Improved output voltage quality using space vector modulation for multilevel inverters

Space vector modulation (SVM) has received wide acceptance due to many benefits over other techniques such as higher output voltages, lower total harmonic distortion (THD), high-efficiency and flexible to be implemented in vector control systems. In digital implementation, the SVM equations can be optimally computed by eliminate the use of complex forms. In this paper, the simple SVM based on twolevel inverter is employed for higher levels of inverters. This is to retain the simplicity of SVM computation for three-level and five-level cascaded H-bridge multilevel inverter (CHMI). Moreover, the proposed method utilizes two controller boards to perform high computational workloads and to eliminate glitch and error problems. Experiment results show that the THD of output voltage in five-level CHMI gives the smallest value among the results obtained from other levels

An improved FPGA implementation of direct torque control for induction machines

This paper presents a novel direct torque control (DTC) approach for induction machines, based on an improved torque and stator flux estimator and its implementation using Field Programmable Gate Arrays (FPGA). The DTC performance is significantly improved by the use of FPGA, which can execute the DTC algorithm at higher sampling frequency. This leads to the reduction of the torque ripple and improved flux and torque estimations. The main achievements are: i) calculating a discrete integration operation of stator flux using backward Euler approach, ii) modifying a so called non-restoring method in calculating the complicated square root operation in stator flux estimator, iii) introducing a new flux sector determination method, iv) increasing the sampling frequency to 200kHz such that the digital computation will perform similar to that of the analog operation, and v) using two’s complement fixed-point format approach to minimize calculation errors and the hardware resource usage in all operations. The design was achieved in VHDL, based on a Matlab/Simulink simulation model. The Hardware-In-the-Loop (HIL) method is used to verify the functionality of the FPGA estimator. The simulation results are validated experimentally. Thus, it is demonstrated that FPGA implementation of DTC drives can achieve excellent performance at high sampling frequency

Integrating Retrofit IOT Controller With Electric Power System For Manual Wheelchair

Persons with physical injuries and disability are struggling to get through places using the conventional handwheelchair The needs of many people with disabilities can be overcome with powered wheelchair, but some portion of this community is finding it difficult to operate standard powered wheelchair due to its big in size and epensive.. This project developed a smatphone phone-controlled wheelchair along with three types of virtual controller which is Joystick control, D-pad control and Voice control through the wireless communication.. It is also equipped with obstacle (ultrasonic) avoidance notification and microcontroller controls the motor that moved the direction either FRONT, BACKWARD, LEFT and RIGHT. The main objective of this project is to facilitate and increase the movement of people who are handicapped and the ones who are not able to move freely with the implementation of IoT platform where this platform could provide data visualization and able to analyze the wheelchair maintenance management and movement. In additional, this project analyzes distinct IoT monitoring system features, including battery level remaining and temperature control. the concept succesfully developed with integration of microcontroller in which provide desired performance control  of the system to desired output with the synchronization of Internet of Thing feature

Constant Switching Frequency For Direct Torque Control Of Induction Motor

DTC drives utilizing hysteresis comparator is one of the simplest and most popular technique used in induction drives. However, due to its disadvantage of variable switching frequency causes serious problem in DTC especially for electromagnetic torque ripple. This paper proposed a technique of constant switching that could reduce the ripple on both torque and phase current for DTC by using triangular waveform or carrier frequency. Thus, the conventional and proposed DTC will be simulated and demonstrated by using Altera field-programmable gate array (FPGA) and digital signal processor. Simulation results presented in this paper shows the torque and stator current ripple with the proposed DTC algorithm when varying the speed and the carrier frequency

Design and Analysis of In-Wheel Double Stator Slotted Rotor BLDC Motor for Electric Bicycle Application

This paper discusses about design and analysis of double stator slotted rotor (DSSR) BLDC motor for electric bicycle application. Usually single stator (SS) BLDC motor is used in an electric bicycle. This type of motor has low performance and need to be charged regularly. The objective of this research is to design and analysis DSSR motor that have high torque. At starts, design specification for the electric bicycle is calculated. Next, design process for DSSR is carried out by using the desired parameter. Lastly, analysis for double stator slotted rotor is simulated using FEM. Result  for average back emf, average inductance, inner stator flux density, outer stator flux density, average torque and estimate torque constant is obtained. Result for average torque from FEM archieve the requirement of motor torque for DSSR design where the maximum average torque is 16.2 Nm. This research will give benefit to mankind and society in term of environment protection and energy consumption