Overview

The electrical industry has seen substantial structural changes in the business and technology framework since the early ‘80s. Those changes have been especially remarked in the last ten years. It is true to say, the renovations in every single country have been in different ways, but in general, they follow the same principles:

• Separation of operational or economy property to the generation, transmission, and distribution areas.

• Creation of free access conditions to electrical networks, practicing non-discriminatory treatments.

• Recognize the regulation needs for transmission and distribution of energy, which means, special attention in the fair competition in the generation and commercialization energy sectors.

This paradigm shift in the industry has had a direct impact on the type of analysis tools needed to be used, making necessary the modification and/or reformulation of models developed in the ‘60s and ‘70s. These models include operational, planning, and strategic development of power electrical systems. The new challenges are focused on explicitly incorporating market models, open access schemes, pricing models and management of network congestion.

Parallel to the changes in the electrical industry, information technologies have had an amazing development in terms of hardware, Internet creation, multimedia elements and new modeling tools such as object-oriented programming. This development has allowed the use of heuristic models capable of efficiently tackling complex optimization/decision problems.

The new challenges for the sector mentioned at the beginning of the section require, as a basis for developments around the issue, a tool that allows describing for the Chilean case the different components of the electricity sector, without decoupling the technical aspects of the economic ones. This motivates the creation of tools that facilitate decision making in competitive market environments.

In summary, the requirements imposed on the development of a computational platform (to address the problems previously raised) are:

• Co-modeling information of technical and market nature contained in a single database.

• Creation of a library of simulation tools with flexible access to the system database.

• Flexibility and easiness in maintaining and expanding modeling options.

• Efficient man-machine communication through a suitable graphical interface.

• Independence of the computational platform used and incorporation of internet technology.

This tool allows to execute in a flexible way the models developed in the framework and necessary for both quantitative and qualitative evaluations.

A description of the electric sector is proposed making use of the object-oriented programming, giving birth to a generic computational platform called "DeepEdit". The main features of this platform are:

• Object-oriented programming, which offers an efficient alternative for the development of an object-oriented database and tools for analysis, design, and programming, with which it is possible to address the new degree of complexity in the modeling of an electric power system.

• The object-oriented model has been implemented as a distributed system, based on a client-server architecture. This facilitates its incorporation into Internet technology and creates a modular structure that is easy to expand and maintain.

• The system has been developed in the Java programming language, obtaining a natural implementation of Internet technology and platform independence.

To meet the specific requirements of this project, "DeepEdit" requires a set of novel developments in the following components:

• Object-oriented database,

• Human-machine interface,

• Integration of tools used in the sector,

• Implementation of Analysis tools.

Figure 1 shows the proposed client-server architecture.

Figure 1. DeepEdit system architecture

The grey arrows (in the figure) represent services required by the clients to the respective servers, while the black arrows symbolize data exchange. The databases BDR (Database of elements Network), BDM (Market Database) and BDH (Database of Hydraulic elements) are the core of the system, with their services requested by all components of the system. In this way, a controlled access to the information of the objects of the system is facilitated. For data storage and loading of this object-oriented database, DeepEdit uses source files in ASCII format and / or relational databases (MS-Access). The information contained in the database can be modified local or online, making use of the network, market, or hydraulic editors. These editors, together with a geographic information system (GIS), have graphical interfaces that allow a flexible man-machine communication. The event management library enables the use of input and output devices as well as the ability to interact with the database through protocols and internet services. The editors associated to the system have the following characteristics:

• Network editor: includes the set of objects directly related to the electrical operation of the system.

• Hydraulic editor: includes the set of objects necessary for the description of the hydraulic behavior of the system.

• Market editor: models the market agents, contracts specification, commercial strategies, and their interaction.

• Geographical information system GIS: geographic visualization of the system.

The integration of market models is done through the analysis and simulation tools class library, which interacts in a flexible way with the databases BDM, BDR, BDH of the system. The system integrates tools oriented to market analysis: daily market simulation based on a Pool system, annual market simulation of physical bilateral contracts, analysis of different toll schemes of transmission systems, etc. Similarly, a set of systems analysis tools, such as: power flows, economic dispatch, optimal power flow, pre-dispatch, calculation of equivalent systems, sensitivity analysis, visualization tools and planning of transmission systems.

Likewise, DeepEdit allows the chronological development of the elements in the system through the definition of the entry and exit year (for each element of the system).

The program, in the same way, is conceived incorporating an intuitive graphic interface to operate different market structures and interact in a flexible way with the analysis tools. The operation of a model is understood as the ability to:

• Introduce all necessary parameters and input data,

• Allow data modification,

• Control the execution options,

• Allow and show the model simulation results in different formats and

• Show the results in its dedicated GUI.

The objects of each of the different databases (BDR, BDM, BDH) are related through attributes and methods. Figure 2 shows the main classes for each source and the existing database relationships.

Figure 2. Existing database relationship schema

• Suppliers are owners or operate generation facilities,

• Suppliers are owners or operate hydraulic units,

• Consumers own or operate cargoes,

• The system operator has technical information of the network objects in the control areas under their responsibility,

• Hydroelectric power plants are related to generating units in BDR, which correspond to the electrical manifestation of turbinated water.

The market model integration is performed through the analysis and simulation tools class library, which interacts in a flexible way with the databases BDM, BDR, BDH of the system. The system integrates tools oriented to market analysis: daily market simulation based on a Pool system, annual market simulation of physical bilateral contracts, analysis of different transmission system tolls schemes. Similarly, a set of systems analysis tools are integrated, such as: power flows, economic dispatch, optimal power flow, pre-dispatch, calculation of equivalent systems, sensitivity analysis, visualization tools and planning of transmission systems. Likewise, DeepEdit allows the chronological development of the elements in the system through the definition of the entry and exit year of elements.