全功率可变速抽水蓄能机组低水头启动过程动态特性研究  

A study on dynamic characteristics of low head start-up process of a full-size converter variable speed pumped storage unit

作　　者：刘璋 刘公成 高院强 张云鹏 赵子文 陈帝伊[1] LIU Zhang;LIU Gongcheng;GAO Yuanqiang;ZHANG Yunpeng;ZHAO Ziwen;CHEN Diyi(College of Water Resources&Architectural Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《振动与冲击》2024年第24期225-233,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(52339006)。

摘　　要：为了解决低水头工况下抽水蓄能机组启动的稳定性问题,该文结合变速技术提出全功率可变速抽水蓄能机组在低水头工况的启动策略,并对全功率可变速抽水蓄能机组低水头启动过程进行模拟。然后,启动转速作为影响变速机组低水头启动特性的重要参数,其对全功率可变速机组低水头工况的启动特性影响规律尚不明晰,因此,针对不同启动转速,分别探究了低水头下启动的动态运行轨迹以及机组的蜗壳压力、尾水管压力的启动动态特性以及励磁系统的启动特性。结果表明:该文提出的变速启动策略,可有效避免机组进入反“S”特性区;在相同初始开度、相同调速器控制等条件下,启动转速为82.5%~87.5%的全功率可变速机组均可快速达到稳态,并且启动运行区域呈现左移现象,机组的蜗壳压力趋于稳定,对励磁系统的影响很小,有利于从根本上解决低水头启动并网困难的问题。该研究为全功率变速机组以及“改造”后定速机组的启动策略提供决策支持。To address the issue of start-up stability in pumped-storage units under low head conditions,this paper introduces a start-up strategy that employs full-size converter variable speed operation in such conditions and simulates the start-up process for pumped-storage units with full-size converter variable speed.It is recognized that the starting speed is a crucial parameter influencing the start-up characteristics of variable speed units with low water head.However,the specific impact of starting speed on the start-up traits of full-size converter variable speed units under low water head conditions remains uncertain,Consequently,this study delves into the dynamic operating trajectories and the starting characteristics,including volute pressure,draft pipe pressure,and excitation system responses,for a range of starting speeds under low water head conditions.The findings reveal that the variable speed start-up strategy presented herein effectively prevents the unit from entering the inverse"s"characteristic zone.With identical initial settings and governor controls,full-size converter variable speed units that commence start-up at speeds between 82.5%and 87.5%can achieve a stable operating state in a shorter time frame.The initiation of the full-size converter variable speed unit at a variable speed results in a leftward shift of the operational starting area along the characteristic curve,thereby enhancing the stability of the volute pressure within the unit.In addition,the impact on the excitation system is minimal,which is conducive to fundamentally solving the challenges brought by low head start-up and grid connection.The insights gained from this research offer valuable decision-making support for the start-up strategies of both full-size converter variable speed unit and fixed speed unit post-modification.

关 键 词：抽水蓄能 可变速机组 低水头工况 反“S”特性 全功率 

分 类 号：TV743[水利工程—水利水电工程]