Power System Assets Research Articles

Comprehensive Real-Time Microgrid Power Management and Control With Distributed Agents

Advances in smart grid technology have yet to coalesce into a comprehensive solution integrating the landscape of future power systems. The microgrid concept may offer a solution for combining advanced components and enabling technologies within an infrastructure that must expand to meet emerging demands. As autonomous power system entities, microgrids require robust real-time power management and control to simultaneously operate jointly with the utility, provide reliable service, and help achieve customer-driven objectives utilizing local power system assets. In this paper, a decentralized control architecture for microgrids is presented, along with a simulation environment appropriate for on-going investigations into real-time, agent-based decision-making. Challenges faced by operating self-organizing multi-agent system (MAS) are presented, as well as results for a representative power management scenario for a multi-asset microgrid capable of operating in grid-interconnected or islanded mode. The system and formulations presented demonstrate the viability and capability of decentralized agent-based control for microgrids and illustrate their potential towards achieving smart grid goals.

Asset management techniques for transformers

In a deregulated/reformed environment, the electric utilities are under constant pressure for reducing operating costs, enhancing the reliability of transmission and distribution equipments, and improving quality of power and services to the customer. Moreover, the risk involved in running the system without proper attention to assets integrity in service is quite high. Additionally, the probability of losing any equipment vital to the transmission and distribution system, such as power and distribution transformers, is increasing especially with the aging of power system's assets. Today the focus of operating the power system is changed and efforts are being directed to explore new approaches/techniques of monitoring, diagnosis, condition evaluation, maintenance, life assessment, and possibility of extending the life of existing assets. In this paper, a comprehensive illustration of the transformer asset management activities is presented. The importance of each activity together with the latest researches done in the area is highlighted.

Design parameter based method of partial discharge detection and location in power transformers

Insulation defect detection in time ensures higher operational reliabi- lity of power system assets. Power transformers are the most critical unit of power systems both from economical and operational front. Hence it becomes necessary to have knowledge of the actual insulation condition of transformer to increase dependability of the system. The performance and ageing of the transformer insulation is mainly affected by Partial discharges (PD). Proper diagnosis in terms of amplitude and location of partial discharge in a power transformer enables us to predict well in advance, with much confidence, the defect in insulation system, which avoids large catastrophic failures. In this work a 20kVA, 230/50kV single phase core type transformer is used for evaluation of the transfer function-based partial discharge detection and location using modeling of the winding, using design data. The simulation of capturing on-line PD pulses across the bushing tap capacitor is done for various tap positions. Standard PD source model is used to inject PD pulse signal at 10 tap locations in the winding and corresponding response signatures are captured at the bushing tap end (across 1000pF). The equivalent high frequency model of the winding is derived from the design parameters using analytical calculations and simulations in packages such as MAGNET and ANSOFT. The test conditions are simulated using ORCAD-9 and the results are evaluated for location accuracy using design parameter based PD monitoring method.