多电平变流器空间矢量和载波调制策略等效关系研究

Multilevel converter is widely researched in high voltage high power area now. The most widely used two kind PWM methods are carrier-based pulse width modulation (CBPWM) and space vector pulse width modulation (SVPWM) in multilevel converter. The process of the CBPWM is simple and easy to implement, but it can not reduce the switching loss and improve the utilization of DC voltage flexibly; The modulation effect of the SVPWM is preferable than the CBPWM. But the SVPWM is difficult to calculate and programming, not easy to expand. When the level of the number is greater than 5, it is seldom used. In fact, the two modulation methods essentially exist certain equivalent relation. If it can achieve the unity of the CBPWM and the SVPWM, through the CBPWM modulation method is simple and easy to realize the SVPWM modulation effect, then the SVPWM can be applied to an arbitrary level. The CBPWM has a lot of control freedom degree ,the SVPWM has many kinds of realisation methods.Furthermore, the essential significance of the various control method of multilevel converter by the CBPWM and the SVPWM will be understood and the optimized control method will be presented by doing that. The project will research the relationship between the SVPWM and the CBPWM with arbitrary segment output sequence for three phase multilevel voltage source inverter, multi-phase multilevel voltage source inverter, multilevel AC/AC matrix converter, multilevel current source inverter. The research will enhance the application capability of multilevel converter in the field of high-voltage large-capacity and has very important research value and application prospect.

多电平变流器近年来成为研究热点。载波调制(CBPWM)和空间矢量调制(SVPWM)是多电平变流器广泛采用的调制方法，载波调制容易实现易于扩展，但不能灵活降低开关损耗和提高直流电压利用率；空间矢量调制性能优越，但计算复杂，电平数大于5很少采用。实际上，这两种调制方法本质上存在一定等效关系，如果能建立CBPWM和SVPWM的统一，则可以理解通过CBPWM和SVPWM实现的各种多电平变流器控制方法的本质意义实现控制调制的优化，通过易于实现的CBPWM实现SVPWM的调制效果，将SVPWM推广到高电平。CBPWM具有多个控制自由度，SVPWM具有多种实现方式，本项目欲研究主流应用的三相多电平电压型逆变器、多相电压型多电平逆变器、多电平AC/AC变流器和多电平电流型变流器任意段输出序列SVPWM与CBPWM的等效关系，该研究对增强多电平变流器在中高压领域应用能力，具有十分重要的理论价值和应用前景。

多电平变流器近年来成为研究热点。载波调制(CBPWM)和空间矢量调制(SVPWM)是多电平变流器广泛采用的调制方法，载波调制容易实现易于扩展，但不能灵活降低开关损耗和提高直流电压利用率；空间矢量调制性能优越，但计算复杂，电平数大于5很少采用。实际上，这两种调制方法本质上存在一定等效关系，如果能建立CBPWM和SVPWM的统一，则可以理解通过CBPWM和SVPWM实现的各种多电平变流器控制方法的本质意义实现控制调制的优化，通过易于实现的CBPWM实现SVPWM的调制效果，将SVPWM推广到高电平。CBPWM具有多个控制自由度，SVPWM具有多种实现方式，本项目研究主流应用的三相多电平电压型逆变器、多相电压型多电平逆变器、多电平AC/AC变流器和多电平电流型变流器任意段输出序列SVPWM与CBPWM的等效关系，该研究对增强多电平变流器在中高压领域应用能力，具有十分重要的理论价值和应用前景。