双馈变速抽水蓄能机组发电工况阻抗建模  

Impedance Modeling of Doubly-fed Variable Speed Pumped Storage Unit in Generator Operating Mode

作　　者：查子健 刘斌 Zha Zijian;Liu Bin(Hubei Provincial Key Laboratory for Operation and Control of Cascaded Hydropower Station,Yichang Hubei 443002;College of Electrical Engineering&New Energy,China Three Gorges University,Yichang Hubei 443002;State Grid Hubei Direct Current Company,Yichang Hubei 443002)

机构地区：[1]梯级水电站运行与控制湖北省重点实验室,湖北宜昌443002 [2]三峡大学电气与新能源学院,湖北宜昌443002 [3]国网湖北省电力有限公司直流公司,湖北宜昌443002

出　　处：《中外能源》2024年第6期33-38,共6页Sino-Global Energy

摘　　要：变速抽水蓄能机组具有优良的调峰调频性能,可有效提高新能源的消纳水平。由于新能源机组和双馈变速抽蓄机组存在多种电力电子装置,且运行工况复杂,在进行电力系统小干扰稳定性分析时,使用基于频域建模的阻抗分析法更容易扩展和建模。然而现有的双馈变速抽蓄机组阻抗模型并未考虑复杂输水系统和水泵水轮机转速的影响,不能反映长输水管道的弹性水击和水泵水轮机变速运行特性,这将影响小干扰稳定性的分析结果。为此,提出发电工况下一管一机带调压室的输水系统降阶弹性水击模型和考虑初始运行工况和转速的水泵水轮机模型。首先基于分布参数弹性水击理论,推导包括引水隧洞、调压室和压力钢管的输水系统降阶弹性水击模型。然后将考虑水头、导叶开度和转速的非线性水泵水轮机模型在初始运行工况点处进行线性化。最后结合发电电动机、调速器、变流器及其控制器模型,构建了双馈变速抽蓄机组发电工况阻抗模型。对比扫频法的测量结果,可验证所提出模型的准确性。Variable speed pumped storage unit has excellent performance of peak and frequency regulation,which can effectively increase the consumption of new energy.Because there are many kinds of power electronic devices in new energy units and doubly-fed variable speed pumped storage units and the operating conditions are complex,it is easier to expand and model using impedance analysis method based on frequency domain modeling when analyzing the small disturbance stability of power systems.However,the current impedance model of doubly-fed variable speed pumped storage unit does not consider the influence of complex water conveyance system and pump turbine speed,and can not reflect the elastic water hammer of long water pipeline and the variable speed operation characteristics of pump turbine,which will affect the analysis results of small disturbance stability.For this reason,a reduced order elastic water hammer model of a onepipe-one-machine water conveyance system with surge chamber in generator operating mode and a pump turbine model considering the initial operating conditions and rotational speed are proposed.Firstly,the reduced order elastic water hammer model of water conveyance system including diversion tunnel,surge chamber and pressure steel pipe is derived based on the distributed parameter elastic water hammer theory.Then the nonlinear pump turbine model considering water head,guide vane opening and rotational speed is linearized at the initial operating point.At last,the impedance model of doubly-fed variable speed pumped storage unit is constructed based on the models of generator motor,governor,converter and its controller.The accuracy of the proposed model can be verified by comparing with the measurement results of frequency sweeping method.

关 键 词：抽水蓄能 弹性水击 变速运行 发电工况 阻抗建模 频域分析 

分 类 号：TV7[水利工程—水利水电工程]