Project 2 - Speed Control of a Direct Current (DC) motor
Answer --->>>The DC motor is the motor which converts the direct current into the mechanical work. It works on the principle of Lorentz Law, which states that “the current carrying conductor placed in a magnetic and electric field experience a force”.The working principle of motor Fleming's left hand rule. It states that, when a current carrying conductor is place in a magnetic field then it experiences a force. The direction of force can be determined by Fleming's left hand rule.
Types of DC motor
Series DC Motor.
Shunt/Parallel DC Motor.
Compound DC Motors.
Permanent Magnet DC Motor
Speed control of DC motor Thus, the speed of a DC motor can control in three ways: By varying the flux, and by varying the current through field winding. By varying the armature voltage, and the armature resistance.
Controller This is the device or algorithm that processes the sensor input and generates the control output. It compares the measured process variable to the desired set point and calculates the error signal. Based on this error signal, the controller generates the control output to the actuator.
controllers are majorly classified as:
Proportional controller
Integral controller
Derivative controller
Integral Controller
A controller with a type of control action, in which the rate of change of the output shows proportionality with the actuating error signal is known as an integral controller.
In the case of the integrating controller, the rate of change of the output of the controller depends on the integrating time constant, till the time error signal becomes 0. Thus it is said to be comparatively slower than the proportional controller.
Here in order to generate an appreciable output comparatively more time is required. But in its case, the processing continues, till the time error signal becomes zero.
Derivative Controller
In the derivative type of controller, the controller output depends on the rate with which the error signal varies.
Practically we can say that the error is a function of time and at any given time instant it can be 0. However, it is not necessary that it will remain zero even after that instant of time.
Thus there must be some action that specifies the rate of change of error signal. Sometimes it is also referred as a rate action mode of the control
: Kd denotes the derivative gain constant which shows the amount of variation in output of the controller for every per second rate of change of actuating error signal.
Hence we can say that every rate of change of error signal provides a significantly different value of the output of the controller.
It serves as an advantageous factor for the system because every time the output varies with the change in error signal, thereby providing significant corrected output before the error approaches a large value.
Practically these modes are not used separately thus a combination of these modes is used.
Proportional Integral Controller: This type of controller is formed by the merger of proportional and integral control action.
Proportional Derivative Controller: When proportional control action is serially combined with derivative control action then it is known as the proportional derivative controller.
Proportional Integral Derivative Controller: The control action combining all the three modes i.e., proportional, integral and the derivative is known as proportional, integral and derivative controller or PID controller.