Laknath Gamage

Series load resonant phase shifted ZVS-PWM high-frequency inverter with a single auxiliary edge resonant AC load side snubber for induction heating super heated steamer

In this paper, a phase shifted PWM controlled full bridge-type series load resonant high-frequency inverter using the IGBT power modules is presented for innovative induction heating applications such as hot water producer, steamer and super heated steamer. The bridge arm side passive capacitor snubber and AC load side active edge resonant snubber-assisted series load resonant soft switching inverter with a phase shifted PWM scheme is evaluated and discussed on the basis of the simulation and experimental results. It is proved from a practical point of view that new multi resonant inverter topology including the improved inverter modifications can expand soft switching area even under low power setting ranges, which is more suitable for induction heated dual packs fluid heater.

Pulse width and pulse frequency modulation pattern controlled ZVS inverter type AC-DC power converter with lowered utility AC grid side harmonic current components for magnetron drive

The grid voltage of commercial utility power source in Japan and USA is 100 V, but in China and European countries, it is 200 V. In recent years, in Japan, 200 V output single-phase three-wire power systems have begun to be used for high power applications. In 100 V utility AC power applications and systems, an active voltage clamped quasi-resonant inverter circuit topology using IGBTs has been effectively used so far for the consumer microwave oven. In this paper, the authors present a half bridge type voltage-clamped high-frequency inverter type AC-DC power converter using which is designed for consumer magnetron drives used in consumer microwave ovens on 200 V utility AC power systems. This zero voltage soft switching inverter can use the same power rated switching semiconductor devices and three-winding high frequency transformer as those of the active voltage clamped quasi-resonant inverter using the IGBTs that has already been used for 100 V utility AC power sources. The operating performances of the voltage source single ended push pull type inverter are evaluated and discussed for a consumer microwave oven. The harmonic line current components in the utility AC power side of the AC-DC power converter operating at ZVS-PWM strategy were reduced and improved upon the basis of sine wave like pulse frequency modulation and sine wave like pulse width modulation for the utility AC voltage source.

High efficient series resonant high frequency inverter with ZCS-pulse density modulation for copy machine fixing roller in office information and automation applications

This paper presents the two lossless auxiliary inductor assisted voltage source type half bridge series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. This high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide power regulation ranges and load variations under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally presented for a constant high-frequency PDM control strategy under a ZCS operation commutation, together with its output effective power regulation characteristics-based on the PDM strategy. The experimental operating performances of this voltage source ZCS-PDM high frequency inverter using IGBTs are illustrated as compared with computer simulation ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The effectiveness of this high frequency inverter appliance is proved from the practical point of view.

Boost transformer linked full bridge soft-commutation DC-DC power converter with secondary-side phase-shifted PWM rectifier switches

This paper presents a novel circuit topology of a voltage source type zero voltage soft-switching full bridge inverter DC-DC power converter with an isolated high-frequency transformer link this power converter incorporates zero-current soft-switching (ZCS) mode phase-shifted PWM active power switches in series with diode into two diode arms of full-bridge rectifier or center-tapped rectifier in transformer secondary-side. This isolated DC-DC power converter circuit can achieve ZVS/ZVT transition commutation for non-controlled active power switches in the primary side of transformer and ZCS/ZCT transition commutation for phase-shifted PWM active power switches in the secondary side of transformer, which can operate under wide load variations from a light load to a heavy load as well as a condition of PWM voltage regulation strategy.

A novel zero-voltage and zero-current soft-switching PWM DC-DC converter with reduced conduction losses

A novel zero-voltage and zero-current soft-switching PWM DC-DC converter with low conduction losses is presented in this paper. A new interleaved two switch forward converter topology is developed to minimize circulating current with no additional auxiliary circuits. This converter has many advantages such as less components, better efficiency, high power density and cost effectiveness for high power applications. The principle of operation is illustrated together with steady-state analysis. Moreover, the effectiveness of the proposed converter topology is verified by implementing a 500 W-100 kHz breadboard.

Transformer parasitic parameters and lossless inductive snubber assisted zero current soft switching DC-DC converter for high power magnetron drive

This paper presents a novel prototype of a high-frequency transformer parasitic parameter and a lossless inductive snubber assisted series-resonant ZCS-PFM DC-DC power converter, which is designed for high power magnetron. When a conventional series-resonant PFM DC-DC converter is designed for magnetron drive, it is very difficult to implement zero current soft switching commutation due to the influence of the magnetizing current through a high-frequency transformer. In order to implement soft switching commutation, the new topology that can actively utilize the magnetizing current is proposed and discussed on the basis of simulation and experimental results.

Performance evaluations of high-frequency inverter-linked DC/DC converter with noncontact pickup coil

This letter presents performance evaluations of an inductive coupling power transferring system using a current-source high-frequency transformer resonant inverter which is designed for an electric conveyance. The performance is evaluated on the basis of circuit analysis and feasible experiments. This power conversion system can implement an innovative noncontact power transfer from the viewpoints of less maintenance, controllability, safety, and clean performance.

Cost effective soft-switching PWM high frequency inverter with minimum circuit components for consumer induction heater

This paper presents a novel prototype soft-switching PWM high frequency inverter with minimum circuit components, which can achieve the wider and more stable soft commutation, simpler circuit configuration, smaller size, lower cost and higher-efficiency as compared with active voltage clamped ZVS-PWM and single-ended ZVS-PFM high frequency inverters developed previously. This quasiresonant soft-switching PWM high frequency inverter operating under ZVS and ZCS arms-related soft commutation is including the voltage-clamped ZVS-PWM inverter in the constant frequency variable power scheme as well as a single-ended ZVS-PFM inverter. The operation principle of soft switching PWM high frequency inverter treated here is described on the basis of the simulation and experimental results, together with its comparative operating performances in steady state. The practical effectiveness of a novel type high frequency soft-switching PWM inverter using state-of-the-art IGBT power modules is actuary proved for consumer induction heated appliances as cooker, super heated steamer and hot water producer.

Series resonant high frequency inverter with zero current switching pulse density modulation for induction heated load

This paper presents the two lossless auxiliary inductor assisted voltage source type half bridge series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. This high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide power regulation ranges and load variations under its constant frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally presented for a constant high-frequency PDM control strategy under a ZCS operation commutation, together with its output effective power regulation characteristics-based on the PDM strategy. The experimental operating performances of this voltage source ZCS-PDM high frequency inverter using IGBTs are illustrated as compared with computer simulation ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The effectiveness of this high frequency inverter appliance is proved from the practical point of view.

Transformer parasitic parameter and lossless inductive snubber assisted zero current soft switching power supply for power microwave generator

This paper present a novel prototype of a high-frequency transformer parasitic parameter and a lossless inductive snubber assisted series-resonant ZCS-PFM DC-DC power converter, which is designed for high power magnetron. When a conventional series-resonant PFM DC-DC converter is designed for magnetron drive, it is very difficult to implement zero current soft switching commutation due to the influence of the magnetizing current through a high-frequency transformer. In order to implement soft switching commutation, the new topology that can actively utilize the magnetizing current is proposed and evaluated the performance in the prototype of power microwave generator.