简体中文
There are many parameters to set, and each parameter has a certain selection range. In use, it is often encountered that due to improper setting of individual parameters, the frequency converter cannot work properly. Therefore, it is necessary to set the relevant parameters correctly.
1. Control method:
The minimum speed at which the motor operates. When the motor operates at low speeds, its heat dissipation performance is poor. Prolonged operation at low speeds can cause the motor to burn out. And at low speeds, the current in the cable also increases, which can cause the cable to heat up.
3. Maximum operating frequency:
The higher the carrier frequency setting, the greater the higher the harmonic component, which is closely related to factors such as cable length, motor heating, cable heating, and frequency converter heating.
5. Motor parameters:
At a certain frequency point, resonance may occur, especially when the entire device is relatively high; When controlling the compressor, avoid the surge point of the compressor.
7. Acceleration and deceleration time
During acceleration, the rate of increase set by the frequency must be limited to prevent overcurrent, while during deceleration, the rate of decrease must be limited to prevent overvoltage.
Also known as torque compensation, it is a method of increasing the low frequency range f/V to compensate for the low speed torque reduction caused by the resistance of the motor stator winding. When set to automatic, it can automatically increase the voltage during acceleration to compensate for the starting torque and ensure smooth acceleration of the motor. If manual compensation is used, the optimal curve can be selected through experiments based on the load characteristics, especially the starting characteristics of the load. For variable torque loads, improper selection may result in excessively high output voltage at low speeds and waste of electrical energy. It may even result in high current when the motor starts with load, but the speed cannot rise.
9. Electronic thermal overload protection
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The upper and lower limits of the frequency output amplitude of the frequency converter. Frequency limit is a protective function designed to prevent incorrect operation or failure of external frequency setting signal sources, which may cause excessive or low output frequency, in order to prevent damage to equipment. Set according to the actual situation in the application. This function can also be used for speed limiting. For some belt conveyors, due to the limited amount of material conveyed, in order to reduce mechanical and belt wear, a frequency converter can be used for driving, and the upper frequency limit of the frequency converter can be set to a certain frequency value, which can make the belt conveyor run at a fixed and lower working speed.
11. Bias frequency
This function is only effective when setting the frequency using an external analog signal. It is used to compensate for the inconsistency between the external set signal voltage and the internal voltage of the frequency converter (+10v); At the same time, it is convenient to select signal voltage for analog settings. When the analog input signal is at its maximum (such as 10V, 5V, or 20mA), calculate the frequency percentage that can output the f/V graph and set it as a parameter; If the external signal is set to 0-5V, and the output frequency of the frequency converter is 0-50Hz, set the gain signal to 200%.
13. Torque limit
The drive torque function provides powerful starting torque. During steady-state operation, the torque function controls the motor slip and limits the motor torque to the maximum set value. When the load torque suddenly increases, even if the acceleration time is set too short, it will not cause the frequency converter to trip. If the acceleration time is set too short, the motor torque will not exceed the maximum set value. A high driving torque is beneficial for starting, and setting it at 80-100% is more appropriate.
The total regeneration amount of the motor is close to 0, so that the motor can decelerate to a stop without tripping when decelerating without using a braking resistor. However, on some loads, such as when the braking torque is set to 0%, there may be a brief idle phenomenon during deceleration, causing the frequency converter to repeatedly start and the current to fluctuate significantly. In severe cases, it may cause the frequency converter to trip, and attention should be paid.
14. Acceleration and deceleration mode selection
Vector control is based on the theoretical belief that almost all frequency converters of asynchronous motors nowadays use non feedback vector control. Due to the fact that frequency converters can compensate for slip based on the magnitude and phase of the load current, the motor has very hard mechanical characteristics, which can meet the requirements for most occasions without the need to set a speed feedback circuit outside the frequency converter. The setting of this function can be selected between valid and invalid according to the actual situation.
Fans and water pumps both belong to reduced torque loads, meaning that as the speed decreases, the load torque decreases proportionally to the square of the speed. Frequency converters with energy-saving control functions are designed with a dedicated V/f mode, which can improve the efficiency of motors and frequency converters. This mode can automatically reduce the output voltage of the frequency converter based on the load current, thereby achieving energy-saving goals. It can be set to be effective or ineffective according to specific circumstances.
