Fault indicating devices such as fault indicators (FIs) have been widely used in distribution systems to improve reliability and reduce outage duration. Recently, FIs with communication interfaces are integrated into distribution automation (DA) to further reduce fault-finding time by reporting FIs' statuses back to control center. When faults occur, a lot of alarms and fault information are received from Outage Management System (OMS), Trouble Call System (TCS) and Customer Information System (CIS) and are shown to system operators. As a result, the identification of faulted line sections in a wide-ranging distribution system from FIs' statuses is not an easy task, especially when multiple faults occur simultaneously and/or distributed generators (DGs) are connected. An automatic and fast faulted line-section location method for distribution systems based on FIs is proposed in this paper. The line sections between adjacent FIs can be treated as a possible fault location (PFL) and the fault current detected by the FI can be considered as line current (LC) flowing between the adjacent PFLs. A relationship matrix between PFLs and LCs is then derived and used to design the proposed automatic and fast faulted line-section location method. The faulted line sections can then be located effectively and efficiently by the proposed method. Test results for an actual distribution system demonstrate the validity of the proposed faulted line-section location method.

Automatic and Fast Faulted Line-Section Location Method for Distribution Systems Based on Fault Indicators

This paper introduces a multi-objective fault indicator (FI) placement method in electric distribution systems. The prevalent FI placement problem formulation is extended by considering effects of existing protection and control devices on customers' restoration time. Moreover, the customers' average restoration time index (CARTI) is proposed, as a new technical objective function with respect to uncertainties of automatic switching. Furthermore, a multi-objective solution approach is developed to simultaneously minimize indispensable economic and technical objectives. The resultant optimization problem is solved through a multi-objective particle swarm optimization (MOPSO) based algorithm, accompanied by a fuzzy decision making method to select the best result among the obtained Pareto optimal set of solutions. Assuming SAIDI and CARTI as technical objectives, the proposed method is applied to bus number four of the Roy Billinton test system (RBTS4), as well as a real-life distribution network with about 5500 customers, followed by a discussion on results.

Fault Indicator Deployment in Distribution Systems Considering Available Control and Protection Devices: A Multi-Objective Formulation Approach

This paper examines the application of the immune algorithm for the problem of optimal placement of fault indicators to minimize the total cost of customer service outage and investment cost of fault indicators. The reliability index of each service zone is derived to solve the expected energy not served due to fault contingency, and the customer interruption cost is then determined according to the customer type and power consumption within the service zone. To demonstrate the effectiveness of the proposed IA methodology and solve the optimal placement of fault indicators, a practical distribution feeder of Taiwan Power Company is selected for computer simulation to explore the cost benefit of fault indicator placement.

Optimal Placement of Fault Indicators Using the Immune Algorithm

Cyber-enabled operation is needed for smart distribution system implementation. The interaction of cyber and power components will affect system reliability. This paper focuses on developing an analytical reliability model for fault detection, isolation, and service restoration for smart distribution feeders. The impact of end-to-end outage probability of data communication along with sending, receiving, and relaying communication node failures is incorporated into the model. Vulnerability of system to cyber attack as an emerging cause of reliability degradation is also investigated. An optimal placement of fault detectors and switching devices are determined in this work to improve reliability. The sum of customer service interruption cost and investment cost is considered as an objective function to be minimized. Bus 2 of the Roy Billinton test system and a typical 27-node distribution network are used to illustrate the role of communication infrastructure malfunction on the planning problem in a distribution feeder. Results and discussions show the necessity of incorporating communication infrastructure failure into the power distribution system planning problem.

Fault Detector and Switch Placement in Cyber-Enabled Power Distribution Network

Fault indicator (FI) plays a crucial rule in enhancing service reliability in distribution systems. This device brings substantial benefits for fault management procedure by speeding up fault location procedure. This paper intends to develop a new optimization model to optimally deploy FI in distribution systems. The proposed model aims to consider a tradeoff between the total customer interruption cost and FI relevant costs, including capital investment, installation, and maintenance costs. As the main contribution of this paper, the problem is formulated in mixed integer programing, which guarantees global optimum solution achieved in an effective runtime. Moreover, the model takes advantages of taking pragmatic fault location procedure into account, which results in more reliable solutions. The effectiveness of the proposed method is scrutinized through various case studies and sensitivity analyses of a test system. In addition, the applicability of the model in practice is appraised by applying it on a real-life distribution network. The resultant outcomes demonstrate the integrity of the proposed model.

Deployment of Fault Indicator in Distribution Networks: A MIP-Based Approach

This paper presents an optimization method of fault indicator placement by genetic algorithms. Requirements such as the network structure with switchgear system, reliability factor, economic parameters and fault localization by switchgear can be taken into account in an objective function to minimize. The influence of dispersed generation, inserted in the distribution network, on the fault indicator placement is also carried out. The tool created provides help to select the optimal fault indicator placement in the network following different objectives.

S. Bonnoit

Papers

Optimization of fault indicators placement with dispersed generation insertion