J. I. Escudero

Analytic model of the measurement errors caused by communications delay

The protocols and communication systems used in the control of the electric networks create delays due to various factors such as limitation of the transmission speed, retransfer among nodes, processing time, etc. These delays introduce some errors in the measurements used in the control center, which depend on the magnitude of the delay and the evolution of the measurements. In this paper an analytic model of the relationship between measurement error and delay is presented. The validity of the model is compared with experimental data from an electric network.

Determining the channel capacity in SCADA systems using polling protocols [power system telecontrol]

This article presents a method for calculating the capacity of a power system telecontrol multi-point communications channel when a polling protocol is used. Both an exact solution and an approximate but easier-to-use solution are obtained. With the results derived here, the number of remote stations that can communicate with the control center over a single channel can be determined. The analytical results are compared to the traffic results measured experimentally.

Deployment of digital video and Audio Over electrical SCADA networks

With the arrival of new hardware and software technologies, supervisory control and data acquisition human-machine interfaces (SCADA/HMI), usually text-based, can now benefit from the advantages the inclusion of multimedia information brings. However, due to the special requirements imposed by such systems, integrating audio and video data into the SCADA interfaces is not a trivial task. In this document we analyze those special characteristics and propose solutions so this integration is possible in power systems communication.

PeMMAS: A Tool for Studying the Performance of Multiagent Systems Developed in JADE

This paper describes the performance measurement for multiagent systems (PeMMAS) tool, a system designed to study and measure the performance of any multiagent system (MAS) developed in JADE. The tool itself is another MAS which is deployed and coexists alongside the one being studied. This characteristic allows us to adapt PeMMAS to any scenario in which MAS deployment in JADE is used. PeMMAS extracts information from the target MAS regarding the use of system resources, the flight time for comprehensive messages according to agent type, as well as the processing time for actions. After processing this information, PeMMAS sends a report to the final user for subsequent analysis.

Facilitating Decision Making and Maintenance for Power Systems Operators through the Use of Agents and Distributed Embedded Systems

This article examines the improvements provided when multimedia information in traditional SCADAS are included in electric facility management and maintenance. Telecontrol use in the electric sector, with the fundamental objective of providing increased and improved service to the operators who manage these systems, is also described. One of the most important contributions is the use of an agent network that is distributed around the electric facility. Through the use of multi-agent technology and its placement in embedded systems, to the authors design a system with a degree of intelligence and independence to optimize data collection and provide reaction proposals for the operator. The proposed agent-based architecture is also reviewed in this article, as are the design of an example agent and the results obtained in a pilot experience using the proposed hardware platform.

IDOLO: multimedia data deployment on SCADA systems

IDOLO project was born with the objective of adding audiovisual information to the usually text-based human-machine interfaces (HMI) used on supervisory control and data acquisition (SCADA) systems. This is not a simple task, as SCADA systems have traditionally been based on proprietary, low transmission speed networks, due to the special requirements that such systems impose in terms of network reliability and timing requirements. Within this paper we describe our efforts on the design, implementation and deployment of a networked computer system that adds multimedia information to the usually text-based SCADA/HMI systems. IDOLO system is based on well-known hardware and software solutions, such as Ethernet networks or MPEG codecs, resulting in a flexible and expandable system that has successfully been deployed on a real electrical facility.

Managing emergency response operations for electric utility maintenance

One of the most important criteria used to measure the quality of service in the electric utility industry is the uninterrupted service supplied to the customers. So, preventive maintenance is very relevant to avoid failures in the electric utility network. However, when failure is inevitable, it is very important that emergency repair operations are accomplished as soon as possible so the operators can avoid high-risk situations. Service unavailability can be decreased, reducing the frequency of power interruptions, number of customers affected per interruption, and duration of the interruption. A MAS for managing maintenance and emergency response operations in the electric utility industry was presented. The proposed system has the capability to support maintenance operations and make planning decisions.

Measurement transmission in power control centers

A protocol is presented for reducing the impact of repetitively sending many values. The results of its application to an actual system are presented. These results can be extended to other distributed control systems.<<ETX>>

Multiple intelligences in a MultiAgent System applied to telecontrol

This paper presents a control system, based on artificial intelligence technologies, that implements multiple intelligences. This system aims to support and improve automatic telecontrol of solar power plants, by either automatically triggering actuators or dynamically giving recommendations to human operators. For this purpose, the development of a MultiAgent System is combined with a variety of inference systems, such as Expert Systems, Neural Networks, and Bayesian Networks. This diversity of intelligent technologies is shown to result in an efficient way to mimic the reasoning process in human operators.

Architecture for Multiagent-Based Control Systems

This paper presents a multiagent architecture that covers the new requirements for the new control systems such as the distribution and decentralisation of system elements, the definition of communications between these elements, the fast adaptation in the control and organizational changes. The agents in this architecture can cooperate and coordinate to achieve a global goal, encapsulate the hardware interfaces and make the control system easily adapt to different requirements through configuration. Finally, the proposed architecture is applied to a control system of a solar power plant, obtaining a preliminary system that achieve the goals of simplicity, scalability, flexibility and optimization of communications system.