What is dd frequency conversion direct drive?

Variable frequency direct drive is a motor designed for frequency converter. Driven by frequency converter, the motor can achieve different speeds and torques to adapt to the change of load demand.

The frequency conversion motor is developed from the traditional squirrel-cage motor, and the traditional motor fan is changed into an independent fan, which improves the insulation performance of the motor winding. Ordinary squirrel-cage motor can be used to replace low-demand occasions, such as low power and low frequency working at rated working frequency.

The motor is fully enclosed and air-cooled, with the protection grade of IP55, and the materials and technology meet the requirements of environmental protection. The motor has high mechanical strength, durability and strong corrosion resistance. The winding has good reliability, adopts F-class insulation structure and passes B-class evaluation. And PTC thermistor or thermistor switch can be added according to user's needs.

The power range of series motors is from 0.25 kW to 3 15 kW, and the center height range of the frame is from 7 1 mm to 355 mm It can be widely used in industries that need speed-regulating rotating devices, such as light industry, textile, chemical industry, metallurgy and machine tools, and is an ideal speed-regulating power source.

Extended data

In the structural design of variable frequency motor, the influence of non-sinusoidal power supply characteristics on insulation structure, vibration and noise cooling mode of variable frequency motor is mainly considered, and the following problems are generally paid attention to:

1) Insulation level, generally F level or higher, strengthen the strength of ground insulation and turn-to-turn insulation, especially considering the ability of insulation to withstand impulse voltage.

2) Regarding the vibration and noise of the motor, we should fully consider the rigidity of the motor parts and the whole, try our best to improve its natural frequency, and avoid the phenomenon that every force wave vibrates.

3) Cooling mode: Forced ventilation cooling is generally adopted, that is, the cooling fan of the main motor is driven by an independent motor.

4) Measures to prevent shaft current, bearing insulation measures should be taken for motors with capacity exceeding 160KW. It is easy to produce magnetic circuit asymmetry and shaft current. When the current generated by other high-frequency components works together, the shaft current will increase greatly, resulting in bearing damage, so insulation measures are generally taken.

5) For constant-power variable-frequency motors, when the speed exceeds 3000 rpm, special high-temperature grease should be used to compensate the temperature rise of bearings.

Baidu encyclopedia-variable frequency electric machinery