Power Quality Disturbances And Custom Power Devices

Indonesian Journal of Electrical Engineering and Informatics (IJEEI), 2017

Electrical power quality (EPQ) in distribution systems is a critical issue for commercial, industrial and residential applications. The new concept of advanced power electronic based Custom Power Devices (CPDs) mainly distributed static synchronous compensator (D-STATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner (UPQC) have been developed due to lacking the performance of traditional compensating devices to minimize power quality disturbances. This paper presents a comprehensive review on D-STATCOM, DVR and UPQC to solve the electrical power quality problems of the distribution networks. This is intended to present a broad overview of the various possible DSTATCOM, DVR and UPQC configurations for single-phase (two wire) and three-phase (three-wire and four-wire) networks and control strategies for the compensation of various power quality disturbances. Apart from this, comprehensive explanation, comparison, and discussion on D-STATCOM, DVR, and UPQC are presented. This paper is aimed to explore a broad prospective on the status of D-STATCOMs, DVRs, and UPQCs to researchers, engineers and the community dealing with the power quality enhancement. A classified list of some latest research publications on the topic is also appended for a quick reference.

Power quality is one of major concerns in the present era due to the increase in modern sensitive and sophisticated loads connected to the Distribution System. Recently, the Power electronics controllers are gain ing concern to provide the quality of power for both power suppliers and consumers. Many power filtering technology i.e. passive filters, active power filters, hybrid filters have applied fro m t ime to time fo r g iving the solution of power quality problems to end users, but the users could not fully satisfied them. New technologies, using power electronics-based concepts, have been developed to provide protection for commercia l and industrial customers fro m power quality problems on the electrical distribution system. Such power electronics based devices are known as Custom Power devices. There are many custom power devices and they are divid ed in two groups: network-reconfiguring type and compensating type. The network reconfiguring devices are: solid-state current limiter (SSCL), solid-state breaker (SSB) and solid-state transfer switch (SSTS). The co mpensating devices are: Distribution Static Co mpensator (DSTATCOM), Dynamic Vo ltage Restorer (DVR), and Un ified Po wer Quality Co mpensator (UPQC). This paper present an overview of custom power devices used in the distribution systems for mitigating the power quality issues. Static Co mpensator (DSTATCOM), Dynamic Voltage Restorer (DVR), Un ified Po wer Quality Co mpensator (UPQC).

The present deregulation market has to face many power quality problems like voltage sag, voltage swell, flickers, voltage imbalances. This paper describes an inclusive review of different compensating devices used for mitigation of different power quality problems. Custom power devices(CPD) like DVR(dynamic voltage restorer), DSTATCOM (distribution static compensator), UPQC(unified power quality conditioner) are the highlighting topics of the review. Organised references proposed in this paper would be beneficial for future work of engineers and researchers.

International Journal of Electrical and Computer Engineering (IJECE), 2011

This paper describes the model and analyzes custom power devices for compensating voltage sag and swell conditions in three phase systems. Faults occurring in power distribution systems or facilities in plants cause the voltage sag or swell. If a fault occurs, it can damage the power system or user's facility. Sensitivity to voltage sags and swells varies within different applications. For sensitive loads (PLC's, paper mills etc.), even voltage sags of short duration can cause serious problems in the entire system. Normally, a voltage interruption triggers a protection device, which causes shutdown of the entire system. In order to mitigate power interruptions, this paper proposes a scheme for voltage sag support based on a pulse width modulated autotransformer. The proposed scheme is able to quickly recognize the voltage sag or swell condition, and it can correct the voltage by either boosting the input voltage during voltage sag events or reducing the voltage during swell events.

A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or mis-operation of end use Equipments. Utility distribution networks, sensitive industrial loads, and critical commercial operations all suffer from various types of outages and service interruptions which can cost significant financial 1oss per incident based on process down-time, lost production, idle work forces, and other factors. With the restructuring of Power Systems and with shifting trend towards distributed and dispersed Generation, the issue of Power Quality is going to take newer dimensions. The aim therefore, in this work, is to identify the prominent concerns in the area and thereby to recommend measures that can enhance the quality of the power, keeping in mind their economic viability and technical repercussions. In this paper three custom power controllers: DVR, DSTATCOM (modelled in MATLAB/Simulink), PWM Switched Autotransformer (modelled in PSCAD/EMTDC & MATLAB/SIMULINK) are presented. Comprehensive results are presented to assess the performance of each device to mitigate the Voltage sag and economical device is proposed.

2016

Widespread applications of power electronic based loads in industry have increased the importance and application of power quality studies. Decrease in the cost of power electronic devices , fast switching characteristics of converters and improvements in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Unified Power Quality Conditioner (UPQC, a combination of series and shunt power filters) is one of the CP devices and compensates voltage and current quality problems. UPQC has become very popular in recent years both in low voltage and medium voltage applications. In this study, an attempt has been made to model the UPQC for voltage and current compensation with the help of two different control schemes. The current harmonics as well as voltage sag and swells compensation are shown. Keywords— Power Quality, Active power...

International Journal Of Engineering And Computer Science, 2016

A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a miss-operation of end user equipment's. Utility distribution networks, sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial losses. The present work is to identify the prominent concerns in this area and hence the measures that can enhance the quality of the power are recommended. This work describes the techniques of correcting the supply voltage sag, swell and interruption in a distributed system. At present, a wide range of very flexible controllers, which capitalize on newly available power electronics components, are emerging for custom power applications. A D-STATCOM injects a current into the system to correct the voltage sag, swell and interruption. Comprehensive results are presented to assess the performance of each device as a potential custom power solution. The STATCOM is applied to regulate transmission voltage to allow greater power flow in a voltage limited transmission network, in the same manner as a static var compensator (SVC), the STATCOM has further potential by giving an inherently faster response and greater output to a system with depressed voltage and offers improved quality of supply. The main applications of the STATCOM are; Distribution STATCOM (D-STATCOM) exhibits high speed control of reactive power to provide voltage stabilization and other type of system control. The DSTATCOM protects the utility transmission or distribution system from voltage sag and /or flicker caused by rapidly varying reactive current demand. During the transient conditions the D-STATCOM provides leading or lagging reactive power to active system stability, power factor correction and load balancing

2015

— In 21th century, the expansion of power system and electronic devices has been grown at very fast rate. The most noticeable topic for electrical engineer is Power quality in recent years. Power quality issues is generate due to nonstandard voltage, current or frequency. With Power quality problem utility distribution networks, industrial loads, sensitive loads etc. are suffered. To overcome the problem related to power quality, custom power devices are introduced. A number of power quality solutions are provided by custom power devices. Power quality encompasses several aspects: voltage sags, swells, harmonics, over voltage, flicker, interruptions etc., lasting only a few cycles can cause significant damage for a manufacturing process and computer hardware installations. Now a days, various range of flexible devices introduce for power application. Voltage source converter based Dynamic Voltage Restorer (DVR) can be used effectively for mitigation of voltage sag and swell. This pa...

International Journal of Emerging Trends in Engineering Research, 2021

The integration of renewable energy sources, smart grid systems and extensive usage of power electronic devices, micro-controlled based device, variable speed drives etc. causes a number of power quality issues including electrical harmonics, voltage sag, voltage swell and imbalance creates an impact on the efficiency of electrical equipment. the energy maintaining poor power quality will affect consumers and their utility equipment's. Power quality means quality of the normal voltage supplied to your facility. Voltage provided should be as close as possible to nominal voltage. The waveform must be pure sine wave free from any harmonics and other disturbances. The growing use of microprocessors and electronic equipment has made us to focus on power quality. Equipment and machinery can be damaged or even fail when subjected to power anomalies. Some of the power quality issues are voltage sag, swell, harmonics, flicker, interruption etc. Among these issues voltage sag is an important issue. This paper investigates about the causes of voltage sag, consequences and its mitigation. Many mitigation devices are available and the most economic effective solution is Dynamic Voltage Restorer (DVR). Simulation has been carried out to evaluate performance. A DVR is simulated in MATLAB/SIMULINK using synchronous reference frame theory.