无极灯用LCCL谐振变换器特性分析与研究

Analysis and Research of LCCL Resonant Converter for Electrodeless Lamps

提出一种适合于无极灯负载特性的LCCL谐振变换器。针对该变换器和无极灯负载,推导出负载变化时谐振回路固有谐振频率表达式,得到不同负载和谐振参数下谐振回路电压增益特性、稳态时最大功率输出条件以及开关管实现零电压开关(ZVS)的临界条件,分析了谐振回路中各参数变化对谐振电路特性和开关管ZVS的影响,在此基础上提出了一种兼顾最大输出功率和开关管ZVS限定条件的谐振参数设计方案。该设计方案保证当电路固有谐振频率发生一定改变时,开关管依然可以实现ZVS,有效地减少了开关损耗。最后设计了一台85W的原理样机,实验结果验证了所提方案是可行的。

A LCCL resonant converter topology for electrodeless lamp is presented. Dedicating to the converter and load characteristic, a resonant frequency expression is derived. Voltage gain with different loads and parameters is given. At stable state, maximum output power condition and zero voltage switching(ZVS) qualification are obtained specializing for design. The effect of the variations of parameters on resonant characteristic and ZVS are analyzed. To ensure ZVS and reduce the switching loss when the inherent resonant frequency is changed, a parameter design method balanced the maximum power and ZVS qualification is proposed. A 85 W laboratory prototype was built. Experimental results were proposed to confirm validity of the method presented.