电力电子接口新能源并网的暂态电压稳定机理研究  

Study on the mechanism of transient voltage stability of new energy source with power electronic interface

作　　者：陈磊[1] 刘永奇[2] 戴远航[1] 闵勇[1] 张玮灵 侯凯元[2] 

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京100084 [2]东北电网有限公司,辽宁沈阳110181

出　　处：《电力系统保护与控制》2016年第9期15-21,共7页Power System Protection and Control

基　　金：国家科技支撑计划项目(2013BAA01B03);国家自然科学基金项目(51377002);东北电网有限公司科技项目~~

摘　　要：为掌握大规模风电、光伏等新能源并网给电力系统稳定性带来的影响,对采用电力电子接口的新能源发电接入系统的暂态电压稳定机理进行了研究。首先对机电暂态过程中新能源发电进行简化建模。采用电力电子变换器的风电、光伏等电源功率控制快速灵活,在机电暂态过程中可以忽略功率调节的快动态,其特性简化为功率平衡代数方程,系统动态方程为微分代数方程。基于微分代数系统稳定性研究了新能源并网的暂态电压稳定机理,暂态过程中轨迹可能遇到微分代数方程的奇异点,对应系统发生暂态电压失稳,此时新能源发电对应的功率平衡方程无解。通过仿真验证了该机理,并在风火打捆送出系统中揭示了系统失稳模式的变化,风电功率增加时,系统失稳模式由同步机主导的功角失稳变为风电主导的电压失稳。To clarify the influence of large scale new energy source like wind power and photovoltaics on power system stability, the mechanism of transient voltage stability of new energy source with power electronic interface is studied. The simplified model of new energy source in electro-mechanic transient is first studied. Variable speed wind turbines and photovoltaics with power electronic interface can control the power quickly and flexibly. In power system electro-mechanic transients, the fast dynamics of power adjustment can be neglected, and the new energy source characteristic is simplified to power balance algebraic equation. The system dynamic equation is a differential algebraic equation. According to the stability theory of differential algebraic systems, the trajectory meeting a singular point of the differential algebraic equation corresponds to transient voltage instability in the system. The power balance equation of the new energy source becomes unsolvable at the point. Simulation results validate the mechanism, and reveal the variation of instability mode of a wind-thermal-bundled sending system. As the wind power increases, the instability mode of the system changes from rotor angle instability dominated by synchronous generator to voltage instability dominated by wind power.

关 键 词：新能源 电力电子接口 暂态电压稳定 微分代数方程 奇异点 

分 类 号：TM712[电气工程—电力系统及自动化]