GPU-Accelerated Batch Solution for Short-Circuit Current Calculation of Large-scale Power Systems

Author(s):  
Boyang Shang ◽  
Yin Xu ◽  
Chengeng Zhang ◽  
Ying Chen ◽  
Zhengyuan Liu ◽  
...  
2020 ◽  
Vol 12 (22) ◽  
pp. 9333
Author(s):  
Sangwook Han

This paper proposes a reinforcement learning-based approach that optimises bus and line control methods to solve the problem of short circuit currents in power systems. Expansion of power grids leads to concentrated power output and more lines for large-scale transmission, thereby increasing short circuit currents. The short circuit currents must be managed systematically by controlling the buses and lines such as separating, merging, and moving a bus, line, or transformer. However, there are countless possible control schemes in an actual grid. Moreover, to ensure compliance with power system reliability standards, no bus should exceed breaker capacity nor should lines or transformers be overloaded. For this reason, examining and selecting a plan requires extensive time and effort. To solve these problems, this paper introduces reinforcement learning to optimise control methods. By providing appropriate rewards for each control action, a policy is set, and the optimal control method is obtained through a maximising value method. In addition, a technique is presented that systematically defines the bus and line separation measures, limits the range of measures to those with actual power grid applicability, and reduces the optimisation time while increasing the convergence probability and enabling use in actual power grid operation. In the future, this technique will contribute significantly to establishing power grid operation plans based on short circuit currents.


2013 ◽  
Vol 805-806 ◽  
pp. 756-762
Author(s):  
Bi Qiang Tang ◽  
Li Wen Wang ◽  
Yi Jun Yu ◽  
Fei Shi ◽  
Shu Hai Feng

With the growing scale of power systems in China, short-circuit current levels of power systems have been significantly increasing. Appropriate grid topology adjustment is an effective method for short-circuit current limitation. The specific measures include transmission line outage, transformer outage, etc. In this paper, a practical optimization algorithm of grid topology adjustment is put forward. A weighted comprehensive sensitivity index is adopted to speed up the procedure of adjustment strategy searching. The detailed calculation method of this index for different measure types is presented. And a security & economy assessment is implemented to ensure the feasibility of potential adjustment strategies. Moreover, the framework of an online topology adjustment decision support software based on this optimization algorithm is proposed. The effectiveness of the presented method is demonstrated by the test on a large-scale power system.


2019 ◽  
Vol 11 (4) ◽  
pp. 1153 ◽  
Author(s):  
Namki Choi ◽  
Bohyun Park ◽  
Hwanhee Cho ◽  
Byongjun Lee

This study analyzed the impact of varying the momentary cessation (MC) voltage level on the short circuit current of inverter-based resources (IBRs). To analyze the impact of the IBR MC function on the short circuit current, this paper proposes an advanced IBR model for fault current calculation to reflect its fault characteristics and a scheme for analyzing the influence of MC on the short circuit current. Based on the proposed methods, the authors conducted case studies using planning data from the Korea Electric Power Corporation (KEPCO). The influence of MC was investigated on the IBRs located at the southwest side of the KEPCO systems by screening the fault currents while varying the MC voltage. This paper demonstrates that the minimum MC voltage level needed for the fault current not to exceed the circuit breaker (CB) capacity can be proposed through analyzing the impact of MC voltage level on the short circuit current. The test results based on the proposed scheme showed that the short circuit current to power systems could not violate CB capacity if IBRs adjusted the MC voltage level higher than the lowest MC voltage level.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jun Yin

With the enlarging scale of doubly-fed induction generators (DFIGs) connected to power systems, it is important to analyze the influence of a short-circuit current to system relay protection. Due to the correct evaluation of the protection operation characteristics, the DFIG short-circuit current needs to be calculated accurately. But the current research on the short-circuit current of DFIG is based on the following assumption: the rotor excitation current is zero after the rotor crowbar is put, and the influence of its dynamic process is ignored. This will bring errors to the calculation results. This paper takes into account the influence of rotor current dynamics by studying the mechanism of the potential transient change of DFIG. The stator rotor flux linkage of DFIG in the event of a three-phase short-circuit is accurately calculated, and an improved RMS calculation method of doubly-fed wind turbine short circuit current is proposed. A physical experiment platform with an actual controller of a doubly-fed fan is established, based on RTDS. It can be seen from the experiment that the short-circuit current calculation method proposed in this paper is more accurate than those methods that ignore the rotor dynamic process. This study lays a foundation for further study of the influence of DFIG on the protection operation characteristics.


Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.


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