PWM逆变器优化控制策略的分析研究

Analysis and Research on Optimized Control Strategy of PWM Converter

为防止逆变器同一桥臂的功率器件发生直通现象,通常是在 PWM 控制波中加人死区时间。PWM 控制信号中死区时间的存在,给变频器带来了很多不利的影响。在分析功率器件不同状态下电压源型 PWM 逆变器电流流向的基础上,提出一种基于负载电流检测的新型优化控制策略,不仅能够彻底消除死区时间,而且大大降低功率器件的开关损耗,提高变频器的转换效率。

In order to avoid conduction through of the power devices in the same bridge of converter, so normal inserted of dead time in the PWM waveforms. Kinds of problems are caused by this dead time. Based on the analysis of the current flow direction of voltage source PWM converter under different states of power devices, a novel optimized strategy based on current detection is proposed in this paper. Which can not only eliminate dead time completely but also reduce the switching loss largely. The inverter＇s efficiency can be improved as well.