SPEED CONTROL OF INDUCTION MOTOR IN SUGAR PLANT Project Members: T.Muthumeenal (91710112017) P.Ponajitha (91710112018) Guide Name: R.Rambrintha M.Tech AP / ICE Eternal guide: Mr.B.R.Sivakumar, Deputy Manager of instrumentation department

ABSTRACT The main purpose of this project work is to vary and control the speed of induction motor based on the level of the sugarcane juice in the mill. The main advantage of the project is to reduce the power consumption and eliminate the recirculation of juice .The speed of the induction motor is varied and controlled based on the juice level. Here the speed is varied by using the relay driver that is rotor resistance method.

EXISTING METHOD

DISADVANTAGES The power loss is occurred due to constant (single)speed of the motor. Recirculation process is time consuming in existing method.

PROPOSED METHOD

BLOCK DIAGRAM Power supply At89s52 Pc (matlab Application) Max 232 Microcontroller At89s52 Max 232 converter Motor Driver(controlling unit) Pc (matlab Application) motor Signal Conditioning unit Level Sensing probe Water tank

BLOCK DESCRIPTION The level sensor is used to read the input signals from the tank and transmits the signal to the Atmel micro controller, which reads the instruction corresponding to the level of the tank. The microcontroller sends signal to pc via MAX 232 serial port cable. Then signal from the pc controls the speed of the induction motor. Voltage divider and zener diode is used as signal conditioning unit which is used to limit voltage from the level sensor. The speed of the induction motor is varied by using relay type driver circuit.

CIRCUIT DIAGRAM

CIRCUIT DESCRIPTION In this circuit voltage divider is used to limit +12v into +5v which is given to the Atmel microcontroller. Normally open type relay switches are connected as the output of the microcontroller and the relay switches add resistance to the rotor of the induction motor. If the level is sensed by the level sensor, the microcontroller releases the corresponding resistance to the rotor. The speed of the induction motor is varied by adding or releasing resistance to the rotor.

LEVEL SENSOR Float type level switches are used as level sensor. Four level switches are used to find the level of the tank. This type of the level switches based on two basic principles namely: Buoyancy, magnetism. Buoyancy causes the float (which contains a magnet) to rise with the liquid and magnetism helps open and close the switch. When the level of the tank reaches the float type level switches, the magnetism in the switches makes the movement in the switch.

INDUCTION MOTOR Slip ring type induction motor is used for the speed control. Speed of the induction motor is varied by using the rotor resistance method. The speed is varied at four stages based on the level input. Relay type driver is used for the purpose of adding or releasing resistance to the rotor.

RELAY DRIVER The speed of the induction motor is controlled through normally open type relay switches. Four relay switches which are corresponding to four level sensors are used. In this project, this type of relay switches is used to add the resistance to the rotor of the induction motor. If the level is sensed, corresponding resistance to the rotor is released. Then the speed is increased.

FLOW CHART

ALGORITHM STEP 1: Start the program. STEP 2: Initialize the level L=0. STEP 3: Check L=4, if yes print speed=12000rpm and go to step 7 otherwise go to step 4. STEP 4: Check L=3, if yes print speed=9000rpm and go to step 7 otherwise go to step 5. STEP 5: Check L=2, if yes print speed=6000rpm and go to step 7 otherwise go to step 6. STEP 6: Check L=1, if yes print speed=3000rpm. STEP 7: Stop the program.

HARDWARE REQUIREMENT SOFTWARE REQUIREMENT Induction motor Level sensor probe Microcontroller Relay switch SOFTWARE REQUIREMENT Mat Lab

ADVANTAGES Reduce the power consumption of the motor. Eliminate the recirculation process of sugarcane juice. Reduces the time consumption. Keeps the juice level as above the motor level. Vary the speed of the induction motor based on the level of the tank.

CONCLUSION This project presents implementation of real time MATLAB interface for speed variation of induction motor using AT89S52 microcontroller. The speed variation of induction motor based on the level is analyzed and the speed of the induction motor is also indicated using MATLAB. This project work is completely automated for the speed variation of the induction motor and both level and speed are monitored on MATLAB. This project focused on automation due to this manpower is avoided

FUTUREWORK In future, In this project can be expanded in the field of plc embedded instead of embedded with MATLAB because this project has some difficulties for the connection between the pc and the microcontroller. In industries, Level transmitter can be used for taking more number of level inputs than the level switches. The speed variation and the level are displayed on a LCD display for the purpose of easy monitoring

SCREEN SHOT Screen shot for level 1

Screen shot for level 2

Screen shot for level 3

Screen shot for level 4

REFERENCE Talukder, P.; Soori, P.K.; Aranjo, B., "Speed control of induction motor drive using universal controller," Power Engineering and Optimization Conference (PEDCO) Melaka, Malaysia, 2012 Ieee International , vol., no., pp.509,514, 6-7 June 2012 Amudhavalli, D.; Narendran, L., "Speed control of an induction motor by V/F method using an improved Z source inverter," Emerging Trends in Electrical Engineering and Energy Management (ICETEEEM), 2012 International Conference on , vol., no., pp.436,440, 13-15 Dec. 2012 Asija, D., "Speed control of induction motor using fuzzy-PI controller," Mechanical and Electronics Engineering (ICMEE), 2010 2nd International Conference on , vol.2, no., pp.V2-460,V2-463, 1-3 Aug. 2010

THANK YOU

SPEED EQUATIONS The equation of torque for three phase induction motor is The speed of induction motor is given by Where, S=slip. Ns=synchronous speed of the induction motor, f =frequency p =number of poles In low slip region

SCHEMATIC DIAGRAM Motor Level sensing probe tank Power supply At89s52 Microcontroller At89s52 Max 232 converter Motor Driver(controlling unit) Pc (matlab Application) Motor Signal Conditioning unit Level sensing probe tank