A Novel Faulty Phase Identification Algorithm and Fast DQ Transform Technique for Voltage Sag Detection

2017 ◽  
Vol 26 (12) ◽  
pp. 1750204 ◽  
Author(s):  
S. Rashmi ◽  
Shankaraiah

The disturbances created in AC transmission line power flow due to various faults and unavoidable natural circumstances have to be monitored carefully for uninterrupted power supply to the consumer and to avoid unacceptable situations. Voltage sag is one such unwanted disturbance occurring in the power system due to varying causes like lightning, loose connections, accidental short circuits, tree branches touching the line, birds hitting the line, etc., owing to non-recoverable damage to sensitive equipment in industries which also leads to financial losses. This paper proposes a new technique using DQ transform and integrator for fast voltage sag detection which is possible within [Formula: see text]th of a cycle and a new algorithm to identify the faulty phase. The authors are able to detect the voltage sag within the lowest time of 0.3[Formula: see text]ms for single-phase fault and 0.2[Formula: see text]ms for two-phase and three-phase faults. The simulation results for various types of power system faults with different point-on-waveform (POW) are presented using MATLAB/Simulink tool.

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3261-3266

The unified power quality conditioner is equipment used for regulated voltage distortion and voltage unbalance in a power system. This device gives unique control on the power flow and voltage stability in the transmission line within their limits and enhancing the power to flow through the preferred path. This paper presents a control scheme and Theoretical derivation of the unified power flow conditioner and the simulation results are compared and contrasted in detail. UPFC is a combination of shunt Active and series active power filters. UPFC contains a DC link capacitor in a single phase voltage source inverter with two back to back connected, three-phase three-wire and three-phase four-wire are arranged. The objective of the study is to introduce a scheme which improves the quality of power in the flexible AC transmission systems on the aspects of voltage sag and harmonic distortion apart from enhancing power transfer capability and stability limit using unified power flow conditioner In this, the power system simulation models are made on MATLAB version. The results obtained show that the UPFC controller had better performance to damp LFO compared to the other UPFC damping controllers.


2011 ◽  
Vol 403-408 ◽  
pp. 4926-4933
Author(s):  
Laxmidhar Sahu ◽  
Jose. P. Therattil ◽  
P. C. Panda

The continuous change in power demand and supply altered the power flow patterns in transmission networks in such a way that some of the corridors are lightly loaded and some of the corridors get over loaded. This raises serious challenge in operating the power system in secure and reliable manner. To cope with this problem Flexible AC Transmission Systems (FACTS) is used. It plays a very important role in improving the power system operating performance. In this paper load flow models for STATCOM and SVC have been developed. Power flow study of a five bus system is carried out with and without FACTS controllers. Results of the power flow studies are obtained with MATLAB programming.


2020 ◽  
Vol 40 (3) ◽  
pp. 21-31
Author(s):  
Mohamed Nassim Kraimia ◽  
Mohamed Boudour

In this paper a study of the impact of the harmonics generated by a static Var compensator (SVC) is presented. The SVC is modeled, in the harmonic domain, as a coupled current source by using the complex Fourier transforms. Then, this model is converted to polar form to be integrated into the harmonic power flow program. This approach has been carried out on the IEEE 14 bus test power system, in order to show its effectiveness in evaluating the impact of harmonics, injected by the shunt compensating devices, and its interaction with the AC transmission system, in meshed power networks. Since the SVC consists of a thyristorcontrolled reactor (TCR) and a fixed capacitor, the harmonic currents are functions of the TCR thyristors firing angles. The variation of the total voltage harmonic distortion as function of firing angle changes and location of nonlinear loads is clearly presented and discussed.


Author(s):  
Lucio Ippolito ◽  
Antonio La Cortiglia ◽  
Michele Petrocelli

The increases in power flows and environmental constraints are forcing electricity utilities to install new equipment to enhance network operation. Some application of Flexible AC Transmission System (FACTS) technologies to existing high-voltage power systems has proved the use of FACTS technology may be a cost-effective option for power delivery system enhancements. Amongst various power electronic devices, the unified power flow controller (UPFC) device has captured the interest of researchers for its capability of regulating the power flow and minimizing the power losses simultaneously. Since for a cost-effective application of FACTS technology a proper selection of the number and placement of these devices is required, the scope of this paper is to propose a methodology, based on a genetic algorithm, able to identify the optimal number and location of UPFC devices in an assigned power system network for maximizing system capabilities, social welfare and to satisfy contractual requirements in an open market power.In order to validate the usefulness of the approach suggested herein, a case study using a IEEE 30-bus power system is presented and discussed.


2014 ◽  
Vol 622 ◽  
pp. 111-120
Author(s):  
Ananthavel Saraswathi ◽  
S. Sutha

Nowadays in the restructured scenario, the main challenging objective of the modern power system is to avoid blackouts and provide uninterrupted quality power supply with dynamic response during emergency to improve power system security and stability. In this sense the convertible static compensator (CSC) that is the Generalized Inter line power flow controller (GIPFC), can control and optimize power flow in multi-line transmission system instead of controlling single line like its forerunner FACTS (Flexible AC Transmission System) controller. By adding a STATCOM (Static synchronous Shunt Converter) at the front end of the test power system and connecting to the common DC link of the IPFC, it is possible to bring the power factor to higher level and harmonics to the lower level and this arrangement is popularly known as Generalized Inter line power flow controller (GIPFC). In this paper a new concept of GIPFC based on incorporating a voltage source converter with zero sequence injection SPWM technique is presented for reinforcement of system stability margin. A detailed circuit model of modified GIPFC is developed and its performance is validated for a standard test system. Simulation is done using MATLAB Simulink.Index Terms—Convertible static controller, Flexible AC Transmission System (FACTS), Generalized Interline Power Flow Controller (GIPFC),STATCOM, SSSC, Reactive power compensation.


Author(s):  
Ramnarayan Patel ◽  
Vasundhara Mahajan ◽  
Vinay Pant

Power engineers are currently facing challenges to increase the power transfer capabilities of existing transmission system. Flexible AC Transmission system (FACTS) controllers can balance the power flow and thereby use the existing power system network most efficiently. Because of their fast response, FACTS controllers can also improve the stability of an electrical power system by helping critically disturbed generators to give away the excess energy gained through the acceleration during fault. Thyristor controlled series compensator (TCSC) is an important device in FACTS family, and is widely recognized as an effective and economical means to solve the power system stability problem. TCSC is used as series compensator in transmission system. In the present work a TCSC controller is designed and tested over a single machine infinite bus (SMIB) as well as a multi-machine power system. Detailed simulation studies are carried out with MATLAB/SIMULINK environment and the effect of the TCSC parameter variations over the system stability is studied.


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