Variable frequency drive
Powerful, compact variable frequency drives
Since 1984, Nord Electronic Drivesystems has been developing and producing electronic drive technology in our own factory in Aurich, Germany. With our extensive know-how and large production capacity, we offer our customers optimum quality and short delivery times for variable frequency drives and motor starters as part of a comprehensive modular range of drive components.
What are variable frequency drives for?
Since the 19th century, electric motors have been used for many purposes. However, they only obtained one important feature with the arrival of the first variable frequency drives in the late 1960s: flexible speed control.
If an electric gearmotor is operated with a constant AC voltage (usually single-phase, 230 volts / 3-phase, 400 volts with a frequency of 50 Hz), its speed is fixed. Variable speeds, for example to vary the volume flow of a pump or to deliberately start a drive slowly, are not possible.
The variable frequency drive is connected between the supply network and the motor. The AC voltage from the network is converted to a high DC voltage by means of the electronics (rectifiers) in the variable frequency drive. From this DC voltage, any required output voltage can be generated using electronic circuits (inverters).
With the aid of these electronic circuits, the variable frequency drive flexibly changes the voltage and frequency at the motor connection, so that the speed of the electric motor can be variably controlled. Modern variable frequency drives from NORD DRIVESYSTEMS® can do this so perfectly, that a three-phase motor can be controlled with relatively high precision, just like a servo motor – from standstill to full speed and from left and right rotation without having to reverse the polarity of the motor.
NORD® inverters have many other intelligent functions and an integrated PLC, and electronically monitor a large number of status parameters for the drive. With this, they have become intelligent control units for electric drive units in all sectors of industry and logistics: Drives for fans, blowers, pumps, cranes, conveyor belts, production machines, machine tools, mixers and agitators, as well as for intralogistics applications for dispatch, transport and travel. Variable frequency drives are an important prerequisite for optimized, automated and energy-efficient production processes.
What types of variable frequency drives does NORD® supply?
With the NORDAC® PRO device series, NORD DRIVESYSTEMS® provides classic control cabinet inverters, which are centrally installed in a closed control cabinet. They cover power ranges of up to 160 kW. Therefore, large and small gearmotors can be used in centralized plant designs. These variable frequency drives are the optimum solution if the entire control technology of a plant is to be monitored from a central point such as a control center.
In parallel, decentralized drive technology is becoming increasingly popular. It can be installed directly on the relevant drive or, for better accessibility due to the space available, in the immediate vicinity of the drive. The NORDAC® FLEX is ideal for extensive plant designs with a large number of drives and long cable routes. This is the case for example in warehouse and logistic installations or complex production plants. Decentralized drive technology is also ideal for the direct control of sensors and actuators in the field.
For usage scenarios in which a large combination of connection and extension options on the variable frequency drives and the use of additional peripherals such as encoders, sensors or actuators are needed, our NORDAC® LINK motor starters SK 155E and the NORDAC® LINK variable frequency drive SK 250E are the right choice thanks to their optimized connection configurations for installation close to the drive within the plant.