A New Phase-Locked Loop Approach for Three-Phase Three-Wire Photovoltaic Grid-Connected Inverter Systems

Abstract

Abstract: Phase, amplitude and frequency of the utility voltage are critical information for the operation of the photovoltaic grid-connected inverter systems. Considering that the traditional phase-locked loop (PLL) methods are difficult to adapt the performance requirements of low voltage ride through (LVRT) in three-phase three-wire photovoltaic grid systems, a new three-phase PLL approach was presented in this paper. Three fundamental functional parts make up the proposed method:①measurement of line voltage amplitude and line voltage phase;②choice of orthogonal signal generator (OSG) ;③transformation between line voltage and phase voltage. Research results show that when grid voltage offsets and dips, this three-phase PLL method can detect the fault signal accurately. It provides a technical support for low voltage ride through of the photovoltaic grid-connected inverter systems.

Key words: Photovoltaic grid, phase-locked loop, three-phase three-wire, second order generalized Integrator

Zhang Yongming,Yue Yuntao,Ding Bao,Zhang Gong,Liu Qun. A New Phase-Locked Loop Approach for Three-Phase Three-Wire Photovoltaic Grid-Connected Inverter Systems[J]. Journal of Electrical Engineering, 2015, 10(7): 26-32.

Figures/Tables 15

References 12

[1]	Zhao Zhengming, Lei Yi, He Fanbo , et al. Overview of large-scale grid-connected photovoltaic power plants[J]. Autornation of Electric Power Systems, 2011,35(12):101-107.
[2]	Varma R K, Salama M, Seethapathy R , et al. Large-scale photovoltaic solar power integration in transmission and distribution networks[C]. Proceedings of 2011 IEEE Power & Energy Society General Meeting, 2011, Detroit, MI, USA:1-4.
[3]	Xu Dianguo, Wang Wei, Chen Ning . Dynamic characteristic analysis of doubly-fed induction generator low voltage ride-through based on crowbar protection[J]. Proceedings of the CSEE, 2010,30(22):29-36.
[4]	Yao Jun, Liao Yong, Zhuang Kai . A low voltage ride-through control strategy of permanent magnet direct-driven wind turbine under grid faults[J]. Autornation of Electric Power Systems, 2009,33(12):91-96.
[5]	Wei Lan, Chen Yuchen, Chen Guocheng . A low voltage ride-through control strategy of doubly fed induction generator[J]. Transactions of China Electrotechnical Society, 2011,26(7):30-36.
[6]	Li Hui, Fu Bo, Yang Chao . Reactive current allocation and control strategies improvement of low voltage ride though for doubly fed induction wind turbine generation system[J]. Proceedings of the CSEE, 2012,32(22):24-31.
[7]	Zheng Fei, Zhang Junjun, Ding Mingchang . Low voltage ride-through modeling and control strategy for photovoltaic generation system based on RTDS[J]. Automation of Electric Power Systems, 2012,36(22):19-24.
[8]	Zhang Junjun, Ju Rongrong, Qin Xiaodi , et al. Latest technical specifications and testing procedures for grid-connected photovoltaic power station in china[C]. Proceedings of Second International Conference on Intelligent System Design and Engineering Application, 2012: 1435-1439.
[9]	Alatrash H, Amarin R A, Cheung Lam . Enabling large-scale PV integration into the grid[C]. Proceedings of IEEE Green Technologies Conference, 2012: 1-6.
[10]	Ma Lin, Liao Hua, Li Jing , et al. Analysis of chinese photovoltaic generation system low voltage ride through characters[C]. Proceedings of 2012 7th International Power Electronics and Motion Control Conference, 2012, Harbin:1178-1182.
[11]	Golestan S, Monfared M, Freijedo F D , et al. Dynamics assessment of advanced single-phase PLL structures[J]. IEEE Transactions on Industrial, 2012,12(7):1-11.
[12]	Rodriguez P, Luna A, Ciobotaru M , et al. Advanced grid synchronization system for power converters under unbalanced and distorted operating conditions[C]. Proceedings of the IEEE 32st Annual Conference on Industrial Electronics, 2006: 5173-51.