基于条件成本收益分析的旋转备用优化配置

Optimal Configuration of Spinning Reserve Based on Conditional Cost/Benefit Analysis

电力系统需要权衡可靠性和经济性以实现旋转备用的优化。基于整体均值的传统可靠性评估方法和指标,将高损失—低概率事件与低损失—高概率事件同质化,无法反映决策者的风险偏好和关注的损失范围,也无法体现旋转备用配置对极端损失情形的敏感性。文中引入条件可靠性评估的方法和指标,建立条件成本收益分析模型,在决策者关注的风险范围内优化旋转备用。通过逐时段地进行时序解耦的机组组合,确定运行成本和开机方式;再对在线机组进行状态抽样,计算条件可靠性成本,确定使该时段条件总成本最小的条件最优旋转备用容量。最后,进行一次完整约束的机组组合,将备用要求分配至机组。算例表明,决策者的主观风险偏好对最优旋转备用方案有显著影响,随着关注的损失范围由整体平均转向极端不利,系统对旋转备用的需求持续提升,甚至超出现有装机容量的提供能力。

In power systems,in order to optimize the spinning reserve(SR),a trade-off between reliability and economy objectives is always needed.The methods and indices of traditional reliability assessment based on overall averages regard highdamage/low-probability events as commensurate with low-damage/high probability events,making it impossible to reflect the risk preference and the range of damages the decision-makers might particularly concern about;nor is it possible to reflect the sensitivity of SR configuration to the catastrophic generation deficits.This paper introduces conditional reliability assessment methods and indices,then develops a conditional cost/benefit analytic model,and optimizes the SR within the risk range of the decision-makers'concern.Firstly,a time-decoupled unit commitment(UC)is made hour by hour to determine the operating cost and dispatch schedule.Secondly,state sampling of the online units is made to calculate the conditional reliability costs.Then the conditional optimal SR capacity making the conditional total cost minimum in the said hour is found.Finally,the reserve is allocated to each unit by a UC with complete constraints.The case study shows that decision-makers'risk preferences have significant influence on the optimal SR:with the damage range concerned transferred from overall average to extreme adverse situations,the SR demand continually increases so much so that it may even go beyond the supply ability of the current installed capacity.