presentation on speed control of 1.5 hp dc motor by open loop control system

By-

Harikesh Bahadur SinghAnkit Kumar GautamPrashant TiwariUnder guidance of-Mr. Arun Kumar Sharma

Content1- Introduction2- LabviewFront panel and block diagramData acquisition3- Block diagram of project4- Driver circuitWorking of driver circuit5- VI of project6- Conclusion

1- Introduction

This project is about developing a speed controller for DC motors. The DC motors are widely used in the industries so there is always a need to control the speed of DC motor for the better performance and economical purpose. Technical DetailsThe methodology is divided into two parts which is software development and hardware implementation The last part is to interface the controller with the hardware.

The controller sends command signal to the DAQ device.

The DAQ device generate analog voltage which is given to motor driver circuit which consist of an auto-transformer and a tap changing circuit.

The tap changing circuit selects proper tap of auto-transformer according to the voltage coming from DAQ device.

LabVIEW is a graphical programming language designed to develop test, control, and measurement applications.LabVIEW programs are called virtual instruments, or Vis. A VI contains the following three component.1-Front panel Serves as the user interface.2-Block diagram contains the graphical source code that defines the functionality of the VI.3-Icon and connector pane identifies the interface to the VI so that you can use the VI in another VI. A VI within another VI is called a subVI. A subVI corresponds to a subroutine in text-based programming languages2- Labview

Front panel and block diagram

Data acquisition is the process of sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer.

4- Driver circuit

There are 6 comparators used in block 1 and different different voltage level is given to negative terminal of each comparator.A varying voltage is given from DAQ to positive terminals off all comparators commonly.When voltage level at positive terminal of a particular comparator is more than voltage level at its negative terminal then it gives output voltage. This voltage is given to base terminal of a NPN transistor.This transistor works as a switch. When switch is ON, the circuit of relay is closed and current starts flowing in relay and relay is energized.At a time two relays are energized. One is used for connecting a tap and another is used for disconnecting a tap which is already connected. So at a time one tap is connected and rest of all are disconnected.

Block 2 circuit is used to obtain 12V DC from 230V AC. The 230V AC is step down to 15 V AC. Then 15V AC is converted into DC with help of a bridge rectifier.The 25V capacitors are used to bypass the AC components.The 12V zener diodes are used to keep the voltage constant at 12V.Working of motor driver.

Result Input 230 v AC

AC(V)DC(V)Step1- 160 144Step2- 175 158Step3- 191 172 Step4- 205 184Step5- 222 200Step6- 235 212

6- conclusion

This project can withstand in competitive environment due to following reasons-1- Reliable- due to lesser complexity in project2- Accuracy.

The dc motors are widely used in industry. Labview is a new platform for designing the control system for Dc motors. This project can be widely used in industries as a control system of dc motors.

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