作　　者： (李国庆）; (刘宇超）; (王鹤）;

机构地区： 东北电力大学电气工程学院,吉林吉林132012

出　　处： 《电测与仪表》 2017年第16期25-31,38,共8页

摘　　要： 为了保证模块化多电平换流器型直流输电的高效和稳定运行,需要对于MMC-HVDC系统的故障形式和故障机理进行详尽的分析,对其继电保护原理及保护判据进入深入的研究。简要介绍了MMC-HVDC保护系统的保护分区、不同保护的动作方式及所需数据的测量方式。深入分析了MMC-HVDC系统站内交流母线故障(接地短路和相间短路)的故障暂态响应,研究了站内交流母线故障后采用的保护策略,提出采用比率制动特性的电流差动保护,能够可靠躲开外部故障时由于电流互感器饱和等因素引起的不平衡电流,同时又能可靠保证站内交流母线内部故障时的灵敏度。在RT-LAB实时仿真平台中验证所做分析和所提保护策略的有效性。 In order to ensure the high-efficient and stable operation of the MMC （modular multilevel converter）- HVDC transmission system, it is necessary to analyze the failure mode and failure mechanism of MMC-HVDC in de- tail. The theory of relay protection and the protection criterion of MMC-HVDC are needed to be further studied. This paper briefly introduces the protection zone of the MMC-HVDC protection system, and the different ways of protection action and the measurement methods for the required data. Furthermore, we deeply analyze characteristic investigation under internal AC bus fault （including single phase ground fault and two-phase short circuit fault）. And the protec- tion strategy under the failure of the AC bus in the station is studied. This paper puts forward a current differential protection by using the percentage restraint. It can reliably avoid the unbalanced current caused by the saturation of the current transformer when an external fault occurs. And it can reliably guarantee the sensitivity of protection under internal fault of AC bus at the same time. In the RT-LAB real-time simulation platform, the effectiveness of analysis and the proposed protection strategy is validated.

关 键 词： 站内交流母线 比率制动特性 电流差动保护