Daisuke Bessyo

Latest development of soft switching inverter power supply using active clamp scheme with a charge up function for magnetron drive

The oscillation voltage (Ebm) is an important parameter of the characteristic constants of a magnetron. When Ebm is made high, it serves so as to be able to improve the efficiency of a magnetron. Thus, the magnetron with 7% higher oscillation voltage than the former one is developed by Matsushita Electric Industrial Co.Ltd, In addition to this, the reduced harmonic type AC-DC converter suitable for driving this magnetron is proposed lately. This inverter type converter has the voltage-boost function of an active clamp scheme with soft switching pulse modulation strategy topology. This paper describes a novel type of active clamp AC-DC converter circuit and the operation of this converter which was developed. The operating characteristics of this soft switching converter are evaluated from a practical point of view as compared with the conventional converter.

Pulse pattern modulated soft commutation inverter-type AC-DC power converter with harmonic current components reduction in utility power side

In this paper, a circuit topology of a half bridge quasi-resonant ZVS-PWM high frequency inverter type AC-DC converter using IGBTs for the consumer magnetron drive is presented, which can use the high frequency high voltage transformer, voltage doubler and power semiconductor switching devices (IGBTs) used in active voltage clamped quasi-resonant PWM inverters suitable for 100 V utility AC power systems. The operating analysis and characteristic evaluations of a switching power supply converter circuit for a microwave oven in a 200 VAC utility power system used in Europe, China and Japan are discussed on the basis of simulation and experimental results. Moreover, a new 60 Hz sinewave partial pulse modulation pattern control scheme of the pulse operating frequency modulation and pulse width modulation is proposed and discussed in order to improve harmonic current components in 200 V utility AC power grid under a condition of the peak limitation of the magnetron anode current.