Thales Sousa

Power Transmission Over Long Distances: Economic Comparison Between HVDC and Half-Wavelength Line

In this paper, the economics of some alternative solutions for point-to-point transmission of bulk power over long distances, namely, HVDC and half-wavelength lines (HWLL), are evaluated. Also, the main technical aspects of the half-wave length transmission technology in order to define the line design and its required equipment are discussed. A two-line, 2500 km transmission system (which is half the wavelength of a 60 Hz power frequency) carrying 6000 MW is used as the base case to perform the comparison. Finally, issues related to the sensitivity of such a cost comparison between the HVDC and HWLL alternative is presented.

Hydroelectric Power Plant Unit Efficiencies Evaluation and Unit Commitment

This work presents a methodology developed to obtain the unit commitment in hydroelectric plants. The methodology consists of three different stages, namely: definition of the system monitoring variable, unit efficiency evaluation, and unit commitment algorithm establishment. The efficiency of the proposed methodology was verified using a pilot project developed together with a hydroelectric plant having a capacity equal to 348 MW.

An evaluation of the HVDC and HVAC transmission economic

Different configurations and transmission technologies regarding the geographic distances and the expansion of the electrical system in large countries can be proposed. These technologies must meet the technical criteria considering the minimal cost. The minimal cost solution aims at bringing low tariffs to the final consumer. Accordingly, this paper will present the assessment of the economic limit of HVDC and both HVAC transmission, when issues like the variation of the voltage level (kV), the transmitted power (MW) and the line length (km) are considered.

A New Approach to Remuneration of Ancillary Services Provided by Generation Agents in Brazil

The restructuring of electrical sector based on the market resulted in the separation of generation, transmission and distribution agents and in the operation costs discrimination. This process lead to the necessity to separate the different services provided by the agents with the objective of organize by function and to define methodologies to identify who offers and who uses these services, as well as methodologies of remuneration to same ones. In this way, the present work presenting studies and methodologies to remunerate some Ancillary Services, such as: Black-start, Active Power Reserve, Special Protection Systems and Reactive Power Support. The studies and methodologies proposed were accomplished starting from the Ancillary Services provided by large Brazilian generation agents.

Spinning reserve opportunity cost in hydroelectric plants

Starting from the deregulated process of the electric sector, there was the need to attribute responsibilities to several agents and to elaborate appropriate forms of remuneration of the services rendered by the same. One of the services of great importance within this new electric sector is the ancillary services. Among the various types of ancillary services, spinning reserve is a service necessary for maintaining the integrity of the transmission system from either generation interruptions or load variations. This paper uses the application of the economic dispatch theory with the objective of quantifies the availability of spinning reserve supply in hydroelectric plants. The proposed methodology utilizes the generating units as well as their efficiencies so as to attend the total demand with the minimum water discharge. The proposed methodology was tested through the data provided by the Agua Vermelha hydroelectric power plant. These tests permitted the opportunity cost valuation to the spinning reserve supply in hydroelectric plants.

Spinning reserve service pricing in hydroelectric power plants

In the last few years, the electric sector has been going through the unbundling process of several participating agents and to the creation of a responsible market for all the occurring transactions. One of the services of great importance within this new electric sector is that pertaining to the services that contribute to the security, reliability and quality of the power supply. Such a group is referred to as ancillary services. Among the various types of ancillary services, spinning reserve is a service necessary for maintaining the integrity of the transmission system from either generation interruptions or load variations. This paper uses the application of the economic dispatch theory with the objective of financially quantify the availability of supplying spinning reserve in hydroelectric systems. The proposed methodology utilizes the generating units as well as their efficiencies so as to attend the total demand with the minimum water discharge. Thereafter, this value of demand is compared to that related with the dispatch which was realized following the guidance of the system operator. The difference in efficiency valorizes the availability for providing active spinning reserve. The proposed methodology was tested through the data provided by the Agua Vermelha hydroelectric power plant.

Characteristics of high power density transformer without a special license to traffic

The increased demand for electricity and the search by grid reliability gain have raised the interest of manufacturers and electric utilities regarding the development of the operating limits of the equipment. In order to meet this goal, the uses of new materials have been increasingly explored. Regarding power transformers, the use of new materials has given emphasis to the solid and liquid insulators. In this sense, this paper presents the features of a mobile transformer with high power density from the use of new materials. The densification of power proposed aims to allocate the maximum power to the transformer, considering the size and weight that do not need special license to traffic.

In site hydroelectric power plant unit efficiency measurement

This work presents a methodology developed to measure a hydroelectric power plant unit efficiency in site. The proposed methodology includes various stages, such as the definition of: the theory to evaluate the unit efficiency, the monitoring system variables, the measurement instruments and the system communication and database. The proposed methodology for evaluating the power plant unit efficiency was verified using a large hydroelectric plant constituted by three units having a total capacity of 348MW.

Sensing, Smart and Sustainable S^3 Enterprises: Principles, Goals and Rules

Currently, traditional companies need of models, skills, processes and technologies to face the challenges imposed by the highly competitive market, which requires constant innovations. Through the concepts of detection and monitoring, intelligence and sustainability, Sensing, Smart and Sustainable (S^3) enterprises exert an important role in the digitization of strategies, decisions and operations, and are efficient to face the challenges intrinsic to the digital economy and intelligent manufacturing. Literature presents the need of development of methods and enterprise models that portray reality of the S^3 Enterprises. In this context, to facilitate the formalization of S^3 Enterprises and understand the dynamics of their operations, this paper aims to develop an enterprise model of such organizations. Through the For Enterprise Modeling method, the enterprise model documents the goals, business rules, processes and concepts of S^3 Enterprises. The contribution of this paper is the identification of guiding principles that allow companies interested in applying the S^3 concepts have a reference as base, once it has been mapped through perspectives of different domains of knowledge.

High power density mobile transformer factory tests

The increased demand for electricity and the search for grid reliability have raised the interest of manufacturers and electric utilities to develop and increase the operating limits of the electric equipment. In order to meet this goal, the uses of new materials have been increasingly explored. Regarding power transformers, the use of new materials has given emphasis to the solid (Nomex) and liquid (vegetable oil) insulators. In this context, this paper presents the factory tests of a mobile transformer with high power density using new materials. The proposed densification of power aims to allocate the maximum power to the transformer, considering both size and weight which should not lead to the requirement of a special traffic license.