Suppliers of energy feedback devices for frequency converters remind you that with the continuous improvement of industrial automation, frequency converters have also been widely used. Energy conservation and environmental protection are the core of China's industrial economic development. While pointing out the direction for the sustainable development of China's industry, they are also effectively driving the sustainable development of China's frequency converter industry, continuously expanding its market share and becoming an important foundation for the development of China's industrial economy with strong development power.
Variable frequency energy-saving is mainly used in situations where it is necessary to change the driving mechanical characteristics by implementing changes in the speed of AC motors to meet production process requirements, and is more commonly applied in fans and water pumps. When the motor can only operate at rated speed, its driving machinery can only operate at a certain rated speed.
1. Speed regulation of ordinary motors:
By changing the input voltage and frequency of a three-phase asynchronous motor, its speed can be controlled. When a regular motor is running at low speed, the efficiency of the cooling fan decreases and the temperature rise increases. Therefore, the motor load should be reduced according to the frequency.
2. Capable of high-speed operation:
The frequency of a typical power supply is 50Hz, which is fixed and unchanging. The output frequency of the frequency converter can reach up to 650Hz (EH600A series). The maximum output frequency of the EH600H series can reach 1500Hz.
General motors cannot achieve high speed simply by increasing frequency, and mechanical strength must also be considered. At high speeds, the carrier frequency of the frequency converter is high, and the frequency converter needs to be reduced in capacity.
3. Capable of soft start and soft stop:
The acceleration and deceleration time of the frequency converter can be set arbitrarily between 0.1-6500.0 seconds. The frequency converter needs to be set with appropriate acceleration and deceleration time during operation.
4. Quick and accurate start stop:
The starting current is small, and the motor generates less heat. Capacity determines acceleration and deceleration time, and the capacity level of the motor and frequency converter should be increased to adjust the proportional relationship between acceleration and deceleration time and load.
5. Easy to achieve forward and reverse rotation:
Switching is carried out by IGBT, so the losses of the original contactor disappear and reliable interlocking operation can be carried out. When used for elevators, a motor with a brake should be used, and a mechanical holding mechanism should be provided when changing direction.
6. Capable of electric braking:
Due to the ability to convert mechanical energy into electrical energy within the frequency converter during deceleration, the motor will automatically brake. Applying DC braking to the motor at zero speed can quickly stop the freely running motor. The frequency converter only has 20% braking force. When increasing braking force, an additional braking unit and braking resistor are required. A frequency converter with a built-in braking unit only requires an external braking resistor.
7. Motor speed regulation for harsh environments:
Due to the availability of three-phase asynchronous motors, explosion-proof, submersible, or special shaped motors can be conveniently used. Explosion proof motors should be matched with frequency converters for explosion-proof testing and certification. The universal frequency converters produced by our company are not explosion-proof.
8. A frequency converter can control the speed of multiple motors:
The frequency converter can adjust the speed of multiple motors simultaneously. The rated current of the frequency converter should be greater than 1.1 times the total current of the motor. At the same frequency, the speed of asynchronous motors may vary due to different characteristics and loads. At the same time, each motor should be protected by a heating overload relay.
9. The power capacity during motor start-up does not need to be too large:
Unlike the high starting current (5-6 times the rated motor) of a power supply, the maximum rated motor current during variable frequency starting does not exceed 100-150%.