Routing and Wavelength Assignment for Constraint Based Optical Networks Using Enhanced s1

JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN ELECTRICAL ENGINEERING COMPARISON OF THREE PHASE INDUCTION MOTOR WITH SIX PHASE INDUCTION MOTOR USING MATLAB SIMULATION

1ARCHANA S. NANOTY, 2A.R. CHUDASAMA

1Parul Institute Of Engineering & Technology 2 Faculty Of Technology, MSU Vadodara, Gujarat

[email protected]

ABSTRACT : If the number of phases is more than three, the machine output power can be divided into two or more solid state inverters within the same power limits. Moreover, additional phases to control bring additional degrees of freedom available for further improvements in the drive system. The advantages of using a six-phase induction motor for industrial drives, over the conventional three-phase drive can be summarized as improved reliability, reduction on the power ratings for the static converters and harmonic reduction. This paper discusses the comparison between three phase induction motor and six phase induction motor on the basis of simulations using Matlab software. Also some practical results of six phase induction motor are also presented. KEY WORDS : six phase Induction motor, Reliability, Vector control

1. INTRODUCTION Three-phase induction machines are today a standard for industrial electrical drives. Cost, reliability, robustness and maintenance free operation are among the reasons these machines are replacing dc drive systems. The need to increase system performance, particularly when facing limits on the power ratings of power supplies and semiconductors, motivates the use of phase number other than three. Many researchers have studied multiphase Induction motor drives and output of these research shows that output Torque of these motors is superior to that of normal three phase IM. Six phase induction motor finds its application in hybrid electric vehicles, ship propulsion, more electric aircraft. 2. MODELING OF SIX PHASE INDUCTION The electromagnetic torque equation is written in MOTOR terms of λ_md and λ_mq as: The equations that describes the behavior of the six- phase induction machine when expressed in the arbitrary reference frame are listed in equations shown below: Similarly, the mechanical model of this machine comprises of the equation of the motor and the driven load, and this is usually represented as:

where J is the inertia and TL is the load torque. 3. SIMULATION EQUATIONS The equations that describe the electrical and mechanical behavior of the machines contain mixed variables (flux linkages and current).of these two quantities could be eliminated from the differential equation by algebraic manipulations of equations (1)- (18). Thus, the currents when solved in terms of flux where ω_k is the speed of the reference frame, ω _r is linkages are obtained as: the rotor speed. Also, the expressions for stator and rotor flux linkages are:

ISSN: 0975 – 6736| NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 21 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN ELECTRICAL ENGINEERING

Fig.1. Simulation Circuit for Six phase IM

Substituting equations (21)-(28) into (1) – (8) and solving the equation in the rotor reference frame, (that is ω_k becomes ω_r) the integral form of the machine voltage and torque equations with flux linkage as state variables is given as:

Fig.2. Flow diagram of the electrical part for the simulation of the six-phase machine

Thus equations (19), (21)-(39) essentially will be used to simulate the six phase (dual) split winding induction machine. These equations are arranged in integral form rather than in the differential form so as to avoid having spikes as a result of differentiation of signals with ripples. 4. PROPOSED SCHEME The classic vector control scheme consists of model of two three phase inverters with vector control and

Fig.3.abc to dq Transformation block

ISSN: 0975 – 6736| NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 22 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN ELECTRICAL ENGINEERING

Fig. 8 Torque of three phase IM

5. RESULTS AND DISCUSSION Rectified voltage is fed to the two voltage source inverters and then output of two inverters, is given to six phase induction motor. Six phase induction motor is modeled using above equations. The motor output is shown in figures 4, 5 and 6. Figure 4 and 5 shows the output of six phase and three phase induction motors respectively. From the waveforms of torque of six phase and three Fig.4.Output waveform of six phase IM phase induction motor (figures7 and 8) it is clear that the torque of six phase induction motor is about 550 N-m and that of three phase motor is about 350 N-m, i.e. six phase motor torque is almost 1.6 times more than three phase induction motor torque. Also figure 6 shows the output of six phase induction motor for step change in speed and torque. 6. CONCLUSIONS: Six phase induction motor finds its application in the area of high power high current applications. Because of its high torque it is suitable to be used in ship propulsion, Hybrid electric vehicle, more electric aircraft etc. We were able to compare the torque of three phase induction motor with torque of six phase induction motor without actually controlling the motors physically with the help of Matlab software. Fig.5. Output waveform of three phase IM 7. REFERENCES: 1. Hamid Toliyat, Emil Levi, “A novel concept of a multiphase, multi-motor vector controlled drive system supplied from a single voltage source inverter” 2. V. Oleschuk, G. Griva, F. Profumo, A. Tenconi, “Synchronized PWM Control of Symmetrical Six- Phase Drives” 3. G. R. Arab Markadeh, J. Soltani, N. R. Abjadi, M. Hajian, “Sensorless Control of a Six-Phase Induction Motors Drive Using FOC in Stator Flux Reference Frame” World Academy of Science, Engineering and Technology 58, 2009 4. Dejan D. Reljic, Darko B. Ostojic, Veran V. Vasic, “Simple Speed Sensorless Control of Induction Motor Drive”, Sixth International Conference, October 18 – 20, 2006, Belgrade, SASA, Serbia 5. Martin Jones, Slobodan N. Vukosavic, Member, IEEE, Emil Levi, Senior Member, IEEE, and Atif Fig. 6. Output of six phase IM for change in step of Iqbal , “A Six-Phase Series-Connected Two-Motor speed and torque Drive With Decoupled Dynamic Control” IEEE Transactions On Industry Applications, Vol. 41, No. 4, July/August 2005

Fig.7. Torque of six phase IM

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