适用于送端系统电压稳定分析的换相失败期间直流过电流解析计算与分析方法  

Analytical Calculation and Analysis Methods of DC Overcurrent During Commutation Failure Applicable for Voltage Stability Analysis of Sending End System

作　　者：廖圣文 甘德强[1] 摆世彬 刘刚 李桐 LIAO Shengwen;GAN Deqiang;BAI Shibin;LIU Gang;LI Tong(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,Zhejiang Province,China;State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan 750001,Ningxai Hui Autonomous Region,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027 [2]国网宁夏电力有限公司,宁夏回族自治区银川市750001

出　　处：《中国电机工程学报》2024年第19期7491-7502,I0001,共13页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国网宁夏电力有限公司科技项目(5229NX19008Q)。

摘　　要：换相失败期间直流电流大幅上升,引发大量无功消耗,对设备安全及送端电压稳定造成威胁。当前对换相失败期间过电流问题关注不足,该文提出适用于送端系统电压稳定分析的换相失败过电流机电暂态模型,从快速计算、影响因素等角度展开分析。首先,该文指出低压限流测量环节在定量计算时不可忽略;其次,推导换流母线电压与直流电流的近似线性关系,进一步结合奇异摄动建立分析过电流的代数解耦二阶模型。基于梯形积分法则,该文提出过电流峰值快速估算方法,结合相图分析控制参数与电网结构对过电流和送端电压的影响。最后,该文初步探究换相失败过电流可能引发的送端电压无解失稳问题,分析结果与快速估算方法经算例分析得到验证。During commutation failure,the DC current rises substantially,causing a large amount of reactive power consumption,which endangers the safety of equipment and the voltage stability of the sending-end system.Considering the insufficient attention to overcurrent during commutation failure,this paper establishes an electromechanical transient overcurrent model applicable for voltage stability analysis of the sending end system and then reports upon some research results from the perspective of influence factors and fast calculation.First,the paper points out that the measuring module of VDCOL cannot be ignored in the quantitative calculation.Then,an approximate linear relationship between the commutation bus voltage and the DC current is deduced,and an algebraically decoupled second-order model for analyzing the overcurrent is established with the singular perturbation method.Based on the trapezoidal integral rule,a fast estimation method for the peak value of overcurrent is proposed.Combined with the phase diagram,the influence of control parameters and grid structure on the overcurrent and low voltage are analyzed.Finally,the voltage instability problem of losing solution caused by overcurrent is preliminarily explored.The analysis results and fast estimation method are verified by numerical examples.

关 键 词：换相失败 过电流 奇异摄动 快速计算 相图 电压稳定 

分 类 号：TM71[电气工程—电力系统及自动化]