基于功率波动和储能可用电量的直流微网改进动态下垂控制算法

Improved Dynamic Droop Control Algorithm Based on DC Microgrid Power Fluctuation and Available Power of Super Capacitor

传统下垂缺乏对电压偏离和分布式储能的灵活控制,对此提出一种直流微网改进动态下垂控制方法。首先构建余弦函数曲线特性的动态下垂系数,在功率波动增大时自动减小下垂系数,抑制母线电压波动;然后引入储能剩余可用电量,对下垂系数进行二次调整,保证直流系统稳定的基础上降低储能过充过放的风险;最后根据可用电量计算均衡系数,提高分布式储能的均衡效果。对3种不同下垂控制进行仿真对比,结果验证了该改进动态下垂控制策略的灵活性和可靠性。

Traditional droop lacks flexible control of voltage deviation and distributed energy storage.An improved dynamic droop control method for DC microgrid is proposed in this paper.Firstly,the dynamic droop coefficient of cosine function curve is constructed.When the power fluctuation increases,the droop coefficient is automatically reduced to suppress the bus voltage fluctuation.Then introduce the remaining available power for energy storage.The droop coefficient is adjusted twice to reduce the risk of overcharge and over discharge of energy storage on the basis of ensuring the stability of the DC system.Finally,the balance coefficient is calculated according to the available power to improve the balance effect of distributed energy storage.The simulation and comparison of three different droop controls have verified the flexibility and reliability of the improved dynamic droop control strategy.