What does the base frequency 60Hz represent in the inverter?
The schematic diagram of the basic frequency parameters of the converter is shown in figure.Below the fundamental frequency, the output voltage of the converter varies with the output frequency, and the V/F= constant is suitable for constant torque load characteristics.Above the fundamental frequency, the output voltage of the inverter maintains the same voltage rating of the power supply, which is suitable for constant power load characteristics.
How to set the frequency converter: inverter frequency parameter should be set to the rated frequency of the motor is set up, and not according to the load characteristic set, even if the selection is not suitable for motor load characteristics or parameters must also try to follow the motor, easy over-current or overload.
For example: if the rated frequency of the motor is 20HZ, the fundamental frequency should be set to 20HZ; if the rated frequency of the motor is 33.3HZ, the fundamental frequency should be set to 33.3HZ; if the rated frequency of the motor is 50HZ, the fundamental frequency should be set to 50HZ; if the rated frequency of the motor is 60HZ, the fundamental frequency should be set to 60HZ; if the rated the working frequency of the motor is 100HZ, the fundamental frequency should be set to 100HZ.
If the motor chooses a special AC frequency conversion motor, the motor is always marked with constant torque and constant power speed range. For example, Mark 5 ~ 100HZ for constant torque, 100 to 150HZ for constant power, the basic frequency should be set to 100HZ. The fundamental frequency parameter directly reflects the relationship between the output voltage and the output frequency of the inverter. If it is not set properly, it is easy to cause the overcurrent or overload of the motor. For example, an AC motor rated voltage 380V, rated frequency is 60HZ, if the frequency is lower than that of converter 60HZ V/F, a high proportion of the output voltage as high frequency, high output current, at startup, easy to cause the flow. If the frequency converter is set higher than 60HZ, low V/F ratio, the output voltage of the same frequency is low, the output current is low, at startup, can easily lead to the start and overload.
