Srawouth Chandhaket

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.

A sinusoidal pulse width modulated inverter using three-winding high-frequency flyback transformer for PV power conditioner

This paper presents a novel prototype of the utility-interfacing sinusoidal pulse width modulation (SPWM) inverter using the high-frequency flyback transformer for the small-scale solar photovoltaic power conditioner (1 kW - 4 kW). The proposed SPWM power conditioner circuit with a high-frequency link has a function of electrical isolation, which is vital for PV power conditioner systems with the viewpoint of safety, noise requirement and convenience. The discontinuous conduction mode (DCM) operation of the flyback transformer link pulse modulation is also introduced to establish a simple topology of the inverter circuit and control scheme. The proposed PV power conditioner operates with ZVS when it turns off the primary-side switches by the high-frequency switching. This reduces the power losses of the semi-conductor device switchings and improves the power conversion efficiency of the total system as PV power processor. The operating principle of the proposed circuit is described for the understanding of the circuit parameters establishment. Then, the digital control scheme is demonstrated herein. The proposed power conditioner is verified on the basis of the computer simulations and experiments. The experimented results show the validity of the proposed power conditioner to have high power conversion efficiency and low harmonic distortions.

Utility-interactive solar photovoltaic power conditioner with soft switching sinewave modulated inverter for residential applications

A utility interactive sinewave pulse width modulation soft commutation inverter using trench-gate IGBTs for the solar photovoltaic power conversion conditioning and processing with a high frequency transformer link is presented for residential applications. As compared with the conventional full-bridge hard switching sinewave PWM inverter with a high frequency AC link, the simplest single-ended quasi-resonant soft switching sinewave modulated inverter with a sinewave duty cycle pulse control scheme is implemented, resulting in size and weight reduction, low-cost and efficiency. This paper presents a prototype circuit and system of the single-ended zero voltage soft switching sinewave PWM inverter for solar power conditioner, along with its operating principle and unique features. In addition to these, this paper proposes a control implementation to deliver high quality output current. Major design of each component and the power loss analysis under actual power conditioning and processing is also discussed and evaluated from an experimental point of view. A newly-developed utility-interactive sinewave power conditioning processor which has 92.5% efficiency at 4 kW output is demonstrated herein. It is designed for 540 mm-300 mm-125 mm in size and 20 kg in weight.

Three-level phase shift ZVS-PWM DC-DC converter with neutral point clamping diodes and flying capacitor for gas metal arc welding

This paper is concerned with some experimental results and practical evaluations of a three-level phase shifted ZVS-PWM DC-DC converter with neutral point clamping diodes and flying capacitor for a variety of gas metal arc welding machines. This new DC-DC converter suitable for high power applications is implemented by modifying the high-frequency-linked half bridge soft switching PWM DC-DC converter with two active edge resonant cells in high side and low side DC rails, which is previously-developed put into practice by the authors. The operating principle of the three-level phase-shift ZVS-PWM DC-DC converter and its experimental and simulation results including power regulation characteristics vs. phase-shifted angle and power conversion efficiency characteristics in addition to power loss analysis are illustrated and evaluated comparatively from a practical point of view, along with the remarkable advantageous features as compared with previously-developed one.

Utility-interactive high-frequency flyback transformer linked solar power conditioner for renewal energy utilizations

This paper presents a novel prototype of the utility-interactive voltage source type sinewave pulse modulated power inverter using a high-frequency flyback transformer link. The proposed power conditioner circuit for the solar photovoltaic generation and small scale fuel cell has an isolation function due to the safety of the power processing system, which is more cost effective and acceptable for the small-scale distributed renewal energy conditioning and processing systems. The discontinuous current mode (DCM) of this power processing conversion circuit is applied to implement a simple circuit topology and pulse modulated control scheme. Its operation principle is described on the basis of simulation evaluations and theoretical considerations. The simulation results obtained herein prove that the proposed inverter outputs with sinusoidal waveforms and unity power factor currents are synchronized to the main voltage in utility power source grid. In this paper, the soft switching topology of high-frequency linked sinewave pulse modulation inverter is proposed and discussed.

Cost effective PWM soft switching high voltage converter with utility AC side harmonic current reduction strategy for microwave oven

This paper presents a new topology of the voltage clamped ZVS-PWM high-frequency inverter-fed DC-DC converter designed for a consumer microwave oven to improve line current distortion and power factor in utility AC power side. Its operation principle in steady state is described. The pulse modulation pattern control implementation is discussed under a condition of allowable magnetron current 1.2 A and heater current.

Energy regenerating snubber assisted sinewave soft switching pulse modulation inverter for renewable and sustainable energy applications

This paper presents a novel prototype of the utility-interfaced soft-switching sinewave pulse modulated inverter using the three-winding high-frequency flyback transformer for the small scale distributed solar photovoltaic power conditioner, which is defined as a cycloinverter. It is noted that the sinewave pulse modulated output current of this inverter with a high-frequency transformer link is synchronous to the AC main grid voltage. The proposed sinewave inverter type power conditioner circuit with a high-frequency link has a function of electrical isolation, which is cost-effective and reliable for small-scale distributed renewal and sustainable energy utilization system from a safety point of view. The discontinuous pulse current mode (DCM) in the secondary windings of the flyback transformer is introduced to implement a simple circuit configuration and control scheme. The auxiliary power regenerating snubber circuits with power generating snubber are mathematically analyzed for the purpose of the parameter settings. Then, the performance of the proposed cycloinverter is evaluated and discussed on the basis of the computer-aid simulation results.

An active auxiliary resonant AC link snubber with a single active power switch for voltage source type soft switching sinewave PWM inverter

This paper presents a novel active auxiliary resonant AC link snubber for soft switching sinewave PWM inverter. Its operating principle is described for current source load model during one sampling period and the circuit design method of this resonant snubber is pointed out by using the operating data. The performance evaluations of single phase zero voltage type soft switching pulse modulated inverter employing an active auxiliary resonant AC link snubber with a single power switch is illustrated as compared with those of a hard switching PWM sinewave inverter.

Active resonant leg-link snubber-assisted three phase soft commutation PFC converter and its practical evaluations

This paper presents steady-state and transient-state performance evaluations of active auxiliary resonant commutation snubber (ARCS)-linked three-phase voltage source soft commutation PFC rectifier using a software control scheme which can operate under the conditions of ZVS on all main active power switches in three-phase bridge arm and ZCS on bi-directional auxiliary active power switches in ARCS. This soft switching PFC rectifier is discussed as compared with a three phase hand switching PFC rectifier. The total system performances of digitally-controlled three phase soft switching PFC rectifier with each phase ARCS, which implements instantaneous power feedback and DC voltage feedback control strategies are illustrated and evaluated on the basis of experimental and simulation results, together with power loss analysis.

A novel type suppressed noise peak dc-dc boost converter introducing delta-sigma modulation technique

Because of achieving high efficiency power conversion, switching power converters are widely used. About the switching power converters, pulse width modulation (PWM) technique is used to produce switching pattern. But this scheme causes large switching noise peak components at the multiple numbers of carrier frequency. And this raises problems of clearing noise regulations. This paper proposes a novel type dc-dc boost converter which is able to suppress switching noise components. The proposed converter introduces delta-sigma modulation circuit. To be used for dc-dc converter, delta-sigma modulation circuit is improved. And it is clarified that the proposed dc-dc converter can reduce switching noise components.