摘要
为了研究分频输电系统频率降低对水轮发电机机端三相短路时所产生的振荡转矩初始幅值的影响,建立了同步发电机的5阶数学模型,推导了5阶模型下同步发电机带负载机端突然三相短路时,振荡转矩初始幅值的解析表达式;比较了工/分频水轮发电机在额定工作状态下经同一短线路向系统送出有功和无功时,机端电压与功角的大小关系;在水轮同步发电机的实际工程应用标准参数与电气参数限定范围内,研究了振荡转矩初始幅值关于机端电压与功角的单调性,比较了相同工况下工/分频系统振荡转矩初始幅值的大小,并量化分析比较了包括频率在内的多种因素对振荡转矩初始幅值的影响程度。研究结果表明:在水轮同步发电机参数、工况相同,仅考虑频率降低的情况下,经短线路向系统送出功率,分频输电系统振荡转矩的初始幅值小于工频系统;在各影响因素中,直轴次暂态电抗对振荡转矩初始幅值影响最大,交轴同步电抗影响最小。
In order to study the effect of frequency reduction of the factional frequency transmission system on the initial amplitude of the oscillation torque generated by the three-phase short circuit in the synchronous generator port,a 5-order model of the generator is derived to resolve the analytical expression of the oscillatory torque.This paper compares the generator terminal voltage and power angle in both the power frequency system and the fractional frequency system with the same rated generator capacity,power factor,and operation state.Within the practical scope of standard parameters and electrical parameters of the synchronous generator,the monotonicity of the initial amplitude of the oscillation torque with respect to the terminal voltage and power angle is studied and the initial amplitudes of the oscillation torque of the fractional frequency system and the power frequency system are compared under the same condition,and the influence degrees of various factors on the initial amplitude of the oscillation torque are quantitatively analyzed and compared.The results show that the initial amplitude is smaller in the factional frequency transmission system when only the frequency reduction is considered,and the direct-axis sub-transient reactance has the greatest influence on the initial amplitude of the oscillation torque,while the quadrature-axis synchronous reactance has the least influence.
作者
周嘉豪
王秀丽
张海涛
魏凤廷
王志维
丁超
ZHOU Jiahao;WANG Xiuli;ZHANG Haitao;WEI Fengting;WANG Zhiwei;DING Chao(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;State Grid Zhejiang Electric Power Co.,Ltd.,Research Institute,Hangzhou 310014,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2024年第5期2020-2029,I0016,I0017,共12页
High Voltage Engineering
基金
国家重点研发计划(2021YFB2401100)
国家电网有限公司科技项目(5211DS22002C)。
关键词
分频输电
同步发电机
机电暂态
振荡转矩
三相短路
新型输电方式
fractional frequency transmission system
synchronous generator
electromechanical transient
oscillatory torque
three-phase short circuit
new type of transmission
作者简介
周嘉豪,1999-,男,硕士生主要从事分频输电系统、新型输电方式方面的研究工作,E-mail:jhzhou7@stu.xjtu.edu.cn;通信作者:王秀丽,1961-,女,博士,教授,博导主要从事电力市场、电力系统规划和新型输电方式等方面的研究工作,E-mail:xiuliw@mail.xjtu.edu.cn。
