A DESIGN DIRECT-CURRENT (DC) MOTOR USING MATLAB

Electrical machine is a practical and dominant medium for achievement of productivity improvement. DC motor is defined when a machine reverses the conversion process to absorb energy in electrical form and reformat the energy to mechanical form on a sustained basis. As the field of industrial application of direct current is very wide, DC machine are produced both generators and motors, which suit for a large range of output powers, voltages, speeds and other. Therefore, an adequate design in de motor is essential in order to meet the industrial practitioners' requirement. This study basically deals in designing de motor based upon the customer specification using interactive computer software, MATLAB programming. The student is acted as the designer whom is requested by the customer to design a de motor which produce correct simulation outcomes in order to meet the desired specifications. The project mainly concentrates on performing and formulating the required MATLAB programming added with C++ coding. The generated programs will demonstrate the plot-curves analysis of shunt excited de motor design. An accurate de motor design is reflected from the curves performed, whether it meet the performance specification or otherwise. MATLAB is fully utilized as the main tool to complete this area of study. As the initial stage of the study, iterative procedures have to be followed in designing the motor. The calculations for all parameters in each design stages need to be performed using the correct equations. The frame designation and units are referred to international standardization, which is NEMA MG-1 Standard. In order to enhance understanding of the conceptual design, literature review and theory is conducted concurrently with endeavor MATLAB programming. As continuous from preliminary stage, the study then focuses on application using MATLAB in order to perform the required analysis. Compared to previous design of de motor, the NEMA frame designation and field winding arrangement play significant roles in differentiating the desired plot-curve representation

Grid integration of renewable power generation

This thesis considers the use of three-phase voltage and current source inverters as interfacing units for renewable power, specifically photovoltaic (PV) into the ac grid. This thesis presented two modulation strategies that offer the possibility of operating PV inverters in grid and islanding modes, with reduced switching losses. The first modulation strategy is for the voltage source inverter (VSI), and exploits 3rd harmonic injection with selective harmonic elimination (SHE) to improve performance at low and high modulation indices, where the traditional SHE implementation experiences difficulties due to pulse dropping. The simulations and experimentation presented show that the proposed SHE allows grid PV inverters to be operated with less than a 1kHz effective switching frequency per device. This is vital in power generation, especially in medium and high power applications. Pulse dropping is avoided as the proposed modified SHE spreads the switching angles over 90°, in addition increasing the modulation index. The second proposed modulation strategy, called direct regular sampled pulse width modulation (DRSPWM), is for the current source inverter (CSI). It exploits a combination of forced and natural commutation imposed by the co-existence of an insulated gate bipolar transistor in series with a diode in a three phase current source inverter, to determine device dwell times and switching sequence selection. The DRSPWM strategy reduces switching frequency per device in a CSI by suspending each phase for 60°, similar to VSI dead-band, thus low switching losses are expected. Other benefits include simple digital platform implementation and more flexible switching sequence selection and pulse placement than with space vector modulation. The validity of the DRSPWM is confirmed using simulations and experimentation. This thesis also presents a new dc current offset compensation technique used to facilitate islanding or grid operation of inverter based distributed generation, with a reduced number of interfacing transformers. The proposed technique will enable transformerless operation of all inverters within the solar farm, and uses only one power transformer at the point of common coupling. The validity of the presented modulation strategies and dc current offset compensation technique are substantiated using simulations and experimentation.This thesis considers the use of three-phase voltage and current source inverters as interfacing units for renewable power, specifically photovoltaic (PV) into the ac grid. This thesis presented two modulation strategies that offer the possibility of operating PV inverters in grid and islanding modes, with reduced switching losses. The first modulation strategy is for the voltage source inverter (VSI), and exploits 3rd harmonic injection with selective harmonic elimination (SHE) to improve performance at low and high modulation indices, where the traditional SHE implementation experiences difficulties due to pulse dropping. The simulations and experimentation presented show that the proposed SHE allows grid PV inverters to be operated with less than a 1kHz effective switching frequency per device. This is vital in power generation, especially in medium and high power applications. Pulse dropping is avoided as the proposed modified SHE spreads the switching angles over 90°, in addition increasing the modulation index. The second proposed modulation strategy, called direct regular sampled pulse width modulation (DRSPWM), is for the current source inverter (CSI). It exploits a combination of forced and natural commutation imposed by the co-existence of an insulated gate bipolar transistor in series with a diode in a three phase current source inverter, to determine device dwell times and switching sequence selection. The DRSPWM strategy reduces switching frequency per device in a CSI by suspending each phase for 60°, similar to VSI dead-band, thus low switching losses are expected. Other benefits include simple digital platform implementation and more flexible switching sequence selection and pulse placement than with space vector modulation. The validity of the DRSPWM is confirmed using simulations and experimentation. This thesis also presents a new dc current offset compensation technique used to facilitate islanding or grid operation of inverter based distributed generation, with a reduced number of interfacing transformers. The proposed technique will enable transformerless operation of all inverters within the solar farm, and uses only one power transformer at the point of common coupling. The validity of the presented modulation strategies and dc current offset compensation technique are substantiated using simulations and experimentation

A DESIGN DIRECT-CURRENT (DC) MOTOR USING MATLAB

Electrical machine is a practical and dominant medium for achievement of productivity improvement. DC motor is defined when a machine reverses the conversion process to absorb energy in electrical form and reformat the energy to mechanical form on a sustained basis. As the field of industrial application of direct current is very wide, DC machine are produced both generators and motors, which suit for a large range of output powers, voltages, speeds and other. Therefore, an adequate design in de motor is essential in order to meet the industrial practitioners' requirement. This study basically deals in designing de motor based upon the customer specification using interactive computer software, MATLAB programming. The student is acted as the designer whom is requested by the customer to design a de motor which produce correct simulation outcomes in order to meet the desired specifications. The project mainly concentrates on performing and formulating the required MATLAB programming added with C++ coding. The generated programs will demonstrate the plot-curves analysis of shunt excited de motor design. An accurate de motor design is reflected from the curves performed, whether it meet the performance specification or otherwise. MATLAB is fully utilized as the main tool to complete this area of study. As the initial stage of the study, iterative procedures have to be followed in designing the motor. The calculations for all parameters in each design stages need to be performed using the correct equations. The frame designation and units are referred to international standardization, which is NEMA MG-1 Standard. In order to enhance understanding of the conceptual design, literature review and theory is conducted concurrently with endeavor MATLAB programming. As continuous from preliminary stage, the study then focuses on application using MATLAB in order to perform the required analysis. Compared to previous design of de motor, the NEMA frame designation and field winding arrangement play significant roles in differentiating the desired plot-curve representation

An effective salp swarm based MPPT for photovoltaic systems under dynamic and partial shading conditions

This study proposes a duty cycle-based direct search method that capitalizes on a bioinspired optimization algorithm known as the salp swarm algorithm (SSA). The goal is to improve the tracking capability of the maximum power point (MPP) controller for optimum power extraction from a photovoltaic system under dynamic environmental conditions. The performance of the proposed SSA is tested under a transition between uniform irradiances and a transition between partial shading (PS) conditions with a focus on convergence speed, fast and accurate tracking, reduce high initial exploration oscillation, and low steady-state oscillation at MPP. Simulation results demonstrate the superiority of the proposed SSA algorithm in terms of tracking performance. The performance of the SSA method is better than the conventional (hill-climbing) and among other popular metaheuristic methods. Further validation of the SSA performance is conducted via experimental studies involving a DC-DC buck-boost converter driven by TMS320F28335 DSP on the Texas Instruments Experimenter Kit platform. Hardware results show that the proposed SSA method aligns with the simulation in terms of fast-tracking, convergence speed, and satisfactory accuracy under PS and dynamic conditions. The proposed SSA method tracks maximum power with high efficiency through its superficial structures and concepts, as well as its easy implementation. Moreover, the SSA maintains a steady-state oscillation at a minimum level to improve the overall energy yield. It thus compensates for the shortcomings of other existing methods