变频器的电压空间矢量调制控制技术研究

摘要

Compared with SPWM control, space vector modulation (SVM) control scheme utilizes the input dc bus voltage fully and is well suited for digital implementation. This paper researches on the voltage SVM and DSP based inverter which drives motors of variable-frequency air-conditioners in passenger trains. The inverter adopts open-loop operation mode in start-up and closed-loop regulation in steady state operation. The realization of constant V/F control and voltage closed-loop regulation is discussed. On the basis of table look-up method, the method of repetitive use of space vector is proposed, which can improve the switching frequency, decrease THD of low-frequency output voltage and save memory space. The model of SVM-based inverter is established by system identification and the digital voltage regulator is designed. Simulation and experiment tests of 40kVA principle prototype are carried out to verify the feasibility of the proposed control scheme.%和SPWM控制相比,空间矢量调制(SVM)技术对直流母线电压的利用率高,适合数字实现.本研究项目是为铁道客车空调机组供电的电压SVM控制变频电源,变频器采用开环起动和稳态电压闭环控制,讨论了恒定V/F控制和电压闭环调节的实现原理,在查表法的基础上提出"复用空间矢量法".该方法可以提高开关频率,降低低频输出电压的失真度并节省存储空间.通过系统辨识建立了电压空间矢量调制变频器的模型,设计了数字电压调节器.仿真和40kVA原理样机的实验测试结果证明所提控制方案可行.