Jose A. Sanchez

Jose A. Sanchez
Universidad Politécnica de Madrid | UPM · Departamento de Ingeniería Civil: Hidraúlica y Energética

PhD. Civil Engineering

About

46
Publications
11,282
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
732
Citations

Publications

Publications (46)
Article
Full-text available
Condition monitoring of large power transformers is of paramount importance in power systems. One of the most common indicators of transformer aging is moisture content in oil. In this paper, a capacitive sensor able to online measuring moisture content is presented. The output of this sensor is recorded using a Frequency Response Analysis (FRA) de...
Article
Full-text available
There are several techniques for current measurement. Most of them are capable of measuring both alternating and direct current (AC/DC) components. However, they have severe drawbacks for rotating applications (large size, sensitivity to external fields, and low signal amplitude). In addition to these weaknesses, measured signals should be transmit...
Article
Full-text available
Electrical industry uses oils for cooling and insulation of several machines, such as power transformers. In addition, it uses water for cooling some synchronous generators. To avoid malfunctions in these assets, fluid quality should be preserved. To contribute to this aim, a sensor that detects changes in fluid composition is presented. The design...
Article
Full-text available
Nowadays, non-toroidal shape primary pass-through current transformers are commonly used for large current machines with several cables per phase. As these transformers exhibit no radial symmetry, it is not clear if they can be tested using the indirect test described in the IEC 61869 standard. In order to answer this question, two non-toroidal sha...
Article
Full-text available
This paper presents a novel method of hydro power plant operation, based on the control of the injectors’ or wicked gates opening time as a function of the upper reservoir level. In this way, a faster power injection, depending on the current water level on the upper reservoir, could be achieved. When this level is higher, the opening time could be...
Article
Full-text available
Frequency control is one of the most critical tasks in isolated power systems, especially in high renewable penetration scenarios. This paper presents a new hydropower pumped-storage dual control strategy that combines variable-speed-driven pumps and fixed-speed-driven pumps. A possible case for implementation of such a control scheme is described...
Article
The wind energy penetration rate is being increased in majority of European countries. However, a high penetration rate could endanger the stability of power systems, particularly in small islands. Hydropower plays an important role in the regulation and control of isolated power systems with renewable sources, but it may not be able to maintain th...
Article
Full-text available
Currently, some small islands with high wind potential are trying to reduce the environmental and economic impact of fossil fuels by using renewable resources. Nevertheless, the characteristics of these renewable resources negatively affect the quality of the electrical energy, causing frequency disturbances, especially in isolated systems. In this...
Article
Full-text available
Sometimes when connecting a crest vertical curve, followed by a sag and another crest, a road disappears from the view of a driver to reappear later. Then, there is a loss of path or a hidden dip in a road. It is essential to avoid losses when they hide dangerous points, such as intersections or unexpected changes in direction. In addition, this lo...
Article
In this paper, the dynamic response of a long penstock pumped-storage hydropower plant which is equipped with a single pump-turbine and a doubly-fed induction machine, is analyzed in detail in generating mode. The pumped-storage hydropower plant is connected to a small island power system with thermal generation, and provides load-frequency control...
Article
Full-text available
In this paper, a hydroelectric power plant with long tail-race tunnel has been modelled for assessing its contribution to secondary regulation reserve. Cavitation problems, caused by the discharge conduit length, are expected downstream the turbine where low pressure appears during regulation manoeuvres. Therefore, governor's gains should be select...
Article
Full-text available
Run-of-river hydropower plants usually lack significant storage capacity; therefore, the more adequate control strategy would consist of keeping a constant water level at the intake pond in order to harness the maximum amount of energy from the river flow or to reduce the surface flooded in the head pond. In this paper, a standard PI control system...
Article
Highway design standards specify several requirements on available sight distance. Usually, compliance with these standards is ensured during the design phase of a new road. This is made through geometric calculations that take into account the terrain and the road. In this paper, a procedure for measuring distances in an existing road from georefe...
Article
Analyzing the distance visible to a driver on a highway is important for traffic safety, especially in manoeuvres such as emergency stops, when passing another vehicle, or when vehicles cross at intersections. Software that calculates highway distances visible to a driver has been developed. This software is supported by a geographic information sy...
Article
Full-text available
Massive integration of renewable energy sources in electrical power systems of remote islands is a subject of current interest. The increasing cost of fossil fuels, transport costs to isolated sites and environmental concerns constitute a serious drawback to the use of conventional fossil fuel plants. In a weak electrical grid, as it is typical on...
Article
Drivers adapt their driving to the conditions that they find. When the design corresponds to what a driver hopes to find, the route is consistent. This diminishes the likelihood of drivers making errors and carrying out uncertain manoeuvres. Most evaluations of highway geometric design consistency are based on the analysis of vehicles' speeds. This...
Article
Full-text available
In this paper, the dynamic response of a hydro power plant for providing secondary regulation reserve is studied in detail. Special emphasis is given to the elastic water column effects both in the penstock and the tailrace tunnel. For this purpose, a nonlinear model based on the analogy between mass and momentum conservation equations of a water c...
Article
A critical factor in highway design is maintaining a good consistency with a road geometry that fits the drivers' expectations. Presently, highway geometric design consistency is usually evaluated on the basis of operating-speed profile analysis, which requires the use of operating-speed models. This paper presents research carried out in Colombia...
Article
Among the existing renewable sources, wind energy is reaching production rates that are becoming important on the worldwide energy scene. Since the control of these wind generators is a very technical discipline, practical teaching methodologies are of special relevance. Paradoxically, in the past, the training of engineers specializing in this are...
Article
Full-text available
Among the existing renewable sources, wind energy is reaching production rates that are becoming important on the worldwide energy scene. Since the control of these wind generators is a very technical discipline, practical teaching methodologies are of special relevance. Paradoxically, in the past, the training of engineers specializing in this are...
Article
This paper describes a new voltage dip generator that allows the shape of the time profile of the voltage generated to be configured. The use of this device as a tool to test the fault ride-through capability of wind turbines connected to the electricity grid can provide some remarkable benefits: First, this system offers the possibility of adaptin...
Article
In many situations, highway geometry is unknown. Using GPS data to reconstructhighway geometry could be the best option in a variety of circumstances. The present workanalyzes the performance of several GPS receivers in this task. Three different commercialreceivers have been chosen for testing and performance comparison. The three devices reachsub...
Article
This paper presents a novel approach to solve the short-term operation scheduling problem of a hydropower plant that sells energy in a deregulated electricity market with the objective of maximizing its revenue. This paper proposes a nonlinear programming based scheduling model that determines both the optimal unit commitment (start-ups and shut-do...
Article
This paper presents a novel approach to solve the short-term operation scheduling problem of a hydropower plant that sells energy in a deregulated electricity market with the objective of maximizing its revenue. This paper proposes a nonlinear programming based scheduling model that determines both the optimal unit commitment (start-ups and shut-do...
Article
Full-text available
This paper presents a control system for low-head diversion run-of-river small hydro plants with pressure conduits. Since these hydropower plants usually have low or null water storage capacity, the water discharged through the turbines should be adapted to the possible extent to the natural river inflow. For this purpose, a control scheme aimed at...
Conference Paper
This paper describes a methodology to assess the quality of teaching using a web based tool, which has been developed and implemented in the School of Civil Engineers of the Technical University of Madrid (UPM). The software has been developed using a combination of tools freely available and widely used. Students use the Internet to fill out and s...
Chapter
This chapter refers to the short-term operation scheduling problem of a multi-unit hydropower plant that sells energy in a pool-based electricity market with the aim of maximizing the revenue. Firstly, the main factors to be considered in hydro and hydrothermal scheduling problems are discussed. Secondly, a review on some of the solution techniques...
Article
In this paper, the development of a physical platform and the description of a specific methodology to be employed for experimental teaching in wind energy electrical generation in the `Electrical Generation with Renewable Energy Sources' course, within the Electrical Engineering educational program at the Universidad Politecnica de Madrid, is pres...
Article
In the 1990s, a new degree, Geodesic and Cartographic Engineering, was created in Spain. It is a post-graduate degree, lasting two years. At present, Spanish university degrees are being redefined for their adaptation to the European Higher Education Area (EHEA). Thus, after more than ten years of experience and in view of the implementation of the...
Article
Although geographic information systems _GISs_ have been applied in different areas of transportation, full use of their potential in speed profile analysis and highway design consistency studies has yet to be made. The possibilities that GISs offer for analysis and the increasing number of highway inventories supported by such systems, including t...
Article
This paper presents a dynamic model for variable speed wind energy conversion systems, equipped with a variable pitch wind turbine, a synchronous electrical generator, and a full power converter, specially developed for its use in power system stability studies involving large networks, with a high number of buses and a high level of wind generatio...
Article
In order to represent the behaviour during fatigue tests of asphalt concrete mixtures, a phenomenological model, based on the continuous damage theory, has been developed. From this model, a method for estimation of fatigue curves was formulated. From a practical point of view, the use of this method enables classic fatigue curves to be estimated w...
Chapter
Because of the high number of accidents occurring on highways, it is necessary to intensify the search for new tools that help in understanding their causes. Design consistency is defined as the conformance of the geometric characteristics of a highway to what the driver expects to find. Geographic Information Systems have been applied in different...
Conference Paper
Nowadays, new small hydro power plants are being built all over the world. In most cases, these power plants lack significant storage capacity; therefore the more adequate control strategy is to keep constant the water level at the intake basin to capture the maximum amount of energy from the river flow. In this paper, the control of a diversion ru...
Article
Detailed studies of traffic safety, as highway design consistency evaluation, require having the geometric definition of the alignment. An efficient and reliable procedure has been developed for obtaining this geometric definition for two-lane rural highways. The method is based on getting data of the highway by means of a GPS receiver mounted in a...
Conference Paper
Full-text available
This paper presents the justification of the need of voltage sag generating equipment for the test and possible certification of the wind generators response to such disturbances. It also includes an overview of the equipment currently used with similar objectives.
Article
Full-text available
This paper presents part of the work carried out within the framework of a research project entitled Application of variable speed and intelligent control technologies to hydropower generation. Specifically, it is focused on the activities performed in order to achieve one of the main objectives of the project: the design of a water level control s...
Article
En esta Tesis se han comparado los modelos de máquina de inducción más utilizados para la simulación de su fimcionamiento en régimen transitorio. El objetivo ha sido buscar el modelo más adecuado para cada tipo de estudio. La metodología empleada ha consistido en elaborar una serie de programas que permitan realizar simulaciones con cada modelo de...

Network

Cited By