Voltage Sag due to Pollution Induced Flashover Across Ceramic Insulator Strings

Author(s):  
Subba Reddy B ◽  
Arup Kumar Goswami

AbstractVoltage sag or voltage dips are significant to industrial reliability. There is a necessity to characterize the feeder level power quality (PQ) and the PQ performance among various utility companies. Contamination/pollution induced flashover is the ultimate consequence of the creeping discharges across the insulator strings which induce voltage sag. These have a severe threat on the safe and reliable operation of power systems. In the present work an attempt has been made to experimentally investigate the occurrence of voltage sag/dips during pollution induced flashovers. Results show significant dip/sag in the voltage magnitude during the flashover process.

2014 ◽  
Vol 622 ◽  
pp. 147-151
Author(s):  
Natesan Saritha ◽  
Venkatesan Jamuna ◽  
N. Nanthini

—– In this paper, problem faced by grid connected pv inverter is presented. Inverters connected to grid are mostly affected due to short circuit problems in the power systems. Therefore it is essential to analyze power quality disturbances in order to improve the quality of the system. Performance of inverter is affected severely by voltage sag compared to other type of power quality disturbances. Also in this paper, multilevel inverter with sag condition and without sag condition is simulated using MATLAB/SIMULINK software


2018 ◽  
Vol 7 (2.8) ◽  
pp. 18
Author(s):  
B Vijaya Krishna ◽  
B Venkata Prashanth ◽  
P Sujatha

In current days, the power quality issues in the interconnected power system are mainly happens due to the demand of electricity and utilization of large non-linear loads as well as inductive/capacitive loads. The power quality cries are voltage sag and swell in multi-bus power system (MBPS). In this article studies on a two bus, three bus and five bus power systems using DPFC. In order to eliminate the voltage sag and swell in the MBPS, a distributed power flow controller (DPFC) is designed. The structure of the DPFC consists of three-phase shunt converter and three single series phase converters. Both these converters are arranged in back-back voltage source inverters (VSIs). These converters are controlled with help of the pulse width modulation (PWM) scheme. The feedback controllers and reference signals are derived the PWM for DPFC to magnify the power quality problems in MBPS. The performance of the model is investigated at different loads by making of MATLAB/Simulink model. The simulation results are presented.


Power quality has become an important factor in power systems, for consumer and household appliances with proliferation of various electric/ electronic equipment and computer systems. The main causes of a poor power quality are harmonic currents, poor power factor, supply voltage variations, etc. In recent years the demand for the quality of electric power has been increased rapidly. Power quality problems have received a great attention nowadays because of their impacts on both utilities and customers. Voltage sag, swell, momentary interruption, under voltages, over voltages, noise and harmonics are the most common power quality disturbances.It proposes a new connection for a unified power quality compensator (UPQC) to improve the power quality of two feeders in a distribution system. It illustrates how UPQC can improve the power quality by mitigating all these PQ disturbances. The proposed configuration of the UPQC is developed and verified for various power quality disturbances by simulating the mode using MATLAB.


Author(s):  
K. Swetha ◽  
V. Sivachidambaranathan

This paper focus on distribution system by applying different control techniques in order to improve the performance of the system. In the distribution system mainly concentrate on power quality issues like reactive power control, harmonic elimination, power factor correction, etc. Because of power quality problems voltage, current, frequency are continuously changing in power systems. These changes will effects the performance of power systems. Power quality problems can be compensated by placing DSTATCOM which is connected at PCC in parallel. It is shunt connected VSI along with the filters, with the help of DSTATCOM voltage sag, swell and THD can be controlled. This paper presents detailed explanation about performance and configuration of latest control techniques to control the DSTATCOM.


Author(s):  
Tamilvanan G. ◽  
Mahendran S.

<p>The maintain power quality is one of the major part of all kind of industry as well as power systems. Voltage sag and voltage swell the common power quality issue. The Dynamic Voltage Restorer is the common Device which is used to mitigate the above problems. In this paper provides review on various type of AC-AC converter based DVR. The use of AC-AC converter can compensate the voltage sag and swell without need of any kind of storage elements like capacitor and batteries. The absence of storage elements can reduce size and weight of the DVR. The feature various type of AC- AC converters based DVR is concentrated in this paper.</p>


2019 ◽  
Vol 139 ◽  
pp. 01055
Author(s):  
L.I. Kovernikova ◽  
Van Chung Luong

Parameters of operating conditions of electric power systems shall ensure efficient and reliable operation of both power generating companies and of consumers, which to a great extent depends on power quality. Most urgent problem in this area is currently non-sinusoidal voltage. Power quality control, development of technical measures to sustain parameters of harmonic modes in conformity with provisions of GOST 32144-2013 require calculations that, in turn, need models adequately representing the electric networks and nonlinear loads in the computing program. Results of studies on parameters of harmonic modes that were obtained by measurements have shown that harmonic modes are random, and their parameters have probabilistic nature. Due to unpredictability of harmonic modes, nonlinear loads can be modeled using measured parameters. The paper presents methodological approach, algorithms and a computing program for modeling the nonlinear loads using parameters measured in the nodes of their connection to the power supply, and gives examples of modeling the nonlinear loads.


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