The frequency converter has many parameters, each parameter has a certain range of choice, often encountered in use due to the improper setting of individual parameters, resulting in the frequency converter can not work properly, therefore, the relevant parameters must be set correctly.

1. Control

That is, speed control, pitch control, PID control or other means. After adopting the control mode, the static or dynamic identification should be carried out according to the control precision.

2. Minimum operating frequency

That is, the minimum speed of the motor running, the motor at low speed, its poor heat dissipation performance, motor running for a long time at low speed, will lead to motor burning. And at low speed, the current in the cable will also increase, will also lead to cable heating.

3. Maximum operating frequency

General inverter maximum frequency to 60 Hz, and some even to 400 Hz, high frequency will make the motor high-speed operation, which for ordinary motor, its bearing can not long time of excessive rated speed operation, whether the rotor of the motor can bear such centrifugal force.

4.Carrier frequency

The higher the carrier frequency setting, the greater the higher harmonic component, which is closely related to cable length, motor heating, cable heating frequency converter heating and other factors.

5.Motor parameters

The inverter sets the motor's power, current, voltage, speed and maximum frequency in the parameters, which can be obtained directly from the motor nameplate.

6. Frequency hopping

At a certain frequency point, resonance may occur, especially when the whole device is high; in the control of the compressor, to avoid the surge point of the compressor.

7. Acceleration and deceleration time

The acceleration time is the time it takes for the output frequency to rise from 0 to the maximum frequency, and the deceleration time is the time it takes for the output frequency to fall from the maximum frequency to 0. Frequency is usually used to set the signal up and down to determine the acceleration and deceleration time. The rate of rise of the frequency setting shall be limited to prevent over-current when the motor is accelerating, and the rate of decline shall be limited to prevent over-voltage when the motor is decelerating. Acceleration time setting requirements: the acceleration current will be limited to the inverter over-current capacity below, so as not to cause overcurrent stall frequency converter trip; Do not stall the regenerative overvoltage and trip the converter. The acceleration and deceleration time can be calculated according to the load, but in the debugging, the long acceleration and deceleration time is usually set according to the load and experience Then, the setting time of acceleration and deceleration is gradually shortened, and the optimal acceleration and deceleration time can be determined by repeated operation for several times.

8. Torque Boost

Also called torque compensation, is to compensate for motor stator winding resistance caused by low-speed torque reduction, and the low frequency range F/V increase method. When it is set to automatic, the voltage of acceleration can be raised automatically to compensate the starting torque and accelerate the motor smoothly. If manual compensation is used, a better curve can be selected by test according to the load characteristics, especially the starting characteristics of the load. For variable torque load, such as improper selection will appear when the low-speed output voltage is too high, and the waste of electricity, and even a motor with load when starting current is large, and speed up the phenomenon.

9.Electronic thermal overload protection

This function is set to protect the motor from overheating. It is used to protect the motor from overheating by calculating the temperature rise of the motor according to the operating current value and frequency of the CPU in the inverter. This function only applies to“One drag one” occasion, and in“One drag more”, it should be installed in each motor heat relay. Electronic thermal protection set value (%) = [ motor rated current (a)/inverter rated output current (a)] × 100% .

10. Frequency limit

That is, the upper and lower limits of the frequency converter output amplitude. Frequency limit is a protection function of setting signal source to prevent misoperation or external frequency from fault, which causes the output frequency to be too high or too low in order to prevent the equipment from being damaged. In the application according to the actual situation can be set. This function can also be used for speed limit, such as some belt conveyor, because the transfer of material is not too much, in order to reduce mechanical and belt wear, can be driven by a frequency converter, and the upper frequency of the frequency converter set to a certain frequency value, this enables the belt conveyor to operate at a fixed, lower speed.

11. Offset frequency

Some are also called deviation frequency or frequency deviation settings. The utility model is used for adjusting the output frequency when the frequency is set by an external analog signal (voltage or current) . When the frequency setting signal is 0% , the deviation value can be applied in the range of 0-fmax, and the bias polarity can be set in some frequency converters (such as electric house and Sanken) . If the frequency setting signal is 0% in debugging, the frequency of the inverter output is not 0 Hz, but XHZ, then set the bias frequency to negative XHZ can make the frequency of the inverter output to 0 Hz.

12. Frequency setting signal gain

This function is only effective when the frequency is set by an external analog signal. It is used to compensate for the inconsistency between the external set signal voltage and the internal voltage of the inverter (+ 10V) , and to facilitate the selection of the analog set signal voltage when the analog input signal is maximum (such as 10V, 5V or 20mA) , the frequency percentage of the output F/V figure can be calculated and set as a parameter, if the external setting signal is 0-5v, if the output frequency of the inverter is 0-50Hz, set the gain signal to 200% .

13. Torque limit

Can be drive torque limit and brake torque limit two. It is based on the output voltage and current of the inverter, and calculated by the CPU. It can significantly improve the impact load recovery characteristics of acceleration and deceleration and constant speed operation. The torque limit function can realize automatic acceleration and deceleration control. If the acceleration and deceleration time is less than the load inertia time, the motor can be automatically accelerated and decelerated according to the torque set value. The drive torque function provides a powerful starting torque, which controls the slip of the motor while limiting the motor torque to a maximum set value when the load torque suddenly increases, even in the acceleration time set too short, it will not cause the frequency converter trip. In the acceleration time set too short, the motor torque will not exceed the maximum set value. Large driving torque is beneficial to start, so 80-100% is a better setting. The smaller the setting value of braking torque, the greater the braking force, suitable for the occasion of rapid acceleration and deceleration, such as excessive setting of braking torque will appear over-voltage alarm phenomenon. If the brake torque is set to 0% , the regeneration amount added to the main capacitor can be close to 0, so that the motor can be decelerated to stop without using the brake resistance without tripping. But in some loads, such as the braking torque set to 0% , there will be a short idling phenomenon when decelerating, causing the inverter to start repeatedly, the current fluctuates greatly, when serious it will make the inverter trip, should be noted.

Source: internet (for study only, intrusion and deletion)