Study on Short Circuit Current Calculation of Power System with UHVDC and New Energy Source
- 1 China Electric Power Research Institute, Beijing, China
- 2 State Grid Shaanxi Power Corporation Economic Research Institute, Xi’an, China
- 3 China Electric Power Research Institute, Beijing, China
- 4 State Grid Shaanxi Power Corporation Economic Research Institute, Xi’an, China
Abstract
With the development of power system, the level of short circuit current will increase accordingly. In general, the influence of the HVDC system and the new energy source is not considered in the calculation of the short circuit current. For the power grid that short circuit current level closes to the interrupting capacity of circuit breaker, it’s necessary to fully consider all kinds of influence factors, careful checking, so as to obtain more accurate calculation results of short circuit current. In 2018, two ±800 kV high-power Ultra High Voltage Direct Current (UHVDC) transmission projects will be connected with Shaanxi power grid, accompanied by a lot of concomitant fossil-fuel generating plants as power resource, and also a large number of new energy source, includes wind power generation and photovoltaic power generation. Around one of the UHVDC converter stations, short circuit current may exceed the withstand limit of some certain circuit breakers. In order to get more accurate short circuit current calculation results, three measures are used: 1) contrastive calculation and analysis by algorithm based on schemes and algorithm based on power flow; 2) analysis the influence of UHVDC by electromagnetic transient and electromechanical transient hybrid simulation; 3) considered a detailed model of Doubly Fed Induction Generator (DFIG) with low voltage ride through characteristics. The calculation results shows that: in the typical operation mode of Shaanxi power grid of 2018, the original calculation results by conventional calculation method are coincident with the results by considering the influence of algorithms, UHVDC and DFIG in large, in which: the results of the algorithm based on power flow are smaller than that of the algorithm based on schemes about 2 - 8 kA; the steady values of the short circuit current provided b y UHVDC converterstation (includes rectifiers and smoothing capacitors) are about 0 - 3 kA; the steady values of the short circuit current provided by DFIG are about 0 - 5 kA. The calculation results can provide reference for the selection of the circuit breaker, and it can be verified by fault recording data in the future.
- Huang, X.L., Liu, Z.R., Zhu, R.J., Yang, Z.H., Zhou, G., et al. (2010) Impact of Power System Integrated with Large Capacity of Variable Speed Constant Frequency Wind Turbines, Transactions of China Electrotechnical Society, 25, 142-149．
- IEC 61660-1: 1997, Short Circuit Currents – Short Circuit Currents in D.C. Auxiliary Installations in Power Plants and Substations – Part 1: Calculation of Short Circuit Currents, June 1998.
- IEC 60909-0: 2001, Short-Circuit Currents in Three-Phase A. C. Systems – Part 0: Calculation of Currents, July2001.
- Andreas, W., Benedikt, J. and Gerd, B. (2013) Contribution of HVDC converters to the DC Short Circuit Current. Proceedings of the 48thInternational Universities’ Power Engineering Conference, 1-6.
- Muljadi, E., Samaan, N., Gevorgian, V. and Li, J. and Pasupulati, S. (2010) Short Circuit Current Contribution for Different Wind Turbine Generator Types. Proceedings of IEEE Power and Energy Society General Meeting, 1-8. https://doi.org/10.1109/PES.2010.5589677
- Adio, O.S., Lin, X.N., Zhao, F. and Bo, Z.Q. (2013) Short Circuit Analysis for Inte-gration of l0MW Windfarm in Nigeria at the PCC. Proceedings of IEEE Power & Energy Society General Meeting, 1-5. https://doi.org/10.1109/PESMG.2013.6672196
- Bhatia, R. and Bahirat, H.(2016)Short Circuit Currents of DFIG based Wind Turbines. Proceedings of IEEE 6th International Conference on Power Systems (ICPS), 1-6. https://doi.org/10.1109/ICPES.2016.7584193