Abstract

Abstract—The usage of photovoltaic for solar energy conversion is a rapidly growing source of green power supply. Enhancing the efficiency of this system is widely seen as important in supporting this trend. This concerns not only the improvement of the PV cell but also of the power electronics circuits and controls associated to them. The various difficulties identified for the development of such a system is that discontinuous mode of conduction must be avoided and ripple content must be reduced. Therefore, in order to achieve this, an interleaved boost converter with maximum power point tracking based irradiance adaptive control is developed.

Index Terms—Interleaved boost converter (IBC), photovoltaic (PV), discontinuous mode of conduction (DCM), Switching frequency modulation (SFM), module integrated converter (MIC).

Abstract— In this paper, a transformer less dynamic voltage restorer (DVR) based on the multilevel inverter is proposed. This multilevel inverter uses reduced number of switches. As a result, the proposed DVR has lower number of switches in comparison with other multilevel inverter based DVR topologies. Also, it has lower loss and cost due to no need for injection transformers. The performance of the proposed model is simulated in MATLAB/Simulink environment.

 Index Terms— Voltage sags/swells, Dynamic Voltage Restorer (DVR), Asymmetrical multilevel inverter.

Abstract: This paper presents a bridgeless PFC boost converter for power supply and battery charging applications. Boost converter operating in CCM is widely used in low power factor corrector due of its simplicity and switching losses. The converter operates in both pulse-width-modulation (PWM) mode and resonant mode in each switching cycle, and use standard average current mode control. The performance of the proposed model is evaluated under varying input voltages and loads by simulating the circuit in MATLAB/Simulink environment.

Keywords: AC-DC converters, PFC, resonant converters, soft-switching, ZCS, ZVS.

Abstract: Brushless dc motor has permanent magnets which rotate around fixed armature. The current in armature rotates as it is electronically commutated. The commutation angle errors reduce the performance and overall efficiency of the motor. The novelty of the work is reducing commutation errors that are obtained based on the relationship between commutation point phase shift and the difference of dc-link current. Based on these relationship analysis is made under ideal, advanced and delayed commutations. The self-compensation method of commutation instant deviation delays the commutation angle by 10º thus eliminating the impact caused by commutation ripple thereby improving dynamic performance and control. The dc-link current difference decrease gradually and phase deviation converges to adjust the commutation angle. The proposed correction method can achieve ideal commutation effect thereby attaining fast convergence speed, current and torque.

Keywords: Brushless DC motor, Commutation signal deviation, dc-link current, Phase shift circuits, Sensorless control.

Abstract: The Space Vector Modulation based direct torque control is a common solution which is used to solve the conventional DTC’s problems, such as high torque ripple and variable switching frequency. Moreover control performance is improved by replacing PI controller in the speed regulation loop by a higher order sliding mode controller. This controller is based on second order super twisting strategy. Furthermore, IM energy optimization is treated as the second objective of this paper. A proposed model based loss minimization strategy is presented for efficiency optimization. The strategy chooses an optimal flux magnitude for each applied load torque

Keywords: Induction motor, Direct Torque Control, Space Vector Modulation, Second order Sliding mode control,  Loss minimization strategy

Abstract: Electric power produced by the use of ordinary fuels will produce toxic gasses like carbon dioxide, carbon monoxide, nitrogen dioxide etc. Which will causes environment contamination and as a result cause to global warming. This bring to the use of renewable energy sources. A Solar Photovoltaic (SPV) system, along with Maximum Power Point Tracking (MPPT), catenated to a three phase grid which feeding a switched reluctance motor is introduced. The catenation of solar photovoltaic system to the grid arise through two stages of operations, which is through a DC/DC boost converter via a current controlled Voltage Source Inverter (VSI). The Maximum power point tracking algorithm used is Perturb & Observe (P &O) algorithm, which is applied to the boost converter. Also reference reimbursement current has been generated by using I cos Φ algorithm. Adaptive hysteresis band current controller is used for switching pulse generation in current controlled VSI. Employing adaptive control, the Total Harmonic Distortion (THD) of supply current is reduced to 0.22% from 28.20%. There by the power factor is increased to a value 0.976%.

Keywords: Distributed generation (DG), power quality, switched reluctance motor (SRM), voltage source inverter (VSI).