On an AC motor you basically vary the frequency on a DC you can vary the voltage.
A change in frequency of the motor will cause a change in the speed of the AC conveyor motor. This frequency change is brought about by a device called a Variable Frequency Drive. It is used to vary the frequency of the motor from 0 to 100%. I have no idea what the second answer is talking about. ANSWER: considering that no mention of type of motor is involved the frequency change theory is quite invalid since 50 or 60 Hz AC line runs clocks from banks to wake up calls and while it is true that the frequency is not accurate from second to second it is however very accurate from minutes to minutes.
The synchronous speed of a single-phase motor is determined by the formula ( N_s = \frac{120 \times f}{P} ), where ( N_s ) is the synchronous speed in RPM, ( f ) is the frequency of the supply, and ( P ) is the number of poles. Therefore, if the applied frequency remains constant, the synchronous speed will not change significantly with variations in the applied voltage or current. However, if the supply frequency changes, the synchronous speed will change accordingly. In practice, variations in load can cause the actual speed to deviate from the synchronous speed, but this is not a change in synchronous speed itself.
The induction motor rotor has different frequency compared to it's stator. The rotor has slip ( s ) frequency. slip = ( Synchronous speed - rotor speed ) / Synchronous speed Synchronous speed = ( 120 * f ) / P where f = supply frequency to the stator. p = no of poles rotor speed is the actual speed the motor is running. Frequency in the rotor = slip * frequency in the stator At starting rotor speed is zero, so slip is one. Let us take the supply frequency is 50 Hz, then rotor frequency is also 50 Hz at starting. The motor attains speed and runs with its full speed at a point of time. Then let us take the slip is 0.04 then the rotor frequency will be 2 Hz.
A frequency converter converts alternating current of one frequency to alternating current of another frequency. Generally it's used for controlling the ac motor speed by changing the supply frequency.
You may or you may not. It all depends on the task you are using the motor. If speed is not a concern for you then you may, but for sensitive systems where changes in motor speed affects the system then you may not. The reason is that the frequency of the power supply affects the motor speed. Frequency is directly proportional to speed.
by using a frequency tuner in input we can change input frequency and in this way speed of dc motor will also vary. <<>> Varying the frequency (VFD) only works on AC motors.
the speed of ac motor can be controlled by controlling the synchronous speed (Ns=120f/p). and synchronous speed can be varried or controlled by changing frequency or by changing poles. but practicaly pole can not be changed. but we can change the frequency. the frequency can be VFD (Variable frequency Drives). so the speed of ac motor can be chaged or controlled by VFD.
If the load is connected to the motor via belts, you can change the speed the load is turning by changing the pulley sizes. To get the load to slow down, increase the size of the pulley on the load; to get it to speed up, increase the size of the pulley on the motor. To reduce the speed of the motor itself, you'll have to alter the line frequency, which you can't do without a variable frequency drive attached to the motor.
frequency of the power supply it is connected to. The speed of a single phase motor is directly related to the frequency of the alternating current (AC) power supply. As the frequency of the power supply changes, the speed of the motor will also change.
A change in frequency of the motor will cause a change in the speed of the AC conveyor motor. This frequency change is brought about by a device called a Variable Frequency Drive. It is used to vary the frequency of the motor from 0 to 100%. I have no idea what the second answer is talking about. ANSWER: considering that no mention of type of motor is involved the frequency change theory is quite invalid since 50 or 60 Hz AC line runs clocks from banks to wake up calls and while it is true that the frequency is not accurate from second to second it is however very accurate from minutes to minutes.
The frequency inverter changes the frequency of power lines to the electric motor, hence to change the speed of the motor, in some applications like conveyor, it does not need full speed running all the times, so the frequency inverter comes in as the speed control role to save electric energy.
The synchronous speed of a single-phase motor is determined by the formula ( N_s = \frac{120 \times f}{P} ), where ( N_s ) is the synchronous speed in RPM, ( f ) is the frequency of the supply, and ( P ) is the number of poles. Therefore, if the applied frequency remains constant, the synchronous speed will not change significantly with variations in the applied voltage or current. However, if the supply frequency changes, the synchronous speed will change accordingly. In practice, variations in load can cause the actual speed to deviate from the synchronous speed, but this is not a change in synchronous speed itself.
If the frequency supplied to a three-phase motor is increased, the motor speed will also increase following the relationship known as the synchronous speed. This increase in frequency will lead to a corresponding increase in motor speed, assuming that the load on the motor remains constant.
Answer #1 It varies the frequency fed to a synchronous AC motor. As the frequency changes, so does the motor speed. Answer #2 The formula for calculating speed is: (120 X motor supply frequency) / number of poles 120 is a fixed number, so is the number of poles for a given motor, hence the only variable is the motor supply frequency. AC drives vary the motor supply frequency in turn achieving speed control.
The speed of a split-phase motor is directly proportional to the frequency of the power supply, not the voltage. As long as the frequency remains constant, the speed of the motor will remain relatively stable regardless of minor fluctuations in voltage within normal operating limits.
Assume a 3 phase AC Induction motor. The speed of the motor is derived by the formula N = (120/f)/P. N speed, f - frequency, P number of poles. In an induction motor P is fixed by the winding. f system frequency. Variable speed drives change the system frequency so that the speed (N) can be varied. Drive is a power electronic device through which the system frequency can be varied
If you're talking about an electric motor, increasing the frequency will increase the speed of rotation of the motor, and decreasing the frequency will decrease the speed of rotation of the motor. The other way of controlling a motor is to control the current; increasing the current increases speed, decreasing current decreases speed.