出于高压隔离目的,大容量级联式电池储能系统中,一般采用光纤传输驱动脉冲信号。由于H桥单元个数众多,驱动脉冲数量庞大,为减少光纤使用数量,降低系统成本,提高工作可靠性,采用编解码技术,对多路脉冲驱动信号进行编码后通过一条光纤信号进行串行传输成为一种可行的解决方案。首先分析了PWM脉冲信号的产生算法,在此之上提出针对多路PWM脉冲进行编解码的算法,指定通信协议,采用光纤信号进行串行通信,并将该方案成功应用于一台6 k V,600 k W电池储能功率调节系统(PCS)中,实验结果表明采用该编解码方案使用一条光纤即可完成传统多路光纤传输任务,功率调节系统输出与理论分析一致,电压谐波含量低,并网电流正弦度高,验证了所提的脉冲编解码方案的正确性与可行性。
To isolate high voltage, optical fiber is applied to transmit the pulse signals of the switches in large capacity cascaded battery energy storage system. And since there are lots of pulse signals in the system, it is practical to encode the signals, which are transmitted by using serial communications by one fiber, so that the number of the fibers can be re- duced, the cost can be lowered, and the reliability can be improved. We firstly analyzed the generation of PWM signals, then researched the technique of using fiber optic serial communication to encode and decode multiple PWM pulse signals, which is validated in a 6 kV/600 kW battery energy storage power conditioning system (PCS). Experimental results indicate that coding scheme used in this article can complete tasks by using one optical fiber which may need lots of optical fiber in conventional way. The output of PCS is consistent with analysis of theory and achieving low harmonic distortion in voltage and current waveforms.