Identification of Linear Power System Models Using Probing Signals

This paper compares the accuracy of two methods to identify a linear representation of a power system: the traditional Eigensystem Realization Algorithm (ERA) and the Loewner Interpolation Method (LIM). ERA is based on time domain data obtained using exponential chirp probing signals and LIM system identification method is based on frequency domain data obtained using sinusoidal probing signals. The ERA and LIM methods are evaluated with the noise produced by the nonlinear characteristics of the system, these characteristics are caused by increasing the amplitude of the applied probing signal. The test systems used are: the two-area Kundur system and a reduced order representation of the Northeastern portion of the North American Eastern Interconnection. The results show that the LIM method provides a more accurate identification than the ERA method

DESARROLLO DE UN NUEVO SISTEMA DE ADQUISICIÓN DE DATOS PARA EL MONITOREO Y SUPERVISIÓN DE LA LÍNEA DE TRANSPORTE POR CABLE AÉREO “LÍNEA L” DEL METRO DE MEDELLÍN

In this paper a new development is performed. The development consists in a data acquisition system for air cable of line L of Metro de Medellín, through the development of a software application and design and implementation of an acquisition card necessary in order to performer of system. The system is responsible for acquiring, recording and presenting data graphically on the following variables: motor current, line speed, motor voltage and wind speed in towers of support. The above mentioned, it is made with the objective to analyze these signals and generate real data that them allow to optimize the maintenance times and improve the control systems and its operation.Este artículo presenta un nuevo desarrollo de un sistema de adquisición de datos para el cable aéreo de la línea L del Metro de Medellín, mediante el desarrollo de una aplicación de software y el diseño e implementación de una tarjeta de adquisición necesaria para el desarrollo del sistema. El sistema se encarga de adquirir, registrar y presentar gráficamente los datos de las siguientes variables: corriente del motor, velocidad de línea, voltaje del motor y velocidad del viento en las torres de sostenimiento del cable aéreo. Lo anterior, con el fin de analizar posteriormente todas estas señales y generar datos reales, los cuales permite optimizar tiempos de mantenimiento y/o mejoras del sistema de control y operación

Examination of wide area control methods to face inter-area oscillations

​© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Transmission systems are prone to experience interarea oscillations, triggered by groups of generators situated on different geographical locations oscillating against each other. In this paper, this particular problem is addressed and different control methodologies using wide-area monitoring that vary on complexity are proposed. The first approach is a proportional (P) gain that consider availability of measurements from different areas of the system and solve an optimization function to command the most influence group of machines in the system. The second approach is a Linear Quadratic Gaussian methodology that uses wide area measurements as control inputs. Finally, a proportional-integral (PI) controller that considers the availability of measurements from different areas is discussed. The first two approaches were tested through different simulations on IEEE benchmark models and the latest approach was tested using a control-in-the-loop and hardware-in-the-loop setup. To conclude, a perspective of wide-area damping controller implementation in a real laboratory demonstrator is presented

Fast hierarchical coordinated controller for distributed battery energy storage systems to mitigate voltage and frequency deviations

This paper proposes a novel hierarchical optimal control framework to support frequency and voltage in multi-area transmission systems, integrating battery energy storage systems (BESSs). The design is based on the coordinated active and reactive power injection from the BESSs over conventional synchronous generator-based control for fast and timely mitigation of voltage and frequency deviations. The principle of this new idea is to use two hierarchical schemes, one physical and one logical. The objective of the first scheme prioritises the power injection from the BESSs installed in the area where a contingency occurs, consequently reducing the disturbance of the dynamics in the neighbouring areas. In the second scheme, operational rules for aggregated BESSs in each are incorporated, increasing the safety of the asset. The proposed approach exploits the advantages of time-synchronised measurements, the eigensystem realisation algorithm (ERA) identification technique, the optimal linear quadratic Gaussian (LQG) controllers and a new aggregating agent that coordinates the power injection of BESSs in a hierarchical and scalable scheme to precisely regulate frequency and voltage of modern transmission grids, increasing their reliability and stability. The feasibility and robustness of the proposal is demonstrated using simulated scenarios with significant load changes and three-phase, three-cycle faults on a modified Kundur-system with four interconnected areas, mitigating frequency and voltage contingencies in less than 450 ms

Real-time co-simulation of transmission and distribution networks integrated with distributed energy resources for frequency and voltage support

This paper proposes a real-time co-simulated framework to experimentally validate the dynamic performance of network-level controllers in power systems. The experiment setup includes the coordinated emulation of a transmission network linked to a distribution feeder and real distributed energy sources, working in a multi-platform and multi-manufacturer environment. The operation of an optimal hierarchical controller for voltage and frequency support of the transmission network, which exploits the power injection from battery energy storage systems (BESS), is investigated to demonstrate the feasibility, accuracy and effectiveness of the proposed setup based on a co-simulation environment. The results of different study cases implemented in the laboratory are presented, where a successful interconnection between real-time emulators and real hardware from different manufacturers was realised. The fast and timely response of the controller to disturbances caused by sudden load changes, three-phase faults and renewable generation losses is experimentally validated. Finally, the robustness of the developed test bench against noise and harmonic distortion of real signals is also demonstrated

Memorias de investigación: Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.

Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.Esta publicación busca divulgar investigaciones y producción académica en diferentes disciplinas, realizadas por estudiantes y docentes de UNIMINUTO Seccional Antioquia – Chocó, así como dar a conocer los semilleros de investigación que participaron en la V Feria de Semilleros, con el fin de visibilizar el trabajo que realiza el Centro de Investigación para el Desarrollo de UNIMINUTO Bello —CIDUB—, con respecto a debates académicos y espacios de interlocución. Igualmente, permite que la comunidad educativa conozca los temas de investigación y las discusiones que se están dando entre los semilleros y grupos de investigación, para así buscar puntos de encuentro y sinergias entre los investigadores. Adicionalmente, el texto se convierte en una invitación para que se vinculen otros investigadores, docentes, estudiantes e incluso otras instituciones a los procesos investigativos coordinados desde el CIDUB

Memorias de investigación: Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.

Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.Esta publicación busca divulgar investigaciones y producción académica en diferentes disciplinas, realizadas por estudiantes y docentes de UNIMINUTO Seccional Antioquia – Chocó, así como dar a conocer los semilleros de investigación que participaron en la V Feria de Semilleros, con el fin de visibilizar el trabajo que realiza el Centro de Investigación para el Desarrollo de UNIMINUTO Bello —CIDUB—, con respecto a debates académicos y espacios de interlocución. Igualmente, permite que la comunidad educativa conozca los temas de investigación y las discusiones que se están dando entre los semilleros y grupos de investigación, para así buscar puntos de encuentro y sinergias entre los investigadores. Adicionalmente, el texto se convierte en una invitación para que se vinculen otros investigadores, docentes, estudiantes e incluso otras instituciones a los procesos investigativos coordinados desde el CIDUB

Herramienta de análisis de estabilidad de tensión para sistemas eléctricos de potencia

En este proyecto se presenta una herramienta de análisis de estabilidad de tensión para Sistemas Eléctricos de Potencia (SEP), fundamentada en el análisis de puntos de equilibrio. Se aborda este problema en tres etapas. En la primera etapa se estructura la condición inicial o punto de partida para el análisis de estabilidad comunmente conocida como Flujo de Cargas o Flujo de Potencias, el cual consiste en realizar un balance de potencia en el SEP para determinar una condición de equilibrio estable a partir de una semilla inicial para las magnitudes y fases de los voltajes en cada nodo. La segunda etapa consiste en determinar los elementos del SEP que pueden ser propensos a hacer inestables (nodos críticos y ramas débiles). En esta fase se aplica la técnica denominada análisis modal, la cual se fundamenta en el cálculo de valores y vectores propios de la matriz Jacobiana que resulta de la linealización del sistema de potencia alrededor de los puntos de equilibrio obtenidos en la etapa anterior. Finalmente, en la tercera etapa se hace un análisis de sensibilidad perturbando cada uno de los nodos críticos identificados previamente; posteriormente haciendo uso del análisis modal se determinan los márgenes de estabilidad del sistema. La perturbación se realiza haciendo pequeños cambios en la potencia activa (P) y reactiva (Q). En cada paso de variación de potencia, se aplica la técnica de descomposición en valores singulares con el fin de calcular la mínima perturbación que hace inestable el sistema. Luego de terminar estas tres etapas, cada una de las técnicas brinda los elementos suficientes para concluir acerca de las condiciones de estabilidad del sistema bajo estudio. Con este trabajo se desarrolló una herramienta para hacer análisis de estabilidad de tensión a SEP, la cual permite inferir acerca del comportamiento estable e inestable del sistema, utilizando MATLAB and Simulink como plataforma de trabajo.Maestrí

Predictive Control-Based NADIR-Minimizing Algorithm for Solid-State Transformer

Solid-state transformers (SSTs) are becoming an important solution to control active distribution systems. Their significant flexibility in comparison with traditional magnetic transformers is essential to ensure power quality and protection coordination at the distribution level in scenarios of large penetration of distributed energy resources such as renewables, electric vehicles and energy storage. However, the power electronic interface of SSTs decouples the nature of the inertial and frequency responses of distribution loads, deteriorating the frequency stability, especially under the integration of large-scale solar and wind power plants. Despite the virtual inertia/voltage sensitivity-based algorithms that have been proposed, the frequency sensitivity of loads and the capability of guaranteeing optimal control, considering the operating restrictions, have been overlooked. To counteract this specific issue, this work proposes a predictive control-driven approach to provide SSTs with frequency response actions by a strategy that harnesses the voltage and frequency sensibility of distribution loads and considers the limitations of voltage and frequency given by grid codes at distribution grids. In particular, the control strategy is centered in minimizing the NADIR of frequency transients. Numerical results are attained employing an empirically-validated model of the power system frequency dynamics and a dynamic model of distribution loads. Through proportional frequency control, the results of the proposed algorithm are contrasted. It is demonstrated that the NADIR improved about 0.1 Hz for 30% of SST penetration

Automated detection of congestive heart failure from electrocardiogram signal using Stockwell transform and hybrid classification scheme

Background and Objective: The congestive heart failure (CHF) is a life-threatening cardiac disease which arises when the pumping action of the heart is less than that of the normal case. This paper proposes a novel approach to design a classifier-based system for the automated detection of CHF. Methods: The approach is founded on the use of the Stockwell (S)-transform and frequency division to analyze the time-frequency sub-band matrices stemming from electrocardiogram (ECG) signals. Then, the entropy features are evaluated from the sub-band matrices of ECG. A hybrid classification scheme is adopted taking the sparse representation classifier and the average of the distances from the nearest neighbors into account for the detection of CHF. The proposition is validated using ECG signals from CHF subjects and normal sinus rhythm from public databases. Results: The results reveal that the proposed system is successful for the detection of CHF with an accuracy, a sensitivity and a specificity values of 98.78%, 98.48%, and 99.09%, respectively. A comparison with the existing approaches for the detection of CHF is accomplished. Conclusions: The time-frequency entropy features of the ECG signal in the frequency range from 11 Hz to 30 Hz have higher performance for the detection of CHF using a hybrid classifier. The approach can be used for the automated detection of CHF in tele-healthcare monitoring systems