Abstract：In order to adapt to the non-ideal grid voltage conditions, a AC voltage sensorless control of 3-phase voltage source inverter under unbalanced grid voltage has been researched. Second order generalized integrator is used to build quadrature filter and voltage observer for unbalanced grid voltage, and grid voltage can be hence observed directly in the two-phase static coordinate. Then positive and negative sequence separation can be carried out by using outputs of the quadrature filter, which also can be synchronized with the grid voltage observation. Finally, combined with PR control in the two-phase static coordinate of the inverter and negative sequence compensation algorithm, the AC voltage sensorless control of the inverter under unbalanced grid voltage can be achieved. Compared with the conventional virtual flux observation, the proposed method can get rid of the problems of windup, initial value sensitivity and static error, and also overcome the problem that the conventional quadrature filter based AC voltage sensorless control cannot adapt to the unbalanced grid voltage. The proposed methods and theories have been verified via simulations and experiments.
胡书举, 孟岩峰, 李丰林, 宋斌, 邓雅. 电网电压不平衡时逆变器无交流电压传感器控制策略[J]. 电工技术学报, 2017, 32(24): 146-152.
Hu Shuju, Meng Yanfeng, Li Fenglin, Song Bin, Deng Ya. AC Voltage Sensorless Control Strategy of Grid-Connected Inverter under Unbalanced Grid Voltage. Transactions of China Electrotechnical Society, 2017, 32(24): 146-152.
[1] 胡书举, 孟岩峰, 龚文明, 等. 非理想电网条件下双馈式风电机组的运行控制策略[J]. 电工技术学报, 2013, 28(5): 99-104. Hu Shuju, Meng Yanfeng, Gong Wenming, et al. Operation control strategy of DFIG wind turbine under non-ideal grid conditions[J]. Transactions of China Electrotechnical Society, 2013, 28(5): 99-104. [2] 肖雄, 张勇军, 王京, 等. 无电压传感PWM整流器的虚拟磁链自适应滑模观测研究[J]. 电工技术学报, 2015, 30(12): 152-161. Xiao Xiong, Zhang Yongjun, Wang Jing, et al. PWM rectifiers based on adaptive sliding-mode observer with virtual flux orientation under non-line voltage sensors control[J]. Transactions of China Electro- technical Society, 2015, 30(12): 152-161. [3] Arkadiusz Kulka. Sensorless digital control of grid connected three phase converters for renewable sources[D]. Trondheim, Norway: Norwegian Univer- sity of Science and Technology, 2009. [4] Toshihiko Noguchi, Hiroaki Tomiki, Seiji Kondo, et al. Direct power control of PWM converter without power-source voltage sensors[J]. IEEE Transactions on Industry Applications, 1998, 34(3): 473-479. [5] Mariusz Malinowski. Sensorless control strategies for three-phase PWM rectifiers[D]. Warsaw, Poland: Warsaw University of Technology, 2001. [6] Arkadiusz Kulka. Sensorless digital control of grid connected three phase converters for renewable sources[D]. Trondheim, Norway: Norwegian Univer- sity of Science and Technology, 2009. [7] 胡书举, 龚文明, 李丰林, 等. 一种并网逆变器无交流电压传感器控制策略研究[J]. 电工技术学报, 2015, 30(14): 325-332. Hu Shuju, Gong Wenming, Li Fenglin, et al. Research on a kind of AC voltage sensorless control strategy of grid-connected inverter[J]. Transactions of China Electrotechnical Society, 2015, 30(14): 325- 332. [8] 钟庆昌. 虚拟同步机与自主电力系统[J]. 中国电机工程学报, 2017, 37(2): 336-348. Zhong Qingchang. Virtual synchronous machines and autonomous power systems[J]. Proceedings of the CSEE, 2017, 37(2): 336-348. [9] Zhong Qingchang, Nguyen Phi-Long. Sinusoid- locked loops based on the principles of synchronous machines[C]//The 24th Chinese Control and Decision Conference (CCDC), Taiyuan, China, 2012: 1518- 1523. [10] 陶玉昆. 无交流电压传感器的三相电压源变换器直接功率控制[D]. 广州: 华南理工大学, 2016. [11] 阳同光, 桂卫华. 电网不平衡情况下并网逆变器控制策略综述[J]. 电工技术学报, 2015, 30(14): 241- 246. Yang Tongguang, Gei Weihua. An overview on control strategies of grid-connected inverter under unbalanced voltage conditions[J]. Transactions of China Electrotechnical Society, 2015, 30(14): 241- 246.
2017, Vol. 32 
