基于DPLL的高频逆变电源建模与研究

采用基于DSP的数字锁相环(DPLL)对高频逆变电源输出频率进行实时控制,可实现逆变器工作频率对负载谐振频率的同步跟踪,确保逆变器开关器件工作在零电压零电流软开关(ZVZCS)状态,显著减小功率器件的开关损耗和提高装置效率。本文以负载串联谐振逆变电源为模型,针对负载参数变化引起的固有谐振频率变化,导致逆变器效率降低及开关器件应力增加的普遍现象,提出一种基于DPLL控制的逆变电源。结合锁相环的数学模型,讨论了DPLL控制的逆变电源的数学建模,在Simulink环境中该电源的构筑及串联谐振负载的模型,给出了相应的仿真波形和实用电源试验波形,为分析和设计逆变电源提供了必要的理论依据。

Modeling and Research on HF-Inverter Power Supply based on DPLL

The Digital Phase-Locked Loop(DPLL)technology based on a Digital Signal Processor (DSP) is applied to control the operating frequency of an High-Frequency-Inverter (HF-Inverter) timely,so as to adapt varieties of the load reso-nant frequency to keep the inverter always working on Zero Votage-Zero Current Switching (ZVZCS) mode.Meanwhile,the losses of switching components are reduced obviously and the efficiency of the power is improved greatly on ZVZCS mode.In this paper,an induction heating power is designed taking the load series-resonant HF-Inverter model as an example.In consideration of the resonant frequency being changed by load parameter variation,which led the power efficiency reduc-tion and the stress increasing of switching components in a conventional inverter,a novel HF-Inverter based on DPLL is designed,and its mathematic models are setted up and simulated.The models of the proposed inverter and the series-reso-nant load are constructed in Matlab/Simulink environment.The corresponding waveforms of simulation and experiments are given.The results show that the control methods and the inverter models based on DPLL are reasonable and correct.It provides a useful and practical method to analyze as well as to design a DPLL controller in inverters.