基于固态变压器直流侧电压平衡控制的SVPWM算法

SVPWM With Voltage Balance Control in DC Side Based on the Solid-State Transformer

固态变压器作为能源互联网的核心设备具有电压等级转换和隔离的功能,可以有效地整合分布式可再生能源,但模块级联H桥型固态变压器也存在各个H桥模块之间的均压问题。本文首先研究了单相任意单元数级联H桥固态变压器的SVPWM及其电压平衡控制原理,提出一种固态变压器电压环控制一个H桥直流母线电压,然后通过在SVPWM中增加一个新控制环控制其他H桥的矢量脉冲宽度,从而使其他H桥电压跟随的控制策略来实现各个H桥均压的目的。最后通过仿真验证了所提控制策略的正确性。

Solid-state transformer has the function of conversion and isolation in different voltage grade as the important equipment of energy internet, and it can integrate distributed renewable energy effectively, but also has some imbalance problem in voltage. At first, the SVPWM of single-phase solid-state transformer cascaded by arbitrary number of H bridge and the principle of voltage balance control are studied in the paper. Then, a control strategy which control one of H bridge＇s voltage through solid-state transformer voltage control loop is proposed, and this strategy control other H bridge＇s voltage to follow master H bridge by adding a new control loop in the SVPWM which control the vector pulse width of each slave H bridge. Finally, the simulation verifies the correctness of strategy proposed.