D.P. Buse

Agent-based substation automation

Agent technology is one of the most interesting developments in the field of distributed artificial intelligence. It has a wide range of applications, with information management, intelligent user interfaces, personal assistants, and Internet commerce among the most popular. This article defines a generic architecture that applies the multiagent systems methodology to the field of substation automation, describes the design of a system to be implemented based on this architecture, and proposes several possible applications. Compared with SCADA or client-server substation automation solutions, an agent-based system offers a number of advantages. Each function or task of the system, such as the management of a single IED, can be encapsulated within a separate agent, making the system highly modular. Agents are loosely coupled, typically communicating via messaging rather than by procedure calls (remote or local), and, using directory services, new functions can easily be added to an agent-based system by creating a new agent, which will then make its capabilities available to others. The inherently distributed power system architecture is suited ideally to a multiagent system, which provides greater autonomy to each of the constituent parts than a traditional system.

Mobile agents for remote control of distributed systems

A modern distributed industrial system, such as a power transmission system, consists of many sites distributed throughout a wide area. Each site contains a number of monitoring and control devices, also known as intelligent electronic devices, which perform various tasks including condition monitoring, control, and protection. However, apart from dedicated links to the control center for control purposes, substations are often connected by networks with relatively low bandwidth, which makes remote access to these devices for control or monitoring relatively difficult. Therefore, we propose the use of mobile agents for remote access to devices. In this paper, the advantages and disadvantages of the use of mobile agents are evaluated by means of a theoretical model and a series of experiments. The results suggest that for networks with high latency mobile agents may provide performance improvements over more conventional client-server systems.

A multi-agent based intelligent monitoring system for power transformers in distributed substations

Power Transformers are distributed across a large number of substations, and many measures have been adopted for their onsite monitoring. Current approaches to transformer monitoring focus primarily on the sampling and display of vital parameters such as voltage and current, and that have been proved insufficient for transformer maintenance. This paper presents a new approach, based on a multi-agent system and an transformer equivalent heat circuit thermal model, which improves the quality and efficiency of distributed onsite transformer condition monitoring in power grids. The thermal model provides transformer temperature predictions and evaluation suggestions, while multi-agents playing the main roles of SCADA system maintenance, transformer autonomous diagnosis and information management.

Mobile agents for data analysis in industrial automation systems

In modern power systems and other industrial concerns, a large quantity of data is produced by condition monitoring and control systems. This data is used for a variety of purposes, and is often distributed over a number of sites. This paper describes part of a prototype system which combines mobile agents with a Foundation for Intelligent Physical Agents (FIPA)-based multi-agent system to provide remote analysis and reporting functions for data stored in power substation databases. A model of mobile agent performance in this application is derived, and a number of experimental results regarding the relative performance of mobile agents and static client-server agents are presented. These results suggest that in certain circumstances mobile agents have the potential to greatly increase the performance of this application. A comparison between using wrapper agents and direct database access for data retrieval is also performed.

Implementation of a power transformer temperature monitoring system

This paper describes the implementation of a power transformer temperature monitoring system that contains a recently developed equivalent heat circuit based thermal model. In this system, four fundamental components cooperate to perform onsite condition monitoring and intelligent analysis, including data acquisition, thermal model prediction and analysis, data storage, and HTTP services. The offline test shows that this thermal model based transformer temperature monitoring system provides useful information for transformer monitoring and maintenance.

Distributed Mobile Communication Base Station Diagnosis and Monitoring Using Multi-agents

Most inherently distributed systems require self diagnosis and on-line monitoring. This is especially true in the domains of power transmission and mobile communication. Much effort has been expended in developing on-site monitoring systems for distributed power transformers and mobile communication base stations.In this paper, a new approach has been employed to implement the autonomous self diagnosis and on-site monitoring using multi-agents on mobile communication base stations.