Abstract：The commonly used short circuit protection strategy is to combine the constant voltage mode (CVM) in normal situation and the constant current control mode (CCM) in abnormal situation. However, the output characteristics discrepancy and different control parameters cause the time variance retreating from CCM to CVM for the parallel inverters, which results in differences in voltage and large circulating currents. It easily causes power flooding inversely, pumping of DC voltage, and over-voltage protection in light load, which can not satisfy the non-stop requirements during short circuit. The proposed strategy of retreating from CCM in terms of the average voltage and instantaneous current is introduced in this paper. It states that several parallel inverters retreat simultaneously from CCM and enter CVM at the rising edge(or failing edge) of synchronous signal. The initial voltage is increased to reduce the recovery time from CCM, when the short circuit is disappeared. The compensation of the experimental results on two 400kVA/50HZ inverters verifies the effectiveness of the proposed strategy.
[1] 王晨, 庄劲武, 张晓锋, 等. 基于IGBT的新型直流电力系统限流装置的工作原理与实验研究[J]. 电工技术学报, 2006, 21(9): 57-61. [2] Jordan J, Esteve V, Dede E, et al. Automated calculation method to determine the output power based on the frequency for induction heating IGBT parallel inverter[C]. Proceedings of IEEE Power Electronics Specialists Conference, Florida, USA, 2007. [3] 陈坚. 电力电子学—电力电子变换和控制技术[M].北京: 高等教育出版社, 2004, 45-47. [4] 周雪松, 向龙瑞, 马幼捷, 等. 故障限流装置的发展和应用[J].电工技术学报, 2004, 20(11): 1-7. [5] 孙俊忠, 马伟明, 宋振海. 双绕组交直流发电机直流侧突然短路分析[J]. 中国电机工程学报, 2005, 25(11): 95-100. [6] 庄劲武, 张晓锋, 杨锋, 等. 船舶直流电网短路限流装置的设计与分析[J]. 中国电机工程学报, 2005, 25(20): 26-30. [7] Chunlian Jin, Roger Dougal. Current limiting technique based protection strategy for an industrial DC distribution system[C]. Proceedings of the IEEE Conference International Symposium on Industrial Electronics, Montreal, Canada, 2006. [8] 林湘宁, 高艳, 刘沛, 等. 基于零序补偿导纳的小电流接地系统单相故障保护新方法[J]. 中国电机工程学报, 2006, 26(10): 45-49. [9] 王林兵, 何湘宁, 张超. 逆变器输出限流技术研 究[J]. 电力电子技术, 2006, 40(4): 65-67. [10] 陈宇, 汪洪亮, 裴雪军, 等. 组合式三相逆变器的限流策略研究[J]. 电力电子, 2008, 6(5): 65-67. [11] 汪洪亮, 岳秀梅, 裴雪军, 等. 组合式三相逆变器软硬件限流保护策略[J]. 电工技术学报, 2008, 23(9): 92-97. [12] Erika Twining, Holmes D G. Grid current regulation of a three-phase voltage source inverter with an LCL input filter[J]. IEEE Transactions on Power Electro- nics, 2003, 18(5): 888-895. [13] 沈国桥, 徐德鸿. LCL滤波并网逆变器的分裂电容法电流控制[J]. 中国电机工程学报, 2008, 28(18): 36-41. [14] 仇志凌, 杨恩星, 孔洁, 等. 基于LCL滤波的并联有源电力滤波器电流闭环控制方法[J]. 中国电机工程学报, 2009, 29(18): 15-20. [15] 侯婷, 裴雪军, 刘明先, 等. 大功率组合式三相逆变电源的统一控制技术[J]. 中国电机工程学报, 2006, 26(25): 46-50. [16] Zhang Xiaoqing, Li Ming. Using the fault current limiter with spark gap to reduce short-circuit currents[J]. IEEE Transactions on Power Delivery, 2008, 23(1): 506-507. [17] 丁辉, 姚蜀军, 韩民晓. 高压变频驱动系统脉冲封锁保护策略[J]. 中国电机工程学报, 2006, 26(6): 123-127. [18] 费万民, 张艳莉, 孟照娟, 等. 基于自关断器件的三相不接地系统短路限流器及其实验研究[J]. 电工技术学报, 2007, 22(5): 64-70. [19] Yamaguchi H, Kataoka T. Current limiting characteristics of transformer type superconducting fault current limiter with shunt impedance[J]. IEEE Transactions on Applied Superconductivity, 2007, 17(6): 1919-1922. [20] Ahmed M R, Ghanim Putrus, Li Ran, et al. Development of a prototype solid-state fault-current limiting and interrupting device for low-voltage distribution networks[J]. IEEE Transactions on Power Delivery, 2006, 21(4): 1997-2005.
2012, Vol. 27 
