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M. Senthil Kumar ¹, P. Renuga ²

Affiliations
1 Sona College of Technology, Salem, Tamil Nadu, IN
2 Thiagarajar College of Engineering, Madurai, Tamil Nadu, IN

Abstract

Loss minimization in power system is an important research issue. Transmission line losses in a power system can be minimized by means of reactive power compensation. The unscheduled increment of load variation in a power transmission system has driven the system to experience stressed condition leading to potential cascading trip on the entire system. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission Systems (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. Identification of the optimal value of compensating devices required proper optimization technique, able to search the optimal solution with less computation burden avoided. This paper presents a technique to provide simultaneous or individuals controls of basic system parameter like transmission voltage, impedance and phase angle, there by controlling the transmitted power using Unified Power Flow Controller (UPFC) approach based on Particle Swarm Optimization (PSO) technique. In this study optimization engine was developed for voltage profile improvement and minimization of losses in a power system which utilized the UPFC as the control variables embedded in to the system’s data. The IEEE 6-bus and IEEE 14-bus systems were used as test systems to demonstrate the applicability and efficiency of the proposed system. The proposed method is compared with Genetic Algorithms (GAs). The test result showed that the location of UPFC improves the voltage profile of the system and also minimize the transmission line losses.

Keywords

Flexible AC Transmission Systems (FACTS), Real and Reactive Power, Unified Power Flow Controller (UPFC), Particle Swarm Optimization (PSO).

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D. Kavitha ¹, P. Renuga ¹, S. Muthamil Priya ¹, S. Sadaiappan ¹

Affiliations
1 Department of Electrical and Electronics Engineering, Thiagarajar College of Engineering, Madurai, Tamil Nadu, IN

Abstract

In this paper, series compensator is proposed to reduce the harmonic distortion in the sensitive load due to the presence of non linear loads in the power system network. The series compensation method is best suited to protect such load against this disturbance. The use of a series compensator (SC) to improve power quality is an isolated power system is investigated. In this paper, a series compensator is proposed and a method of harmonic compensation is described using PI controller and Fuzzy controller. The proposed series compensator consists of Energy Storage System (ESS) and Voltage Source Inverter (VSI), Injection Transformer. The ESS can be a capacitor of suitable capacity. ESS would act as a buffer. Injection Transformer is used to inject the voltage in transmission line in appropriate level. In this way the terminal voltage of the protected sensitive load can be regulated to maintain a constant level. The modeling and simulation of the proposed series compensator was implemented in Matlab Simulink work space. Simulation results showed that the proposed series compensator was efficient in mitigating harmonics and compare with the both controllers and thus improve the power quality of the isolated power system. This approach is different from conventional methods and provides effective solution. If this method is enhanced in future it could provide much more improved power quality.

Keywords

Power Quality Problem, Fuzzy Logic Controller, Series Compensator, ESS, VSI, Harmonics, MATLAB.

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D. Kavitha ¹, P. Renuga ¹, M. Seetha Lakshmi ¹

Affiliations
1 Department of Electrical and Electronics Engineering, Thiagarajar College of Engineering, Madurai, Tamil Nadu, IN

Abstract

In this paper, exponential wave fitting algorithm is proposed for the estimation of harmonics and interharmonics in power system. A appropriate control approach must be provided to ease the harmonics. To obtain suitable control parameter, the harmonics present in the system is to be estimated. In this work, the estimation of interharmonics was done with and without noise. Interharmonics can be thought of as the inter-modulation of the fundamental and harmonic components of the system with any other frequency components and can be perceived in an increasing number of loads. These loads include static frequency converters, cycloconverters, sub-synchronous converter cascades, induction motors, arc furnaces and all loads not pulsating synchronously with the fundamental power system frequency. International Electro technical Commission (IEC) which is the international body recognized as the curator of electric power quality standards (IEC-1000-2-1) officially defined this terminology as ‘Between the harmonics of the power frequency voltage and current, further frequencies can be observed which are not an integer of the fundamental, They can appear as discrete frequencies or as a wide- band spectrum’. A recent IEC-61000-2-2 draft redefines interharmonic as ‘Any frequency which is not an integer multiple of the fundamental frequency’. IEEE Interharmonic Task Force adopted this definition. As harmonics and interharmonics have much adverse effects on the equipment, a proper control strategy must be provided to alleviate the harmonics.

Keywords

Exponential Wave Fitting Algorithm, Frequency Estimation, Power System, Noise, Harmonics Mitigation, Power Quality.

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M Rajvikram ¹, P. Renuga ², G. Aravind Kumar ³, K. Bavithra ⁴

Affiliations
1 PG Scholar, EEE Department, Thiagarajar College of Engineering, Madurai-625015, IN
2 Associate Professor, EEE Department, Thiagarajar College of Engineering, Madurai-625015, IN
3 PG Scholar, EEE Department,Kalasalingam University, Madurai-625015, IN
4 Assistant Professor, EEE Department PSG Institute of Technology and Applied Research, Coimbatore -641062, IN

Abstract

In order to minimize the environmental pollution and to meet the demand of power generation, the electrical power is generated through the renewable energy resources. The wind energy is the massive energy resource compared to other mode of renewable energy resources. This paper deals on the fault ride-through capability of Permanent Magnet Synchronous Generator (PMSG) wind turbines. The main attention in the paper is, to control the PMSG wind turbine and its power converter and to the ability to protect itself without disconnection during grid fault is the main work focused in this project. Also this paper provides the necessary information on the interaction between variable-speed PMSG wind turbines and the power system subjected to faults, such as short circuit faults. The PMSG based WECS is subjected to the grid faults it will cause the oscillations in the DC link voltage at back to back converter. A crowbar and Super Conducting Fault Current limiters (SCFCL) is proposed to supress the DC link voltage oscillations and to enhance the Low Voltage Ride-through (LVRT) Capability of PMSG based wind turbine. To achieve the reactive power support at the grid side the STATCOM is implemented. The simulation results implemented in Matlab/Simulink show that the proposed control strategy not only improves the stability of PMSG by means of suppressing the DC-link voltage oscillation, but also provides a transient stability support to restraint the disturbance of the grid voltage.

Keywords

PMSG (Permanent Magnet Synchronous Generator), DC link voltage, grid faults.

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S. M. Kannan ¹, P. Renuga ², S. Mary Raja Slochanal ³, A. R. Rathina Grace Monica ¹

Affiliations
1 Department of Electrical and Electronics Engineering, K.L.N. College of Engineering, Anna University, Madurai, Tamil Nadu-630611, IN
2 Department of Electrical and Electronics Engineering, Thiagarajar College of Engineering, Anna University, Madurai, Tamil Nadu-625015, IN
3 Department of Electrical Engineering, Higher Institute of Engineering, Hoon, LY

Abstract

Electric distribution systems are becoming large and complex leading to higher system losses and poor voltage regulation. This has stressed the need for an efficient and effective distribution network The objective of this work is to determine optimal location and size of the capacitor to be placed in radial distribution feeders to improve the voltage profile and to reduce the energy loss. This problem of capacitor placement is solved using fuzzy expert system and sizing is solved using particle swarm optimization method.

Firstly, an efficient load flow solution for the radial feeder is obtained by forward sweeping algorithm. Voltage and real power loss index of distribution system nodes are modeled by fuzzy membership function. Then, a fuzzy inference system containing a set of heuristic rules is designed to determine candidate nodes suitable for capacitor placement in the distribution system. Capacitors are placed on the nodes with highest sensitivity index. The sizing is found by using Particle Swarm Optimization (PSO). The proposed method is tested on IEEE-11kV, 12 bus system (without lateral) and an existing 15 bus system (with lateral) in India.

Keywords

Radial Distribution Feeders, Fuzzy Expert System, Capacitor Placement, Particle Swarm Optimization.

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