Abstract：In order to improve reliability and reduce cost for three-phase grid-connected inverters, this paper proposes a novel control strategy based on phased lock loop (PLL) and virtual grid flux without grid voltage sensors. According to the dynamic mathematical model in synchronous rotating frame for three-phase grid-connected inverters, the virtual grid flux vector orientation and d-axis current and q-axis current close-loop control are used, which achieves the decoupling control for d-axis current and q-axis current. The active power and the reactive power for three-phase grid-connected inverters are independently controlled by q-axis current and d-axis current. Experimental results show that the output currents are sinusoidal with less distortion and it has a good dynamic and static performance. So the feasibility and correctness for the control strategy is verified.
杨勇, 阮毅, 汤燕燕, 叶斌英. 基于锁相环和虚拟电网磁链的三相并网逆变器[J]. 电工技术学报, 2010, 25(4): 109-114.
Yang Yong, Ruan Yi, Tang Yanyan, Ye Binying. Three-Phase Grid-Connected Inverters Based on PLL and Virtual Grid Flux. Transactions of China Electrotechnical Society, 2010, 25(4): 109-114.
[1] Carrasco J M, Franquelo L G, Bialasiewicz J T, et al. Power-electronic systems for the grid integration of renewable energy sources: a survey[J]. IEEE Transactions on Industrial Electronics, 2006, 53(4): 1002-1016. [2] 伍小杰, 罗悦华, 乔树通, 三相电压型PWM整流器控制技术综述[J]. 电工技术学报, 2005, 20(12): 7-11. [3] 方宇, 裘迅, 邢岩, 等. 三相高功率因数电压型PWM整流器建模和仿真[J]. 电工技术学报, 2006, 21(10): 44-49. [4] Kaura V, Blasko V. Operation of a phase locked loop system under distorted utility conditions[J]. IEEE Transactions on Industry Applications, 1997, 33(1): 58-63. [5] Chung Se-Kyo. A phase tracking system for three phase utility interfaceinverters[J]. IEEE Transactions on Power Electronics, 2000, 15(3): 431-438. [6] Ahmed T, Nishida K, Nakaoka M. Advanced control of PWM converter with variable-speed induction generator[J]. IEEE Transactions on Industry Applications, 2006, 42(4): 934-945. [7] Lee W C, Hyun D S, Lee T K. A novel control method for three-phase PWM rectifiers using a single current sensor[J]. IEEE Transactions on Power Electronics, 2000, 15(9): 861-870. [8] Agirman I, Blasko V. A novel control method of a VSC without AC line voltage sensors[J]. IEEE Transactions on Industry Applications, 2003, 39(2): 519-524. [9] Noguchi T, Tomiki H, Kondo S, et al. Direct power control of PWM converter without power-source voltage sensors[J]. IEEE Transactions on Industry Applications, 1998, 34(3): 473-479. [10] Kwon B H, Youm J H, Lim J W. A line-voltagesensorless synchronous rectifier[J]. IEEE Transactions on Power Electronics, 1999, 14(9): 966-972. [11] Malinowski M, Kazmierkowski M, Hansen S, et al. Virtual-flux-based direct power control of three-phase PWM rectifiers[J]. IEEE Transactions on Industry Applications, 2001, 37(7): 1019-1026. [12] Blasko V, Kaura V. A new mathematical model and control of a three-phase AC-DC voltage source converter[J]. IEEE Transactions on Power Electronics, 1997, 12(1): 116-123. [13] Yang Yong, Ruan Yi, Shen Huanqing, et al. Grid- connected inverter for wind power generation system[J]. Journal of Shanghai University, 2009, 13(1): 51-56. [14] Hu Jun, Wu Bin. New integration algorithms for estimating motor flux over a wide speed range[J]. IEEE Transactions on Power Electronics, 1998, 13(5): 969-977. [15] Comanescu M, Xu L. An improved flux observer based on PLL frequency estimator for sensorless vector control of induction motors[J]. IEEE Transactions on Industrial Electronics, 2006, 53(1): 50-56.
2010, Vol. 25 
