposed with bidirectional active power switches and voltage clamping diodes for a new high-power high-voltage application. The voltage clamping diodes in the active resonant snubber are more effective in protecting the bidirectional active switches in the bridge-leg linked auxiliary resonant snubber from surge voltage spikes caused by energy stored in the auxiliary quasiresonant inductors and inductive parasitic wiring components. A variety of resonant snubber circuit topologies with voltage clamping diodes are presented and demonstrated. As an example of the variations of the proposed auxiliary active resonant-commutation snubber topologies, operation of a single-IGBT bidirectional switch with two voltage clamping diodes is analysed and discussed in detail for the auxiliary resonant bridge-leg link snubbers. The operating performance of the new active auxiliary resonant snubber-associated inverter-fed DC to DC power converter with voltage clamping diodes is practically demonstrated and evaluated to verify its effectiveness for a high-power high-voltage X-ray generator.