Variable Speed Drives

To Know About Variable Speed Drives

 

Drives on the speed of electric motors that operate at the controlled frequency (AC) motor.
Other names for these drives, air conditioning, Micro Drive, and frequency converters.

They are used in industrial applications, such as units of machine tools, elevators, conveyors, pumps.
When the induction motor is the maximum load that is on a couple of times base (about 6 times) the rated current. Since the charge is accelerated, the torque is usually a little and then increases, although the current remains high until the motor reaches full speed.

Then the motor VFD is essentially a low-frequency and voltage to the motor. The first frequency of 2 Hz or less. This low level to avoid high inrush current when the engine is started with a lightweight tool (net) operating the switch. accelerate after the departure of the VFD, and often the stress at a certain speed and on-site to share the load without too much power. This method can usually starts at 150% of rated torque of the motor and the VFD less than 50% of the rated voltage power deserve to grow at the bottom. VFD can be configured to receive constant torque of 150% of full speed attack. Note [16], however, that the engine cooling system is generally not well at low speeds. Therefore, the use of low speed and torque for a long time is not possible to assess, since the engine to overheat. If the continued use of high torque at low speed fan outside is often necessary. The engine manufacturer and / or VFD sets the cooling mode. 

Inverter is in voltage and current for most engines are functioning public services (net) of energy. VFD controller designed to operated at 111 V to 690 V classified as low-voltage devices. Low-voltage switchgear is designed for smaller engines, 0.2 or 1.4 kW (CV), a few megawatts. estimated, for example, the reader is most ACS800 5.6 MW [21]. Medium voltage VFD controllers designed to in 2400 / 4162 operating V (60 Hz), 3.000 V (50 Hz) or 10 kV. In some applications, the transformer in the unit and the medium voltage drop will be placed. Medium voltage drives are designed for smaller engines provide 375 kW or 500 hp or more. Units of medium-voltage rating of more than 7 kV and 5000, or 10,000 miles, it is likely to be exceptional (once) models are considered [22]. 

Medium voltage drives are generally classified as one of the following voltage: 2.3 kV - 3.3 kV - 4 kV - 6 kV - 11 kV
These two, the voltage is usually possible. SN units are typically about 0.3 to 100 MW, but the broad involvement of multiple devices with different technologies.

There are too many travel providers, we propose a supplier of information about the manufacturer of backup and excellent technical support is available. Drives are not cheap to buy, and always worth a look, as some retailers offer discounts up to 20% of the drives .