Performance of Fault Detection And Location Algorithms For Power Transmission Lines

Vol. 1 No. 2

Year: 2013

Issue: Mar-May

Title : Performance of Fault Detection And Location Algorithms For Power Transmission Lines

Author Name : Sk.Nazeer, B.R.K.Varma

Synopsis :

Any reliable transmission line protection scheme is expected to quickly detect faults and isolate the faulted section immediately. Ability to locate the fault, further helps fast restoration of service in case of permanent faults or identifying the weak spots in the system. This paper explores different fault detection and location algorithms and their performance is analyzed using different types of faults, fault resistance and inception angles. Influence of series compensation on fault location is also studied. Two fault detection techniques i.e. moving-sum approach and cumulative-sum approach are evaluated. Fault location is done by using travelling wave theory, which is utilized in capturing the travel time of the transients along the monitored lines between the fault point and relay. Wavelet transform is used for analyzing power system fault transients in order to capture the travel time. Performance of location algorithms for both single ended and two ended measurements is analyzed. Results of the performance studies on the algorithms for detection and the location with compensated and uncompensated lines are presented. The performance of the algorithm is tested in MATLAB simulation environment.

A Complete Analytical Model for Circular Diaphragm Pressure Sensor with Clamped edge

Vol. 1 No. 2

Year: 2013

Issue: Mar-May

Title : A Complete Analytical Model for Circular Diaphragm Pressure Sensor with Clamped edge

Author Name : Sumit Kumar Jindal, S. K. Raghuwanshi

Synopsis :

MEMS offer various fabrication process to fabricate diaphragms for various applications such as microphones, capacitive sensors, pressure sensor, micro-pumps etc. The working principle of all the devices is based on the force uniformly applied on the diaphragm and cause the diaphragm to deflect. The parameter optimization of the diaphragm is a challenge in order to achieve the best performance of the device.

Distributed Static Series Compensator for Improving Distribution Performance

Vol. 1 No. 2

Year: 2013

Issue: Mar-May

Title : Distributed Static Series Compensator for Improving Distribution Performance

Author Name : Dr Rama Rao PVV, K. Bhanu Priya

Synopsis :

This paper proposes a Distributed Static Series Compensator (DSSC) for improving the active power flow in the distribution systems. The DSSC can be operated to control the impedance of the line so as to improve the active power flow by clamped round the existing distribution line. In this paper it is proposed that a distributed approach to power flow control can simultaneously solve some of the most daunting issues that have held back widespread commercialization of flexible AC transmission technology (FACTS). The effect of DSSC is investigated by simulating the model using the PSCAD and also in MATLAB/ Simulink environment.

Neuro-Wavelet Approach for Transient Current based Transmission line Protection Scheme

Vol. 1 No. 2

Year: 2013

Issue: Mar-May

Title : Neuro-Wavelet Approach for Transient Current based Transmission line Protection Scheme

Author Name : G.Ravi kumar, S.Tejasree , CH.Pavani , P.Sajitha

Synopsis :

This paper presents a wavelet based protection scheme for a single line transmission system is connected to load. A wavelet based multi resolution analysis is used to find the detailed coefficients of the signals which are utilized to calculate fault index. These fault indexes are compared with the threshold value to detect and classify faults on transmission system and for the location of fault using artificial neural networks. The proposed algorithm is proved for the detection, classification and location of faults on Transmission lines which is almost independent of fault impedance, fault inception angle and fault distance of transmission line.

Fuzzy Based Power Quality Improvement In Grid Connected Microgrid At The Distribution Level

Vol. 1 No. 2

Year: 2013

Issue: Mar-May

Title : Fuzzy Based Power Quality Improvement In Grid Connected Microgrid At The Distribution Level

Author Name : BOLISETTI NAVEEN, MOTHI RAM bhukya

Synopsis :

This paper suggests a new control strategy that consists of a grid interfaced four leg inverter control system using adaptive fuzzy controller for a 3-phase 4-wire distribution system that is capable of simultaneously compensating problems like power factor, current imbalance and current harmonics, and also of injecting the energy generated by Renewable Energy Sources (RES). The grid interfacing can thus be utilized as:1)power converter to inject power generated from rest the grid, and 2)shunt APF to current unbalance, load current harmonics and load reactive power demand. All of these functions may be accomplished either individually or simultaneously. This new control concept is demonstrated with extensive MATLAB/simulink simulation studies.

Power Quality Improvement In Grid Connected Windenergy System Using Statcom

Vol. 1 No. 1

Year: 2013

 
Issue: Dec-Feb

Title : Power Quality Improvement In Grid Connected Windenergy System Using Statcom 

  

Author Name : S.Rajesh Rajan  

Synopsis : 

Injection of the wind power into an electric grid affects the power quality. The performance of the wind turbine and thereby power quality are determined on the basis of measurements and the norms followed according to the guideline speci?ed in International Electro-technical Commission standard, IEC-61400.This paper demonstrates the power quality problem due to installation of wind turbine with the grid. In this proposed scheme Static Compensator (STATCOM) is connected at a point of common coupling with a battery energy storage system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the real power source under ?uctuating wind power. The STATCOM control scheme for the grid connected wind energy generation system for power quality improvement is simulated using MATLAB/SIMULINK in power system block set. The effectiveness of the proposed scheme relives the main supply source from the reactive power demand of the load and the induction generator. The development of the grid co-ordination rule and the scheme for improvement in power quality norms as the grid has been presented.

Wind Generator Allocation in Distribution Systems Considering Uncertainty In Generation And Time Varying Load Profile

Vol. 1 No. 1

Year: 2013

 
Issue: Dec-Feb

Title : Wind Generator Allocation in Distribution Systems Considering Uncertainty In Generation And Time Varying Load Profile

Author Name : Dr. K. Ravindra, R. Srinivasa Rao , SVL Narasimham

Synopsis :

In this paper, a simultaneous approach to choose optimal number of wind based Distributed Generation (DG) units and their locations is proposed with an objective of minimizing annual energy loss in a distribution network. Most of the methods developed so far for optimal allocation of DG units assumed constant DG output and network load profile which is unreal. Optimal DG sizes and locations found with above assumptions would not lead to minimum annual energy loss when employed in realistic scenario where there is uncertainty in the DG output power generation and network loads have a time-varying load profile. In this work, wind based generation units are considered as the DG sources for allocation. In order to gauge the effect of uncertainty in wind power generation and time-varying load profile on optimal DG allocation problem, a meta-heuristic method which employs Harmony Search algorithm is used to solve multiple wind based DG units. Performance and effectiveness of the proposed method is demonstrated by carrying out simulations on 33-bus and 69-bus radial distribution systems. Simulation results indicate that consideration of uncertainty in wind power generation and time varying load profile significantly affects location and size of DG resources in distribution systems.
 

Fuzzy Logiccontrol Of Differential Protection For Large Power Transformer

Vol. 1 No. 1

Year: 2013

 
Issue: Dec-Feb

Title : Fuzzy Logiccontrol Of Differential Protection For Large Power Transformer

  

Author Name : S.Padmini, Subransu Sekhar Dash , Shruti Chandrasekhar , Priyanka Vedula

Synopsis :

Advances Differential prot ecti on system is us e d t o protect most of the power transformers in power systems. The protection system is based on the differential currents/voltages of the primary an d secondary of the transformers under fault conditions and under normal operating conditions. The inrus currents or the magnetizing currents are generated in the transformer when it is switched on to the transmission system or the external fault in the system is cleared. The inrush currents other than the fault currents may activate the differential protection system if suitable blocking scheme is not incorporated in the protection system of the power transformer. Therefore, identification of inrush current and the fault currents is the key to improve the security of the differential protection scheme. This paper proposes the development of a new algorithm to improve the differential protection performance by using fuzzy logic and Clarke's transform. The result obtained concludes an effective method to differentiate the different internal faults with accuracy as well as shows an improvement in the time taken to detect faults.

Reducing Clock Power Wastage By Using Conditional Pulse Enhancement Scheme

Vol. 1 No. 1

Year: 2013

 
Issue: Dec-Feb

Title : Reducing Clock Power Wastage By Using Conditional Pulse Enhancement Scheme 

Author Name : saisudheer amba, Muralipraveen

Synopsis :

  

In this paper, a low-power pulse-triggered flip-flop (FF) designed and a simple two-transistor AND gate is designed to reduce the circuit complexity. Second, a conditional pulse-enhancement technique is devised to speed up the discharge along the critical path only when needed. As a result, transistor sizes in delay inverter and pulse-generation circuit can be reduced for power saving. Various post layout simulation results based on UMC CMOS 50-nm technology reveal that the proposed design features the best power-delay-product performance in several FF designs under comparison. Its maximum power saving against rival designs is up to 18.2% and the average leakage power consumption is also reduced by a factor of 1.52.