风电潮流优化控制系统的超电容均压策略

Voltage Equalizing Strategy for Supercapacitor in Wind Power Flow Optimization and Control System

超级电容器是风电潮流优化控制系统中的关键储能元件之一,而高效可靠的串联均压策略是其实现中大功率场合应用的前提,为较好地实现均压效果,引入了一种超电容电压均衡控制策略的模型,并在此基础上提出了一种新颖的超电容电压均衡方法—相邻电感储能电压均衡法。该方法实时检测超电容组中各电容器电压,以电感为能量传递媒介,以半导体开关管为控制开关,将电压高的电容器能量转移到电压低的电容器中,实现了各超电容器的电压均衡。在详细介绍了该方法的工作原理后,给出了控制开关占空比的调节规律和电感参数的设计原则。最后,对两组串联超级电容器模块分别进行了仿真和实验,结果表明该方法极大地改善了超电容模块的电压一致性,电压均衡速度快、精度高,在风电潮流优化控制系统中有较高的应用价值。

The supercapacitor is one of key energy storage elements in wind power flow optimization and control system, while highly efficient and reliable voltage equalizing strategy is a precondition that the supercapacitor is used in middle and high-power applications. A model for supercapacitor voltage equalizing strategy is introduced in the paper, accordingly, a novel supercapacitor voltage equalizing method having fast equalizing speed and high equalizing precision, namely adjoining inductor voltage equalizing method is proposed. The method detects the voltage of each supercapacitor in real time, uses the inductor as energy transfer medium and uses the semiconductor switching device as control switch, which can transfer the energy in the capacitor with the higher voltage into that with the lower voltage. The working principle and the working process of the proposed method are analyzed in detail, then the rule to adjust duty ratio of control switch and the principle to choose parameter of inductor are presented. Finally, simulation analysis and experiment of the two modules composed of 12 supercapacitors are performed. Simulation and experiment results show that the adioining inductor voltage equalizing method reduces the voltage discrepancy between the supercapacitor modules, increases the average voltage of serial modules, and markedly improves the consistency of the module voltage. So the proposed voltage equalizing strategy has comparatively high practicable value in wind power flow optimization and control system.