Mochammad Rameli

Linearization and decoupling controller for quadruple tank

Quadruple Tank Process (QTP) is a nonlinear system that has four state variables in the form of a level of four tanks with two inputs of flow discharge. In addition to the non-linearity, each state on the QTP dynamics is coupled, and the level sensor is only installed on two tanks to be set, this adds to its complex QTP control issues. By performing the linearity using Nonlinear State Feedback Decoupling (NSFD) method, we can establish a closed loop system that is linear and meets specific response specifications in accordance with the desired design specifications. Since NSFD requires measurements of all states, it is necessary to add a Non-Linear State Observer (NLSO) so that the other two states can be observed from two measured states. By specifying time response design in the form of time constants T1 = 4 seconds, and T2 = 4 seconds for tank one and tank two respectively, and installing a 1st order low pass filter with time constants t = 0.2 second for Cross Coupled Error Feedback (CCEF) on NLSO, then we can obtain a simulation result that meets the specification of the desired transient response.

Speed control of three phase induction motor using method hysteresis space vector pulse width modulation

Induction motor speed control was relatively difficult, because the generated torque and flux are related or not free. In addition to adjusting the speed, it required inverter control. The inverter output was not a pure sinusoidal signal but it is the result of the switching. Therefore, it was necessary to be able to fix the method of switching the inverter output signal that can adjust induction motor speed with load changes. This study applied the indirect method of vector control for setting the speed and incorporates methods of SVPWM (space vector pulse width modulation) with hysteresis then became hysteresis space vector pulse width modulation (HSVPWM) on the inverter. This study also reconstructed current signal. The setting speed three phase induction motor vector control using indirect methods were successfully applied. A change of pace on HSVPWM method successfully achieves the set point of 600 rpm with a rise time of 0.5267 seconds, 0.723 second steady state and has over shoot of 0.8%.

Design of self commutation BLDC motor with torque control strategy using fuzzy logic in hybrid electric vehicle (HEV)

Hybrid Electric Vehicle (HEV) is vehicle with least two energy sources. Internal combustion engine (ICE) and BLDCM are combination of commonly used energy sources. BLDCM serves to provide additional torque, with the purpose of HEV can reach set point speed according to the reference model. Commutation of BLDCM is still quite complicated because between the rotational speed of the motor and the speed of the rotary field on the stator shall be kept synchronized. Self Commutation is used to maintain synchronization between the rotation of the rotor to rotary field velocity on BLDCM stator. In addition, this research also applies torque control strategy using fuzzy-PI controller. The BLDCM Self commutation scheme can be applied to the HEV plant. The applied strategy can reduce undershot at HEV speed by represents steady state error value of 0.0049 rpm.

Comparison between SVPWM two level in internal and external circle of hexagon

This study presents a space vector pulse width modulation (SVPWM) method. Switching time for SVPWM two level is used to generate a sinusoidal waveform from the inverter. This waveform using as input for the induction motor. Usually, we use the internal circle to generate sinusoidal method. However, from the calculation, we can get two different equations, for the internal circle in hexagon and external circle for the hexagon. Comparison between voltage vector in the internal and external circle of hexagon using THD (Total Harmonic Distortion) value for each circle.