V/Hz, or volts per hertz, is a parameter used in AC drives, which represents the relationship between the voltage and frequency of the AC power supplied to the motor. In a basic AC drive, the frequency and voltage supplied to the motor are typically varied together in a fixed ratio, such that the ratio of voltage to frequency (V/Hz) is constant.
The V/Hz ratio is an important parameter that affects the operation and performance of the motor. As the frequency of the AC power supplied to the motor increases, the voltage supplied to the motor also needs to increase in proportion to maintain the V/Hz ratio. Similarly, as the frequency of the AC power supplied to the motor decreases, the voltage supplied to the motor needs to decrease in proportion to maintain the V/Hz ratio.
By controlling the V/Hz ratio, an AC drive can control the speed and torque of the motor. As the frequency and voltage of the AC power supplied to the motor are varied together, the V/Hz ratio determines the torque produced by the motor at any given speed. By adjusting the V/Hz ratio, an AC drive can optimize the torque and speed of the motor for a particular application.
In more advanced AC drives, the V/Hz ratio can be adjusted dynamically, allowing for greater control and optimization of the motor performance. By adjusting the V/Hz ratio in response to changes in the motor speed and load, an AC drive can maintain optimal torque and speed control for a wide range of applications.
The V/Hz ratio is typically set to a value of 300 for most AC drives, which is considered an optimal value for achieving maximum torque output and motor efficiency. This means that the applied voltage is directly proportional to the frequency of the AC drive, ensuring that the motor operates within its designed range.
