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P. Radika ¹, Subhransu Sekhar Dash ²

Affiliations
1 Department of Electrical and Electronics Engineering, Sathyabama University, Chennai, IN
2 Department of EEE, SRM University, Kattankulathur, Chennai, IN

Abstract

DC-AC power converters (inverters) are widely used today mainly in uninterruptible power supply systems, AC motor drives, induction heating and renewable energy source systems etc., High-Frequency Inverters (HFI) have been applied in DC-AC power conversion in which size and weight are of important considerations. The basic such model uses an RCD snubber to dampen the voltage spike which occurs due to transformer leakage inductance. But this causes a snubber power loss which reduces the system efficiency. Whereas the implementation of the regenerative snubber reduces the voltage spike and at the same time snubber stored energy is fed back to the input/output side to improve the system efficiency. This paper presents the HFI with active regenerative snubber to recover the snubber energy into the output side. MATLAB/SIMULINK simulation results and experimental results are presented.

Keywords

Inverter, High-Frequency Inverter, High-Frequency Transformer, Snubber, Leakage Inductance, Spike Suppression.

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P. Radika ¹, Subhransu Sekhar Dash ²

Affiliations
1 Department of Electrical and Electronics Engineering, Sathyabama University, Chennai, IN
2 Department of EEE, SRM University, Kattankulathur, Chennai, IN

Abstract

Snubber circuits can be used to protect power semiconductor devices from turn-on and turn-off voltage transients. It is also possible to obtain soft-switching by means of snubbers. There are two kinds of soft-switching snubbers namely active and passive snubbers are used in power converters to reduce the switching loss of the main switching device so as to improve the performance of the system. A soft-recovery DC-DC boost converter that operates in a more reliable and an efficient manner than the conventional converter by employing a passive regenerative snubber is presented. The snubber provides soft-switching at turn-off condition of the main switch. Thus, reduces the turn-off loss of the switch. Also recovering the snubber stored energy into the output side. The operation of the conventional and the proposed circuits are supported by MATLAB/Simulink/PLECS simulations results.

Keywords

Regenerative Snubber, Boost Converter, Passive Snubber, Snubber Capacitor, Soft-Switching, Switching Loss, Zero-Voltage Switching, Turn-Off Snubber.

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D. Rajasekaran ¹, Subhransu Sekhar Dash ²

Affiliations
1 Electrical and Electronics Engineering Department, R.M.D. Engineering College, Kavaraipettai, Chennai, Tamil Nadu, IN
2 Electrical and Electronics Engineering Department, SRM University, Kattankulathur, Chennai, Tamil Nadu, IN

Abstract

Devices such as power electronics converters inject harmonic currents in the AC system and increase overall reactive power demanded by the loads.  Also the number of sensitive loads that require ideal sinusoidal supply voltages for their proper operation has increased.  In order to keep power quality under limits proposed by standards, it is necessary to include some sort of compensation. Traditionally, fixed, mechanical switched reactor/capacitor banks and Static Var Compensator have been used for improving the power quality issue in distribution systems. In recent years, applications of inverter based power quality conditioner have been growing for reactive power compensation in distribution systems, since their response is faster than that of the conventional compensators. Distribution STATCOM (D-STATCOM) is an inverter based power quality conditioner device used to improve the power quality issues in distribution systems.  This paper deals with modeling and simulation of DSTATCOM with Energy Storage System based on the synchronous reference frame method for improving the power quality (mitigation of voltage sag and harmonics compensation) of distribution systems. Simulation of DSTATCOM is carried out using simulink in MATLAB.  Simulation studies demonstrate the effectiveness of the proposed control approaches in the synchronous-rotating d-q reference frame for DSTATCOM to improve power quality issues in Distribution System.

Keywords

DSTATCOM, Voltage Sag, Harmonics Compensation, VSI, SIMULINK, Synchronous Reference Frame (SRF) Theory.

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S. Harish Kiran ¹, Subhransu Sekhar Dash ¹, C. Subramani ¹, Somashree Pathy ¹

Affiliations
1 Department of Electrical and Electronics Engineering, SRM University, Kattakulathur, Chennai - 603203, Tamil Nadu, IN

Abstract

The objective of this study is the Predetermination of stability in power system network by optimization techniques by two different line stability indices. A hybrid optimization technique has derived by modifying Particle Swarm Optimization (PSO) with Hybrid Genetic Algorithm (HGA) and implemented in identifying the power system network stability conditions. Two line stability indices, such as Fast Voltage Stability Index (FVSI) and Apparent Line Power Stability Index (ALPSI) are used as a stability proximator tool. The performance of the proposed hybrid technique is effectively instigated in "IEEE - 14 Bus System" and its outcomes are compared with conventional method.

Keywords

Particle Swarm Optimization (PSO), Hybrid Genetic Algorithm, Voltage Stability, Fast Voltage Stability Index (FVSI), Apparent Line Power Stability Index (ALPSI)

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N. Manoharan ¹, Subhransu Sekhar Dash ², K. S. Rajesh ²

Affiliations
1 Department of Electrical Engineering, Sathyabama University, Chennai – 600119, Tamil Nadu, IN
2 Department of Electrical Engineering, SRM University, Chennai – 603203, Tamil Nadu, IN

Abstract

Background/Objectives: Firefly Algorithm (FA) is employed to for Load Frequency Control (LFC) of nonlinear power system. Methods/Statistical Analysis: The supremacy of FA technique is established by comparing the outcomes with Genetic Algorithm (GA). Findings: Additionally, sensitivity study is conducted by changing system parameters like time constants of turbine, speed governor and inertia constant as well as generator initial loading condition by +50% to -50% from their normal values in addition to the magnitude and location of load disturbance to illustrate the effectiveness of the suggested design approach. Application/Improvements: A nonlinear three area thermal system is taken as the system under study and the parameters of the LFC controller are tuned using FA technique.

Keywords

Firefly Algorithm (FA), Generation Rate Constraint (GRC), Load Frequency Control (LFC), Proportional Integral Derivative Controller, Sensitivity Analysis.

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