【作者】 蒋炜炜；

【导师】 沈锦飞；

【作者基本信息】 江南大学 ， 电力电子与电力传动， 2008， 硕士

【摘要】 本文从感应加热基本原理出发,概述了感应加热技术的现状及发展趋势,在分析串联谐振逆变器各种功率控制策略原理及优缺点的基础上,对于移相调功轻载时的缺陷,本文将有限双极性PWM法引入逆变器轻载时的输出控制,通过DPLL锁相,使滞后桥臂的电压与电流始终保持一定的相位,同时结合非轻载时移相功率调节良好的特性,提出了一种基于DSP的新型功率控制策略,克服了传统移相全桥的缺点,使得高频逆变电源在轻载条件下仍能实现软开关,且轻载时电流连续调节范围广,三角畸变程度轻于PSPWM,大幅度的扩大了负载的适用范围,提高了电源整机效率。在对新型PWM功率控制串联谐振逆变器工作过程进行分析的基础上,解决了所有开关管的软开关问题;并通过分析功率输出单元的输出电压、电流、功率等,进而得到一个脉冲周期的输出电压、电流及功率的计算式。在这些理论分析的基础上,本文设计了基于新型PWM功率控制策略的感应加热电源实验系统,对主电路各元器件进行了精确计算与设计,设计了以TMS320LF2407A为核心的控制与保护电路,并对DSP外围电路进行设计,同时编写了基于新型PWM功率控制策略,以数字环相环及功率控制算法为核心的DSP程序,相关的仿真与实验系统得到的输出波形很好的验证了新型PWM控制策略的可行性。更多还原

【Abstract】 First, this paper gives a brief introduction to the basic theory of induction heating and outlines the development and the status of the induction heating technique. Based on the analasys of all kinks of power modulation strategies of series resonant inverters, a new power modulation strategy called Limited Double-polarity&PSPWM is presented, which regulates output power of inverters by regulating both pulse-width and phase-shift angle. When compared with Limited Double-polarity only schemed inverters, the Limited Double-polarity&PSPWM schemed inverters achieve continuous power regulation and more steady output current, continuous power regulation, and operating in continuous current mode (CCM); When compared with PSPWM only schemed inverters, new schemed inverters have smaller phase-shift as well as hardly any distortion in output current. Even working under light load status, the inverter can realize quasi-sinusoid output current waveform with less fluctuation in peak value.On the basis of elaborate analysis to working process of Limited Double-polarity &PSPWM controlled inverter, soft-swiching of all four swiches is achieved. Formulas in calculating output voltage, current and power in one PWM cycle are aquired by analyzing one power outputing cycle. An experimental induction heating system is designed to illustrate the feasibility of the new power regulating strategy, of which every part in main circuit as well as the control system consists of DPLL and so on is designed. The experimental results illustrat the favorable performance of the new power regulating strategy.更多还原