摘要
模块化多电平转换器(MMC)由大量子模块构成,子模块的可靠性对MMC系统的安全可靠运行有着重要影响。特定工况下的可靠性评估表现是子模块设计指标之一,搭建较完整的MMC系统对子模块进行可靠性测试和验证成本高且效率低,因此提出了一种针对多个MMC子模块的工况模拟测试电路及其相应的控制方法。通过设计负载电流控制策略以及增加辅助桥臂、反串子模块及其控制策略,可以使待测子模块的流入电流、电容电压以及开关序列与实际MMC系统中一致。该电路能够同时对多个子模块进行测试,极大地减小了测试电路对直流源电压的要求,可在保证测试工况与运行工况一致的前提下,大幅提高测试效率、降低测试成本。通过搭建仿真模型实验,验证了所提方法的有效性。本方法可以应用于子模块装机前的可靠性验证,以及子模块电气特性、热特性及可靠性等工厂测试,为子模块控制及设计研发提供参考。
A modular multilevel converter(MMC)may contain a large number of submodules(SMs),which primarily govern the reliability performance of the MMC.However,it is expensive and inefficient to build a complete MMC system for the testing and validation of SMs.In this paper,a test circuit and control strategies is presented to simulate actual operating conditions of MMC’s multiple submodules with NLC modulation.In the proposed testing scheme,the electrical behaviors(load current,capacitor voltages,switching sequence)of the SMs are close to actual MMC applications.Multiple SMs in the same arm can be tested simultaneously.The requirement of DC voltage for power supply is considerably reduced by employing auxiliary bridge arms,reversed SMs.The effectiveness and accuracy of the proposed test scheme are shown via simulation.The proposed test scheme can be used to check functions of SMs before packing and to test electrothermal characteristics on factory test platform to improve SMs’reliability.
作者
杨云霄
马柯
YANG Yunxiao;MA Ke(Department of Electrical Engineering,Shanghai Jiao Tong University,Minhang District,Shanghai 200240,China)
出处
《全球能源互联网》
2020年第2期199-204,共6页
Journal of Global Energy Interconnection
基金
国家重点研发计划(2018YFB0905801).
