The application of frequency converters in industrial production is extremely important. In addition to speed regulation and soft start functions, the most important 

thing is that they can save energy.

There are many functional parameters for frequency converters, usually dozens or even hundreds of parameters for users to choose from. In practical applications

it is not necessary to set and debug every parameter, most just use the factory settings. However, some parameters are closely related to actual usage and some are 

also interrelated, so they need to be set and debugged according to the actual situation.

Due to the differences in the functions of various types of frequency converters, and the names of the same functional parameters are also inconsistent, but the 

basic parameters are almost universal among all types of frequency converters, making it possible to achieve a similar approach.

The following parameters are mostly used:

1、 Acceleration and deceleration time

1. Acceleration time: Acceleration time is the time from its startup frequency to its operating frequency.

2. Deceleration time: The time required for the motor to stop from operating frequency can be set.

Acceleration time refers to the time required for the output frequency to rise from 0 or the set minimum frequency to the maximum frequency, while 

deceleration time refers to the time required for the output frequency to fall from the maximum frequency to 0 or the set minimum frequency. Usually, the 

acceleration and deceleration time is determined by the frequency setting signal rising and falling. When accelerating the motor, the rising rate of the frequency 

setting must be limited to prevent overcurrent, and when decelerating, the falling rate must be limited to prevent overvoltage.

Acceleration time setting requirements:

Limit the acceleration current below the overcurrent setting of the frequency converter to prevent overcurrent from causing the frequency converter to trip;

The key points for setting deceleration time are:

To prevent excessive voltage in the smoothing circuit and prevent the regeneration overvoltage from stalling and causing the frequency converter to trip.

The acceleration and deceleration time can be calculated based on the load, but in debugging, it is common to set a longer acceleration and deceleration time 

based on the load and experience, and observe whether there are overcurrent and overvoltage alarms by starting and stopping the motor; Then gradually shorten 

the acceleration and deceleration setting time, based on the principle of no alarm during operation, and repeat the operation several times to determine the optimal 

acceleration and deceleration time.

2、 Motor parameter setting

Relevant parameters can be set in the frequency converter according to the rated voltage and rated current on the nameplate of the motor used.

1. Operation direction: mainly used to set whether reversal is prohibited.

2. Shutdown mode: used to set whether to brake and stop or stop freely.

3. Voltage upper and lower limits: Set limits based on the voltage of the equipment motor to avoid burning out the motor.

3、 Torque increase

Also known as torque compensation, it is a method of increasing the low-frequency range f/V to compensate for the decrease in torque at low speeds 

caused by the resistance of the motor stator winding.

When set to automatic, the voltage during acceleration can be automatically increased to compensate for the starting torque, allowing the motor to accelerate smoothly.

When using manual compensation, the optimal curve can be selected through testing based on the load characteristics, especially the starting characteristics of the load.

For variable torque loads, improper selection can result in high output voltage at low speeds, wasting electrical energy, and even causing high current 

when starting the motor with a load without increasing the speed.

4、 Frequency setting signal gain

This function is only effective when setting the frequency with an external analog signal.

It is used to compensate for the inconsistency between the external set signal voltage and the internal voltage (+10v) of the frequency converter; At the same time, it is convenient to simulate the selection of signal voltage settings. When setting, when the analog input signal is at its maximum (such as 10v, 5v, or 20mA), calculate the frequency percentage that can output f/V graphics and use it as a parameter for setting; If the external setting signal is 0-5V and the output frequency of the frequency converter is 0-50Hz, then the gain signal can be set to 200%.

5、 Torque

It can be divided into two types: driving torque and braking torque. It calculates torque through the CPU based on the output voltage and current 

values of the frequency converter, which can significantly improve the recovery characteristics of impact loads during acceleration, deceleration, and 

constant speed operation. The torque function can achieve automatic acceleration and deceleration control. Assuming that the acceleration and 

deceleration time is less than the load inertia time, it can also ensure that the motor automatically accelerates and decelerates according to the torque setting value.

The driving torque function provides powerful starting torque. During steady-state operation, the torque function controls the motor slip and keeps the 

motor torque within the maximum set value. When the load torque suddenly increases, even when the acceleration time is set too short, it will not cause 

the inverter to trip. When the acceleration time is set too short, the motor torque will not exceed the maximum set value. A large driving torque is beneficial 

for starting, so it is more appropriate to set it at 80-100%.

The smaller the set value of the braking torque, the greater the braking force, which is suitable for situations of rapid acceleration and deceleration. If the set 

value of the braking torque is too high, an overvoltage alarm phenomenon may occur. If the braking torque is set to 0%, it can make the total amount of regeneration 

added to the main capacitor close to 0, so that the motor can decelerate to a stop without using a braking resistor and will not trip. But on some loads, such as when 

the braking torque is set to 0%, there may be a brief idling phenomenon during deceleration, causing the frequency converter to repeatedly start and the current to 

fluctuate greatly. In severe cases, it may trip the frequency converter, which should be taken seriously.

6、 Acceleration and deceleration mode selection

Also known as acceleration and deceleration curve selection. Generally, frequency converters have three types of curves: linear, nonlinear, and S-curve, and linear 

curve is usually chosen; Nonlinear curves are suitable for variable torque loads, such as fans, etc; The S-curve is suitable for constant torque loads, and its acceleration 

and deceleration changes slowly.

When setting, the corresponding curve can be selected based on the load torque characteristics, but there are exceptions. When debugging the frequency converter 

of a boiler induced draft fan, the author first selected a non-linear curve for the acceleration and deceleration curve, and when the frequency converter was operated 

together, it tripped. Adjusting and changing many parameters had no effect, and then changed it to an S-curve to restore normal operation.

The reason for this is that the induced draft fan rotates on its own due to the flow of flue gas before starting, and reverses to become a negative load. Therefore, the 

S-curve is selected to slow down the frequency rise rate at the beginning of the start-up, thereby avoiding the occurrence of frequency converter tripping. Of course

this is a method used for frequency converters without DC braking function during start-up.

7、 Electronic thermal overload protection

This function is designed to protect the motor from overheating. It calculates the temperature rise of the motor based on the operating current value and frequency 

by the CPU inside the frequency converter, thereby providing overheating protection.

This function is only applicable to "one to one" situations, and in "one to many" situations, thermal relays should be installed on each motor. Electronic thermal 

protection setting value (%)=[rated current of motor (A)/rated output current of frequency converter (A)] × 100%.

8、 Frequency

The upper and lower limit amplitudes of the output frequency of the frequency converter. Frequency is a protective function used to prevent misoperation or 

external frequency setting signal source failure, which may cause the output frequency to be too high or too low, in order to prevent damage to the equipment.

Set according to the actual situation in the application. This function can also be used as a speed limit. For some belt conveyors, due to the limited amount of 

material being conveyed, a frequency converter can be used to reduce mechanical and belt wear. The upper limit frequency of the frequency converter can be 

set to a certain frequency value, so that the belt conveyor can operate at a fixed and lower working speed.

1. Panel speed regulation: The frequency can be adjusted through the buttons on the panel.

2. Sensor control: The frequency can be controlled by using the voltage or current changes of the sensor as signal input.

3. Communication input: Control its frequency with upper computer such as PLC.