Integration of an energy storage system (ESS) into a distribution network not only affects the supply reliability of the customer, but also has distinct reliability implications and consequences to the utility. The reliability value associated with an ESS highly depends on the ownership, market and regulatory structures. This paper presents a probabilistic framework to evaluate the reliability value of ESS to the distribution system considering aforementioned factors. In this regard, a new probabilistic reliability model of ESS is developed and integrated into a sequential Monte Carlo based simulation framework. The developed ESS model consists of the Markov based component model and the mixed integer linear programming based formulation of operating strategies that incorporate different scenarios of ownership, market structures, and the ESS characteristics. The reliability/financial risk performance of the Distribution System Operator (DSO) with ESS under quality regulations are quantified. Furthermore, the developed ESS model is utilized to explore the prospect of investor-owned ESS providing supply recovery and distribution grid capacity services to the DSO. Case studies are conducted on a test distribution network to show the effectiveness of the proposed model. Finally, the paper presents discussions on important considerations for efficient utilization of ESS in active distribution systems.

The random failures in a distribution network lead to different reliability events, such as voltage sags, momentary interruptions, and sustained interruptions. Even momentary reliability events i.e., voltage sags and momentary interruptions cause significant financial losses to many customers. This paper develops a novel aggregated reliability event model for the reliability studies of distribution systems integrating the momentary reliability events in addition to sustained interruptions. The developed model incorporates the impacts of temporary and permanent failures on the customers considering different reliability events. A graph theory-based search algorithm is utilized to efficiently recognize different protection settings, alternate supplies, and presence of Distributed Energy Resources (DERs)/microgrids in the network. Furthermore, the proposed model incorporates the possible mitigation measures brought by the DERs/microgrids while quantifying the reliability profile of load points and the overall system. The case studies conducted on a practical test system show the effectiveness of the proposed model to evaluate the reliability and to carry out system upgrades in the context of active distribution systems.

This paper presents a Monte-Carlo simulation based framework to quantify the reliability benefit brought by the integration of an Energy Storage System (ESS) to an active distribution system. The benefits associated with ESS integration, such as reliability improvement at load point and system level, the reliability worth, deferral of immediate distribution system expansion, and better utilization of renewable distributed generation resources are quantified using a suitable reliability model of ESS. Assessments are conducted on a radial distribution test network with photovoltaic arrays and ESS. A range of case studies are performed to assess the reliability contribution of ESS, and conclusions are drawn based on the results obtained.

This paper investigates the effect of varying photovoltaic and synchronous machine based distributed generation source type penetrations on the reliability of a microgrid. An investigation into the effect of varying the percentage penetrations of photovoltaic and traditional generation sources on the load point reliability indices in a microgrid is conducted under fluctuating solar energy and loading conditions. In the context of this paper, an assessment of the reliability worth for each penetration condition is conducted with consideration to customer outage and environmental costs. Assessments are conducted on a typical microgrid test network utilizing an analytical method based on failure mode and effect analysis approach.

Distributed generation (DG) devices can be strategically placed in power system for grid reinforcement, reducing power losses and on-load operating costs, improving voltage profiles and load factors, differing or eliminating for system upgrades and improving system integrity, reliability and efficiency. The main focus of this study is the optimal location and sizing of DG. This paper presents a new analytical methodology to obtain the optimal location and size of DG using B-coefficient matrix concept for loss evaluation in a distribution network for different combination of DG. The benefit of developing B-coefficient matrix is that it is capable of giving the size and the location as well as power loss in each attempt. Use of B-coefficient matrix does not require a separate load flow to calculate loss. Since this study concentrates on the power distribution system, it is assumed that there is always sufficient power supplied by the substations, (the failures of components within substations, such as transformer and switches, are not taken into account).