基于改进时间延迟环节的集群电动汽车参与电网调频的动态特性研究

Research on Dynamic Characteristics of Electric Vehicles Participating in Frequency Regulation of Power System Based on Improved Time Delay

电动汽车数量的增多和其快速响应功率控制指令的优势使其在电力系统调频服务中得到广泛关注,从需求响应的角度看,考虑电动汽车参与系统调频的动态特性是增加电网弹性的有效途径之一。首先介绍了集群电动汽车参与电网调频的分层分布式控制的结构框架与市场机制;其次,基于集群电动汽车的动态响应模型,建立了基于改进时间延迟环节的集群电动汽车参与电网一、二次调频的动态模型,讨论了集群电动汽车参与电网调频的时间延迟参数设置对于调频动态特性的影响。然后,提出了计及车辆限制和用户需求个体差异性的电动汽车参与电网调频的控制策略。最后,通过3个算例进行多场景定量模拟。仿真结果表明:相比于目前已有的电动汽车参与电网调频模型中参数普遍采用平均值的方法,文中所建立的一阶时滞模型更接近实际响应情况,且能抑制频率超调。

Electric vehicles(EVs) attract wide attention in frequency regulation service market because of its increase in quantity and fast response to power control instruction. From perspective of demand response, taking the dynamic characteristics of EVs participating in frequency regulation into account is an effective way to increase grid resilience. Firstly, the framework and operation mechanism of centralized control of EVs in power system are presented. Secondly, based on the basic dynamic model of EVs, a dynamic model of EVs participating in frequency regulation of power system, using improved time delay, is established. Then the impact of time delay on frequency regulation is discussed. After that, the control strategy considering differences between vehicle constraints and users’ demands is proposed. Finally, the proposed model is implemented in three case studies. Results show that the established first-order delay model is closer to actual response and can greatly reduce phenomena of frequency overshoot compared to existing method with EVs participating in frequency regulation of power system with average parameters.