蓄电池-超级电容混合储能系统控制方法研究

Comparison of control strategies in a battery/supercapacitor hybrid energy storage system

电池-超级电容半主动混合储能系统广泛应用于短时大脉动功率的场合。通过对电力电子设备的控制,可以对瞬时功率进行合理地分配,最终达到延长电池和超级电容使用寿命及提高系统输出性能的目标。低通滤波和移动平均是两种重要的功率分配方法,而更适用于脉动负载的方法至今还没有文献给出。选用电池直接并联流母线,超级电容通过双向直流-直流变换器接直流母线的半主动混合储能系统,分析和建立了基于移动平均和低通滤波控制的两种SAHS模型。在脉动负载下,比较了低通滤波和移动平均这两种控制算法。此外,还设计了超级电容的过压和欠压保护控制。研究表明,两种控制方法在脉动负载下都能很好地减小电池的电流波动,但是移动平均控制下的电池电流更平滑。同时,超级电容的保护控制也保证超级电容工作在正常的电压范围内。

A battery/supercapacitor hybrid energy storage system is widely used in many applications. The instantaneous power can be smoothed reasonably by the control of power electronic devices. So lives of batteries and supercapacitors can be extended and the output performance of system can be improved. Low pass filter and moving average both are very important power smoothing control methods, but the better one has not yet been given. Low pass filter and moving average control methods used in semi-active hybrid energy storage system were analyzed and modeled. The simulation results were compared in pulsed load power. Besides, the over and under protects of supercapacitor were presented in this paper. The results show that two control methods both decrease the current fluctuation, but the moving average control are better. At the same time, the protection control of supercapacitor ensured that the voltage was within the normal range.