scholarly journals Network Attack Path Selection and Evaluation Based on Q-Learning

2020 ◽  
Vol 11 (1) ◽  
pp. 285
Author(s):  
Runze Wu ◽  
Jinxin Gong ◽  
Weiyue Tong ◽  
Bing Fan

As the coupling relationship between information systems and physical power grids is getting closer, various types of cyber attacks have increased the operational risks of a power cyber-physical System (CPS). In order to effectively evaluate this risk, this paper proposed a method of cross-domain propagation analysis of a power CPS risk based on reinforcement learning. First, the Fuzzy Petri Net (FPN) was used to establish an attack model, and Q-Learning was improved through FPN. The attack gain was defined from the attacker’s point of view to obtain the best attack path. On this basis, a quantitative indicator of information-physical cross-domain spreading risk was put forward to analyze the impact of cyber attacks on the real-time operation of the power grid. Finally, the simulation based on Institute of Electrical and Electronics Engineers (IEEE) 14 power distribution system verifies the effectiveness of the proposed risk assessment method.

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Dalila M.S. ◽  
Zaris I.M.Y. ◽  
Nasarudin A. ◽  
Faridah H.

This paper purposely to examine and analyse the impact of the distribution capacitors banks operation to the transition of total harmonic distortion (THD) level in distribution network system. The main advantage of this work is the simplicity algorithm of the method and the system being analysed using free access open software which is known as electric power distribution system simulator (OpenDSS). In this paper, the harmonic current spectrum which is collected from the commercial site was injected to a node point on IEEE13 bus in order to provide the initial measurement of THD for the network. The proper sizing of the capacitors banks has been set and being deactivated and activated throughout the network to see the transistion in the THD level in the system. The results were achieved by simulation of the data on the configured IEEE13 bus. The simulation work was done by using the combination of C++ source codes, OpenDSS and Microsoft Excel software. From the output results, the THD current has increased up to two times from the initial value in certain phases and for the THD voltage, the THD has increased up to three times from its initial value in all phases.


Author(s):  
Zuhaila Mat Yasin ◽  
Izni Nadhirah Sam’ón ◽  
Norziana Aminudin ◽  
Nur Ashida Salim ◽  
Hasmaini Mohamad

<p>Monitoring fault current is very important in power system protection. Therefore, the impact of installing Distributed Generation (DG) on the fault current is investigated in this paper. Three types of fault currents which are single line-to-ground, double line-to-ground and three phase fault are analyzed at various fault locations. The optimal location of DG was identified heuristically using power system simulation program for planning, design and analysis of distribution system (PSS/Adept). The simulation was conducted by observing the power losses of the test system by installing DG at each load buses. Bus with minimum power loss was chosen as the optimal location of DG. In order to study the impact of DG to the fault current, various locations and sizes of DG were also selected. The simulations were conducted on IEEE 33-bus distribution test system and IEEE 69-bus distribution test system. The results showed that the impact of DG to the fault current is significant especially when fault occurs at busses near to DG location.</p>


2014 ◽  
Vol 986-987 ◽  
pp. 187-191
Author(s):  
Bo Zeng ◽  
Kai Wang ◽  
Xiang Yu Kong ◽  
Yi Zeng ◽  
Qun Yang

With high penetration of distributed generation connected to the grid, distribution system will have some huge impacts, and system reliability calculation models and assessment methods are changing. Based on Monte-Carlo method, a heuristic reliability analysis method for distribution system with distributed generations was proposed in the paper, which focuses on the mode of distributed generation in parallel to system power supply. Functional role of distributed generation in the power distribution system failure and distributed power adapter with load strategies were analyzed in this method. Cases simulation analysis was used to verify its effectiveness.


2015 ◽  
Vol 785 ◽  
pp. 167-171
Author(s):  
Saidu Kumo Mohammed ◽  
Norman Mariun ◽  
Mohd Amran Mohd Radzi ◽  
Noor Izzri Abdul Wahab

The increasing penetration of photovoltaic (PV) Distributed Generation (DG) systems in the electric power distribution system necessitates the development of power electronics inverter to interface the PV DG with the grid. The output parameters of the DG are determined by the inverter control strategy. An open-loop control (NCTRL) and two close-loop controls; Constant-Current Control (CCC) and Constant-Power Control (CPC) were considered for the inverter. The impact of inverter control techniques are compared based on power transformation efficiency and islanding behaviour of the DG. A grid-connected PV DG and the control techniques were simulated using MATLAB Simulink. A mathematical formulation of the inverter islanding voltage at the point of common coupling was driven and validated by simulation. Results indicated that a closed loop control of inverter is essential for maximum efficiency and stability of DG in post islanding


2015 ◽  
Vol 785 ◽  
pp. 403-408 ◽  
Author(s):  
Hadi Suyono ◽  
Muammar Zainuddin

Utilization of photovoltaic power plants on distribution system has been widely used in many countries. Commonly, the photovoltaic system has been injected to the distribution system and called as photovoltaic distributed generations (PVDG) through medium or low voltage levels. The injection of the PVDG on the distribution system has been claimed to improve the voltage profile and reduce power losses. However, the good performance of the distribution system in term of the steady-state point of view, cannot directly guarantee to give a good response during the system disturbed. Therefore, to show the impact of the PVDG injection on power system stability is concerned in this paper. The size of the power injection and location of the injection site that have been determined by using the optimization technique, are then analyzed based on three scenarios, each of which represents the PVDG injection of 2x0.5MW, 4x0.5MW, and 6x0.5MW respectively at different bus locations. The voltage-, frequency-, and rotor angle-stabilities are analyzed to show the dynamic impact of the PVDG during three-phase fault condition. The analysis results indicate that the second scenario gives the best response in term of the rotor angle-, frequency-, and voltage-responses during dynamic conditions which supplies active power around 28.78% of the total load. The PVDG injection power in the first scenario (14.39% of total load) and also in the third scenario (43.18% of total load) would result in rotor angle and frequency responses with more oscillations being compared to the second scenario. However, the system dynamic responses for all scenarios show damped oscillations to reach the steady-state conditions.


2021 ◽  
Vol 257 ◽  
pp. 02062
Author(s):  
Longju Bai

This study aims to enhance the reliability of the urban power grid system and decrease the economic loss due to power network faults. Based on the analysis of the traditional algorithms for restructuring the urban distribution system after faults, this study proposes an upgraded genetic algorithm (GA) and ant colony algorithm (ACA) and combines these two to overcome the limitations of the local optimum of GAs and low convergence speed of ACAs. Taking the IEEE33-node system as the research object, the network loss, maximum recovery of the power-loss load, and the number of switching operations as the objective function, the impact of different algorithms on the restoration and reconfiguration of the distribution system was examined according to MATLAB system simulation and the optimal algorithm for the reconfiguration of the urban distribution system failure recovery. The experimental results revealed that compared with the current distribution system reconfiguration algorithm, the genetic-ant colony algorithm (GACA) has higher algorithm time efficiency and solution accuracy and can markedly decrease the recovery time and improve the impact of the distribution system in a short period. Overall, the proposed GACA is an efficient self-healing algorithm of urban distribution systems and useful for augmenting the reliability of the urban power system.


2011 ◽  
Vol 21 (3) ◽  
pp. 2161-2164 ◽  
Author(s):  
Jong-Fil Moon ◽  
Sung-Hun Lim ◽  
Jae-Chul Kim ◽  
Sang-Yun Yun

2015 ◽  
Vol 785 ◽  
pp. 532-537 ◽  
Author(s):  
Khairul Anwar bin Ibrahim ◽  
Mau Teng Au ◽  
Chin Kim Gan

Distribution system planning involves a set of complex analysis as the amount of data and associated parameters needed for the analysis are huge. Simplified reference network models (or a generic representative network) would help to reduce the amount of data to be handled, and thereby simplify the complexities of analysis. Depending on the parameters used, reference network models could be applied to assess the technical and economic performance of a network, such as, investment consequences against impact of customer end tariff pricing. The inherent idea is to develop a generic reference models that would help to visualize the impact of different planning parameters, such as adequacy, reliability, and quality against cost. These models have the potential capability for flexible usage on fast developing networks. This paper discusses an indigenous conceptual development of a reference network based on the Malaysian distribution system


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