1Speed Control Of Induction seminar.pptx (Size: 139.7 KB / Downloads: 256)
“SPEED CONTROL OF THREE PHASE INDUCTION MOTOR USING DSPIC30F4011”
Induction motors are widely used in high performance drive systems ,because of its advantages like high efficiency, very simple in construction , good power factor and it does not require any starting motor. Variable speed operations can be achieved by induction motor .Therefore ,now a days in many applications such as washing machine & all induction motors are only preffered.
Speed Control Method
Various induction motor speed control techniques such as Variable Voltage Variable frequency (VVVF) are in practice today but the most common & popularly used method of speed control technique is V/F method, where in the voltage & frequency are varied in proportion but maintaining the flux constant so that a constant torque is developed throughout the speed control range .
Features Of Dspic
High performance modified RISC CPU.
48kb of on-chip Flash program space.
2kb of on-chip data RAM
1kb of non-volatile data EEPROM
4MHz-10Hz oscillator input with active PLL.
16*16-bit working register array.
2 UART modules with FIFO buffer.
6-PWM output channel.
Analog to Digital Converter with 4 S/H inputs.
DSP Vs DSPIC
DSP is complicated than the DSPIC.
Cost of the DSP is higher than DSPIC.
Writing and loading of the program is easy in DSPIC
DSPIC have on-chip peripheral device due to which the board space is reduced
Using DSPIC, the system performance will be increased.
Alfredo,Thomas A. Lipo and Donald W. Novotny, “A New Induction Motor V/f Control Method Capable of High-Performance Regulation at Low Speeds” IEEE Trans. Industry Applications, Vol. 34, No. 4 July/ August 1998.
Z.Cucej and Svecko, “Optimal pwm controller for an inverter driven induction motor.” ” IEEE Trans., Vol. 53, No. 2 .
K.Koga, R.Ueda and T.Sonada, “constitution of v/f control for reducing the speed error in induction motor system.” In Conf.Rec. IEEE-IAS Annu.Meeting, 1990.
W. Slabiak and L.Lawson, “ Preceise control of three phase induction motor using single phase supply” ACSE Journal, Volume (6), Issue (3), Oct. 2006
Three Phase inverter bridge
Simple, cost-effective & high efficiency control topology.
V/F method not only controls the speed of the motor, it also improves the dynamic & steady state characteristics of the motor.
Because of the absence of the high inrush current, effective life of the machine is improved.
Maximum torque is attained within a short time.
Due to high initial torque, the performance of the machine is improved.
By V/F method, Precise speed control can be achieved & the average energy consumption will be reduced.
The prototype will be developed and tested for different set speeds and loads from which different waveforms will be observed in DSO. Also line to line current can be observed. The proposed work is expected to show that by varying voltage and frequency in proportion speed control of three phase induction motor is acheived.