Driving and Controlling of three Phase Induction Motor with the Help of Single Phase Supply

Transcription

1 Driving and Controlling of three Phase Induction Motor with the Help of Single Phase Supply 1 Neeraj Solanki, 2 Rupendra Singh, 2 Astitva Gupta, 2 Dheeraj Kumar, 2 Himanshu Kein 1 Lecturer, EE Department, R.B.S. Engineering Technical College, Agra, U.P., India 2 B.Tech. Scholar, R.B.S. Engineering Technical College,Bichpuri Agra, U.P., India ABSTRACT:- Variable speed motors are widely used in domestic and industry loads to control the speed of electromechanical systems like as fans, blower, pumps, machine tools, drilling machine, lifts, conveyer belts and other applications that is require variable speed-torque load drive. Three phase induction motor can be considered as a selfstarting motor with voltage-frequency dependent motor i.e. V/f control, With the development of advanced technology power electronic devices and with the use of microcontrollers, we are able to adjust the frequency and consequently the speed of the motors with less prices compared with those of dc motors speed drives. This paper deals with Microcontroller variable frequency based technique to control the speed of a relative small power three phase induction motors applications. The proposed system consists of an ac voltage supply rectified through diode-bridge to feed PWM inverter, controlled and fired, through PIC 16F676A microcontroller. The PWM inverter is controlled to produce constant input voltage with adjustable frequency used as input of the three phase induction motor. The proposed speed drive of three phase 90 watt 50Hz induction motor. KEYWORD:-variable speed drive, PWM, IGBT driver, electronics, transformer, regulator inverter, microcontroller, induction motor, and power 1. INTRIDUCTION:-Our project idea is a simple converter topology for driving a 3-phase motor with a single-phase ac supply. Using only six active switch IGBT s. The converter supplies balanced output voltages at rated frequency, the proposed topology permits to reduce the rectifier switch currents, the harmonic distortion at the input converter side, and presents improvements on the fault and control approaches are supported by test results. The convertor takes single phase supply and converts it into three phase supply with the help of thyristors. The single phase supply is first converted into dc supply by using rectifier again dc supply of rectifier is given to inverter where IGBT s are used and converts the dc supply again into three phase ac supply. The experimental result showed that square waveform produced remained approximately constant with increase in load and the developed hardware has satisfactory converted the single phase power to three phase power supply. In the past, single-phase to three-phase conversion systems were made possible by the connection of passive elements capacitors and reactors with autotransformer converters. Such kind of system presents well knows disadvantages and limitations. so to overcome from this disadvantages the newly adopted thyristors and power electronics devices were used mainly thyristors like SCRs, MOSFETs, GTOs, IGBTs etc. Since the beginning of the solid state power electronics, the semiconductor devices were the major technology used to drive the power processors. Looking at the semiconductor devices used in the former controlled rectifiers and comparing them with the new technologies it makes possible to figure out the astonishing development. Beyond the improvement related to power switches, it was also identified a great activity in terms of the circuit topology innovations in the field of three-phase to three-phase, single phase to single phase and three-phase to single phase conversion systems. The single-phase induction motor drives by the three-phase induction motor drives in some low-power industrial applications and. However, in some rural areas where only a single-phase utility is available, we should convert a single-phase to a three-phase supply. Our project proposes an alternative solution for phase conversion with very low overall cost, moderate motor performance during start up and high steady-state performance at line frequency. 451 Neeraj Solanki, Rupendra Singh, Astitva Gupta, Dheeraj Kumar, Himanshu Kein

2 2. METHODOLOGY:-The single phase 220v supply is given to the input and the rectifier circuit is connecting after that to convert single phase AC to DC. The two filter in parallel having 450V,10µf and 450V,47µf is connected to reduce the harmonics present in the ac and gives the pulsating DC, the fuse is connected to protect the circuit and the resistor is connected to limit the current and then the converter circuit is connected in which the six IGBT switching device is connected to convert DC to three phase AC. Each gate of IGBT is connected to each terminal of PIC16f676 microcontroller. In microcontroller the embedded mikro C program is installed and which drives the IGBT. We are giving 220v supply to rectifier, for positive pulse two diodes are trigger and for negative another two diodes are trigger and AC supply is converted to DC. In inverting stage we are using six IGBT(25N120) as inverter. Upper side three IGBT are called as positive group IGBT and lower side three IGBT are called as negative group IGBT. IGBT work in 180 degree mode of operation in which one IGBT from upper group and another two from lower group and after that one from lower group another from upper group. Same procedure is fallow by whole inverter circuit. diode are connect across each IGBT to limiting the reverse current flowing through the inverter. in this way we getting the three phase from middle of two IGBT. Block diagram of working of circuit A full control over the motor is achieved via the microcontroller and IGBT pair in the inverter stage. The inverter consists of six IGBT s, two IGBT s for each motor winding. phase. The microcontroller sends gate signals and the IGBT s are switched on and off creating an average AC voltage close to a sinusoidal waveform. The duty cycle of the IGBT is varied which provides equivalent sine wave output. The modulation of duty cycle is phase shifted by 120 degree for each phase. An effective control over fundamental frequency and voltage of the output is achieved. When the IGBT s are switched off, a back emf is produced in the motor winding that generates a very high and potentially damaging voltage across the IGBT. To overcome this problem, the inverter has antiparallel diodes connected across each IGBT that will allow current flow from the motor winding to the dc link when the IGBT s are switched off. The back emf is directly proportional to the rotational velocity and opposite in polarity to the voltage applied across inverter. To drive the current through 452 Neeraj Solanki, Rupendra Singh, Astitva Gupta, Dheeraj Kumar, Himanshu Kein

3 the motor windings and to increase motor speed and torque, both modulating frequency and voltage must be increased. The back emf and the motor speed are proportional to each other. Therefore, to maintain the current flow the supply voltage to the motor winding must be above this emf 453 Neeraj Solanki, Rupendra Singh, Astitva Gupta, Dheeraj Kumar, Himanshu Kein

4 The Single phase to Three phase converter using IGBT for driving three-phase induction motor by using switching frequency about 7 khz. Varying above frequency this result is smooth increasing and decreasing the spindle speed of motor Tree phase motor. The square waveform of three-phase which converted from the single phase input. Fig.Generation of three output circuit 3. ADVANTAGES:- Main advantage of our project is that we can drive a 3-Phase Motor from single phase supply. Another main advantage of our project is that we can also control the speed of 3-phase induction motor. 1-Phase supply is available everywhere so we can drive a 3-phase motor anywhere from 1-phase supply. Using our circuit we can also drive 3-Phase motor by high voltage DC. 4. CONCLUSION:-A PIC Microcontroller based PWM controlled three phase drive system has been designed and implemented successfully. It can be effectively used for speed control of the three phase induction motor usingsingle phase supply. As a conclusion the Microcontroller based low power with variable frequency drive of 3-phase induction motor can be effectively used with frequency not exceed 50% and not less than 25% of the rated value 454 Neeraj Solanki, Rupendra Singh, Astitva Gupta, Dheeraj Kumar, Himanshu Kein

5 REFERENCES FarzanRashidi, Sensor less speed control of induction motor drives using robust and adaptive neuro-fuzzzy based intelligent controller,ieee international conference on industrial technology (ICIT), 2004, pp Rashidi, F., Rashidi,M., Design of robust sliding mode speed control with fuzzy approach for induction motor, IEEE international conference on industrial technology(icit03),pp Mr. AungZawLatt, Dr.Ni Ni Win, Variable speed drive of single phase induction motor using frequency control method, International conference on education technology and computer 2009,pp W.I.Ibrahim, R.M.T. Raja Ismail, M.R.Ghazali, Development of variable speed drive for single phase induction motor based on frequency control, Proceedings of Encon th engineering conference Kuching, Sarawak, Malaysia. H.N.Hickok, Adjustable speed a tool for saving energy losses in pumps,fan blower and compressors, IEEE transaction industrial applications,vol IA21, no.1,pp ,Jan M.M.M. Negm, Torque optimized speed control of a three phase induction motor, in Proc. Int. Conf. power system technology, power con 2000,pp R.D.Lorendz, Tuning of field oriented induction motor controller for high performance applications,ieee 455 Neeraj Solanki, Rupendra Singh, Astitva Gupta, Dheeraj Kumar, Himanshu Kein