IJEECM Journal of Electrical Engineering (IJEECM-JEE)

Direct Torque Control of Brushless DC Motor with Non-sinusoidal Back-EMF

Authors: T.Vamsee Kiran, M.Sunil Kumar

Abstract: Abstract—In this paper, a direct torque control (DTC) technique for brushless dc (BLDC) motors with non-sinusoidal back-EMF operating in the constant torque region is presented. This approach introduces a two-phase conduction mode as opposed to the conventional three-phase DTC drives. In this control scheme, only two phases conduct at any instant of time. Unlike conventional six-step PWM current control, by properly selecting the inverter voltage space vectors of the two-phase conduction mode from a simple look-up table at a predefined sampling time, the desired quasi-square wave current is obtained. Therefore, a much faster torque response is achieved compared to conventional PWM current control. In this paper, it is also shown that in the constant torque region under the two-phase conduction DTC scheme, the amplitude of the stator flux linkage cannot easily be controlled due to the sharp changes and the curved shape of the flux vector between two consecutive commutation points in the stator flux linkage locus. Furthermore, to eliminate the low- frequency torque oscillations caused by the non-ideal trapezoidal shape of the actual back-EMF waveform of the BLDC motor, a pre-stored back-EMF versus position look-up table is designed. As a result, it is possible to achieve DTC of a BLDC motor drive with faster torque response due to the fact that the voltage space vectors are directly controlled while the stator flux linkage amplitude is deliberately kept almost constant by ignoring the flux control in the constant torque region. Since the flux control along with PWM generation is removed, fewer algorithms are required for the proposed control scheme. A theoretical concept is developed and the validity and effectiveness of the proposed DTC scheme are verified through the simulations and experimental results. Index Terms—Direct torque control, brushless dc motor drives, non-sinusoidal back-EMF, two-phase conduction, fast torque response, low-frequency torque ripples.

Keywords: Direct torque control, brushless dc motor drives, non-sinusoidal back-EMF, two-phase conduction, fast torque response, low-frequency torque ripples.

Harmonic reduction of non-inverting buck – boost dc/dc converter by introducing LC filters in network

Authors: V Vijaya Lakshmi, V Chennakesavulu

Abstract: This paper displays an execution of versatile double current mode control (ADCMC) on non-altering buck-support converter. A confirmation of the converter operation with the proposed ADCMC has been performed in consistent state and amid the unsettling influences in the information voltage and the heap resistance and by presenting LC channels. The given recreation with LC channel can give preferable execution over customary converter comes about.

Keywords: Digital controller, duty–discontinuity, mode-transition technique, non-inverting buck-boost converter

A new topology Based 13-Level inverter with various PWM Techniques

Authors: Crucypriya Darshnibhimala, N Balakrishna

Abstract: When contrasted with routine inverter topologies like diode clasped and capacitor cinched inverters, the cascaded multilevel inverter has lesser music and also lower switching stress. The fell topology has more number of power changes prompting more prominent warmth misfortunes, bigger size, higher cost and more door drive hardware. The proposed configuration contains less number of switches and creates lesser harmonics in the yield voltage than the fell topology. A comparison between four distinct sorts of heartbeat width regulation (PWM)techniques, to be specific, In-stage mien (IPD), Anti-phase disposition (APD), Carrier Overlap (CO) and Variable Frequency (VF) PWM strategies, has been finished. The outcomes have been checked through reproduction contemplate in MATLAB/Simulink in order to choose the best PWM technique that gives minimum THD in the yield voltage. A LC channel has been outlined to improve the consonant profile.

Keywords: Multilevel inverter, PWM procedure, add up to harmonic distortion, LC channel.

A Fuzzy based MMC STSTCOM for Enhance Dynamic behavior of the Network

Authors: P Rangababu, V Chennakesavalu

Abstract: A fuzzy based controller is proposed to control the voltage and current of the DC System. The voltage and current control loops are with fuzzy controller is monitor and control the error. The current loop control, a nonlinear controller based on the passivity based control theory is used in this cascaded structure STATCOM for the first time. The dc capacitor voltage control, overall voltage control is realized by adopting fuzzy controller. Clustered balancing control is obtained by using active disturbances rejection controller (ADRC). Individual balancing control is achieved by shifting the modulation wave vertically which can be easily implemented in FPGA .The proposed system is providing good dynamic performance while compared with the conventional STATCOM topology because of its robust procedure.

Keywords: Fuzzy logic controller, Cost-of-energy, DFIG, loss dissipation, reactive power.

VSC Converter with fuzzy controller for Non-linear and Unbalanced Loads

Authors: Jani Basha, V N Malleswari

Abstract: In this paper, demonstrate prescient control is connected to control a three-stage inverter. Demonstrate prescient control (MPC) is known for its effortlessness and convenience. The talked about inverter is generating unadulterated sinusoidal voltages for delicate applications for example, uninterruptable power supply frameworks with low voltage total symphonious twisting (THD) request. This strategy utilizes the model of the framework to foresee the conduct of the voltage on the next examining interim for every conceivable exchanging state. A cost function is likewise used to choose which changing state to be applied based on limiting the voltage deviations from the reference value and exchanging misfortunes. Reproductions have been done using MATLAB interfacing and comes about demonstrate the achievability of MPC to control inverters bolstering straight, nonlinear or unbalanced loads.

Keywords: Fuzzy, voltage source inverter; model predictive control; total harmonic distortion; Nonlinear and Unbalanced Loads.

Reactive Power Management of DFIG using Optimized Grid Filter

Authors: M Venkatesh, M V Ravi Kumar

Abstract: The cutting edge matrix necessity has created that the wind control framework carries on more like regular turning generators, and it can bolster certain measure of the responsive power. For a normal doubly nourished acceptance generator (DFIG) wind turbine framework, the receptive power can be upheld either through the rotor-side converter or the network side converter. This paper first thinks about the present swells and steady responsive power runs between the traditional L and streamlined LCL channel, if the receptive power is infused from the framework side converter. At that point, the misfortune distribution is assessed both for the generator and the wind influence converter regarding the responsive influence done by the rotor-side converter or the framework side converter with different network channels. Afterward, the yearly vitality misfortune is additionally evaluated in view of yearly wind profile. At long last, test aftereffects of the misfortune dissemination are performed in a down-scaled DFIG framework. It is presumed that overexcited receptive power infused from the lattice side converter has bring down vitality misfortune every year contrasted with the overexcited reac-tive influence secured by the rotor-side converter. Besides, it is additionally found that the yearly vitality misfortune could even progress toward becoming lower with the improved channel and in this manner more vitality creation for the wind turbine.

Keywords: Cost-of-energy, DFIG, loss dissipation, reactive power.

Analysis and control of reactive power in Islanded microgrid

Authors: Kalahasti Sharon Nissi, N Archana

Abstract: A microgrid (MG) is a neighborhood vitality framework comprising of various vitality sources (e.g., wind turbine or sun oriented boards among others), vitality stockpiling units, and burdens that work associated with the fundamental electrical framework or self-sufficiently. MGs give adaptability, lessen the fundamental power lattice reliance, and add to changing vast incorporated creation worldview to neighborhood and dispersed era. In any case, such vitality frameworks require complex administration, propelled control, and enhancement. Also, the power gadgets converters must be utilized to right vitality transformation and be interconnected through basic control structure is essential. Established hang control framework is regularly actualized in MG. It permits rectify operation of parallel voltage source converters in lattice association, as well as islanded method of operation. Nonetheless, it requires complex control administration calculations, particularly in islanded MGs, which adjust the framework and enhances unwavering quality. The novel responsive power sharing calculation is produced, which takes into account the converters parameters as evident power restrain and most extreme dynamic power. The created arrangement is checked in reenactment furthermore, contrasted and other known responsive power control techniques.

Keywords: Distributed system, microgrid (MG), control converters, responsive power sharing.

A new control strategy Energy Management for Standalone DC Microgrids

Authors: D. Shiva Ramakrishna, D.Rajani Kumar

Abstract: As the demand of Electricity is increasing day by day and is already more than the production of Electricity whereas reserves of fossil-fuel are depleting, there is a strong need to shift for other sources which are renewable energy sources. Regarding this, DC micro grids and their energy management of these renewable energy sources have gained more importance which is discussed in this paper. The main objective of the proposed system is to provide uninterrupted power supply to the load systems which are located at isolated sites of remote and rural areas. The proposed system mainly deals with implementation of Energy Management System (EMS) to DC microgrid using maximum power point tracking (MPPT) algorithm. A coordinated and multivariable EMS is proposed that employs a wind turbine and a photovoltaic array as controllable generators by adjusting the pitch angle and the switching duty cycles and a storage system consisting of batteries. In order to realize constant current, constant voltage (IU) charging regime and increase the life span of batteries, the proposed EMS require being more flexible with the power curtailment feature. The proposed strategy is developed as an online nonlinear model predictive control (NMPC) algorithm based on individual MPPTs of the system. The entire designed system is modeled and simulated using MATLAB/Simulink Environment.

Keywords: Battery Management, Maximum Power Point Tracking (MPPT), Nonlinear Model Predictive Control (NMPC), Power Sharing, and Voltage Regulation.

A Novel Control Strategy of Alternate Arm Converter for DC-Fault Blocking Capability in Hybrid Multilevel Converter

Authors: GURINDAPALLI MAHESH BABU, SITARAM APPARI

Abstract: An Alternate Arm Modular Multilevel Converter (AAMMC) is the recently introduced power electronics converter topology suitable for High Voltage DC Transmission (HVDC) system applications. This paper focuses on the operating principle of an Alternate Arm Modular Multilevel Converter. At the beginning the advantages of multilevel converter, basic schematic of converter topology, and its operation is discussed. For the controlling of the converter the simple sorting technique is employed. The AAMMC is a new converter topology which offers several advantages over existing multilevel converter topologies such as scalable and modular structure, low switching losses, DC fault tolerance property which eliminates the need of AC/DC breakers of large size and ratings, lower number of cells as compared to modular multilevel converter. The performance of the 21 level AAMMC without sorting and with sorting technique is verified with MATLAB Simulation.

Keywords: Alternate Arm Modular Multilevel Converter (AAMMC), Voltage Source Converter (VSC), submodule (SM),

Fuzzy based STATCOM for Improving the Dynamic Stability of Parallel Connected PMSG Offshore Wind Turbines

Authors: Geera Sudheer, Subbi Naidu Bora

Abstract:

This paper proposes a dynamic stability improvement of four parallel connected Offshore wind turbines with a shunt connected static synchronous compensator (STATCOM). Permanent magnet synchronous generator (PMSG) is used for power generation in wind farms while the onshore power system is simulated by a synchronous generator (SG) fed to an infinite bus through two parallel transmission lines. A damping controller of the proposed STATCOM is designed by using FUZZY logic controller, Which is improves the performance point of STATCOM. It can be concluded from the simulation results that the proposed STATCOM joined with the designed damping controller can effectively improve the stability of the studied SG-based onshore power system under various disturbance conditions.

Keywords: Dynamic stability, permanent-magnet synchronous generator (PMSG), pole-assignment approach, static synchronous compensator, wind turbine generator (WTG).
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