speed control of DC Motor with Pulse width modulationDescription complète
PAPER MOTOR DC SHUNTDeskripsi lengkap
Manejo Del Pwm Con Un Motor DcDescripción completa
Deskripsi lengkap
motor dcDeskripsi lengkap
Full description
Description complète
Model identification of a nonlinear DC MotorDescripción completa
Description complète
CONVERSOR DC AC PWM ARDUINODescripción completa
CONVERSOR DC AC PWM ARDUINO
Descripción: informe acerca del funcionamiento de pwm
penjelasan tipe - tipe motor dcDeskripsi lengkap
moter dcpenguat terpisahDeskripsi lengkap
SPEED CONTROL OF DC MOTOR USING PULSE WIDTH MODULATION
Submitted by :Nidhi Vijaywargiya Abhishikt Animesh Vishwakarma
Content : • Introduction • D.C. motor Working principle • Method of speed control Pulse width modulation Circuit diagram & its description Disadvantages • Advantages & Disadvantages • Application • Conclusion
Introduction : • Almost all the machine machine in industries operated using electrical motors. Among them most of motors are DC motors. • DC series motor is specially used for traction, electric locomotive, trolley systems, cranes and conveyor belt.
control for • All these works require frequent speed control preparation of job. • A PWM (Pulse Width Modulation) wave can be used to control the speed of the motor.
Working Principle: • A machine that convert d.c power into mechanical power.
current • It is based on electromagnetism i.e. when a current carrying conductor is placed in the magnetic field there is some mechanical force exerted on the current carrying conductor which is perpendicular to both the conductor and the magnetic filed. • The most common DC motor types are the shunt wound and series wound types.
Speed control of dc motor : • The purpose of a motor speed controller is to take a signal representing the required speed, and to drive a motor at that speed.
Motor speed can be controlled by controlling- Armature voltage (Va) - Armature current (Ia) •
Cont……… • It is obvious that the speed can be controlled by varying flux/pole,
(Flux Control)
resistance
Ra of armature circuit (Rheostatic Control) Cont rol)
applied
voltage V (Voltage Control)
Cont… • The above methods have some demerits i.e A large amount of power is wasted in the controller resistance. Hence, efficiency is decreased. It
needs expensive arrangement for dissipation of heat produced in the controller resistance.
It
gives speeds below the normal speed.
Electronic Speed Control Methods for DC Motors : • compared to the electric and electromechanical systems of speed control, the electronic methods have higher accuracy greater reliability quick
response
higher
efficiency
Pulse Width Modulation : • Pulse width modulation (PWM) is a method for binary signals generation, which has 2 signal periods (high and low). • The width (W) of each pulse varies between 0 and the period (T). • The duty cycle (D) of a signal is the ratio of pulse width to period. D=(t1+t2) / T •
Pictures of the Waveform : •
•
•
The motor is on for most of the time and only off a short while, so the speed is near maximum The switch is on 50% and off 50%. The motor will only rotate slowly.
High Speed Signal (90%) • The signal at the right shows the motor on for most of the time. • The white dips indicate when the motor isn’t receiving power.
Signal With The Motor Half Speed (50%)
• The signal at the right shows the motor receiving power half the time.
Low Speed Signal (10%)
• The signal at the right shows the low speed signal which turns the motor slowly
Power Supply :
Circuit Description: • The transformer is a center tap 12-0-12V 500mA and supply 12v to the circuit. • The i/p sine wave is rectified by using full wave rectifier which convert it to one constant polarity.
• A 1000Fcapacitor is used for filtration purpose. • The three terminal voltage regulators 7812 provides regulated DC 12 v outputs for the operation of the circuit.
Advantage : • PWM duty cycle control techniques enable greater efficiency of the DC motor . • PWM switching control methods improve speed control and reduce the power losses in the system. • The pulses reach the full supply voltage and will produce more torque in a motor by being able to overcome the internal motor resistances more easily.
Disadvantages
:
• The main Disadvantages of PWM circuits are the added complexity and the possibility of generating radio frequency interference . • It can give speed below the full speed, not above. • It cannot be used for fast controlling of speed.
Applications : • Traction application • Conveyor Belt carrying loads control • Various motors requiring smooth speed control • DC motors of all range can be controlled, which are used for the production of materials • Electric locomotives • DC motor using precise job preparations
Conclusion • The present project is practical one and high feasibility according to economic point of view, reliability & accuracy. It is programmable one therefore it can control various motors ranging small one to several hp motors.
