In this paper,an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load a...In this paper,an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load and PV power variations in a stand-alone DC microgrid.The strategy includes primary and secondary control.Among them,the primary control suppresses the DC microgrid voltage fluctuation through the I and II section control,and the secondary control aims to correct the P-U curve of the energy storage system and the PV system,thus reducing the steady-state bus voltage excursion.The simulation results demonstrate that the proposed control strategy effectively achieves SOC balancing and enhances the immunity of bus voltage.The proposed strategy improves the voltage fluctuation suppression ability by approximately 39.4%and 43.1%under the PV power and load power fluctuation conditions,respectively.Furthermore,the steady-state deviation of the bus voltage,△U_(dc) is only 0.01–0.1 V,ensuring stable operation of the DC microgrid in fluctuating power environments.展开更多
在“碳达峰•碳中和”国家能源战略变革背景下,大规模可再生能源的加速并网加剧了电力系统对于快速调频资源需求的迫切性,如何充分发挥以电池储能系统(battery energy storage systems,BESS)为代表的新型快速资源在电网调频中的作用是解...在“碳达峰•碳中和”国家能源战略变革背景下,大规模可再生能源的加速并网加剧了电力系统对于快速调频资源需求的迫切性,如何充分发挥以电池储能系统(battery energy storage systems,BESS)为代表的新型快速资源在电网调频中的作用是解决该问题的关键。首先,为满足电网各类型调频资源在自动发电控制(automatic generation control,AGC)系统中的接入监视与分类决策需求,提出“域-群-机”三级控制模型架构;然后,从BESS的荷电状态(state of charge,SOC)主动管理出发,提出基于改进的动态调频容量(dynamic available AGC,DAA)的多元集群协同控制策略,以及引入SOC影响因子的多点BESS功率分配策略;最后,结合实际电网的持续扰动工况及模拟跳机扰动工况进行仿真分析,验证了文中所提控制策略的有效性。文中所提策略不但可以显著改善各单点BESS的SOC一致性,而且能够提升电网调频品质。展开更多
基金supported by the NationalNatural Science Foundation of China(No.52067013)the Natural Science Foundation of Gansu Province(No.20JR5RA395)as well as the Tianyou Innovation Team of Lanzhou Jiaotong University(TY202010).
文摘In this paper,an improved sag control strategy based on automatic SOC equalization is proposed to solve the problems of slow SOC equalization and excessive bus voltage fluctuation amplitude and offset caused by load and PV power variations in a stand-alone DC microgrid.The strategy includes primary and secondary control.Among them,the primary control suppresses the DC microgrid voltage fluctuation through the I and II section control,and the secondary control aims to correct the P-U curve of the energy storage system and the PV system,thus reducing the steady-state bus voltage excursion.The simulation results demonstrate that the proposed control strategy effectively achieves SOC balancing and enhances the immunity of bus voltage.The proposed strategy improves the voltage fluctuation suppression ability by approximately 39.4%and 43.1%under the PV power and load power fluctuation conditions,respectively.Furthermore,the steady-state deviation of the bus voltage,△U_(dc) is only 0.01–0.1 V,ensuring stable operation of the DC microgrid in fluctuating power environments.
文摘在“碳达峰•碳中和”国家能源战略变革背景下,大规模可再生能源的加速并网加剧了电力系统对于快速调频资源需求的迫切性,如何充分发挥以电池储能系统(battery energy storage systems,BESS)为代表的新型快速资源在电网调频中的作用是解决该问题的关键。首先,为满足电网各类型调频资源在自动发电控制(automatic generation control,AGC)系统中的接入监视与分类决策需求,提出“域-群-机”三级控制模型架构;然后,从BESS的荷电状态(state of charge,SOC)主动管理出发,提出基于改进的动态调频容量(dynamic available AGC,DAA)的多元集群协同控制策略,以及引入SOC影响因子的多点BESS功率分配策略;最后,结合实际电网的持续扰动工况及模拟跳机扰动工况进行仿真分析,验证了文中所提控制策略的有效性。文中所提策略不但可以显著改善各单点BESS的SOC一致性,而且能够提升电网调频品质。
