Electromechanical oscillation damping in one hydraulic central

Studies, simulations, and tests carried out to damp electromechanical oscillations are described. The solution was to install Power System Stabilizer (PSS) in 4 generator of 118 MW each one, located in one hydraulic plant. This plant is connected to “Sistema Eléctrico Patagónico Interconectado (SEPI)” trough a double 330 kV transmission line, with its far end connected to one aluminum plant with two 160 MW series of 200 electrolytic cells each one. Studies began with whole system data base validation, included the aluminum plant dynamic load model. Modal analysis and temporal simulation of event that excite dominant electromechanical oscillation mode were done. PSS tuning parameters were found, and the reciprocal influences between PSS and turbine governor were minimized. PSS commissioning test were carried out, and the results are compared with previous studies, showing a good agreement.Este trabajo también fue presentado en la I Conferencia Internacional del Área Andina del IEEE (IEEE-ANDESCON) (Isla Margarita, Venezuela, septiembre de 1999).Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Apagones: ¿es posible evitarlos?

Esta presentación pretende definir técnicamente que son los “apagones”, cuáles son las posibles causas (climáticas, técnicas y humanas) que los pueden originar, y que se puede hacer para minimizar su ocurrencia. A modo de ejemplo se muestran algunos de los apagones de mayor magnitud ocurridos en el mundo y que causaron un gran impacto en los países donde ocurrieron. También se muestran algunos grandes apagones ocurridos en Argentina que atrajeron la atención, y también la protesta, de nuestra sociedad. Se explican cuáles son las causas de estos y otros apagones para entender como se originan, y así poder determinar si son posibles de evitar a un costo razonable o admisible para la sociedad. En este sentido daremos una mirada al “estado de situación” a nivel mundial para prevenir “apagones” con el objeto de comparar con el estado de situación en nuestro país.Disertación del ingeniero Jorge Luis Agüero en el marco de la recepción del mismo como nuevo miembro de la Academia de la Ingeniería de la provincia de Buenos Aires.Academia de la Ingeniería de la provincia de Buenos Aire

Grid frequency control : Secondary frequency control tuning taking into account distributed primary frequency control

A new method developed and applied to tune Secondary Control Loop (SCL) for grid frequency control is presented. The presented method is based on an equivalent representation of all active distributed Primary Control Loop (PCL) in the grid for frequency control. The characteristic of each PCL is associated to prime mover and its governors: Hydraulic, gas or steam. The equivalent model of distributed PCL takes into account all active representative composition of PCL in the grid for each typified power flow (seasons, working/not-working day, peak/valley, morning/afternoon/night, etc). By this way, each equivalent model of distributed PCL allows to find the best tuning of SCL for each typified power flow. This method was applied to tune the SCL of Yacyretá, a hydraulic power plant with 20 Kaplan turbines of 155 MW each one. Yacyretá is one of the power plants that have SCL in the “Sistema Argentino de Interconexión” (SADI), the largest power grid of Argentina.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

STATCOM modeling for mitigation of voltage fluctuations caused by electric arc furnaces

Voltage fluctuations caused by rapid industrial load changes have been a major concern for both power companies and customers in the area of power quality. The fast response of the Static Compensator (STATCOM) makes it an efficient solution for improving power quality in distribution systems. This paper describes a model for a PWM-based STATCOM used in a distribution system for mitigation of voltage fluctuations produced by an Electric Arc Furnace (EAF). The analyzed system is modeled using MATLAB/Simulink Power System Blockset (PSB), including a complete STATCOM model with its power circuits and its control system. The complete model is validated by field test. Static and dynamic performance of STATCOM is evaluated and voltage fluctuation mitigation studies are performed and discussed. The voltage fluctuation mitigation is obtained by measurements and according to international standards.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctrico

Grid frequency control : Secondary frequency control tuning taking into account distributed primary frequency control

A new method developed and applied to tune Secondary Control Loop (SCL) for grid frequency control is presented. The presented method is based on an equivalent representation of all active distributed Primary Control Loop (PCL) in the grid for frequency control. The characteristic of each PCL is associated to prime mover and its governors: Hydraulic, gas or steam. The equivalent model of distributed PCL takes into account all active representative composition of PCL in the grid for each typified power flow (seasons, working/not-working day, peak/valley, morning/afternoon/night, etc). By this way, each equivalent model of distributed PCL allows to find the best tuning of SCL for each typified power flow. This method was applied to tune the SCL of Yacyretá, a hydraulic power plant with 20 Kaplan turbines of 155 MW each one. Yacyretá is one of the power plants that have SCL in the “Sistema Argentino de Interconexión” (SADI), the largest power grid of Argentina.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Flexible tool for small signal stability analysis

This paper presents the development of a flexible tool for the calculation of the state matrix A of the power system. This program is called SIAM (Sistema Informático para Análisis Modal - Computational System for Modal Analysis). The state matrix is obtained from the load flow solution data and from the dynamic model parameters employed. The detailed models of synchronous machines, automatic voltage regulators and power system stabilizers are linearized for the calculation. To evaluate the method proposed, there is a comparison of results between SIAM and a commercial program for a reference case published.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Flexible tool for small signal stability analysis

This paper presents the development of a flexible tool for the calculation of the state matrix A of the power system. This program is called SIAM (Sistema Informático para Análisis Modal - Computational System for Modal Analysis). The state matrix is obtained from the load flow solution data and from the dynamic model parameters employed. The detailed models of synchronous machines, automatic voltage regulators and power system stabilizers are linearized for the calculation. To evaluate the method proposed, there is a comparison of results between SIAM and a commercial program for a reference case published.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Voltage Flicker Mitigation using a simplified STATCOM model suitable for long time simulations

Voltage fluctuations caused by fast changes of industrial loads have been a major concern for both power companies and customers in the area of power quality. The fast response of the Static Compensator (STATCOM) makes it an efficient solution for improving power quality in distribution systems. This paper describes a simplified model for PWM-based STATCOM used in a distribution system for mitigation of voltage fluctuations produced by an Electric Arc Furnace (EAF). The analyzed system is modeled using MATLAB/SIMULINK Power System Blockset (PSB), including a complete STATCOM model with its power circuits and its control system. Static and dynamic performance of STATCOM is evalueates and voltage fluctiation mitigation studies are performed and discussed. The voltage fluctuation mitigation is obtained by simulations and according to international stardards.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Power system linear modeling : Application for small signal stability analysis

This paper presents the calculation of the state matrix A of the power system through a program developed under MATLAB. This program is called SIAM (Sistema Informático para Análisis Modal - Computational System for Modal Analysis). The state matrix is obtained from the load flow solution data and from the dynamic model parameters employed. The detailed models of synchronous machines, automatic voltage regulators and power system stabilizers are linearized for the calculation. To evaluate the method proposed, there is a comparison of results between SIAM and a commercial program for a reference case published.Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE

Aluminum plant : Load modeling for stability studies

The “Sistema Eléctrico Patagónico Interconectado (SFPI)” is an elechic system that involves the Argentina south region. This electric system is isolated fiom the other one in the north of the country. The 60% of its load is consumed by an aluminum production plant consisting of two 160 MW series of 200 electrolytic cells each one. Dynamic and transient stability studies carried out over this system, taking into Bccount present and future situations, with load and genedon grown at the aluminum plant and in the remaining system, require adequate modeling of this particular load. Tests and simulations canied out to obtain the electrolytic process load model are &scribed. Statistical behavior of the aluminum plant load variations is analp4 to estimate the spinning reserve in the system. By the way, available load shedding mechanisms at the aluminum plant, as a system control element, were tested and the results are analyzed.Este trabajo también fue presentado en la I Conferencia Internacional del Área Andina del IEEE (IEEE-ANDESCON) (Isla Margarita, Venezuela, septiembre de 1999).Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE