Hairul Nizam Talib

Dual motor drives for PMSM using average phase current technique

Dual motor drives designs are attractive for high power application because of their mechanical simplicity, traction and regenerative braking control on low friction surfaces. However, such configurations normally require two power inverters with coordinated control. The high cost and large size of packaging needs of the inverters make such dual inverter, dual motor drive configurations economically less competitive. Therefore, the need for dual motor drives fed by single inverter rising consequently to reduce sizes and costs with respect to the single motor drives, either in industrial or in traction application. This paper aims to investigate the behavior of dual motor drives fed by single inverter using averaging technique. MATLAB/Simulink has been chosen as the simulation tools. And the averaging technique that has been used is mean phase current method. The results show that the technique that has been applied gives the significant responses due to reference value given.

Simulation a shunt active power filter using MATLAB/Simulink

Along with increasing demand on improving power quality, the most popular technique that has been used is Active Power Filter (APF); this is because APF can easily eliminate unwanted harmonics, improve power factor and overcome voltage sags. This paper will discuss and analyze the simulation result for a three-phase shunt active power filter using MATLAB/Simulink program. This simulation will implement a non-linear load and compensate line current harmonics under balance and unbalance load. As a result of the simulation, it is found that an active power filter is the better way to reduce the total harmonic distortion (THD) which is required by quality standards IEEE-519.

Implementation of Space Vector Two-Arm Modulation for Independent Motor Control Drive Fed by a Five-Leg Inverter

This paper presents the implementation of two-arm modulation (TAM) technique for the independent control of a two-induction motor drive fed by a five-leg inverter (FLI). A carrier-based space vector pulse width modulation technique for TAM is proposed to generate switching signals for FLI. Two independent three-phase space vecto modulators are utilized to control two motors. The motor drive system applies two separate indirect field-oriented control methods. The stationary voltage outputs from the vector control are synthesized in the three-phase space vector modulator to generate switching signals for FLI. The performance of the independent control of the motors and the voltage utilization factor are likewise analyzed. Simulation and experimental results verify the effectiveness of the proposed method for the independent control of the two-motor drive system. The proposed technique is successfully validated by dSPACE DS1103 experimental work.

Characteristic of Induction Motor Drives Fed by Three Leg and Five Leg Inverters

This paper aims to compare the performance of three phase induction motor drives using Five Leg Inverter (FLI) and Three Leg Inverter (TLI) configurations. An Indirect Field Oriented Control (IFOC) method using a TLI is well established and incorporated for high performance speed drives in various industries. The FLI dual motor drive system on the other hand shows good workability in the independent control of two induction motor drives simultaneously. In this experiment, the IFOC method is utilized for both drive systems, and Space Vector Pulse Width Modulation (SVPWM) is used to generate pulses for both inverters. For the FLI, the Double Zero Sequence (DZS) Injection technique is used to generate the modulation signal. The complete experiment setup is done by using a DSpace 1103 controller board. The individual motor performances are analyzed using similar schemes, equipment setups and controller parameter values. The results show similar speed performance response capability between the single motor operation using a TLI system and the two motor operation using a FLI system based on the variable speed range either in forward or reverse operation. They also show similar load rejection abilities. However, the single motor with a TLI has a better power quality aspect such as ripple current and total harmonics distortion (THD).

Computer Aided Protection (Overcurrent) Coordination Studies

A well designed and reliable power system requires an efficient and reliable protection scheme with protection coordination at its core. This paper discusses computer aided protection coordination in brief comprising of its significance, procedures and vital components. Basically, this paper focuses on the usage of computer based programs to conduct the analyses and simulations required in coordination studies. The steps in a computer aided protection coordination analysis are detailed in this paper. Furthermore, the components related in the coordination studies are also discussed for a better understanding of the studies and its relationship to manual calculations and analyses.