200kW/400kHz固态高频感应加热电源

随着大功率半导体器件的发展,固态高频电源在容量和频率两方面都得到很大提高,除在一些特殊应用领域(如高频介质加热等行业)外,固态高频电源完全能取代电子管高频电源,而成为新一代感应加热电源的代表。本文以MOSFET作为逆变器的开关器件,以多管并联的方式开发出容量为50kW的单桥,然后以逆变桥并联的方式研制出200kW/400kHz的逆变器。设计了特殊的大功率驱动电路,实现了对器件多管并联的可靠驱动。采用PI控制的锁相环(PhaseLockedLoop,PLL)方法,实现了对负载频率的准确跟踪和对逆变状态的可靠控制,保证了逆变器的安全。采用高频变压器实现负载阻抗的匹配,不仅保证了逆变器的高输出功率,而且实现了逆变器之间的均流。

Development of 200kW/400kHz High Frequency Inverter for Induction Heating

With the development of semiconductor devices,great improvement at capacity and frequency of solid-state high frequency power supply has been achieved and solid-state high frequency power supply can replace the vacuum tube based high frequency power supply except some special application field(for example,dielectric heating and so on).In this paper,a 200kW/400kHz inverter which adopt MOSFET as switch devices and is composed of four inverter bridges with capacity 50kW is developed.A special high power drive circuit is developed to drive paralleled devices.A Phase Locked Loop(PLL) with PI controller is adopted to tracking the load frequency and controlling the inverter mode,which guarantee the safety of the inverter.By adopting high frequency transformer the impedance matching and sharing current among inverters are achieved.