【作者】 周红卫；

【导师】 余健明； 曾明；

【作者基本信息】 西安理工大学 ， 电气工程， 2007， 硕士

【摘要】 乌江渡30MW水轮发电机组独立地向三个铁合金厂供电,形成单机电网运行方式。但运行过程中出现发电机组的有功出力下降、功率因数很低、频率调节越限和整个电网电压水平严重偏低等问题。对此,本文首先从铁合金厂负荷(即矿热炉)和众多变压器的特性出发,分析乌江渡单机电网运行问题的主要原因是该系统的无功功率不足,估算出该系统的无功缺额,并初步提出无功补偿的多种方案,包括补偿地点、容量、方式等;然后,利用电力系统分析综合程序PSASP对该单机电网进行仿真,计算分析无功功率补偿前和各种补偿方案下整个电网的电压水平、功率因数和功率损耗等;最后,考虑到技术可行性、经济性和电网生产实际,对该电网选取当前合适的无功补偿方案,即在矿热炉变压器的高压母线上加装补偿电容器组,并给出相应的电容器、电抗器数值。按此方案,乌江渡30MW单机电网投运无功补偿成套设备以来,现场测试表明:相对于补偿前,电网电压得以大为提升并基本达到额定电压水平,同时发电机组的出力、功率因数提高,系统稳定性得到改善,电厂的发电效益和铁合金厂的经济效益显著。因此,无功补偿方案的选取和实施对保障乌江渡30MW单机电网的设备安全运行、稳定产品质量取得良好的技术经济效果。更多还原

【Abstract】 A 30 MW water-turbine generator set in Wujiangdu singly supplies power to three ferroalloy factories, which forms the operation mode of single-machine network. In the operation process, a series of problems occur such as active power declining, low power factor, frequency regulation fails and seriously low-level voltage. This paper firstly analyses the characteristics of many smelting electric furnaces and power transforms, and figures out that the main reason of occurring problems is lack of reactive power. At the same time, the paper estimates the number of reactive power lack, and preliminarily proposes various schemes of the reactive power compensation, which includes the location, capacity, manner, and so on. Then Power System Analysis Software Package (PSASP) is used to simulate the operating of the single-generator network on the conditions of pre- and post-compensation, and the simulation results involve voltage level, power factor and power loss. Considering the technology feasibility, economical efficiency and power network status quo, the paper chooses an appropriate var compensation scheme, which is to parallel capacitor bank on the bus bar of smelting- electric-furnace transform, and the paper also provides the corresponding values of the capacitor and the reactor. The var compensation scheme has been implemented. The field tests indicate that the network voltage come back to the rated voltage value basically, the active power and power factor of the generator is increased, and the efficiency of the power plant and the economic benefits of the ferroalloy factories are all obvious improved. Therefore, the selection and implementation of var compensation scheme have gained favorable technical and economy effect on the equipment safety operation and the ferroalloy product quality in the Wu Jiangdu single machine grid.更多还原