基于减载优先顺序的低周减载方案研究  

Research on Under-Frequency Load Shedding Scheme Based on Load Shedding Priority

作　　者：曾丕江 刘思呈 罗吉 李劲秋 张哲铭 石立宝 Zeng Pijiang;Liu Sicheng;Luo Ji;Li Jinqiu;Zhang Zheming;Shi Libao(Yunnan Power Dispatching Control Center,Kunming 650011,China;Shenzhen International Graduate School,Tsinghua University,Shenzhen 518073,China)

机构地区：[1]云南电力调度控制中心,云南昆明650011 [2]清华大学深圳国际研究生院,深圳518073

出　　处：《云南电力技术》2022年第4期20-25,共6页Yunnan Electric Power

摘　　要：低周减载是电力系统存在大量功率缺额时保持频率稳定、防止频率持续下降甚至系统崩溃的最主要措施之一。低周减载方案整定的关键环节在于切除负荷优先级别和减载容量的确定。提出采用基于灵敏度和基于相关度的减载优先度方法来确定低周减载方案整定中优先切除负荷的顺序。其中,基于灵敏度的减载优先度方法通过减载量与系统频率变化之间的关系推导得出;基于相关度的减载优先度方法则重点关注造成大量功率缺额的故障发电机组正常运行时的出力在各负荷之间的分配情况。在此基础上,提出基于求取近似解和精确解的两步法低周减载方案的整定流程。以中国云南电网为例,通过仿真对两种方法进行对比分析,结果表明,基于相关度的减载优先度方法得到的低周减载方案不论是暂态特性还是稳态特性均具有较好表现。Under-frequency load shedding(UFLS)is one of the most principal measures to maintain frequency stability and prevent successive frequency drop or even blackouts when there exists a large unbalanced power in the power system.The key points of setting UFLS scheme are to determine the priority level of load shedding and load shedding capacity.The load shedding priority methods based on sensitivity and relativity are proposed to determine the priority of load shedding in the setting of UFLS scheme,in which the sensitivity based method is derived from the relationship between the amount of load shedding and system frequency change;the relativity based method focuses on the distribution of output of the fault generator that causes large unbalanced power among loads during normal operation.On this basis,the setting process of UFLS scheme based on two-step method of solving approximate solution and exact solution is proposed.Taking the Yunnan power grid in Southern China as a case,the corresponding simulations and comparative analysis are carried out on these two methods,and the results show that the UFLS scheme obtained by the relativity based method has good performance in both transient and steady-state characteristics.

关 键 词：低周减载 减载优先度 灵敏度 相关度 频率稳定 

分 类 号：TM74[电气工程—电力系统及自动化]