江都第三抽水站反向发电方式比较与效益分析

针对南水北调东线工程源头江都第三抽水站利用上游余水发电、抽水时间远大于发电时间的特点,为了优选出可逆式水泵机组最佳发电方案,介绍了利用水泵机组倒转发电的基本情况及其效益,从技术层面分析了水泵机组倒转发电方式;从经济方面对水泵机组倒转发电方式进行了比较;对江都三站多年发电收益进行了归纳总结,从投资与收益的关系方面,分析比较了3种发电方式的净效益终值.结果表明,大型泵站利用上游余水倒转发电,可以取得良好的经济效益和社会效益,但其发电功能的取舍与发电方式的选择,应考虑抽水与发电的主次关系和综合效益;与建站时采用变极发电方式相比,江都第三抽水站更新改造采用变频发电方式,虽然增加了变频机组,但主电动机成本下降,总设备费用下降,发电功率提高了30%～35%,且不影响水泵机组抽水效率,技术可行,运行可靠,容易实施.

Comparison of power generation scheme and benefit analysis for pump units in Jiangdu No.3 Pumping Station in reverse mode

Jiangdu No. 3 Pumping Station is located at the source of East Route of South-to-North Water Diversion Project. The station is subject to amount of redundant water from the upper reach, so it can utilize the water to generate power; however, the time for pumping water is much longer than that for generating power. Considering those features, it is necessary to optimize the power generation scheme for this reversible pump unit. In doing so, the basic situation and benefits of power generated by the pump unit in reverse mode were introduced; the technical issues were analyzed and the economic benefits were compared when the pump unit is reverse mode. The benefits of the pumping station due to power generation in the past more than 3 years were summarized, and the net benefits of three power generation schemes were analyzed and compared from the relationship between investment and income. The results indicated that large pumping station generating power by exploiting redundant water from upper reach can achieve better economic and social benefits. However, if a pumping station can be used to generate power or not and what scheme will be adopted should depend on the consideration about the primary and secondary relationship between pumping water and power generation as well as the economic and social benefits. For Jiangdu No. 3 Pumping Station, the initial power generation equipment was updated to frequency converters. Though the frequency converters were installed, the cost of the main electric motors was reduced, causing the total cost of equipments was decreased. As a result, the power output was increases by 30% -35%. Besides, the frequency converters have no influence on the pumping efficiency of pump units, so they are technologically feasible. Moreover, the frequency converters are reliable in operation and can be installed easily.