Atsushi Okuno

Feasible development of soft-switched SIT inverter with load-adaptive frequency-tracking control scheme for induction heating

This paper describes the latest feasible developments of a voltage-source-type series-capacitor-commutated load-resonant high-frequency bridge inverter using static induction transistors (SITs) for industrial induction-heating and melting applications. A load-adaptive variable-frequency tuned controller, composed of a phase-locked loop integrated circuit (PLLIC) device, a pulse amplitude modulation (PAM) power controller employing a phase-controlled AC/DC converter, and protective control schemes for overvoltage and/or overcurrent generation, is also demonstrated for this series resonant inverter. In addition to these, a short-circuit test of a high-power SIT incorporated into the bridge leg high-frequency series resonant inverter is carried out from a practical point of view and evaluated, in order to obtain important design data considering reliable switching characteristics of large-capacity SITs and to realize cost-effective protective circuits for SITs.

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.

An improved zero voltage soft switching PWM high-frequency inverter with active inductor snubber for induction heated roller

This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.

Electromagnetic induction eddy current-based far infrared rays radiant heater using soft switching PWM inverter with duty cycle control scheme

This paper presents an innovative prototype of a new electromagnetic induction eddy-current heated type far infrared rays radiant heating appliance using the voltage-fed edge-resonant ZVS-PWM high frequency inverter using IGBTs for food cooking and processing. This soft switching inverter can operate under a constant frequency variable power regulation scheme in order to heat the spiral planar induction heater made of the stainless steel plate. This power electronic appliance with soft switching high frequency inverter using IGBTs has attracted special interest from some advantageous viewpoints of safety, cleanliness, compactness and rapid temperature response, which is more suitable for consumer power electronics applications.

High frequency eddy current-based far infrared rays radiant heater using zero voltage soft switching inverter with asymmetrical PWM implementation

This paper presents an innovative electromagnetic induction eddy current heated type far infrared rays radiant heater using the voltage-fed edge-resonant ZVS-PWM high frequency inverter for food cooking and processing. Its operating principle is described. Its operating performances such as the voltage and current peak stress. soft switching condition, and power regulation are illustrated on the based of duty cycle time ratio control strategy due to asymmetrical PWM scheme. The effectiveness of the electromagnetic induction eddy current based for infrared radiant heater using the soft switching inverter is treated here.

Latest electromagnetic induction-based fluid-heating appliance using voltage-source series loaded-resonant pulse-width modulation high-frequency inverter

This paper presents a prototype of a new concept of electromagnetic inductionbased fluid heating appliance using a voltage-source type series capacitorcompensated load-resonant high-frequency inverter using IGBT modules, which incorporates a phase-shifted pulse-width modulation (PWM) power regulation scheme. Proposed are also the load-resonant and quasi-resonant hybrid circuit topology of the voltage-fed soft-switching PWM inverter with inductive and capacitive hybrid lossless snubbers. In addition, some new types of electromagnetic induction heater to produce hot water, hot dry air and hightemperature superheated steam vapour are demonstrated. The feasible appliance employing the inverter mentioned above for electromagnetic induction-based liquid heating or gas heating is implemented from a practical point of view, along with the steady-state operating principle of this inverter system in addition to its remarkable features. The steady-state and dynamic-state operating characteristics of this high-freque...

Power transmission characteristics of inverter-fed noncontact pick-up coil

A noncontact power delivering system using high-frequency inverter is an electric power transmission equipment implemented under principle of noncontact magnetic inductive coupling. This power delivering scheme enables innovative electric power supply systems for the vehicles, carriers and battery charger as well as electric double layer energy storage capacitor charger in the view point of maintenance free, safety and clean performance as compared with a performance of conventional trolly. The purpose of this research is to discuss the noncontact electric power transmission characteristics through circuit analysis, magnetic analysis and feasible experiments.