Improvement of based sector and dynamic response of direct torque control using supercapacitor

Energy demand worldwide is rising at an unprecedented pace. This has already shown its impact on the depletion of energy sources and environmental issues (global warming and the weakening of the ozone layer). This growing pattern of energy insufficiency will, of course, intensify in the future. Referring to the literature, significant energy savings can be achieved by controlling the speed of the electric motor system using variable frequency drives (VFDs). Direct torque control (DTC) is one of the most effective torque control techniques for induction motors. Nowadays, supercapacitor (SC) technology is widely regarded as one of the most promising and energy-efficient technologies for next generation energy storage systems as compared to DC battery. Rotating machinery produce vibration that leads to rotor dynamic. Due to that, the improvement of based sector of DTC can reduce the increasing of rotor dynamic compared to conventional DTC. This thesis is demonstrated the improvement of based sector for six sector and twelve sector method of induction motor in MATLAB/Simulink simulation framework by using different energy storage (supercapacitor and DC battery). The result of the system that been design in MATLAB Simulink has been compared and analysed in term of rotor speed, electromagnetic torque and d-q stator current. In aspect of rotor speed, the uses of twelve sector method 0.04 second speed transition to achieve steady state response as compared to six sector method which need 0.06 second to achieve steady state when load disturbance is introduced for DC battery and supercapacitor. The electromagnetic torque that uses twelve sector method give more smoothly following the load torque compare six sector method for DC battery and supercapacitor. The electromagnetic torque in twelve sector method produces spiky torque about 15.5N while in six sector method produce 18N when load disturbance is introduced. The use of supercapacitor is better when at motor start-up compared DC battery whether in electromagnetic torque and stator current. In electromagnetic torque aspect, the use of supercapacitor produces 15N while the uses of battery produce about 50N for six sector and twelve sector method. In stator current aspect, the uses of battery produce 40A while the uses of supercapacitor produce 20A for both methods. The implementation of twelve sector method better dynamic performance to achieve steady waveform as compared to six sector method.