Paper Title
Multi-Agent Approach for Reliability Assessment and Improvement of Power System Protection

Assessment of reliability is one of the important topics in a power system which needs a more decentralized mechanism to enable an electrical load to continue receiving the power in the event of its disconnection from the main power grid. Despite the huge remarkable breakthrough in software technologies, most judgments have to be based on human experts in most of the planning and operation in power system. Most of the techniques are used to address the power system reliability which consumes long computation time. Hence, an inaccurate result for system operators is inevitable as most of the variables affecting the reliability changes with time. As a result of this setback, Multi Agent System (MAS). MAS is a collection of agents that have been applied to several power system problems such as, those in operation, markets, diagnosis and protection. In this study, in order to assess system reliability, distribution protection system design and coordination, two models of MAS techniques to determine the suitability of the DG location based on power system reliability and new index reliability of the relay operating time are proposed. The simulation results for two models are created using the data obtained from Malaysia distribution network (DISCO-Net) and 69 bus test system that was implemented using Java Agent Development Framework package software. The simulation results show that the effectiveness of proposed MAS approaches for selecting the best Distributed generation (DG) location in a function of improved power system grounding and reliability. Meanwhile, the simulation results for second model shown that the failure rate decreased to approximately 40% for over current and earth fault relays. The fast reliability indices are also obtained in assessing the performance of the protection system from the selection of DISCO-Net. Index Terms- Multi-agent system, Generation Reliability Indices, Distributed generation , Jade package. I. INTRODUCTION DG provides many advantages in term of improvements in losses and reliability, or both [1]. In addition, there are many DGs locations which can lead to minimize fault current in the event of faults and provide the necessary effective grounding to solve bus voltage problems when unfault phases over voltage in bus are encountered. When DGs are connected into the distribution power grid, the grounding methods should be taken into account[2]. In effectively grounded system, all faults including grounds must be cleared by opening the line. For using a DG without a transformer, special attention should be paid to the zero sequence impedance design so that effective ground can be provided. Unlike the DG with a transformer providing the effective ground passively, the DG without a transformer must shape the zero sequence impedance characteristic using an active control approach [3]. Relay protection (over current relay and earth fault relay) of power system is based on three principles in its operation, the type of fault, the fault location and the number of interconnections. Therefore, DGs can supply an additional contribution to the fault level. The setting of protective relays that were formerly prepared for the system without DGs may not significantly manage faults [4]. The reliability indices determined by using life data analysis will provide more accurate or realistic information as it uses the past failure data of the relays. The protection relays (over current relay (OC) and earth fault relay (EF)) and the added DG produced a reliable family,