基于电力支撑的新型电力系统电力电量平衡

Electric power-energy balance in new-type power system based on power support

可靠的电力支撑是电力系统安全稳定运行的重要基础。各类电源的可靠电力支撑作用是指在其可靠电力范围内,可根据系统负荷需求随时满发顶峰。本文提出基于可靠电力支撑的电力电量平衡计算方法,总体计算框架为结合电源装机和系统负荷需求进行备用及机组检修安排,在此基础上通过电力平衡确定各类电源各月(或旬、或周)的可靠电力支撑,进一步进行全年8760 h的电力电量平衡模拟,模拟思路为在满足各类电源最小技术出力或强迫出力前提下,尽量为风、光让出位置,在负荷高峰且风、光出力小时发电顶峰,总体实现各时刻电力电量平衡且尽可能吸纳风光。利用本计算方法分析山西电网不同抽水蓄能规模下的电力电量平衡,并分析了风电不确定性对电力电量平衡的影响,结果显示系统抽水蓄能增加将替代部分火电容量并增加抽水电量,从而增加新能源吸纳;若过多考虑风电的电力支撑,一旦风电受天气等影响降低出力,火电、水电等满发也难以满足负荷需求,将直接影响电力系统安全稳定。

The reliable power supply is critical for the safe and steady operation of a power system.The reliable power support function of power supplies refers to the immediate full-load operation within its reliable capacity according to the load demand of a power system.This paper presents a calculation method of power-energy balance based on the reliable power support.The overall framework is to arrange the units on standby and in maintenance according to the power supply installation and system load demand.On this basis,the support capacity of each month(or week,or ten days)for various power sources was determined through power balance,and the annual 8760 h power-energy balance simulation was carried out.The simulation idea is to make room for wind and photovoltaic power as much as possible while meeting the minimum technical output or forced output of various power sources,so as to realize the overall power-energy balance at all time with the wind and photovoltaic power being absorbed as much as possible.This calculation method has been applied to an analysis of the Shanxi power grid with different scales of pumped storage plants,and the impact of wind power uncertainty on power-energy balance was evaluated.The results show the increase in the system’s pumped storage capacity will replace part of the thermal power capacity and increase the power for pumping,thus promoting the absorption of new energy sources.If the wind power committed too much as the power support role,in the case of wind power output is reduced by weather and other factors,the load demand could be difficult to be met even if the thermal power,hydropower and other kinds of power operate at full load,which suggests the harm to the safety and stability of power system.