高频软开关逆变器数学模型研究

分析了高频软开关逆变器-交流异步电动机构成的拖动控制系统,建立了该系统的数学模型,导出了谐振直流环节波形可靠回零所依赖的最小初始条件。即谐振电感具有最小初始电流I_(Lmin)(0),求出了要获得I_(Lmin)(0)时谐振电容短路开关所需的最小导通时间t_(1min)(0)。研究了负载条件变化对系统谐振特性的影响,其结论为:当直流电源内阻及谐振电感直流电阻足够小时,谐振直流环节谐振特性不仅与谐振参教L、C有关,而且亦强烈地依赖于负载电阻R_2。文中给出了仿真波形。

Study on Mathematical Models of High-Frequency Soft-Switched Inverters

In this paper, high-frequency soft-switched inverter AC induction motor drive systems are analyzed, the mathematical models of the systems are established, the minimal initial conditions for making resonant DC bus voltage return to zero volts during one oscillation period are derived, i.e.the resonant inductor has the minimal initial current ILmin(0), the minimal conducting time t1min of the oscillator switching device VT for obtaining the minimal initial current ILmin(0) of resonant inductor is found. The system oscillation characters under variable load conditions are studied. Of even greater importance is the conclusion that when internal resistance of DC voltage source and DC effective series resistance of the resonant inductor are smaller enough, the characteristic of resonant DC link not only relates to resonant element parameters L, C, but also depends on load resistance R2. The numerical analysis and simulation waveforms are given.