Xiangjian SHI, Heqing HUANG, Teng LIU, Wei MU, Jianfeng ZHAO

Optimized idling grid-connection strategy for synchronous condenser

The rise of large-scale HVDC transmission technology has introduced new requirements for dynamic reactive power compensation in power systems. The new generation of synchronous condensers is independent of grid voltage and does not need to be dragged by a coaxial prime mover, which can improve the dynamic reactive power compensation of the power grid. This new generation of synchronous condensers is dragged by the static frequency converter to a 105% rated speed, after which the static frequency converter logs out. In the process of idling, the excitation mode switching is completed and the unit is connected to the grid simultaneously. The synchronous device passively captures the connection-dot in the process of idling; as a result, increasing the grid-connection success rate and reducing the impact of grid connection become a pair of contradictions. In this paper, the boundary conditions of the new generation of synchronous condenser grid-connection systems are analyzed. These provide the basis for setting the synchronous device parameters. Furthermore, this paper proposes an optimized grid-connection strategy to ensure the new generation of synchronous condensers possesses good grid-connection characteristics.

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1] Fan X, Zhou Y, Ruan L, Zhou K, Wang T et al. Study on coordinated control strategy of reactive power compensa- tion device in DC converter station with new-generation synchronous condensers. In: 2018 International Conference on Power System Technology; Guangzhou, China; 2018. pp. 2966-2971.
[2] Ramachandra SK, Vinoth KN, Harada Y. Impact of renewable energy control center on voltage stability and transmission network efficiency in wind farm integrated grid. In: 2014 IEEE International Conference on Power Electronics, Drives and Energy Systems; Mumbai, India; 2014. pp. 1-6.
[3] Wang X, Wei X, Meng Y. Experiment on grid-connection process of wind turbines in fractional frequency wind power system. IEEE Transactions on Energy Conversion 2015; 30 (1): 22-31. doi: 10.1109/TEC.2014.2358498
[4] Givaki K, Rahman HM, Vozikis D, Giveki. A. Analysis of integration of multi-terminal HVDC network to weak grids. The Journal of Engineering 2019; 2019 (16): 3219-3224. doi: 10.1049/joe.2018.8447
[5] Rabiee A, Soroudi A, Keane A. Risk-Averse preventive voltage control of AC/DC power systems in- cluding wind power generation. IEEE Transactions on Sustainable Energy 2015; 6 (4): 1494-1505. doi: 10.1109/TSTE.2015.2451511
[6] Pu Y, Zhong Q, Li X, Hu Y, Xu G. In: Influence of synchronous condenser on voltage stability of HVDC. In: 2018 IEEE Power & Energy Society General Meeting; Portland, OR, USA; 2018. pp. 1-5.
[7] Zhuang Y, Menzies RW, Nayak OB, Turanli. HM. Dynamic performance of a STATCON at an HVDC inverter feeding a very weak AC system. IEEE Transactions on Power Delivery 1996; 11 (2): 958-964. doi: 10.1109/61.489357
[8] Kalsi SS, Madura D, Ingram M. Superconductor synchronous condenser for reactive power support in an electric grid. IEEE Transactions on Applied Superconductivity 2005; 15 (2): 2146-2149. doi: 10.1109/TASC.2005.849481
[9] Fan X, Zhou Y, Ruan L, Zhou K, Wang T et al. Study on transient reactive power characteristics of new-generation large synchronous condenser. In: 2018 China International Conference on Electricity Distribution; Tianjin, China; 2018. pp. 1851-1855.
[10] Wu M, Dong Z, Li P, Ma X, Jin Z et al. Impact of new-type synchronous condenser on voltage stability of jarud sending-end system. In: 2018 International Conference on Power System Technology; Guangzhou, China; 2018. pp. 2654-2659.
[11] Rather ZH, Chen Z, Thøgersen P, Lund P. Dynamic reactive power compensation of large-scale wind integrated power system. IEEE Transactions on Power Systems 2015; 30 (5): 2516-2526. doi: 10.1109/TPWRS.2014.2365632
[12] Teleke S, Abdulahovic T, Thiringer T, Svensson J. Dynamic performance comparison of synchronous condenser and SVC. IEEE Transactions on Power Delivery 2008; 23 (3): 1606-1612. doi: 10.1109/TPWRD.2007.916109
[13] Wang Q, Li T, Tang X, Liu F, Lei J. Study on the site selection for synchronous condenser responding to commutation failures of multi-infeed HVDC system. The Journal of Engineering; 2019 (16): 1413-1418. doi: 10.1049/joe.2018.8807
[14] Ryu H, Kim B, Lee J, Lim I. A study of synchronous motor drive using static frequency converter. In: 2006 12th International Power Electronics and Motion Control Conference; Portoroz, Slovenia; 2006. pp. 1496-1499.
[15] Chai X, Zhang C, Wang Y, Gao J, Yang H. Analysis on idle-load grid-connection transient impact current of DFIG. In: 2011 International Conference on Electrical Machines and Systems; Beijing, China; 2011. pp. 1-5.
[16] Wang P, Mou Q, Liu X, Gu W, Chen X. Start-up control of a synchronous condenser integrated HVDC system with power electronics based static frequency converter. Access 2019; 7 (1): 146914-146921. doi: 10.1109/IFEEC.2017.7992178
[17] Wang P, Liu X, Mou Q, Gu W, Zhao X. Start-up control and grid integration characteristics of 300 MVar syn- chronous condenser with voltage sourced converter-based SFC. Access 2019; 7 (1): 176921-176934. doi: 10.1109/AC- CESS.2019.2953052
[18] Yang H, Zheng Y, Wang X, Jian Y, Hu J. Calculation method of success rate for idling grid-connection of large syn- chronous condensers. Automation of Electric Power Systems 2018; 42 (24): 74-78. doi: 10.7500/AEPS20180320003
[19] Zhang H, Hasler J, Johansson N, Ängquist L, Nee H. Frequency response improvement with synchronous condenser and power electronics converters. In: 2017 IEEE 3rd International Future Energy Electronics Conference and ECCE Asia; Kaohsiung, Taiwan; 2017. pp. 1002-1007