输入串联输出串联逆变器系统的控制策略

Control Strategy of Input-series Output-series Inverters System

针对一种结构新颖的输入串联输出串联逆变器系统分析了其输入均压与输出均压的关系。指出该逆变器系统的控制目标是要在实现输入均压的同时,实现输出均压。基于这一控制思路,提出2种可使系统稳定工作的控制策略,即输入均压的控制策略和输入均压结合输出同角度的控制策略。前者在控制输入均压的同时,实现了输出有功功率的均衡,但无功功率未必均衡,所以该策略不能保证输出均压。后者引入了输出角度环,它与输入均压环共同作用,使系统在实现输入均压的同时,也使各模块的输出电压幅值和相位均相等,即实现了输出均压。研制了一台样机,对以上2种控制策略进行对比实验,验证了理论分析的正确性。

The relationship between input voltage sharing and output voltage sharing are analyzed in this paper about a novel configuration, namely the input-series and output-series inverters system. The paper points out that the control objective of the ISOS inverters system is to realize input voltage sharing and output voltage sharing. Based on the viewpoint two control strategies are proposed： the method of input voltage sharing and the strategy of input voltage sharing combined with the identical output angle. The former one can fulfill the balance of the output real power by controlling the input voltage sharing, whereas it can not always attain the balance of the output reactive power. That is, the strategy can not realize output voltage sharing. The latter strategy can not only achieve input voltage sharing, but make equal in magnitude and phase of output voltage of each module by the effect of the input voltage sharing loop in company with the output angle loop. So the strategy can accomplish input and output voltage balanced sharing. Last, the prototype is built and experimental results under two methods are compared to verify theoretical analysis.