负荷冲击性对独立电力系统暂态特性的影响  

Influence of Impact Load on Transient Characteristics of Isolated Power System

作　　者：刘正春 朱长青 王勇[1] 刘金宁[1] 解璞[1] 

机构地区：[1]军械工程学院导弹工程系,石家庄050003

出　　处：《高电压技术》2017年第10期3443-3452,共10页High Voltage Engineering

基　　金：国家自然科学基金(51307184)~~

摘　　要：冲击负荷强烈的冲击性严重威胁到独立电力系统的安全稳定运行。针对现有评估指标无法准确、有效评估冲击负载的瞬时动态特性问题,提出了一套基于瞬时功率理论及源端关键参数的暂态评估指标,并对2种具有冲击性的常用负荷的启动、加减载等工作过程进行评估,该指标更能表征非线性负荷对独立电力系统影响的动态过程和暂态特性。通过改变2种负荷关键参数,使系统逐步达到不稳定极限;对电压、功角和频率进行稳定性分析,发现2类冲击负荷在系统中成为不稳定因素的区别在于产生冲击的功率类型不同,将分别引起系统频率失稳或电压失稳,进而造成电源的转速跌落或励磁保护。储能设备负载可采用恒功率充电或改善源端调速系统的方式,电动机负载可采用软启动或无功功率调节装置来缓解系统稳定性。The strong impact characteristics of the impact loads is a serious threat to the security and stability of an isolated power system.As the existing evaluation index cannot accurately and effectively assess the instantaneous dynamic characteristics of the impact loads,a set of transient evaluation index is proposed based on the instantaneous power theory and key parameters from the source,which is used to assess the starting,loading,and shedding processes of the two types of the common used impact loads.The index can better represent the dynamic process and transient characteristics of the effect of the nonlinear loads to the isolated power system.By controlling the key parameters of the two impact loads to approach the unstable state,and the stability analysis of voltage,work angle and frequency is carried out.It is found that the difference of the instability factor between the two impact loads is the different types of impact power,which brings the frequency instability and voltage instability to the system,respectively,and cause the rotate speed drop and protection of exiter system in the source.It is indicated that the constant-power charging or improving the speed regulating system can be adopted for the load of energy storage device,while the soft-start or the reactive power regulator can be used for the motor load to enhance the system stability.

关 键 词：独立电力系统 冲击负荷 暂态特性 电压稳定 频率稳定 

分 类 号：TM712[电气工程—电力系统及自动化]