scholarly journals Control Method of Buses and Lines Using Reinforcement Learning for Short Circuit Current Reduction

2020 ◽  
Vol 12 (22) ◽  
pp. 9333
Author(s):  
Sangwook Han
Keyword(s):  
Reinforcement Learning ◽  
Power Systems ◽  
Large Scale ◽  
Control Method ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Control Methods ◽  
Grid Operation ◽  
Short Circuit Currents

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.

Study on Power Transmission Plan of the Nuclear Power Base in Shandong Peninsula

2016 ◽  
Author(s):  
Chengzhu Yin ◽  
Miao Wang
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Large Scale ◽  
Power Transmission ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Jiaodong Peninsula ◽  
Power Load ◽  
Power Base

The nuclear power site resource is very rich in Jiaodong Peninsula of Shandong Province. It is suitable for construction of the large nuclear power base. The transmission scope and direction of Jiaodong Peninsula nuclear power base is analyzed, and optional transmission plans of Plant 1, Plant 2, Plant 3 and Plant 4 are proposed. The transmission plans are recommended based on technical and economic comparison, which provide good references for construction of the large-scale nuclear power base and power grid development planning. Jiaodong Peninsula nuclear power base is planned to be built in the year of 2016–2030, planning capacity of which is 30500MW. The site of nuclear power base is 100∼400km away from the power load center. The nuclear power will use AC transmission and mainly meet the demand of local power load. The early 15500MW gensets will be accessed to the power grid at 500kV, as the following 15000MW gensets will be accessed at 1000kV UHV (Ultra-high voltage) grid. As the accessing of many large-capacity gensets will produce huge impact to the short-circuit current, sectionalized double-bus configuration is recommended in the 500kV main electrical wiring to reduce the short-circuit current of 500kV bus of nuclear power plant. Double bus section cross wire connection is presented to make sure that every two generators on each bus will be connected to different substations on two transmission lines which are set up on different poles and in different paths, to improve the reliability of the power plant. Through analysis and provement, the construction of large nuclear power base must be based on large and stronge power grid, especially the UHV (Ultra-high voltage) AC grid, to meet the demand of huge nuclear power transmission, and to improve the ability of power exchange and ensure the safety of regional power supply. Also, as the nuclear power plant should better be in base-load operation, the construction of large-scale nuclear power base, would make the system load-control demands increase, which leads to more prominent problems. In order to avoid adding additional depth of peaking power operation and reducing the overall economic operation of power system, power grid should have the necessary means to load-control. Namely the construction of peaking units, such as pumped storage units or gas-fired units at about 5000MW. By analyzing and demonstration, large-scale nuclear power base must rely on large-scale power grid, particularly the support of UHV power grid in order to meet the demond of large-scale power transmission and electricity exchange, and also to ensure regional security of electricity supply.

A Method of Online Topology Adjustment Decision Support for Short-Circuit Current Limitation

2013 ◽  
Vol 805-806 ◽  
pp. 756-762
Author(s):  
Bi Qiang Tang ◽  
Li Wen Wang ◽  
Yi Jun Yu ◽  
Fei Shi ◽  
Shu Hai Feng
Keyword(s):  
Decision Support ◽  
Power Systems ◽  
Optimization Algorithm ◽  
Large Scale ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Sensitivity Index ◽  
Detailed Calculation ◽  
Current Limitation ◽  
Grid Topology

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.

A Novel Method of Static Security Analysis Based on Multithread Technology

2013 ◽  
Vol 732-733 ◽  
pp. 639-645
Author(s):  
Bi Qiang Tang ◽  
Yi Jun Yu ◽  
Shu Hai Feng ◽  
Feng Li
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Power Grid ◽  
Security Analysis ◽  
Power Grids ◽  
Long Time ◽  
Grid Construction ◽  
Static Security ◽  
Bulk Power ◽  
Grid Operation

With the UHV (Ultra High Voltage) power grid construction and the interconnection of regional power grids, the scale of power grids in China is increasing rapidly. At the same time, significant uncertainty and variability is being introduced into power grid operation with the integration of large-scale renewable energy in power systems. All of these pose an enormous challenge to the operation control of power systems in China. For a long time, online static security analysis, as an important part of EMS (Energy Management System), has been an effective tool for power grid operation. However, it is increasingly difficult for traditional static security analysis in serial computing mode to be online applied in bulk power grids in China. A new practical parallel approach for online static security analysis is put forward in this paper. A multithread parallelism is introduced into contingency screening, detailed contingency evaluation and decision support for reducing the execution time. By employing the multithread technology, the hardware resources of multi-processor/multi-core computer can be fully used and the program can be speeded up effectively. The performance of the parallel static security analysis is demonstrated by tests on two large-scale power systems. The test results show that the proposed method can be online applied in real bulk power grids.

scholarly journals Three-Phase Short-Circuit Current Calculation of Power Systems with High Penetration of VSC-Based Renewable Energy

Energies ◽  
2018 ◽  
Vol 11 (3) ◽  
pp. 537 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Renewable Energy ◽  
Steady State ◽  
Power Systems ◽  
Short Circuit ◽  
Power Grid ◽  
Current Source ◽  
Transient State ◽  
Experimental Tests ◽  
Short Circuit Current ◽  
High Penetration

Short-circuit current level of power grid will be increased with high penetration of VSC-based renewable energy, and a strong coupling between transient fault process and control strategy will change the fault features. The full current expression of VSC-based renewable energy was obtained according to transient characteristics of short-circuit current. Furtherly, by analyzing the closed-loop transfer function model of controller and current source characteristics presented in steady state during a fault, equivalent circuits of VSC-based renewable energy of fault transient state and steady state were proposed, respectively. Then the correctness of the theory was verified by experimental tests. In addition, for power grid with VSC-based renewable energy, superposition theorem was used to calculate AC component and DC component of short-circuit current, respectively, then the peak value of short-circuit current was evaluated effectively. The calculated results could be used for grid planning and design, short-circuit current management as well as adjustment of relay protection. Based on comparing calculation and simulation results of 6-node 500 kV Huainan power grid and 35-node 220 kV Huaisu power grid, the effectiveness of the proposed method was verified.

Sign in / Sign up

Export Citation Format

Share Document