基于功率突增的稳控切负荷策略研究

Study of Load Shedding Strategy for Stability Control Based on Power Surges

随着国家经济水平的不断提高,电网的用电负荷不断增加,同时用户对供电可靠性的要求也越来越高,DL 755—2001《电力系统安全稳定导则》(安稳导则)和599号令分别从电网安全稳定和供电可靠性角度对电网规划、系统运行与控制等方面提出了严格的要求。但是由于电网网架结构复杂和断面功率传输大,电网发生故障情况下,将导致断面超极限以及地区电网电压稳定性和频率稳定性问题,采用传统的稳控切负荷策略配合困难以及策略复杂甚至可能导致过切,传统的稳控切负荷方案已不满足要求。通过对电网故障情况进行分析,找出电网故障时的共性,提出功率突增的概念,结合断面功率突增的特性提出基于功率突增的稳控切负荷方案。运用PSASP程序对某电网进行模拟仿真分析,验证在保证电网安全稳定运行前提下,所提出的切负荷方案能有效减少切负荷量且切负荷策略简单,各参数整定容易,具有重要的实用价值。

With the constant improvement of national economy, the customers' load in power grid is increasing, meanwhile, there are more requirements from users about the power supply reliability, and DL 755-2001《guide on security and stability for power system》(guide on security and stability) and decree 599 put forward strict requirements to power grid planning, system operation and control, etc. from the perspective of power grid security and stability and power supply reliability respectively. However, due to the complex grid structure of the power grid and the large interface power transmission capacity, when power grid fault occurs, it will lead to the cross-section go beyond the limit and result in the problems such as voltage stability and frequency stability in regional power grid. It is difficult for traditional load shedding strategy for stability control to cooperate and its complicated strategy may even lead to over shedding, so the traditional load shedding strategy for stability control does not meet the requirements. Through the analysis of power grid fault, the commonness of power grid fault is found out, the concept of power surges is put forward, and in combination with the characteristics of the cross-section power surges, the load shedding strategy for stability control based on power surges is proposed. Simulation analysis of a power grid is made by using PSASP program, which proves that on the premise of ensuring safe and stable operation of power grid, the proposed load shedding strategy can effectively reduce load shedding, and the load shedding strategy is simple and the parameters setting is easy, and it has important practical value.