A. Thamilmaran

Bio: A. Thamilmaran is an academic researcher from VIT University. The author has contributed to research in topics: AC power & Power factor. The author has an hindex of 1, co-authored 2 publications receiving 3 citations.

Design of STATCOM using CHB and its Comparison with other RPC Devices

Abstract: Background/Objectives: Due to the immense development in distributed generation, the entire power system network requires flexible control of power flow and increased stability. Methods/Statistical analysis : In order to achieve this as well as to improve the reliability of the network, power electronics switches are incorporated at several locations as the control of these switches are comparatively easy and accurate. Cascaded multilevel inverter based static synchronous compensator is one such device that provides better reactive power compensation, improves voltage profile as well as enhances the power factor of the system. Findings: This paper is intended to design and analyze static synchronous compensator (STATCOM) utilizing cascaded H-bridge (CHB) multilevel inverter. The designed STATCOM has been used for the Reactive Power Compensation (RPC) and power factor improvement for the single end fed power system network modeled in Simulink. Seven levels CHB multilevel inverter has been designed for STATCOM using sine pulse width modulation (SPWM). The output of the inverter is then filtered using the pi filter to obtain nearly sinusoidal voltage profile. Single end fed power system network has been modeled in Simulink. STATCOM majorly provides reactive power and improve the power factor of the system without any further loading on it. For confirming the effectiveness of the proposed STATCOM compensation, the system has also been analyzed with shunt compensation by fixed capacitor and thyristor switched capacitor (TSC) individually and the same study has been carried out to compare them. Applications/Improvements: It has been found that with the STATCOM implemented, the voltage profile of all the bus has increased nearly to 1 pu and the power factor has improved to 0.97 when compared to the other compensating devices.

Location of UPFC Based on Critical Bus Ranking Index.

Abstract: Unified power flow controller (UPFC) is one among the versatile devices from the FACTS family that has a great potential to enable power system engineers maintain the required security level of a large power systems that are interconnected by controlling the amount of active and/or reactive power flow. Identification of suitable location for installing this costly device is relatively very difficult task. Various criteria need to be satisfied before selecting the location for installation of UPFC. In this paper, a novel method is proposed which identifies the best location for UPFC placement based on the net reduction in the critical bus ranking index under various line outage contingencies. The proposed method was implemented on a 5-bus system. The UPFC was placed at the identified location and it is found that the installation of UPFC has reduced the criticality of the selected bus and it also enhanced the voltage stability margin of the system under selected line outage contingencies.

Improving Power Quality by DSTATCOM Based DQ Theory with Soft Computing Techniques

Abstract: The development of non-linear loads at consumers has significantly impacted power supply systems. Since, the poor power quality has been found in the three-phase distribution system due to unbalanced loads, harmonic current, undesired voltage regulation, and extreme reactive power demand. To overcome this issue, Distributed STATicCOMpensator (DSTATCOM) is implemented. DSTATCOM is a shunt-connected Voltage Source Converter (VSC) that has been utilized in distribution networks to balance the bus voltage in terms of enhancing reactive power control and power factor. DSTATCOM can provide both rapid and continuous capacitive and inductive mode compensation. A rectified resistive and inductive load eliminates current harmonics in a three-phase power supply. The synchronous fundamental DQ frame is a time-domain approach developed from three-phase system space vector transformations has been designed using MATLAB/Simulink. The DQ theory is used to produce the reference signal for the Pulse Width Modulation (PWM) generator. In addition, a traditional Proportional Integral Derivative (PID) controller is designed and compared with proposed soft computing approaches such as Fuzzy–PID and Artificial Neural Network (ANN-PID) and compared accurate reference current determination for Direct Current (DC) bus through DC link. An Analytical explores the proposed control strategies given to establish superior outcomes. Finally, total harmonic distortion analysis should be taken for performance analysis of the proposed system with IEEE standards.

Finite Impulse Response Filter Design Using Fuzzy Logic-Based Diversity-Controlled Self-Adaptive Differential Evolution

Abstract: The design of finite impulse response (FIR) filters involves the estimation of effective filter coefficients, making the designed filter exhibit infinite stopband attenuation and have a flat-shaped passband. The few conventional filter design methods such as impulse response truncation (IRT) and windowing technique exhibit undesirable characteristics owing to the Gibbs phenomenon, thus making them unsuitable for various practical complexities. This research work employs the fuzzy logic-based diversity-controlled self-adaptive differential evolution algorithm (FLDCSaDE) for the design of FIR band stop (BS) and high pass (HP) filters. In order to validate the results of the proposed technique, various population-based evolutionary computing techniques such as the covariance matrix adaptation evolution strategy (CMAES), differential evolution (DE), self-adaptive differential evolution (SaDE), and Jaya algorithm have also been applied for determining the effective filter coefficients. The performance of the various algorithms has been analysed and compared based on the parameters such as stopband attenuation, passband attenuation, and ripples. The simulation results show that the FLDCSaDE algorithm outperforms other evolutionary algorithms having 4% and 1.5% lower ripples than the SaDE algorithm for high pass and band stop filters, respectively. Experimental results depict that the performance of the fuzzy approach causes positioning and tracking accuracy obtained to be improved by 27% and the corresponding false positive rate (FPR) is substantially reduced to 0.11 from the mean amplitude value obtained from the fuzzy approach in the frequency response. The frequency response obtained from the FLDCSaDE algorithm is close to the ideal response of the BS and HP FIR filters.

Application of Static Synchronous Compensator (STATCOM) to enhance Voltage Profile in IEEE Standard 5 Bus Transmission System

Abstract: Background/Objectives: This paper presents implementation of Static Synchronous Compensator (STATCOM) which can control reactive power through transmission lines in an IEEE standard 5 bus system to meet constraints on bus voltage magnitude, thermal limits and power factor. Methods/Statistical Analysis: This is made possible by appropriately controlling compensation current of shunt compensator. Findings: Simulation results on performance of STATCOM are studied in MATLAB/SIMULINK and validated the effectiveness of the controller. The results show reduction in losses, improvement in power factor and improvement in bus voltage profile are obtained with STATCOM. Application/Improvements: Power flow through the transmission line had improved from 0.014 p.u. to 0.154 p.u.

A 7-level inverter with less number of switches for grid-tied PV applications

Abstract: In the current context, Medium Voltage High Power (MVHP) applications are developing industrial technologies. The direct connection of a Photovoltaic (PV) system to an MVHP system may cause various connectivity challenges. To address the interconnection difficulties, this paper describes a 7-Level Cascaded H-Bridge Multilevel Inverter (CHB-MLI) architecture with fewer switches and lower harmonics. This article proposes the Reduced Switch Multilevel Inverter (RSMLI). This design is less expensive than traditional Multilevel Inverter (MLI) topologies, and it is ideally suited for medium voltage and high-power applications since it synthesizes numerous Direct Current (DC) sources. The innovative 7-Level inverter is represented with a decreased number of switches using the Phase Opposition Disposition (POD) methodology. The lower switch count helps the construction of simple converter structures. To boost performance, the MATLAB/Simulink results are evaluated.

Utilizing Unified Power Flow Controller for Stability Improvement of the Electric Power Transmission System of Ghana

Abstract: Interconnecting power transmission systems provide reliability of electric power supply. The security of the system is however questioned when a disturbance in any part of the interconnected system causes instability in the entire network. Unified Power Flow Controller (UPFC), which is a member of the flexible alternating current transmission system (FACTS) family, has the capability of controlling active and reactive power flow in a transmission line thereby improving the voltage stability of the system especially at the 500 kV configuration level. The performance of a 161-kV UPFC modelled in SimPowerSystems is tested on Ghana’s power transmission network. The optimal placement of the UPFC is done using fast voltage stability index (FVSI) and maximum loadability assessment (MLA). The results show that the device improved the connecting bus voltage from 0.88 p.u. to 0.98 p.u. Active power loss in the network was also reduced from 13.40 MW to 10.39 MW when the UPFC was in circuit. Keywords : Ghana , Stability, Transmission system and Unified Power Flow Controller (UPFC)