Abstract:The control mechanism of direct current control mode and indirect current control mode for grid-connected inverter is analyzed according to mathematical model of inverter. The d-axis component of inverter voltage (ud) is always equal to peak voltage of inverter when power factor (PF) is equal to 1 and line equivalent resistor (R) is ignored. A novel indirect current control strategy, which uses closed-loop of d-axis component of inverter current (#em/em#d) adjusting q-axis component of inverter voltage (uq), is proposed according to this conclusion. The power factor is affected by R and accuracy of detecting voltage. In order to improve the power factor, a control strategy for grid-connected inverter based on double d-q coordinates is proposed. The different variables are located in different coordinates. However, all variables satisfy parallelogram law and the inverter can run in unity power factor. The validity and advancement of the proposed control scheme are verified by the simulation results.
吴云亚, 阚加荣, 谢少军. 基于双d-q坐标系的并网逆变器控制策略[J]. 电工技术学报, 2011, 26(8): 106-112.
Wu Yunya, Kan Jiarong, Xie Shaojun. Control Strategy for Grid-Connected Inverter Based on Double d-q Coordinates. Transactions of China Electrotechnical Society, 2011, 26(8): 106-112.
[1] Nigim K A, Zobaa A F. Development and opportunities of distributed generation fuelled by renewable energy sources[J]. International Journal of Global Energy Issues, 2006, 26(3): 215-231. [2] 姚志垒, 王赞, 肖岚, 等. 一种新的逆变器并网控制策略的研究[J]. 中国电机工程学报, 2006, 26(18): 61-64. [3] Lee T S. Lagrangian modeling and passivity-based control of three-phase AC-DC voltage-source converters[J]. IEEE Transactions on Industrial Electronics, 2004, 51(4): 892-902. [4] 张纯江, 郭忠南, 王芹, 等. 基于新型相位幅值控制的三相PWM整流器双向工作状态分析[J]. 中国电机工程学报, 2006, 26(11): 167-171. [5] Ho M T, Chung H. An integrated inverter with maximum power tracking for grid-connected PV systems[J]. IEEE Transactions on Power Electronics, 2005, 20(4): 953-962. [6] Taesik Yu, Sewan Choi, Hyosung Kim. Indirect current control algorithm for utility interactive inverters for seamless transfer[C]. IEEE PESC, 2006, 1-6. [7] Tirumala R, Mohan N, Henze C. Seamless transfer of grid-connected PWM inverters between utility-interactive and stand-alone modes[C]. IEEE Applied Power Electronics Conference, Dallas, USA, 2002: 1081-1086 [8] Dixon J W, Ooi B T. Indirect current control of a unity power factor sinusoidal current boost type three-phase rectifier[J]. IEEE Transactions on Industrial Electronics, 1998, 35(3): 508-515. [9] Hyosung Kim, Taesik Yu, Sewan Choi. Indirect current control algorithm for utility interactive inverters in distributed generation systems[J]. IEEE Transactions on Power Electronics, 2008, 23(3): 1342-1347. [10] 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. [11] 钟炎平, 沈颂华. PWM整流器的一种快速电流控制方法[J]. 中国电机工程学报, 2005, 25(12): 52-56. [12] IEEE-SA Standards Board. IEEE Std 929-2000 IEEE recommended practice for utility interface of photovoltaic (PV) systems[S]. New York: The Institute of Electrical and Electronics Engineers, Inc., 2000.