Power Supply Reliability Evaluation Research Articles

Power supply reliability evaluation of distribution network based on non-intrusive low-voltage power load identification and time series algorithm

Power supply reliability evaluation of distribution network based on non-intrusive low-voltage power load identification and time series algorithm

Power supply reliability evaluation of distribution network based on non-intrusive low-voltage power load identification and time series algorithm

Power supply reliability evaluation of distribution network based on non-intrusive low-voltage power load identification and time series algorithm

Evaluation Method of the Incremental Power Supply Capability Brought by Distributed Generation

More and more distributed generation (DG) and energy storage (ES) devices are being connected to the distribution network (DN). They have the potential of maintaining a stable supply load during failure periods when using islanding operations. Therefore, DG and ES have capacity value, i.e., improving the power supply capability of the system. However, there are strong fluctuations in DG outputs, and the operations of ES devices have sequential characteristics. The same capacity of DG has different load-bearing capabilities compared to conventional thermal or hydroelectric units. This paper proposes a method for evaluation of power supply capability improvement in DNs. First, the temporal fluctuation in both power source and load demand during fault periods is considered. A DN island partition model considering the secondary power outage constraint is established. Then, a modified genetic algorithm is designed. The complex island partition model is solved to achieve accurate power supply reliability evaluation. And the incremental power supply capability associated to DG and ES devices is calculated. Finally, a case study is conducted on the PG&E 69-bus system to verify the effectiveness of the proposed method. It is found that with a 20% configuration ratio of ES devices, the power supply capability improvement brought about by 6 MW DG can reach about 773 kW.

Research on reliability evaluation of complex distribution network considering N-1 verification

With the rapid development of power system, the distribution network structure is gradually mature and the connection situation is more complex. The traditional distribution network reliability calculation method can not accurately calculate the reliability index of complex distribution network. Based on the traditional simple power supply reliability evaluation method of radial distribution network, this paper completely considers the influence of circuit breaker, tie switch, branch line, standby transformer and other equipment, and puts forward an improved network equivalence method model. The model first treats the complex distribution system in layers, and then gradually equates it into a simple radial distribution network to calculate the reliability of the system. At the same time, this paper analyzes the distribution network with multi connection structure in a provincial capital city. The results show that this model simplifies the complexity of distribution system reliability calculation, improves the accuracy and speed of reliability calculation, and more truly reflects the reliability of actual distribution system.

Interval Reliability Evaluation of a Hybrid Energy Generation System With Energy Storage

To deal with the uncertainties of wind power and load residing in the power supply reliability model, an interval reliability evaluation method is proposed by combining the wind power generation and energy storage system (ESS). Firstly, the interval power supply reliability evaluation model, which belongs to an interval mixed integer program (IMIP), is established based on the interval variables. Secondly, the IMIP model is transformed into the deterministic optimization model under two extreme circumstances by utilizing the possibility degree theory of interval numbers. The maximum power supply probability, considering the wind power interval to meet the load demand interval, is sought by optimizing outputs of the ESS and generators, i.e., the upper boundary of the load shedding is the smallest. Finally, the states of wind turbines and generators are generated based on sequential Monte Carlo simulation, and the reliability of the hybrid energy generation system is evaluated by calculating the loss of load expectation, expected energy not supplied, and maximum power supply probability, which provides a basis for establishing interval optimal allocation model of energy storage. IEEE RTS-24 test system is utilized to verify the performance of the proposed method, and the model is solved by the CPLEX 12.7 solver. The simulation results demonstrate the effectiveness and applicability of the proposed method.

Power supply reliability evaluation based on big data analysis for distribution networks considering uncertain factors

The safety and reliability of urban power supply are critical to the sustainability of cities and society. Based on the analysis of big data, a power supply reliability evaluation method for urban distribution networks considering uncertain factors is proposed in this paper. The method has good adaptability and can support the analysis of safety improvement measures. By investigating historical data on distribution network topology and parameters, the main influencing factors affecting power supply reliability and the uncertainties of these factors are screened out. An improved Elman neural network (IENN) is used, and the main process of reliability evaluation is obtained for the complex urban distribution network. It can effectively simplify the calculation and includes multiple uncertain factors to improve evaluation accuracy. Case studies with actual urban distribution network data are used to verify the feasibility and effectiveness of the proposed method. Finally, some useful conclusions are given, including the problems of urban distribution network power supply, and the improvement measures for power supply to support the development of sustainable cities and society.

Reliability Evaluation Method of Distribution Network Based on Consumers’ Sensitivity Classification

In order to improve the accuracy of power supply reliability evaluation, this paper proposes a reliability evaluation method of distribution network based on consumers’ voltage quality sensitivity. Firstly, 6 indexes of power supply reliability are extracted and divided into general and other indexes to measure consumers-side experience and failure repair capability respectively. Secondly, according to the consumers’ voltage quality sensitivity, they are classified into sensitive consumers, general consumers and insensitive consumers. Based on the data of regional electricity consumers, consumers’ voltage sensitivity classification is obtained. After combining the voltage sensitivity classification of consumers with distribution network reliability index data, a reliability evaluation model of distribution network is established. Finally, an instance analysis shows that consumers’ sensitivity and the proportion of different consumers have significant influence on the evaluation results.

Reliability Evaluation of Power Supply for More-Electric-Aircraft Based on Information Entropy

In order to overcome the shortcomings of traditional power supply reliability evaluation model of multi-electric aircraft in the process of multi-component system research, this paper introduces the approximate probability distribution of multi-component system by cross-entropy, it proposes a Monte Carlo method based on information entropy to evaluate the power supply reliability of multi-electric aircraft, and obtains the approximate probability distribution by differential evolution to make the reliability evaluation. The estimated variance is approximately zero. Finally, taking an aircraft power supply system as an example, the convergence and accuracy of several reliability analysis methods are compared and analyzed. The results show the superiority of this method.

Power Supply Reliability Evaluation of Distributed Network with Distributed Generation Considering Load Nodes’ Equivalent Loss of the Electric Quantity

As the network is becoming complicated and two-way interactive, it’s necessary to analyze every user’s power supply reliability based on the operating of the network. The essay evaluated the power supply reliability of different nodes in the distributed network with distributed generation from the perspective of the users’ power outage consequence, according to the equivalent load tree model of distributed network, combining load nodes’ loss of electricity and the value of electricity loss, the concept and computational model of load nodes’ equivalent loss of the electricity quantity was proposed. Combining the concept model of equivalent loss for load nodes’ electricity and the power outage duration index of the reliability of distribution network, the evaluation method of the power supply reliability calculation of Monte Carlo considering the equivalent loss index of the electric quantity was proposed. The efficiency for the method is proved by the example, and the method also provides suggestions for network specific rebuilding and the selection of operation mode of distribution network.

Power Supply Reliability Evaluation Based on the Characteristics Mode of Large-Scale Medium Voltage Distribution Network

It is difficult to evaluate and analyze power supply reliability of large-scale medium voltage distribution network by detailed modeling method. The paper proposes a power supply reliability evaluation method of large-scale medium voltage distribution network, which is based on the network reliability characteristics model. Lines with similar structural characteristics are designated as one model. The reliability index of each mode can be represented by the typical lines. The assessment principle, process and the advantages of this method are elaborated. The medium voltage distribution network of Nanjing area is taken as an example to evaluate power supply reliability. And the results are compared with historical statistics. The result shows that the method can greatly reduce the workload and has high accuracy. It can be used to evaluate the reliability of large-scale medium voltage distribution network.

High-speed Railway External Power Supply Reliability Evaluation of Bayesian Network

Reliability evaluation is important in high speed railway external power supply design, based on probability reasoning bayesian network applied in high-speed railway external power supply reliability evaluation, establish the minimum cut and the minimum path of bayesian network model, quantitative calculation external power supply system in each element posterior probability, and the example analysis verified the feasibility and correctness of the above method. Using bayesian network bidirection reasoning technology, quantitative calculation the posterior probability of each element in external power supply system, realized the identification of weak link in external power supply. The research methods and the results of the study can be used in the scheme optimization design of high speed railway external power supply.

Optimal Operation Scheduling of Pumped Storage Hydro Power Plant and Thermal Power Plants in Power System with a Large Penetration of Photovoltaic Generations

In recent years, a substantial amount of photovoltaic (PV) generations have been installed in power systems. However, the power output from the PV is random and intermittent in nature. Therefore, the PV generation poses many challenges to the power system operation. To evaluate the impact of the behavior of PV on power supply reliability, we have developed a power supply reliability evaluation model considering a large integration of PV generation into power system. As a result, the power supply reliability is getting worse as the PV penetration level increases. To solve this issue, we have proposed that pumped storage hydro power plant (PSHPP) is used effectively to improve the reliability. In this paper a cooperative scheduling method for the PSHPP and thermal power plants that makes it possible to improve both reliability and economy is presented. being considered as a solution in most situations. This paper proposes an effective use of Pumped Storage Hydro Power Plant (PSHPP). PSHPP is installed originally for hot reserve of the power system and load leveling. The energy is stored in the form of water pumped up from a lower reservoir to an upper reservoir. The PSHPP is usually operated as a generator in the daytime and a pump in the nighttime. A new operation scheduling of PSHPP is proposed to solve the problem in this paper. It will be operated with the proposed pattern solving the surplus power problem caused by the PV generation. The authors have already proposed how the PSHPP operation pattern is changed effectively to improve the power system reliability in case of a large integration of PV into the power system (1). However, the scheduling method for obtaining the optimal PSHPP operation pattern that makes it possible to improve both reliability and economy has not been developed yet. In this paper, we propose a new method for planning PSHPP operation pattern considering the surplus power problem, power supply reliability and fuel cost reduction, which is represented by pareto optimal solutions. The power supply reliability and the fuel cost are estimated for each PSHPP operation plan by using Monte Carlo simulation.

Impact of Operational Scheduling of Pumped Storage Power Plant Considering Excess Power on Power Supply Reliability in a Power System with a Large Penetration of Photovoltaic Generations

In recent years, a substantial amount of photovoltaic (PV) generations have been installed in Japanese power systems. However, the power output from the PV is random and intermittent in nature. As is known, the PV generation poses many challenges to the power system operation. To evaluate impact of the behavior of PV, we developed power supply reliability evaluation model considering a large penetration of PV generation into the power system. As a result, power supply reliability is getting worse as the PV penetration increases. To mitigate these issues, we proposed that pumped storage power plant (PSPP) is used to improve the reliability. This paper presents a fundamental study on the impact of the operation scheduling of PSPP taking into account the excess power caused by PV generations on the power supply reliability, which is evaluated by Monte Carlo simulation.