Applied Mechanics and Materials Vol. 785

Abstract: In this paper, a new type of power electronic distribution transformer (PET) has been introduced based on the power electronics converter on the primary and secondary sides of the transformer. This PET has three stages and the input stage has a three-level, three-phase rectifier. The middle stage has two three-level single-phase converters and a high-frequency transformer; and, the output stage is a three-phase, two-level inverter. This power electronic distribution transformer provides many advantages, such as power factor improvement, reactive power compensation, eliminating harmonics, and controlling and protecting itself (PET) with minimum size, compared to the traditional transformer. The MATLAB/Simulink was used to analyze and validate the power electronic distribution transformer.

Abstract: When the heat losses sense is adopted for some solar system and power conversion components in residential building application, it is benefit to use those losses, that are consequently acts inversely on system efficiency, as a useful energy to modify the performance of that system instead of dissipated. In terms of efficiency of solar-battery charge controller, power dissipation is always associated with every power component and the losses would be either results from switching and conducting components or from the OFF state of the main switching component. This paper proposed a high efficiency solar-battery charge controller as an alternative to the main solar charge controller in most conventional residential solar system , the concept of the proposed controller circuit based on using the off state energy duration as well as that power losses coming from the main switching component and complexity of the conventional controller, and using this energy in a separate current path to energize an auxiliary battery or directly load used to cool or even to ventilate the system components causing in improving its performance. This will leads to electronic circuit with low losses as a compared with the conventional charge controller to be a part of the integrated and automated building solar system, the design has an algorithm based on some environment parameters like sun Irradiance and weather temperature, this algorithm seems to be inversely calculated because its start from the value of full charge battery voltage. A Simulink Matlab simulator is attempted in the simulation phase of this research as well as an experimental data has been collected to verify the circuit function and energy saving goal.

Abstract: In this paper, a new controller scheme for seven-level cascade multilevel converter based shunt active power filter has been proposed aimed to overcome the disadvantages of the existing controller schemes by reducing the complexity, number of measurement signals and computing time. The feasibility of the proposed controller schemer is verified by the digital simulation in MATLAB/SIMULINK platform. The simulation results indicate that the proposed method can be used to compensate for balanced/ unbalanced current, reactive power beside neutral conductor current in case of four-wire distribution systems.

Abstract: The increasing penetration of photovoltaic (PV) Distributed Generation (DG) systems in the electric power distribution system necessitates the development of power electronics inverter to interface the PV DG with the grid. The output parameters of the DG are determined by the inverter control strategy. An open-loop control (NCTRL) and two close-loop controls; Constant-Current Control (CCC) and Constant-Power Control (CPC) were considered for the inverter. The impact of inverter control techniques are compared based on power transformation efficiency and islanding behaviour of the DG. A grid-connected PV DG and the control techniques were simulated using MATLAB Simulink. A mathematical formulation of the inverter islanding voltage at the point of common coupling was driven and validated by simulation. Results indicated that a closed loop control of inverter is essential for maximum efficiency and stability of DG in post islanding

Abstract: This paper presents the capability of Arduino for responding to the robust controller which has been applied to the 3 phase rectifier and 3 phase inverter. The interface between the converters and the Arduino has been established by using MATLAB-Simulink environment. This is the fastest interface due the Arduino library that is available in the MATLAB which can be used before downloading the program to the board. Two types of controllers have been tested which are, P-Resonant and Fuzzy-PI controller. The voltage or current feedback mechanism also has been applied between the converters with the Arduino input port in order for responding to the design controller for signal generating pattern. At the end, it shows that, the Arduino is capable to receive the signals from the converters, process the signals in the board and generating the signal out for controlling the converters.

Abstract: This paper presents the development of single-phase single stage string inverters for grid connected photovoltaic system. The inverter is designed to generate an AC current in phase with the grid voltage and to extract the maximum power from the PV array. The maximum power point tracking (MPPT) is achieved by adjusting the modulation index and phase angle of the inverter’s voltage accordingly using fuzzy logic control algorithm. The prototype system is tested using 2 series of STP170s-24/Ac PV modules. Insulated Gate Bipolar Transistors (IGBTs) are used as power switches while the Sinusoidal Pulse Width Modulation (SPWM) scheme is used as the switching technique to synthesize the output waveform. Simulation model was developed in MATLAB/Simulink environment to study and evaluate behavior of the proposed converter. The results of the prototype system show good agreement with the simulation model.

Abstract: Cascaded H-bridge multilevel inverter is among the most preferred topology in solar systems. While traditional asymmetric cascaded H-bridge multilevel inverter is easy to achieve higher number of output voltage levels compared to traditional symmetric cascaded H-bridge multilevel inverter, charge balancing between the voltage sources remains a challenge for asymmetric cascaded H-bridge multilevel inverter. This drawback results in unsteady DC voltage levels due to unbalanced power drawn from each voltage sources. Besides that, in battery powered applications, unbalanced power drawn results in unequal discharged in the batteries. In this paper, two three-phase asymmetric cascaded H-bridge multilevel inverter topologies are proposed which offer easier in terms of modularity while maintaining the ease in charge balancing control. The performance of these two proposed topologies with charge balance control has been evaluated using PSIM software.

Abstract: Conventional Maximum Power Point Tracking (MPPT) controllers are widely used due to simple implementation and show a good performance in tracking Maximum Power Point (MPP) when solar irradiance is uniform. However, when partial shading occurs on the PV array, tracking to MPP becomes complicated as multiple peaks exist on the Power-Voltage (P-V) characteristic curve. Several methods based on stochastic algorithm and artificial intelligence has been developed to track true MPP under partial shading conditions. This paper focuses on the performance of MPPT controller to extract maximum power from PV system under partial shading condition. The selected MPPT algorithms that have been implemented in the PV system include Fuzzy Logic Controller and Particle Swarm Optimization. Results show that both the simulated MPPT controllers are capable of tracking the maximum power.

Abstract: — This paper proposes modification of an adaptation scheme which aims to replace the conventional PI controller for MRAS by using Fuzzy Logic Control (FLC). This FLC based on Takagi-Sugeno Fuzzy Logic Inference System (FIS). To achieve this goal, field oriented control (FOC) method has been utilized to control the speed of PMSM with the implementation of MRAS to observe the rotor position and speed of the motor. PMSM becomes the reference model for MRAS while the current model in the rotor reference frame is set as the adjustable model. The Takagi Sugeno Fuzzy FIS is executed in the MRAS adaptive scheme in order to tune the errors between the reference and adjustable model. The effectiveness of the Takagi Sugeno FIS to tune the errors in MRAS scheme is compared with the conventional PI controller. The proposed method clearly indicates improved motor performance over a wide range of operating speeds since is capable of tracking the motor speed effectively.

Abstract: The most of the industrial welding applications involving of electronic circuits such as AC-DC, and DC-AC and AC-DC converters. The input power factor of such a system is reduced due to the presence of more harmonics due to the non-linear devices within the converters which leads to creates more adverse effects. There by a need of suitable AC-DC converter with power factor correction technique to condition the supply current. The power factor correction rectifier that requires best current control from i) Peak current control ii) Average current control and iii) Hysteresis current control. This paper presents a comparative analysis from above mentioned power factor correction control topologies. The simulation of these control techniques are carried out using “Plecs” with “MATLAB/SIMULINK”. The simulation results shows that Hysteresis control has low THD, good DC link voltage regulation and better performance than other control techniques. The same control technique is implemented in TMS320F2812 DSP and results are proved.