Find out in this e-book how a VSD can work for your business.
VSD stands for variable speed drive. Hidden behind these letters is (inverter) technology that automatically adjusts the compressor’s motor speed to the compressed air demand in real-time. This often saves a lot of energy and money. In fact, depending on which type of VSD compressor you use, energy consumption can drop by up to 60%.
To understand the operating principle of a VSD compressor, let’s first look at its different components.
The motor and inverter
The variable speed drive adjusts the compressor’s speed (RPM) by means of an inverter. Instead of sending all the power directly into a traditional AC motor that runs at full capacity, the inverter provides the VSD compressor only with the specific frequency required to meet the current demand. And that can save a lot of energy.
The element
Rotary screw compressors are best suited to take advantage of the benefits of VSD technology. The reason is that a rotary screw compressor’s flow rate and power consumption are virtually proportional to speed. Therefore, as the motor adapts its speed to reflect the current demand, the rotary screw elements adapt in sync so the amount of compressed air being delivered matches that demand.
Some manufacturers offer retrofitted fixed-speed compressors with an add-on inverter as VSD units. These compressors should come with a disclaimer. To get the most out of VSD technology, a compressor must be designed, built and tested as a VSD compressor. All components, not just the inverter, must work together to deliver maximum energy savings and a reliable operation. That is why Atlas Copco VSD compressors so clearly outperform the pretend ones. Because only a dedicated design and custom-built, quality components will get the most out of VSD technology.
The brain
Obviously, as a smart technology, a VSD compressor also requires a “brain.” In the case of Atlas Copco VSD compressors, that is the Elektronikon® on-board controller. Sensors continually measure system pressure, temperature, and in the latest premium VSD comp even relative humidity. In response to this data, the system adjusts the motor speed to meet the actual air demand.
The main benefit of using a VSD compressor is that it can drastically reduce your energy costs and therefore save you a lot of money.
However, the technology has other advantages as well. Here are a few:
1. A VSD compressor can start/stop under system pressure. There is no need to unload, which saves both time and energy.
2. No time is lost to idling.
3. No blow-off losses occur in normal operations.
4. You can avoid power company penalties for peak current at startup.
5. The air system pressure is more consistent, and leakages can be minimized.
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