摘要
从换相的本质出发,研究不同系统支撑强度对直流系统换相难易程度的影响。采用EMTDC电磁暂态仿真工具,搭建带详细控制保护系统的双极十二脉直流系统,对系统阻抗大小以及系统阻抗角大小对换相影响进行了仿真研究。研究表明,系统阻抗大小是影响换相难易程度的主要因素,系统阻抗角影响直流系统的初始运行工况进而对换相造成影响。在电网强度较弱时增大系统强度可有效加速换相过程,但电网强度增加到一定程度后,对换相影响较弱;另外,当电网强度较弱时增大交流系统强度可有效减小系统波动,有助于系统的恢复。
From the essential reason of commutation failure,the influences of different AC system strength to commutation failure were studied. Using PSCAD/EMTDC,the typical bipolar 12 Pulse DC system model with detailed control system was set up and the influences of different system impedance,different system impedance angle were calculated. According to the simulation results,system impedance is the main factor affecting the degree of difficulty commutation failure and system impedance angle will affect the initial operating conditions of DC system, thus affect the commutation failure. Increasing AC system strength can increase the difficulty commutation failure effectively,when the grid is weak in strength. The impact to commutation failure will be weaker,when the strength of AC system to a certain extent.In addition,when the grid is weak in strength,increase the strength of AC system can reduce the system fluctuations effectively and help to restore the system.
出处
《机电工程技术》
2016年第2期67-74,共8页
Mechanical & Electrical Engineering Technology
基金
国家自然科学基金资助项目(编号:51377059)
