scholarly journals Dynamic Voltage Restorer for Sag and Swell Issues in Power System

Author(s):  
Lakshmi Lakshmi Kumari ◽  
Uma Vani Uma Vani

<p>This paper presents the application of dynamic voltage restorers (DVR) on power distribution Systems for mitigation of voltage sags/swells at critical loads. DVR is one of the compensating types of custom power devices. The power quality is affected mainly due to the sensitive loads which results in voltage sag and voltage swells. It is necessary to investigate the suitable methods for mitigation of voltage sags. Sensitivity is the main cause of the above power quality problems and it cannot be eliminated completely as it has many other operating properties. So the next possible solution is to correct the problems caused by the sensitive equipments connected to the faulty loads. The occurrence of sag and swell varies with equipment, environment, process operations, desired control schemes etc. From the wide range of mitigation methods, the selected one has to be observed for the effect on the characteristics. These problems can be mitigated with voltage injection method using custom power device, Dynamic Voltage Restorer (DVR). In this paper we design a Dynamic Voltage Restorer (DVR) which is utilized for power quality improvement. The main power quality problems like voltage sag and swell are studied in this paper. The device used to phase out voltage sags and a swell in the distribution lines is the Dynamic Voltage Restorer (DVR). The Dynamic Voltage Restorer is a special type of power device used for providing consistent and reliable supply power to the load devices. Dynamic Voltage Restorer uses a vector control strategy for mitigating power quality problems by automatically detecting and injecting the voltage components through an injection transformer. Here comes the importance of soft computing techniques like PI controller. The system will be able to correct repeated occurrences of the power quality problems. </p>

2012 ◽  
Vol 622-623 ◽  
pp. 1830-1834 ◽  
Author(s):  
Mojtaba Hakimzadeh ◽  
Reza Sedaghati

Power quality has become an increasingly important topic in the performance of many industrial applications. One of the major issues in improving power quality in distribution networks is the mitigation of voltage sags. Voltage sag can be mitigated by voltage and power injections into the distribution system using Dynamic Voltage Restorer (DVR). The DVR is a powerful controller that is commonly used for voltage sags mitigation at the point of connection. This paper describes of modeling and analysis of DVR. Different types of faults are applied for DVR in distribution network and the responses of the system for these disturbances are examined. Simulation results obtained in PSCAD/EMTDC also prove that the DVR can mitigate voltage sag and protect bus bar voltage from various types of faults.


Author(s):  
Soe Soe Ei Aung ◽  
May Phone Thit

Electrical ac power systems consist of generation systems, transmission and distribution networks. The large three phase industrial loads at various distribution and transmission voltages as well as single-phase residential and commercial loads are supplied by the networks. Nowadays, the power quality such as voltage sags/swell, transient interrupts and harmonic distortions in sinusoidal waveforms are concerned with most of the electrical loads. The power quality problems such as voltage sags, swells and harmonics are caused by the widespread using of power electronics devices in power system. In this paper, electrical voltage sags/swells of power quality problems are considered because this problem is one of the most severe disturbances to the industrial equipment of distribution system. Thus, mitigation of these voltages in distribution system is necessary. So, series connected power electronics based device such as Dynamic Voltage Restorer (DVR) is chosen to compensate these voltage for mitigating quickly the voltage sag/swell in the system and restoring the load voltage to the nominal value. For case study, Myaungtagar industrial zone is chosen due to furnaces and large motor drives that cause the common problems such as voltage sag/swell in this system. In this paper, performance analysis of voltage sag/swell compensation of power distribution system with Dynamic Voltage Restorer (DVR) under various fault conditions is carried out. The proposed configuration model uses MATLAB/SIMULINK and the performance of voltage compensation and restoration of load voltage to the nominal value with DVR under various fault conditions is verified by the simulation results.


Author(s):  
Mahmoud Zadehbagheri ◽  
Rahim Ildarabadi ◽  
Majid Baghaei Nejad ◽  
Tole Sutikno

As a consequence of sensitive, diverse and complex loads in today's distribution networks, improving power quality in distribution systems has attracted great attention. Power quality issues involve voltage sags, transient interrupts and other distortions in sinusoidal waveforms. Enormous methods have been proposed for power quality modification. One of the methods by which power quality problems might be addressed is to apply power electronic devices in the form of custom power devices. One of such devices is Dynamic Voltage Restorer (DVR) which is connected in series to distribution networks. At the same time, through injection of voltage to the network it is able to control voltage amplitude and phase. It is adopted lend to compensate for voltage sags through injecting series and synchronous three phase voltage. Consisted of three single phase inverters and a DC bus, it can protect susceptible loads against various types of voltage sags as well as other disturbances in the power supply. Moreover, it is capable of generating and absorbing active and reactive power. Therefore, in this paper, different structures of  DVR have been investigated and eventually proposed a new structure for DVR based on Γ-Source asymmetric inverter. With the proposed structure, severe voltage sags can be retrieved 80- 90 percent. The simulation results that obtained by using MATLAB/Simulink indicate the properly functioning of proposed structure.


Author(s):  
S. Balaji, Et. al.

Electrical systems are subjected to a wide range of power quality problems which interrupt production processes. Equipment sensitivity may lead to downtime scrap and capacity losses. Also, good power quality saves more energy and money. One approach to address voltage sag problem is by implementing Dynamic Voltage Restorer (DVR) as it gives compensation to sag, swell, improves the line regulation and restores load voltage within a few milliseconds. DVR are a relatively new static VAR device that has seen applications in a variety of distribution and transmission applications. Due to its miniaturization, and cost reliability it includes fast dynamic response. This proposal presents modelling, analysis of voltage sags and correction of power factor for improved power quality using MATLAB/SIMULINK which includes as PI Controller and Discrete PWM generator for the control purpose of DVR


Author(s):  
A. Sathik Basha ◽  
M. Ramasamy

Increased utilization of nonlinear loads in the power distribution system with profound integration of renewable energy requires improved power quality control. This paper proposes a Reformed Second Order Generalized Integrated (R-SOGI) control scheme for enhancing the output of the Dynamic Voltage Restorer (DVR) for the objective of achieving the desired sinusoidal voltage wave shape at the common point of services and harmonic reduction. The DVR incorporates a Solar Photovoltaic (SPV) system using the Z-source Inverter (ZSI), providing the necessary active power to mitigate the voltage sag/swell and power demand. ZSI offers step-down as well as step-up abilities, it makes the converters to operate in the conditions of shoot-through. Therefore, the application of ZSI-based DVR topology seems very promising. The compensating reference voltage is generated by the R-SOGI algorithm, which offers superior output under conditions for grid voltage irregularities, including voltage sag/swell and unbalanced and distorted utility grid voltages. In comparison to DVR based on the VSI voltage inverter (VSI), the response from ZSI-DVR to a reduction of voltage distortions and harmonics is investigated. An experimental SPV ZSI-DVR prototype is developed in the laboratory to check the effectiveness of the controller and is tested under balanced and unbalanced supply and dynamic load conditions.


2016 ◽  
Vol 818 ◽  
pp. 52-57 ◽  
Author(s):  
Faridullah Kakar ◽  
Abdullah Asuhaimi bin Mohd Zin ◽  
Mohd Hafiz bin Habibuddin

Voltage sag and harmonics are the most frequent power quality problems faced by industrial and commercial customers today. Situation has been aggravated by modern sensitive industrial equipments which introduce system harmonics due to their inherent V-I characteristics. In this paper, proportional integral (PI) control technique based dynamic voltage restorer (DVR) is implemented in power distribution system to suppress voltage sag and harmonics under linear, non-linear and induction motor load conditions. Real-time power distribution system and DVR test models are built in Matlab/Simulink software. Simulation results exhibit excellent PI control approach with effective performance yielding excellent voltage regulation.


Author(s):  
Diksha Wasnik ◽  
Radharaman Shaha

Today most of the industries and customers are using sensitive and sophisticated electrical equipment based on semiconductor devices, these may causes power quality disturbance. The major problems are voltage sag and swell. The sag and swell not only occur by disturbed power quality but also due to high system tapping at point of common coupling. To overcome this problem and to improve power quality the distribution companies uses various custom power devices. Among the various custom power devices Dynamic voltage restorer is used for compensation in this paper, which is most popular and widely used method. Here, In phase compensation technique of DVR is used with battery energy storage system. The voltage at PCC have been observed. The control technique employed here is SRF theory with PI controller. The overall work is carried out in MATLAB Simulink.


Transmisi ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 73-79
Author(s):  
Arief Trisno Eko Suryo ◽  
Wijono Wijono ◽  
Bambang Siswojo

Makalah ini mendiskusikan tentang analisis kompensasi tegangan sag. Tegangan sag disebabkan oleh gangguan hubung singkat 3 fasa ke tanah. Gangguan tersebut memiliki dampak besar terhadap kerusakan pada saluran beban Penyulang Pujon. Tegangan sag dapat diatasi dengan kompensasi menggunakan Dynamic Voltage Restorer (DVR), yang mana DVR merupakan salah satu dari custom power device yang paling efektif. Hysteresis dan ANN diusulkan untuk mengatur kompensasi tegangan sag dari DVR. Hasil simulasi menunjukkan bahwa kontrol Hysteresis mampu mengkompensasi tegangan beban rata-rata sebesar 95.9 %, dan ANN 104.3%. Kontrol Hysteresis lebih baik dibandingkan dengan kontrol ANN dalam mengkompensasi tegangan beban, yang mana tidak melebihi tegangan beban normal pada saat kompensasi tegangan sag.


2020 ◽  
Vol 32 ◽  
pp. 01006
Author(s):  
Abhishek Chalwadi ◽  
Kiruthika M ◽  
Bindu S

The power system network is becoming dense and much more complex. Dynamic and continuous monitoring of the power system network is required to avoid power outages. Phasor Measurement Unit (PMU) is one such device that provides state estimation parameters of dynamic power system networks that are used for designing relays and controlling the system network. Power Quality problems such as voltage sags and swells can damage the sensitive load and cause abnormal voltage, current, and frequency conditions in a power system network. Fast and major developments in power electronics technology have made it possible to mitigate the power quality problems. Dynamic Voltage Restorer (DVR) is a voltage sag compensation device that compensates the difference in voltage avoiding interruptions and restores the voltage to the pre-fault value. This paper discusses a technique used for monitoring, protecting, and controlling the system under fault condition using PMU and compensate voltage sag for a sensitive load using DVR based on the data collected by placing PMU in an optimal location. The outcome of the above analysis is recorded which shows that effective monitoring, controlling, and voltage sag compensation can be done with less number of PMU’s placed optimally in conjunction with DVR.


Sign in / Sign up

Export Citation Format

Share Document