CPS-SPWM技术在级联H桥型变流器上的具体实现方法

CPS-SPWM技术是多重化技术和SPWM技术的有机结合。该技术能够在较低的器件开关频率下实现较高等效开关频率的效果,通过低次谐波的相互抵消提高等效开关频率,而不是简单地将谐波向高次推移,因而具有良好的谐波特性。具有独立电源的级联H桥多电平变流器具有每个H桥单元结构相同、所用元器件数少、易于实现电路的模块化设计和封装等一系列优点,因而在无功补偿和有源电力滤波器等领域有广泛的应用前景。重点提出了基于CPS-SPWM技术的级联H桥型多电平变流器,是CPS-SPWM技术与级联H型变流器拓扑结构的结合,同时具备二者的优点,在大功率变流器领域具有很好的应用前景。

Method of Implementing CPS-SPWM on Cascade H Bridge Converter

The operation principal of carrier phase-shifted SPWM (abbreviated as CPS-SPWM) has been analyzed. The key idea of this approach is the combination of multi-modular technique and SPWM technique. The high equivalent switching frequency can be obtained with low switching frequency devices. This technique improves the equivalent switching frequency through the counteraction of lower order harmonics but not simply through processing the harmonic from lower order to higher order, so that it is with a perfect performance on harmonic feature. In reactive power compensation and active power filter, cascaded H-bridge multilevel converter with separated dc sources seems to be the most feasible topology for many reasons. The cascaded converter is constructed with a number of identical H-bridges inverters. This modular feature makes the cascaded converter very attractive. The cascaded converter topology not only simplifies hardware manufacturability, but also makes the entire system flexible in term of power capability.