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Rotary Screw Air Compressor (Variable Speed Drive)

VSD Series Rotary Screw Air Compressor

It is not recommended that you run your rotary screw air compressor at one fixed speed continuously. In your industrial process, there are hours throughout the day when the work load is very small, and large amounts of compressed air will go to waste. Due to that, don't assume that your 95% efficient air compressor works better than one with 85% efficiency, as the first is more likely to waste energy when running at small loads. To fix this issue, add a variable speed drive to the compressor, so the unit can vary its speed to match real-time load requirements.

As the VSD series rotary screw air compressor equipment is designed with a variable speed drive, it can deliver air on demand and save anywhere from 25-35% of your electricity costs each month. Whenever a required air supply during your day or night shift changes dramatically on your production line, this air compressor system can adjust its working speed in response.

Unique Structural Design
1. Both the motor and the rotary screw produce intense heat during their operations. Due to that, we build two heat sources separately to reduce the risk of the motor stators losing their magnetic power under high temperatures. This unique design brings a longer service life of the motor by reducing repair times.
2. Optimized pipeline arrangements, seals and protections all keep the compressor running efficiently, and without failure.
3. Designed to be easy to use, the compressor requires very little effort to install, operate and maintain.

Significant Energy Savings

1. Continuous flow control
2. Load/No Load Control
3. VSD
4. Energy efficiency
5. Load

The above picture is a load-speed graph, which indicates the energy saving performances of the VSD air compressor.

Woyo Rotary Screw Air Compressor Control Mode

1. Standalone control
2. Pre-set value
3. Real-time value
4. Air compressor
5. Pressure system

6. Inline control
7. start/stop
8. Pressure
9. Fluctuation in pressure 2%
10. Time

Based on the real-time air pressure inside the compressor chamber, the servo drive will automatically adjust the working speed to keep the unit working at its peak performance and ensure a consistent air pressure output.

The motor driver and starter come with feedback sensors to monitor the operating status on the go. According to these feedbacks, the motor control system automatically makes changes to ensure a constant air pressure output.

Full Load Current

1. Full load current
2. Wye-delta starting
3. Direct starting
4. Soft starting
5. VSD


1. Absolute torque
2. Motor torque (for wye-wound motor)
3. Motor torque (for delta-wound motor)
4. Air compressor torque
5. VSD torque
6. Rotary speed

Woyo's variable speed drive air compressor uses a wye-delta starter rather than a soft starter to ensure a smoother and more stable motor startup without causing current or voltage spikes. This eliminates shock load conditions during the motor's startup that might damage the moving parts in the compressor. This all leads to a longer service life of the rotary screw.

Technical Specifications

Model Code Motor Power
Working Pressure
Volumetric Flow Rate
Noise Level
Dimensions/Air Inlet Size
(L×W×H MM)/G
VSD11-7 11 7.5 0.41-1.60 70 370 800×700×950G3/4
VSD11-8 8.5 0.39-1.50
VSD11-10 10.5 0.33-1.35
VSD11-12.5 12.5 0.26-1.20
VSD15-7 15 7.5 0.58-0.25 72 450 870×850×1320G1
VSD15-8 8.5 0.54-2.35
VSD15-10 10.5 0.46-2.20
VSD15-12.5 12.5 0.38-1.80
VSD18-7 18.5 7.5 0.64-3.10 73 480 870×850×1320G1
VSD18-8 8.5 0.58-2.85
VSD18-10 10.5 0.54-2.60
VSD18-12.5 12.5 0.44-2.20
VSD22-7 22 7.5 0.74-3.60 75 510 870×850×1320G1
VSD22-8 8.5 0.70-3.30
VSD22-10 10.5 0.64-3.15
VSD22-12.5 12.5 0.54-2.70
VSD30-7 30 7.5 1.12-5.20 75 900 1130×1110×1400G1-1/2
VSD30-8 8.5 1.08-5.00
VSD30-10 10.5 0.64-3.15
VSD30-12.5 12.5 0.54-2.70
VSD37-7 37 7.5 1.36-6.70 76 950 1130×1110×1400G1-1/2
VSD37-8 8.5 1.30-6.40
VSD37-10 10.5 1.16-5.80
VSD37-12.5 12.5 0.92-4.60
VSD45-7 45 7.5 1.62-7.90 77 1000 1130×1110×1400G1-1/2
VSD45-8 8.5 1.56-7.50
VSD45-10 10.5 1.40-6.90
VSD45-12.5 12.5 1.16-5.80

**Note The above data is for reference only. We can customize rotary screw air compressors based on a customer's specific needs

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