多种特殊负荷集中区域电网的电能质量问题分析

甘肃电网作为西北电网的中心，其负荷分布具有特殊性。一方面，丰富的风力资源使千万千瓦级风电基地坐落于河西区域，另一方面，其在东西部交通运输中所承载的特殊地位使多条电气化铁路横贯整个甘肃电网。此外，各种大型钢铁企业也在甘肃区域电网集中分布。风力发电、电气化铁路以及冶炼负荷这些非线性、冲击性负荷在区域电网中的集中分布，可能给电网带来更加严重的电能质量问题，甚至影响电网的供电可靠性。系统对这三类特殊负荷的主要电能质量特性进行了介绍，利用PSCAD／EMTDC对甘肃电网某特殊负荷集中区域的电能质量问题进行仿真分析，对稳态极端工况以及暂态不同工况的仿真结果表明了这些特殊负荷接入对甘肃电网可能造成的影响，从而为电能质量治理及管理提供了参考依据，避免其可能带来的损失。

Analysis of Power Quality Problems in a Regional Grid with Many Types of Disturbing Loads

As the centre of northwest grid, the load distribution in Gansu grid has its specific characteristics. On the one hand, the kilowattslevel wind power bases are seated in Hexi area on account of its abundant wind resources ; on the other hand, several electric railways cross over Gansu grid for its spectial position in traffic. Besides, various kinds of large steel enterprises are intensive distributed in the reginal grid. The concentrated distribution of nonliner and impact loads such as wind power generation, electric railway and smelting loads will bring more serious power quality problems, even reduce the power supply reliability. The power quality characters of the three kinds of special loads mentioned above are introduced systematicly firstly. Then the power quality problems in a regional grid of Gansu which has many types of disturbing loads are analysed using PSCAD/EMTDC. The simulation results of steady state analysis in extreme conditions and transient state analysis in different operating modes show the possible power quality impacts caused by these loads when they accessing to Gansu Grid. The analysis results can provide references to power quality control and management, and avoid the possible losses.