Inverter setting parameters are more, each parameter has a certain selection range, the use of often encountered due to individual parameters are not set properly, resulting in inverter can not work properly, therefore, must be related to the correct setting of the parameters.
1. Control mode:
That is, speed control, turn distance control, PID control or other ways. After taking the control mode, generally according to the control accuracy of static or dynamic identification.
2. Minimum operating frequency:
That is, the minimum speed at which the motor operates. When the motor operates at a low speed, its heat dissipation performance is very poor, and the motor runs at a low speed for a long time, which will lead to motor burnout. And low speed, the current in the cable will also increase, which will also lead to cable heating.
3. Maximum operating frequency:
General inverter maximum frequency to 60 Hz, some even to 400 Hz, high frequency will make the motor running at high speed, which for ordinary motors, its bearings can not be a long time to run over the rated speed, the motor's rotor can withstand such a centrifugal force.
4. Carrier frequency:
The higher the carrier frequency is set, the higher the high harmonic component is, which is closely related to the length of the cable, the heat of the motor, the heat of the cable, the heat of the inverter and other factors.
5. motor parameters:
Inverter in the parameters set motor power, current, voltage, speed, maximum frequency, these parameters can be obtained directly from the motor nameplate.
6. Frequency hopping:
At a certain frequency point, there is a possibility of resonance phenomenon, especially when the whole device is relatively high; when controlling the compressor, avoid the compressor's wheezing point.
7. Acceleration and deceleration time
Acceleration time is the time required for the output frequency to rise from 0 to the maximum frequency, and deceleration time is the time required for the output frequency to fall from the maximum frequency to zero. The acceleration and deceleration times are usually determined by the rise and fall of the frequency setting signal. The rate of rise of the frequency setting must be limited to prevent overcurrent when the motor is accelerated, and the rate of fall must be limited to prevent overvoltage when it is decelerated.
Acceleration time setting requirements: the acceleration current is limited to below the overcurrent capacity of the frequency converter, so as not to cause the frequency converter to trip; deceleration time setting points are: to prevent the smoothing circuit voltage is too large, so as not to regenerate the overvoltage stall and make the frequency converter trip. Acceleration and deceleration time can be calculated according to the load, but in the debugging is often taken according to the load and experience first set a longer acceleration and deceleration time, through the starting and stopping motor to observe whether there is overcurrent, over-voltage alarm; and then acceleration and deceleration set time is gradually shortened to the operation of the alarm does not occur in the principle of repeating the operation a few times, you can determine the optimal acceleration and deceleration time.
8. Torque increase
Also called torque compensation, it is a method to increase the low frequency range f/V in order to compensate for the reduced torque at low speed 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 so that motor acceleration can be carried out 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 loads, if not properly selected, the output voltage will be too high at low speeds, wasting power, and even the phenomenon of high current when the motor starts with loads and the speed does not go up.
9. Electronic thermal overload protection
This function is set to protect the motor from overheating, it is the CPU in the inverter calculates the temperature rise of the motor according to the value of the running current and the frequency, so as to carry out the overheating protection. This function is only applicable to " one towing one ' occasion, but in ' one towing many ", it should install thermal relay on each motor.
Electronic thermal protection setting value (%) = [ motor rated current (A) / inverter rated output current (A) ] × 100%.
10. Frequency limitation
That is, the upper and lower limit amplitude of inverter output frequency. Frequency limit is a protection function to prevent misoperation or external frequency setting signal source failure, and cause the output frequency is too high or too low, in order to prevent damage to the equipment. It can be set according to the actual situation in the application. This function can also be used as a speed limit, such as belt conveyor, due to the transport of materials is not too much, in order to reduce the wear and tear of machinery and belts, can be driven by a frequency converter, and will be the upper limit of the frequency converter frequency is set to a certain frequency value, so that the belt conveyor can be run at a fixed, lower working speed.
11. Bias frequency
Some are also called deviation frequency or frequency deviation setting. Its use is when the frequency is set by an external analog signal (voltage or current), this function can be used to adjust the output frequency when the frequency setting signal is the lowest. Some inverters when the frequency setting signal is 0%, the deviation value can act in the range of 0 ~ fmax, some inverters (such as Mingdensha, Sanken) can also be set on the bias polarity. For example, in debugging when the frequency setting signal is 0%, the frequency converter output frequency is not 0Hz, but xHz, then set the bias frequency to negative xHz that can make the frequency converter output frequency is 0Hz.
12. Frequency setting signal gain
This function is only effective when the frequency is set by external analog signal. It is used to make up for the inconsistency between the external setting signal voltage and the voltage inside the inverter (+10v); at the same time, it is convenient to select the analog setting signal voltage, when setting, when the analog input signal is the maximum (such as 10v, 5v or 20mA), find out the frequency percentage of the output f/V graph and set it with this as a parameter; such as the external setting signal is 0 ~ 5v, if the inverter output frequency is 0 ~ 50Hz, then the inverter output frequency is 0 ~ 50Hz, then the inverter output frequency is 0 ~ 50Hz, then the frequency is 0 ~ 50Hz. If the external setting signal is 0～5v, if the output frequency of inverter is 0～50Hz, then set the gain signal as 200%.
13.Torque limitation
It can be two kinds of torque limitation: driving torque limitation and braking torque limitation. It is based on the output voltage and current value of the frequency converter, and the CPU carries out torque calculation, which can significantly improve the shock load recovery characteristics during acceleration/deceleration and constant speed operation. The torque limiting function can realize automatic acceleration and deceleration control. Assuming that the acceleration and deceleration time is less than the load inertia time, it also ensures that the motor automatically accelerates and decelerates according to the torque setting value.
The drive torque function provides powerful starting torque, and during steady state operation, the torque function will control the motor torque difference and limit the motor torque to the maximum setting value, so that it will not cause the inverter to trip when the load torque suddenly increases, even when the acceleration time is set too short. When the acceleration time is set too short, the motor torque will not exceed the maximum setting value. A large driving torque is favorable for starting, so it is better to set it at 80 to 100%.
The smaller the setting value of braking torque is, the larger the braking force is, which is suitable for the occasions of rapid acceleration and deceleration, if the setting value of braking torque is set too large, there will be the phenomenon of over-voltage alarm. If the braking torque is set to 0%, the total amount of regeneration added to the main capacitor can be close to 0, so that the motor can decelerate to a standstill without using the braking resistor when decelerating without tripping. However, in some loads, such as braking torque set to 0%, when decelerating, there will be a short idling phenomenon, resulting in repeated starting of the inverter, the current fluctuates greatly, and in serious cases, the inverter will be tripped, which should be noted.