What kind of inverter, the basic knowledge of the inverter - News - Global IC Trade Starts Here Free Products

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1. What is a frequency converter?
The frequency converter converts the power frequency power source into a continuously adjustable power control device by using the power semiconductor device.
2. What is the difference between voltage type and current type?
The main circuit of the inverter can be roughly divided into two types: the voltage type is a frequency converter that converts the direct current of the voltage source into an alternating current, the filtering of the direct current circuit is a capacitor, and the current type is a frequency converter that converts the direct current of the current source into an alternating current. Its DC loop filtering is an inductor.
3. Why does the voltage of the inverter change in proportion to the frequency?
The torque of the asynchronous motor is generated by the interaction between the magnetic flux of the motor and the current flowing through the rotor. At the rated frequency, if the voltage is constant and only the frequency is reduced, the magnetic flux is too large, and the magnetic circuit is saturated. The motor will be burned. Therefore, the frequency and voltage should be changed in proportion, that is, the frequency of the inverter is controlled while changing the frequency, so that the magnetic flux of the motor is kept constant to avoid the occurrence of weak magnetic and magnetic saturation. This type of control is mostly used for energy-saving inverters such as fans and pumps.
4. How does the torque of the motor change when V and f are changed proportionally?
When the frequency is lowered to completely reduce the voltage proportionally, since the AC resistance becomes small and the DC resistance does not change, the torque generated at the low speed tends to decrease. Therefore, given V/f at low frequencies, the output voltage must be increased to obtain a certain starting torque. This compensation is called enhanced starting. It can be implemented in various ways, such as an automatic method, selecting a V/f mode, or adjusting a potentiometer.
5. For the combination of general motors, the torque is required to be above 60 Hz. Is it ok?
Usually not allowed. Above 60Hz (also in the mode above 50Hz) the voltage is constant, generally constant power characteristics, when the same torque is required at high speed, you must pay attention to the choice of motor and inverter capacity.
6. What does it mean to open a ring?
A speed detector (PG) is provided for the motor device to be used, and the actual speed is fed back to the control device for control, which is called "closed loop". If the PG is not operated, it is called "open loop". General-purpose inverters are mostly open-loop, and some models use PG feedback.

7. What should I do if the actual speed is different for a given speed?
When the ring is open, even if the inverter outputs a given frequency, the motor's speed will fluctuate within the range of rated slip (1%~5%) when the motor is running with load. For the requirement that the speed regulation accuracy is relatively high, even if the load is changed, it is required to operate at a speed close to a given speed, and an inverter (optional) having a PG feedback function can be used.
8. What are the meanings of the models that can be given separately for the acceleration time and deceleration time, and the acceleration and deceleration time?
Acceleration and deceleration can be given separately. It is suitable for short-time acceleration, slow deceleration, or for small machine tools where the production tact time is strictly required. However, for fan drive and other occasions, the acceleration/deceleration time is longer. The acceleration time and deceleration time can be given together.
9. What is regenerative braking?
When the motor is lowered during operation, the motor becomes a non-synchronous generator state and operates as a brake. This is called regenerative (electrical) braking.
10. How to get more braking power?
The energy regenerated from the motor is stored in the filter capacitor of the inverter. Due to the relationship between the capacity of the capacitor and the withstand voltage, the regenerative braking force of the general-purpose inverter is about 10% to 20% of the rated torque. If the optional brake unit is used, it can reach 50%~100%