Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item High-efficiency improved 12kW switched mode telecom rectifier(Institute of Electrical and Electronics Engineers Inc., 2016) P, P.; Kalpana, R.; Singh, B.; Bhuvaneswari, G.In this paper an improved switched mode telecom rectifier for a 12kW telecommunication system is presented. An improved telecom rectifier is a combination of phase-shift transformer based ac-dc converter and passive high pass filter. The phase-shift transformer and high pass filter is realized with a fractional magnetic rating of the load. The supply current is almost sinusoidal with low total harmonic distortion, and the power factor (PF) is close to unity. The complete design of phase-shift transformer based ac-dc converter and passive high pass filter is presented in this paper. The 12kW telecom rectifier is designed, modeled and simulated to reduce the total harmonic distortion (THD) of the input ac mains current and to improve the power factor. A laboratory prototype of phase-shift transformer based ac-dc converter is developed and the results are presented to validate the design topology. © 2015 IEEE.Item High performance front-end PFC rectifier for telecom power supplies(Institute of Electrical and Electronics Engineers Inc., 2017) P, P.; Kalpana, R.; Singh, B.; Bhuvaneswari, G.High-current low-voltage (HCLV) rectifiers are used in the telecom industries, electroplating and induction heating system. Typical power rating of these rectifiers varies from tens of kW to hundreds of MW. In this paper, a three-phase three-level boost type PWM rectifier is proposed as an active front-end PFC scheme for telecom load. The proposed active front-end PFC converter is modeled by switching cycle average model and relation between duty ratio and the dc-link capacitor voltage is derived as in terms of system input currents. Also, the switching states have been derived for the feasible converter operation. The detailed analysis of front-end PFC converter is carried out by equivalent circuit. The power quality also well improved by proposed active front-end PFC rectifiers. The experimental setup for a 12 kW active front-end PFC rectifier is developed in the laboratory to validate the MATLAB simulation results. © 2016 IEEE.Item Current injection based front-end power quality improved converter for telecom load(Institute of Electrical and Electronics Engineers Inc., 2017) P, P.; Kalpana, R.; Singh, B.; Bhuvaneswari, G.In this paper a front-end converter having third harmonic current injection technique is used for improving input current shape as near sinusoidal. Here zig-zag transformer is used as the current injection device so that the advantages pertaining to zig-zag transformer is utilized effectively. The third harmonic current injection device along with the three-level boost converter at the output stage will increase the dc-link voltage and the current is injected through zig-zag transformer. The power quality is well improved using third harmonic current modulated front-end structure which is very well applicable to telecom load having the high current low voltage. Extensive simulation is carried out for the 12 kW load and the results are verified through experimental setup. The experimental setup is tested for reduced voltage rating and the test results are presented. © 2016 IEEE.Item Power quality improvement in front-end hybrid AC-DC converter based on current injection technique(Institute of Electrical and Electronics Engineers Inc., 2017) P, P.; Kalpana, R.; Singh, B.; Bhuvaneswari, G.This paper highlights the power quality issues and explains the remedial measures taken by means of hybrid frontend third harmonic current injection rectifiers. Here zig-zag transformer is used as the current injection device so that the advantages pertaining to zig-zag transformer is utilized effectively. The third harmonic current injection device along with the three-level boost converter at the output stage will increase the dc-link voltage. Also, the power quality is well improved using third harmonic current modulated front-end structure which is well appropriate to medium/higher power applications. The experimental prototype of hybrid front-end PFC rectifier is developed in the laboratory to validate the MATLAB simulation results. © 2017 IEEE.Item Investigations on Single-Phasing Effect of Zigzag Autoconfigured Transformer Based 12-Pulse Rectifier(Institute of Electrical and Electronics Engineers Inc., 2018) Kalpana, R.; P, P.S.; Vidyasagar, V.S.; Singh, B.High power industrial loads are often fed from front-end multi-pulse rectifier as its ability to effectively and inexpensively mitigate the harmonics on the AC side is achieved by the multi-pulse autoconfigured transformer. This paper analyzes and investigates the operability of the zigzag autoconfigured transformer based 12-pulse rectifier when one of the input terminals is open, i.e., single-phasing. Contrary to the prior art multi-pulse rectifiers, the availability of neutral point in zigzag autoconfigured transformer results in normal operation at DC side during single-phasing. A detailed MATLAB Simulation is carried out to understand the single-phasing operation of the zigzag autoconfigured transformer. Further, the experimental results from the laboratory prototype are presented to validate the simulated results. © 2018 IEEE.Item Power Quality Enhancement in AC-DC Converter Using Voltage Sensorless Control Technique(Institute of Electrical and Electronics Engineers Inc., 2018) P, P.S.; Kalpana, R.; Singh, B.This paper presents the power quality improvement in power supply systems and explains the corrective measures taken by means of front-end AC-DC converter. The front-end AC-DC converter having a boost type delta connected rectifier with voltage sensorless control technique is proposed. The delta switch rectifier enables the zero-sequence component circulation and thereby reduces the third harmonic component in the input mains. Further, the input voltage sensorless control is developed for the proposed converter which can maintain the power quality well within the IEEE and IEC standards and also, yields lesser switching loss, reduced switching stress and high output voltage. The performance of the front-end AC-DC converter configuration is validated by simulating in the MATLAB Simulink environment and the results are presented. The experimental setup for the front-end AC-DC converter is implemented in the laboratory to validate the MATLAB simulation results. © 2018 IEEE.Item Multi-Pulse Converter Based DSTATCOM for Power Quality Improvement in Distribution System(Institute of Electrical and Electronics Engineers Inc., 2019) Prakash, S.P.; Kalpana, R.; Singh, B.In this paper, analysis of two 12-pulse autoconnected transformers, namely delta-polygon and zigzag transformers for compensating different fault voltages in distribution system is presented. Both the multi-pulse transformers are used in conjunction with three leg three-wire voltage source converter-based distribution static compensators to provide the compensation which includes compensation for reactive power along with load current, voltage, voltage regulation and elimination of harmonics currents at the point of common coupling (PCC). The switching behavior for the two configurations is also observed. The load is a combination of linear unbalanced load and a non-linear load connected at PCC. The MATLAB based simulations are performed and the results are presented for verification. © 2019 IEEE.Item Third Harmonic Current Injection Based Front-End AC-DC Converter for Power Quality Improvement in DC Distribution Systems(Institute of Electrical and Electronics Engineers Inc., 2020) Prakash, P.S.; Kalpana, R.; Singh, B.This paper presents the design and implementation of a three-phase buck type unity power factor rectifier used for distribution systems. The AC-DC converter topology considered in this paper is named as SWISS rectifier, consists of front-end three-phase diode bridge rectifier with active current injection circuit and back-end DC-DC buck converter. The characteristics of the AC-DC converter topology, including the principle of operation, modulation schemes, conduction state analysis, and control strategy are discussed in detail. Further, the analytical expression for the loss calculation is performed. Extensive simulation is carried out for the converter system, and the practicability of the converter system is verified by conducting a test on the constructed hardware prototype. © 2020 IEEE.Item A Zig-Zag Multiwinding Transformer Based AC-DC Converter for EV Battery Charger Using Interleaved Buck DC-DC Converter(Institute of Electrical and Electronics Engineers Inc., 2024) Sinha, S.; Kalpana, R.Electric vehicles (EVs) are depending on reliable and efficient battery charging infrastructure. This work provides a 2 set of three phase ac-dc converter-based power-quality (PQ) compliant IEEE-519 battery charging system. The zigzag multi-winding transformers (ZZMWTs) will play a role in reducing total harmonic distortion (THD) without the use of any power factor correctors or filter circuits. The secondary side star and delta arrangement of the ZZMWTs will have a phase shift of ± 150. This paper focuses on designing, optimizing, and managing a DC-DC interleaved buck converter for EV battery charging in both constant current (CC) and constant voltage (CV) modes. The planned EV charger performance is assessed using the MATLAB/Simulink environment in terms of THD and PF. A laboratory prototype hardware arrangement of the suggested battery charger is used to validate the results while providing controlled feedback. To support the theoretical analysis, further experimental findings from the lab prototype are presented. © 2024 IEEE.