【作者】 张敏；

【导师】 南海鹏；

【作者基本信息】 西安理工大学 ， 水利水电工程， 2019， 硕士

【摘要】 随着风电、光伏等可再生能源的大规模并入大电网,对电网的稳定性带来极大影响,抽水蓄能机组在电网中的调峰调频就显得尤为重要。常规抽水蓄能机组的运行模式一般都为负荷高峰发电,负荷低谷抽水,而机组在水泵工况运行时,只能整台开停机,机组的输入功率不能实现连续变化,无法根据电网需求对机组的输入功率进行连续调节。可变速抽水蓄能机组可根据电网频率变化通过改变转速实现机组输入功率的变化,进而对电网频率调节,可增加电网的调频资源。因此本文针对可逆式可变速抽水蓄能机组水泵工况运行特性展开研究,主要完成以下几方面工作:(1)模型建立。采用交流励磁电机作为抽水蓄能机组的发电/电动机实现抽水蓄能机组在水泵运行工况下的变速运行。在分析总结引水系统、电液伺服系统、水泵水轮机、交流励磁电机、变流器及其控制方式、功率调节器和频率调节器数学模型的基础上,建立了可变速抽水蓄能机组水泵工况的数学模型。(2)水泵工况下机组功率响应的研究。通过励磁系统调节机组转速,使得水泵输入功率在负荷允许变化范围内连续调节,并通过在功率命令给定端输入阶跃扰动进行仿真试验,对水泵工况功率响应进行研究。由于电网运行相关准则中未对水泵机组功率响应指标进行规定,因此本文参考其它并网机组AGC运行指标规定对仿真结果进行分析,结果表明可变速抽水蓄能机组水泵工况功率响应的调节速度远比规定要求的快,响应时间和稳态误差也远比规定要求的小。(3)对水泵工况下参与一次调频能力的研究°本文采用带PI环节的频率响应控制方式,并通过在频率给定端输入频率突增和突减的阶跃扰动进行开环特性仿真试验,对水泵工况一次调频特性进行研究。山于相关准则中未对水泵机组一镒调频指标进行规定，因此本文参考水轮发电机组一次调频指标规定对仿真结果进行分析,结果表明可变速抽水蓄能机组在水泵工况不仅能够参与一次调频，而且一次调频的各项指标均优于水轮发电机组的指标要求。更多还原

【Abstract】 With the large-scale integration of wind power,photovoltaic and other renewable energy into the large power grid,the stability of the power grid has been greatly affected.Peak shaving and frequency regula,tion of pumped storage units in the power grid is particularly important.The operation mode of conventional pumped storage units is usually peak load generatio.n and low load pumping.When the units are operating under pump conditions,they can only start and shut down the whole unit.The input power of the units can not be continuously changed,and the input power of the units can not be continuously adjusted according to the demand of the power grid.Variable-speed pumped storage unit can change the input power of the unit by changing the speed according to the frequency change of the power grid,and then adjust the frequen cy of the power grid,which can increase the frequency control resources of the power grid.Therefore,this paper studies the operating characteristics of pumps of reversible variable speed pumped storage units,mainly completing the following aspects:(1)Modeling.AC excitation motor is used as generator/motor of pumped storage unit to realize variable speed operation of pumped storage unit under pump operation condition.Based on the analysis and summary of the mathematical models of diversion system,electro-hydraulic servo system,pump turbine,AC excitation motor,converter and its control mode,power regulator and frequency regulator,the mathematical model of variable speed pumped storage unit is established.(2)Study on power response of unit under pump condition.Through the excitation system to regulate the speed of the unit,the input power of the pump can be continuously adjusted within the allowable range of load.The power response of the pump is studied by simulating the step disturbance at the given end of the power command.Because the power response index of pumping units is not stipulated in the relevant criteria of power grid operation,the simulation results are analyzed by referring to the AGC operation index of other grid-connected units.The results show that the adjusting speed of the pump power response of variable speed pumped storage units is much faster than the prescribed requirements,and the response time and steady-state error are much smaller than the prescribed requirements(3)Participating in the primary frequency modulation capability research under pump condition.In this paper,the frequency response control method with PI link is adopted,and the open-loop characteristic simulation test is carried out by the step disturbance of input frequency sudden increase and decrease at the given frequency end,and the primary frequency modulation characteristic of pump operation is studied.Because the primary frequency regulation index of pumping unit is not stipulated in the relevant criteria,the simulation results are analyzed by referring to the primary frequency regulation index of hydroelectric unit.The results show that the variable speed pumped storage unit can not only participate in primary frequency regulation,but also the primary frequency regulation indexes are better than those of hydroelectric unit.更多还原