兼具开路故障诊断能力的MMC电容电压测量方法

发布时间：2018-07-04 23:36

本文选题：模块化多电平换流器 + 电容电压测量　；参考：《电力系统自动化》2017年07期

【摘要】：模块化多电平换流器在高电压等级、大输送容量场合的应用中,各桥臂大量子模块的电压需要实时采集并维持在允许范围内,但电压传感器配置数量的增加影响了系统的经济性与可靠性。为解决以上问题,提出了一种基于电容电压预估和组电压测量的子模块电容电压测量方法。该方法对桥臂子模块进行了分组,每组仅配备一个电压传感器,从而使传感器数量得以减少。在该测量方法基础上提出了一种子模块开路故障诊断策略,通过比较电压实测值与预估值完成开路故障的快速诊断,并且对传感器设置了故障冗余,在传感器发生故障的情况下系统仍能保持稳定运行。基于PSCAD/EMTDC搭建了21电平基于模块化多电平换流器的高压直流仿真系统。仿真结果表明,所述方法具有与传统方法近似的测量精度,同时能在较短时间内诊断子模块开路故障与传感器故障。
[Abstract]:In the application of modularized multilevel converter in high voltage level and large conveying capacity, the voltage of a large number of submodules of each arm needs to be collected in real time and maintained within the allowable range. However, the increase in the number of voltage sensors affects the economy and reliability of the system. In order to solve the above problems, a submodule capacitance voltage measurement method based on capacitor voltage estimation and group voltage measurement is proposed. In this method, the submodules of the bridge arm are grouped, each group is equipped with only one voltage sensor, so the number of sensors can be reduced. On the basis of the measurement method, a submodule open circuit fault diagnosis strategy is proposed. By comparing the voltage measured value with the pre-estimated value, the open circuit fault diagnosis is accomplished quickly, and the fault redundancy is set up for the sensor. The system can still operate stably in the event of sensor failure. A 21 level HVDC simulation system based on modularized multilevel converter is built based on PSCAD / EMTDC. The simulation results show that the proposed method has the same accuracy as the traditional method, and it can diagnose the open circuit fault and sensor fault of the submodule in a short time.
【作者单位】：山东大学电气工程学院;
【基金】：国家自然科学基金资助项目(51347008)~~
【分类号】：TM933.2

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