Reliability Evaluation Of Distribution Network Research Articles

Reliability Evaluation of Distribution Network with Electric Vehicles and Distributed Generations Based on Network Equivalence and Sequential Monte Carlo Method

Reliability Evaluation of Distribution Network with Electric Vehicles and Distributed Generations Based on Network Equivalence and Sequential Monte Carlo Method

Reliability Evaluation of Distribution Networks Considering Natural Gas Network Integration

Abstract With the transformation of energy structure, the distribution network in the form of multi-energy interconnection is gradually emphasized. The access of gas turbines to the distribution network puts high requirements on the reliability assessment of the distribution network counting and natural gas network access. Models of distribution network components and natural gas network equipment are established. Based on the traditional sequential MC reliability assessment, the calculation of reliability indexes for the distribution network with gas turbine access is accomplished by identifying the islanded areas under fault conditions and judging the gas turbine output state, taking into account the energy flow constraints. The results of the calculations show that the reliability of the distribution network with natural gas network access is improved, and the reliability of the load nodes near the gas turbine is improved significantly.

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

Reliability evaluation of distribution network for educational purpose: An analytical approach to results analysis

Despite the decade-long development in distribution networks, they are still unable to fulfil society's increasing need for reliable power supply. Investment is necessary for reliability enhancement, which will increase the consumer supply costs. This paper presents a new strategy to enhance the reliability of the network based on network restructuring. This study offers the cost-worth reliability indices, followed by an associated mathematical model with the objective function to reduce the well-known reliability indices Expected Interruption Cost (ECOST) and Energy Not Served (ENS). A Modified Greedy Search Algorithm (MGSA) is introduced to the network optimization for global optimal configuration. Furthermore, to make the model more efficient and realistic, the suggested approach incorporates the effects of fuse failure probability. The impact of the system's islanded operation on the reliability indices is also evaluated. The simulation results show 3.33 % reduction in System Average Frequency Index (SAIFI) as compared with the Fast Adequacy Analysis Method. The results shows that the value of ENS using the proposed MGSA compared to SA and GA improved by 100 %. The application of the proposed strategy on the distribution network connected at BUS-2 of Roy Billinton Test System (RBTS), shows the accuracy and computational effectiveness of the proposed model compared to the state-of-the-art conventional simulation-based topology-variable-based approaches.

Combing data-driven and model-driven methods for high proportion renewable energy distribution network reliability evaluation

To accurately evaluate the reliability of the renewable energy distribution network, a combined data-driven and model-driven method of distribution network reliability evaluation are proposed. The approach improves the traditional reliability evaluation method in the uncertainty scenario generation and fault consequence analysis stages. In the scenario generation stage, an interpretable network architecture capable of adaptively learning the inherent randomness, volatility, and time variability properties of renewable energy is designed. The proposed DG output uncertainty generation method integrates the Conditional Wasserstein Generative Adversarial Network (CWGAN) based scenario generation and clustering-based scenario reduction. It accurately portrays uncertainty in distributed generation (DG) output power. In the fault consequence analysis stage, an optimization model for the reliability evaluation of distribution networks based on mixed integer linear programming is proposed. The model fully accounts for substation protection, branch line protection, network reconfiguration, DG, and energy storage system (ESS) components. Time-series analytical expressions for the corresponding reliability indices are established. Finally, with the combination of data-driven and model-driven methods, a distribution network reliability evaluation framework considering the uncertainty of renewable energy is proposed. Simulation tests are performed on a modified IEEE 123 bus system. The results verify the effectiveness and feasibility of the method. The proposed simulation analysis method can effectively quantify the distribution networks’ reliability compared to the traditional method. It has higher calculation accuracy.

Reliability Evaluation of Distribution Networks Considering the Randomness of Wind Turbine Outputs

With more and more distributed generators integrated into the distribution networks, the uncertain outputs of distributed generators make the reliability evaluations of distribution networks harder to be handled. However, the existing studies such as the analytical method and simulation method cannot take into account the accuracy and calculation efficiency at the same time in a real time operation. So this paper proposes a reliability evaluation method for distribution networks considering the randomness of WT outputs. Firstly, based on the probability level of the WT outputs in different scenarios by prediction error of wind speed, the island division method under multi-scenario conditions is proposed. Then, the reliability of the distribution network with WTs is evaluated by the improved minimal path method. Finally, numerical simulations on the IEEE-RBTS 6 bus system show the superiority of the proposed algorithm over existing methods.

Reliability Evaluation Method of New Energy Distribution Network Based on Improved Correlation Weight Method

The reliability of the distribution system includes adequacy and security. Adequacy refers to the degree to which the system capacity meets the power and energy demand of the load. Security is the evaluation of the system’s ability to withstand sudden failures. In view of the uncertainty of decision factors and the difficulty to quantify the weights in the process of reliability evaluation of distribution network, an evaluation method for load restoration of a smart distribution network based on the improved relevance weight with index correlation and improved analytic hierarchy process (AHP) is proposed. The paper also proposes an evaluation system including distribution network structure level indexes. The planning scheme of the distribution network is comprehensively evaluated, and the effectiveness of the method is analyzed through the comparison of actual cases combined with the indicators of the grid structure level. Experimental analysis shows that compared with the traditional power supply reliability or system average outage time, the global index considering LRP is more refined in describing the impact of outage, and the evaluation results are more accurate.

Reliability Assessment of Distribution Network Considering Multiple Types of Cyber Disturbances

The improvement of power grid intelligence depends on the development of communication technology. The wide application of communication technology in power grid has brought new security threats. In order to comprehensively and quantitatively evaluate the impact of external threats and cyber element failureson power supply reliability in the whole process of distribution network operation, reliability state models of different types of cyber disturbances are proposed, the impact of different types of cyber disturbance on the cyber availability is analyzed and a framework of distribution network reliability evaluation considering multiple types of cyber disturbance is constructed. Finally, the simulation test of IEEE33 bus distribution system verifies the feasibility and effectiveness of the proposed model and method.

Reliability Evaluation of Distribution Network Considering Demand Response and Road-Electricity Coupling Characteristics of Electric Vehicle Load

Reliability Evaluation of Distribution Network Considering Demand Response and Road-Electricity Coupling Characteristics of Electric Vehicle Load

Fuzzy comprehensive evaluation method of variable weight for power distribution equipment group

The evaluation of equipment group status has some reference value for maintenance strategy optimization and distribution network reliability evaluation. In this paper, the fuzzy evaluation method of variable weight is applied to evaluate the equipment group of power distribution network hierarchically. The importance degree of individual equipment in the evaluation of equipment group is determined by the load size and the importance degree of load borne by the equipment, the network equivalent method is applied to calculate the weight of individual equipment, and the conjoint analysis optimization algorithm is applied to realize dynamic weight variation. A set of transformer winding and casing and a partial 10kV line are taken as examples to verify the effectiveness of the proposed method.

Reliability evaluation of active distribution network considering various active adjustment means

With the large-scale configuration of distribution automation and the widespread implementation of distributed generation (DG) and flexible load (FL), the distribution network can achieve active regulation, which makes the traditional fault restoration strategy and distribution network reliability evaluation more complicated. Given this background, a method of reliability evaluation for the active distribution network considering ‘supply-grid-load’ is proposed. On the supply side, a distribution network islanding model considering DG is established, with the objective of supplying power to the maximised amount of equivalent power load. On the grid side, the influence of distribution network automation on the distribution network reliability is elaborately analysed and the time-varying failure rate model of equipment which considers the life cycle characteristics is presented. On the load side, an incentive-based FL model is proposed based on the elastic coefficient matrix. Finally, simulation results of RBTS-BUS6 system demonstrate the effectiveness of the proposed model and method.

The Reliability Evaluation of Power Supply Distribution System Based on Distribution Automation

This paper presents an improved failure mode and effect analysis for reliability evaluation of distribution network. By introducing the state factor of switch automation, the calculation formula of power supply reliability index of load point is modified, and the traditional consequence analysis method of fault mode is improved. Taking the test model of overhead lines as an example, the effectiveness of the improved method is verified, and the importance of distribution automation in the reliability improvement of distribution network power supply is affirmed, and the practical principle of terminal configuration is given in conjunction with the situation of distribution network in Anhui Province.

Reliability evaluation of distribution network based on fuzzy spiking neural P system with self-synapse

This paper proposes a fuzzy spiking neural P system with self-synapse (in short, FSNPSS) which is applied to the reliability assessment of distribution networks. The method maps the operation or fault states of the distribution network component and the load to the excited or resting states of neurons, and converts electrical relationships among components, loads and targeted systems into a synaptic connection relationship. Then, the occurrence probabilities of the states are transmitted by spikes, and reliability indices are computed by accumulating pulse values of the spikes. Finally, the feasibility and effectiveness of solving reliability assessment of distribution networks by membrane systems are verified in case studies.

Charging Load Prediction and Distribution Network Reliability Evaluation Considering Electric Vehicles’ Spatial-Temporal Transfer Randomness

Integration of large-scale cluster electric vehicles (EVs) and their spatial-temporal transfer randomness are likely to affect the safety and economic operation of the distribution network. This paper investigates the spatial-temporal distribution prediction of EVs’ charging load and then evaluates the reliability of the distribution network penetrated with large-scale cluster EVs. To effectively predict the charging load, trip chain technology, Monte Carlo method and Markov decision process (MDP) theory are employed. Moreover, a spatial-temporal transfer model of EVs is established, and based on which, an EV energy consumption model and a charging load prediction model are constructed with consideration of temperature, traffic condition and EV owner’s subjective willingness in different scenarios. With the application of sequential Monte Carlo method, the paper further evaluates distribution network reliability in various charging scenarios. In the evaluation, indices including per unit value (PUV), fast voltage stability index (FVSI), loss of load probability (LOLP), system average interruption frequency index (SAIFI), system average interruption duration index (SAIDI), and expected energy not supplied (EENS) are incorporated. To validate the proposed prediction model and evaluation method, a series of numerical simulations are conducted on the basis of taking the traffic-distribution system of a typical city as an example. The result demonstrates that the proposed spatial-temporal transfer model is more practical in charging load prediction than the popularly used Dijkstra’s shortest path algorithm. Moreover, high temperature, congestion and the increment of EV penetration rate will further weaken distribution network reliability.

Distribution Network Reliability Evaluation with Load Importance Degree and Isolated Island Operation

Supply power for important load in priority is the fundamental principle during power shortage. For the reason that the existing power load classification principle is too simple to compare the importance degree of loads at the same level, this paper proposed a comprehensive evaluation method of load importance degree. First, an indicator system is established to measure load importance. Then a comprehensive evaluation model is designed basing on improved rank correlation analysis method, which sets weights based on subject and object analysis and calculates the importance degree value according 4 indicators, including outage cost. Finally, evaluating the distribution network reliability with load importance degree. Simulation results on IEEE-RBTS BUS6 system shows the validity and practicality.

Availability, Performance and Reliability Evaluation for PV Distributed Generation

Nowadays, renewable energy resources play an important role in replacing conventional energy resources such as fossil fuel by integrating solar, wind and geothermal energy. Photovoltaic energy is one of the very promising renewable energy resources which grew rapidly in the past few years, it can be used to produce electric energy through photovoltaic process. The primary objective of the research proposed in this paper is to facilitate the increasing penetration levels of PV systems in the electric distribution networks. In this work, the PV module electrical model is presented based on the mathematical equations and was implemented on MATLAB to simulate the non-linear characteristics I-V and P-V curves with variable input parameters which are irradiance and temperature based on Riyadh region. In addition, the reliability evaluation of distribution networks, including distributed generators of solar photovoltaic (PV) with varying output power capacity is presented also. The Monte Carlo simulation algorithm is applied to test the distribution network which is RBTS Bus 2 and the same has been conducted on the original case of distribution network substation 7029 which is located at KSA Riyadh. The two distribution networks have been modified to include the PV’s distributed generators. The distributed generators contribute to supply a part of the load during normal mode and supply the entire load during component failure or failure of grid operation supply. The PV stochastic models have been used to simulate the randomness of these resources. Moreover, the study shows that the implementation and integration of renewable resources as distributed generations have improved the reliability of the distribution networks.

Reliability evaluation of distribution network considering controllable distributed generation, battery swapping station and controllable switches

Distributed generation (DG) and battery swapping station (BSS) access to the distribution network has brought impact to the reliability of distribution network. The method to assess the reliability of power distribution network with DG and BSS is proposed. First, according to the island formation strategy with DG, the case of island unable to form due to DG power shortage is analysed. Then, considering the energy storage characteristics of BSS while DG power shortage, the island formation strategy with DG and BSS is proposed and the island formation probability can be calculated. Finally, the correctness of algorithm is verified by using the IEEE three-feeder distribution system.

Reliability Evaluation of Distribution Network Considering Islanded Operation of Microgrid

A novel reliability evaluation method suitable for both traditional distribution network and distribution network connected with distributed generations(DG) is proposed. Firstly, according to the islanded operation mode of Microgrid the fault classification mode for traditional distribution network is modified; secondly, through the research on the generation characteristics of traditional DG and renewable DG, probabilistic models of various kinds of DG are given; finally, synthetically considering load shedding and load rejection, a probabilistic model of the abundance of supplying power by DG during islanded operation of microgrid to consumers is put forward and successfully applied in the reliability evaluation of complex distribution network containing microgrids. The effectiveness of the proposed evaluation method is validated by simulation results of RBTS-BUS6, to which the DG is added.

Intellectualization and Reliability Evaluation of Distribution Network Based on Principal Component Analysis

Principal component analysis is performed on the operation and management evaluation of smart distribution network because of its objectivity, synthesis and simplification to original data information. According to the demand on the evaluation that focuses on intellectualization and reliability of distribution network, an index system for intelligent and reliable evaluation is built. The performance indicators and the principal component analysis are used to analyze the intelligent and reliable level of distribution network operation and management. The feasibility of the evaluation index system is verified by the evaluation results of some distribution networks.