Impact of Demand and Price Uncertainties on Customer-side Energy Storage System Operation with Peak Load Limitation

This article investigates customer-side energy storage system operations to minimize the electricity bill under a peak load limitation constraint and uncertain environments. Specifically, it is discussed how the demand and price uncertainties impact the system performance. It is shown that the energy storage system operation based on the Markov decision process with stochastic information has near-optimum performance, which is achieved by an iterative method with perfect information when the electricity price and demand are slightly varied. To address a problem, such as the failure of peak load reduction due to high uncertainties, two heuristic methodologies are suggested by modifying the peak load threshold and the charge/discharge reservation quantity. It is demonstrated that the proposed approach can effectively manage the uncertainties with marginal performance degradation.     

一起相间接地短路故障引起的负荷损失事故分析

分析和研究了一起复杂相间接地短路故障引起的大量负荷瞬间损失事故。根据能量管理系统（energy management system,EMS）的事故追忆、功角测量装置（phasor measurement unit,PMU）的波形及故障录波,对事故过程和原因进行了分析。得出负荷损失的主要原因是系统电压在事故过程中瞬间降低,用户侧设备低压、失压保护或脱扣装置动作跳闸所致。采用BPA分析计算软件,对事故进行了模拟仿真,仿真计算结果与实际故障时所采集到电压变化曲线趋势及规律基本一致。最后,对类似事故的防范措施及用户侧低压、失压脱扣装置的管理工作提出了建议。