| 引用本文: | 梅军,管州,丁然,范光耀,葛锐,王冰冰,梁东,宗瑾.直流配电网MMC-H型直流变压器回流功率的变频优化[J].电力自动化设备,2020,40(2): |
| MEI Jun,GUAN Zhou,DING Ran,FAN Guangyao,GE Rui,WANG Bingbing,LIANG Dong,ZONG Jin.Variable-frequency optimization strategy based on backflow power of MMC-H DC transformer in DC distribution network[J].Electric Power Automation Equipment,2020,40(2): |
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| 摘要: |
| 研究适用于直流配电网的模块化多电平换流器H桥(MMC-H)型直流变压器，其由模块化多电平(MMC)桥臂、H桥和交流变压器组成。MMC采用阶梯波调制，H桥采用方波调制。推导出基于移相控制的传输功率与回流功率表达式，总结影响回流功率的因素与零回流功率的边界条件。为抑制回流功率，提出了变频优化策略，通过工作频率的变化来调节移相比落入零回流功率区域，减小回流功率与电流应力。最后，搭建实验平台对变频优化控制策略进行验证，实验结果表明变频优化控制策略能够调节移相比，降低电流应力与损耗，提高直流变压器效率。 |
| 关键词: 模块化多电平换流器 直流变压器 功率表达式 零回流功率区域 变频优化 |
| DOI：10.16081/j.epae.202001016 |
| 分类号:TM64;TM421 |
| 基金项目:国家电网公司科技项目(520101170022) |
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| Variable-frequency optimization strategy based on backflow power of MMC-H DC transformer in DC distribution network |
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MEI Jun1, GUAN Zhou1, DING Ran1, FAN Guangyao1, GE Rui1, WANG Bingbing1, LIANG Dong2, ZONG Jin2
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1.School of Electrical Engineering, Southeast University, Nanjing 210096, China;2.State Grid Jibei Electric Power Co.,Ltd.,Beijing 100054, China
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| Abstract: |
| The MMC-H(Modular Multilevel Converter-H-bridge) DC(Direct Current) transformer suitable for DC distribution system is studies, which is composed of MMC arm, H-bridge and AC transformer. MMC utilizes staircase modulation and H-bridge adopts square-wave modulation. Besides, the formula of transmission power and backflow power based on phase-shift control are derived, and the factors that affect the backflow power and the boundary conditions of zero backflow power are summarized. In order to suppress the backflow power, a variable-frequency optimization strategy is proposed. The phase-shift ratio can be adjusted to fall into the zero backflow power zone through variable operating-frequency strategy, so as to reduce the backflow power and current stress. Finally, an experimental prototype is built to verify the feasibility of variable-frequency optimization strategy. The experimental results show that the variable-frequency optimization strategy can adjust the phase-shift ratio, reduce the current stress and loss, and improve the efficiency of DC transformer. |
| Key words: modular multilevel converter DC transformer power formula zero backflow power zone variable-frequency optimization |
