双闭环VF控制MMC输出短路电流特性分析与计算方法OA北大核心CSTPCD
Short-Circuit Current Characteristics Analysis and Calculation Methods of Modular Multilevel Converter in Double Closed-Loop Voltage-Frequency Control
新能源直接通过模块化多电平换流器(modular multilevel converter,MMC)孤岛送出时,MMC需要采用电压-频率(voltage-frequency,VF)控制方式,为新能源并网提供稳定的电压支撑.针对换流器交流侧发生三相对称短路故障时,对双闭环VF控制MMC输出的短路电流进行了精细化计算.结合系统电路特性和MMC控制特性,首先对VF控制MMC交流侧发生三相对称短路故障后换流器的节点特性进行了分析,研究表明故障后换流器可能表现类似电流源特性或电压源特性.在此基础上,提出了MMC呈电流源特性时短路电流超调量的计算方法,以及MMC呈电压源特性时短路电流直流分量和稳态量的计算方法.最后,在PSCAD平台上进行了仿真分析,验证了所提出方法的正确性.
When a modular multilevel converter(MMC)is connected to an islanded renewable power system,voltage-frequency control must be adopted to provide stable voltage support.This study focuses on the calculation of the short-circuit current of an MMC in the double closed-loop voltage-frequency mode after a three-phase symmetrical short-circuit fault occurs.Considering the circuit and control system characteristics,this study first analyzes the output characteristics of a MMC after a fault occurs and proposes that the MMC can be represented as a current source or a voltage source.Then,calculation methods are proposed for the short-circuit current overshoot when the MMC is represented as a current source and for the short-circuit current DC component when the MMC is represented as a voltage source.Simulations are conducted using PSCAD to verify the accuracy of the proposed method.
陈怡静;李春华;李英彪;郭小江;王有超;张宇;陈双印
中国华能集团清洁能源技术研究院有限公司,北京市 102209华中科技大学电气与电子工程学院,武汉市 430074华能国际电力股份有限公司江苏清洁能源分公司,南京市 210015武汉新能源研究院有限公司,武汉市 430034
动力与电气工程
模块化多电平换流器(MMC)VF控制短路电流计算方法
modular multilevel converter(MMC)voltage-frequency controlshort-circuit currentcalculation method
《电力建设》 2024 (010)
90-99 / 10
This work is supported by National Key R&D Program of China(No.2021YFB2400600)and China Huaneng Group Co.,Ltd Science and Technology Project(No.HNKJ20-H54). 国家重点研发计划资助项目(2021YFB2400600);中国华能集团有限公司科技项目(HNKJ20-H54)
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