Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item A novel fifteen level inverter for photovoltaic power supply system(2004) Beig, A.R.; Udaya Kumar, R.Y.; Ranganathan, V.T.A novel dc to ac inverter for photovoltaic power supply system is presented in this paper. The objective is to develop a low cost, reliable and efficient photovoltaic power supply unit for domestic applications. A fifteen level cascaded H-Bridge configuration using low voltage MOSFETs as switching devices is used. This configuration results in sinusoidal output voltages with step modulation and fundamental frequency switching. The proposed configuration has reduced conduction loss and switching loss. Simple gate drive circuit is designed using commonly available integrated circuit components. The simulation results are presented.Item Novel integral cycle voltage controller for self excited induction generators(2006) Murthy, S.S.; Pinto Pius, A.J.P.; Beig, A.R.This paper presents the theory of a new var regulator used for voltage control of self excited induction generators (SEIG). In this approach the excitation capacitors of each phase are switched individually by IGBTs at the zero crossing of respective capacitor currents, thereby eliminating switching losses and harmonics and reducing component count. Simulation results using Matlab-Simulink are presented and compared with experimentally obtained results. The developed integral control scheme presented here overcomes all the shortcomings of existing control schemes and, in addition to being self-starting is also capable of handling capacitive loads, thus making its application in standby generators acceptable with associated reduction in unit costs.Item FPGA based control model with derivative filter for converter(2010) Veeranna, S.B.; Yaragatti, U.R.; Beig, A.R.In this paper, the control model for a digitally controlled DC-DC converter is presented along with derivative filter. The digital implementation of this model gives the detailed description about the gain and phase responses of each block in the digital controller loop. Key problems such as quantization resolution of digital pulse width modulator (DPWM), steady state limit cycle oscillations and loop delay of the controller are discussed and solutions are presented. The controller is implemented in an altera Quartus II 9.0 tool and simulated with an inbuilt simulator. It is observed that the controller utilizes less resource and consumes less power, means that the controller cost can be reduced. ©2010 IEEE.Item Synchronized SVPWM algorithm for overmodulation region for three-level VSI(2010) Veeranna, S.B.; Yaragatti, U.R.; Beig, A.R.Synchronization is essential for the satisfactory operation of VSI in high power applications. With proper selection of switching states it is possible to obtain synchronization and symmetry in space vector pulse width modulation (SVPWM) algorithm. A novel SVPWM based switching algorithm, which results in improved THD and increased fundamental voltage in overmodulation region by maintaining synchronization and symmetry is presented in this paper. A simple method to determine the switching sequence to achieve synchronization, quarter wave symmetry, half wave symmetry and three phase symmetry in overmodulation region is presented. The proposed algorithm is simulated and its performance in terms of the THD and magnitude of fundamental voltage of output is studied in the overmodulation region. The results show the improved performance of the proposed algorithm compared to the existing algorithms. The proposed algorithm is verified experimentally on a constant v/f three level VSI fed induction motor drive. © 2010 IEEE.Item Performance analysis of PWM strategies for cascaded H-bridge three-level inverter(2011) Veeranna, S.B.; Beig, A.R.; Yaragatti, U.R.Multilevel inverters with various pulse width modulation strategies have established their importance in high power high performance industrial applications, as they can synthesize output waveform with improved harmonic spectrum. This paper presents the performance analysis and comparison of different PWM strategies for cascaded H-bridge three-level inverter in terms of line voltage and motor current THD with their fundamental components. It is shown that harmonic loss minimized optimal-SHEPWM strategy gives better results in terms of voltage THD compared to SPWM, SVPWM and SHEPWM strategies. © 2011 IEEE.Item Torque Ripple Minimization of Four-phase Switched Reluctance Motor using Direct Torque Control with an Innovative Switching Sequence Scheme(Institute of Electrical and Electronics Engineers Inc., 2019) Pittam, P.K.; Ronanki, D.; Parthiban, P.; Beig, A.R.; Williamson, S.S.Direct torque control (DTC) technique is the prominent control strategy, used to control the switched reluctance motor (SRM) with a reduced torque ripple in comparison to the traditional current control techniques. However, it draws higher phase current in order to maintain the required electromagnetic torque during phase commutation, thus reduces torque per ampere. To circumvent this issue, a new DTC method with an innovative switching sequence is introduced in this paper, which minimizes torque ripple as well as power loss. The efficacy of the proposed scheme is validated for four-phase SRM through detailed simulation studies and compared with the conventional DTC scheme. The results show that the proposed scheme exhibits an improved steady-state as well as dynamic performance under various operating conditions. © 2019 IEEE.Item Direct Instantaneous Torque Control of Five-Phase Segmented Switched Reluctance Motor with Bipolar Excitation for In-Wheel Electric Vehicles(Institute of Electrical and Electronics Engineers Inc., 2020) Ronanki, D.; Dekka, A.; Parthiban, P.; Beig, A.R.Multi-phase segmented switched reluctance motors (SRMs) are the better option for in-wheel electric vehicles due to higher specific torque (70% more) and torque density than conventional toothed SRMs. Furthermore, it allows to excite two or more phases simultaneously in order to avoid torque dips during the phase commutations. However, conventional control schemes cause severe torque pulsations. In this paper, a new direct instantaneous torque control technique for a five-phase segmented SRM (SSRM) with bipolar excitation is proposed. SSRM is fed by the five-phase voltage source inverter (VSI) instead of a conventional asymmetric H-bridge (AHB) converter. The performance of the proposed control algorithm is validated through MATLAB simulations. Results show that the proposed control scheme exhibits an improved performance under a vehicle load. © 2020 IEEE.Item Phase current reconstruction algorithm for four-phase switched reluctance motor under direct torque control strategy(Institute of Electrical and Electronics Engineers Inc., 2021) Ronanki, D.; Pittam, K.R.; Dekka, A.; Parthiban, P.; Beig, A.R.Existing phase current reconstruction algorithms are developed for switched reluctance motor (SRM) operated under current chopping control (CCC), which generates high torque ripple. Therefore, the direct torque control (DTC) technique is mostly used to control the SRM with minimal torque pulsations. However, the reconstruction of phase currents using the existing one or two sensor methods developed under CCC control will be more difficult to adopt for the DTC scheme due to the simultaneous conduction of all phases. To circumvent this issue, a novel DTC method with reduced sensors is introduced in this paper, which exhibits better performance in comparison to the conventional DTC method. The proposed DTC method avoids the long tail currents thereby limits the conduction of all phases simultaneously. The efficacy of the proposed scheme is validated for four-phase SRM through MATLAB simulations. The results show that the proposed approach helps to operate the drive at the lower torque ripple with reduced cost under various operating conditions in comparison to the conventional DTC. © 2021 IEEE.