基于滞环控制的电压型变流器开关频率分析

Switching Frequency Analysis of Voltage Source Converter Based on Hysteresis Current Control

滞环控制方法存在开关频率变化不定的缺点。该文结合单相H桥和三相桥式变流器等电压型改换流器所共有的半桥单元电路模型,通过研究其滞环电流跟踪控制的物理过程和开关频率的变化机理,对开关频率的影响因素进行理论分析,给出了定量分析方法和计算公式,便于变流器控制系统的器件选择和参数设计。通过计算机仿真波形证实了理论分析方法和定量分析结果的正确性。

Hysteresis control has disadvantage of unstable switching frequency. Influencing factors on the switching frequency are analyzed theoretically in this paper, also the related quantitative analysis method and formula are given by researching the physical process and switching frequency unstable mechanism of hysteresis current tracking control, which are combined with the common half bridge model of the single phase H-bridge and three phase converter. So it can be easier for choosing the equipments and designing the parameters of the converter control system. The validity of theoretic analyzing method and quantitative result are verified by simulations.