Voltage Sags and Interruptions Research Papers (original) (raw)

Power system components are susceptible to failures which causes undesirable interruptions to consumer's power supply thus affecting the overall power system availability. Reliability evaluation is therefore important in power system studies to ensure continuity of power supply in line with the country's increasing population and the need to foster industrialization. This study is centered on reliability assessment of Mofor Injection Substation. This assessment evaluates the performance of the Mofor Injection substation considering various system parameters which contribute to the seamless operation of the station. Historical data obtained from the power substations from January, 2017 to December, 2017 were used to analyze the Injection Substation power reliability. The results obtained revealed a power availability index (ASAI) of 0.7683796 and 0.768968 for Ekete and Orhuwhorun substations respectively. Also, other reliability indices evaluated were SAIDI, CAIDI and SAIFI. The aforementioned reliability results reveals that power distribution at Mofor injection substation can be said to be unreliable, inefficient, undesirable and unstable.

El documento evalua los hundimientos de tensión considerando diferentes variables estocásticas incluyendo el despacho de generación y carga en el momento de la falla, asi como el tipo de falla y la reistencia de falla. Evalúa el impacto del cambio de configuración especialmente en el aspecto económico por las paradas de equipos y/o procesos industriales

This paper presents a study to investigate response of adjustable speed drives due to voltage sags. A small ASD of 0.39 kW, 50/60 Hz, and 400-480 V was used for testing how drives
will respond to voltage sag types; A, B, C and D. The drive response is influenced by sag magnitude, sag duration and phase angle shift. Behavior of the diodes rectifier for conducting is influenced by sag magnitude and phase angle shift represented by sag of types C and D. The diodes rectifiers are reverse biased when it was supplied by voltage sags. Even though there are no charging currents to dc bus capacitor during voltage sags, the drives did not directly trip to certain
sag magnitude and sag duration. Sensitivity of the ASD to voltage sag types is presented in voltage tolerance curve. Sag of type A produces highest sensitivity on the ASD and it trips for sag magnitude of 62.5% and 250 milliseconds in duration.

Adjustable speed drive (ASD) is an equipment designed to control the speed of an induction motor. Because of easy process control and energy saving, it mainly found in commercial and industrial facilities. Unfortunately, ASD is sensitive to power disturbances such as voltage sags. This paper analyzes the behavior of diodes rectifier current under normal condition and voltage sags of type A and C. Based on the experiment results, the behavior of diode currents are reverse bias during voltage sag and high inrush current appears after the voltage sag ends. Impact of type A voltage sag with various conditions are presented by voltage tolerance curve

- by Muhd Hafizi Idris and +1
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- Electric Machinery, Electric motor drives, Voltage Sags and Interruptions, Electrical Machines

"En este artículo se presenta una revisión del estado del arte de la caracterización, identificación y localización de los huecos de tensión. Los métodos presentados son el producto de diferentes análisis aplicados a la perturbación electromagnética, específicamente a las formas de onda de tensión y corriente, donde basándose en la teoría de circuitos eléctricos, transitorios electromagnéticos y el conocimiento del fenómeno se proponen atributos y descriptores que permiten caracterizar las perturbaciones de acuerdo a cierta característica de interés. Se hace una revisión tanto de caracterizaciones básicas como de metodologías que integran clasificadores y descriptores más complejos. Se hace énfasis en los métodos de caracterización, junto con sus atributos y descriptores, incluyendo sus limitantes y posibles mejoras. De acuerdo al nivel de desarrollo encontrado en estos estudios, resulta la necesidad de nuevas metodologías que integren módulos de caracterización, de diagnóstico de causas, de localización, de valoración y módulos de extracción de información y/o conocimiento, con la intención de orientarlo a una herramienta para la gestión automática de perturbaciones del sistema eléctrico"

- by Revista Ingeniería y Ciencia and +2
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- Electrical Engineering, Power Electronics, Power Quality, Electronics

The main dimension of the electricity quality is the supply continuity. It is evaluated by indices SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index). This paper presents a new implementation of the yardstick competition that combines two Data Envelopment Analysis models (DEA) to set the continuity standards for the electricity distribution utilities and their groups of consumption units. The approach has two stages. First, a classical DEA model performs a comparative analysis between utilities to define global continuity standards for each utility; next, based on global standards, a model for resource allocation based on DEA establishes the local continuity standards for groups of consumption units in the same utility. Local standards for the consumption units groups of the main distribution utilities in the Rio de Janeiro State are presented.

- by Luiz da Costa Laurencel and +1
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- Electrical Engineering, Energy Economics, Quality Management, Data Analysis (Engineering)

In this paper, voltage sag compensation of point of common coupling (PCC) using a new structure of fault current limiter (FCL) is proposed. The proposed structure prevents voltage sag and phase-angle jump of the substation PCC after fault occurrence. This structure has a simple control method. Using the semiconductor switch (insulated-gate bipolar transistor or gate turnoff thyristor at dc current rout leads to fast operation of the proposed FCL and, consequently, dc reactor value is reduced. On the other hand, the proposed structure reduces the total harmonic distortion on load voltage and it has low ac losses in normal operation. As a result, other feeders, which are connected to the substation PCC, will have good power quality. Analytical analysis and simulation results using PSCAD/EMTDC software and experimental results are presented to validate the effectiveness of this structure.