According to Sustainability Victoria, it is estimated that electric motors account for nearly 30% of total energy consumption in Australia across all industries, from pumps moving fluids to fans moving air to compressors, conveyors, and every type of machine that depends on rotational force to get its job done, highlighting the important role that electric motors play in our everyday lives, whether it’s personal or business-related.
Motors can result in inefficiency when the electricity consumed is not aligned with the required power (speed and torque). This leads to wasted materials and energy. Maximising the efficiency of this equipment is integral to meeting not only industry but government targets to achieve net zero emissions, globally.
What is a variable speed drive?
IPD offers ABB’s variable speed drives (VSD) as a critical tool for increasing motors’ energy efficiency. The VSD’s basic function is to control the flow of energy from the mains to the process. The VSD sits between the electrical supply and the motor, where power from the electrical supply is fed into the drive, and the drive regulates the power fed to the motor.
How do variable speed drives regulate power?
1. Convert incoming AC to DC
The input power is run through a rectifier that converts the incoming AC power to DC power.
2. Smooth the DC wave
The DC power is fed into the capacitors inside the drive. This effectively smooths out the electrical waveform which provides a clean DC power supply.
3. Convert DC to variable AC
The VSD calculates the motor’s required voltage and current. The DC power is fed into an inverted producing AC power at the precise voltage and current needed.
4. Calculate and repeat
The VSD continuously calculates and adjusts the frequency and voltage in alignment with the required power (speed and torque).
What are the benefits of using variable speed drives?
- Optimised energy efficiency
ABB’s variable speed drives allow you to run your AC motors in alignment with the power (speed and torque) requirements of the task, therefore reducing wasted energy and materials. The VSD efficiently reduces power consumption by 25%. Through this reduced power consumption, we are able to lower energy consumption, which helps to cut emissions from greenhouse gases, whilst saving more than 39 tonnes of emissions annually (Sustainability Victoria 2022)
- Improved operational efficiency
The use of VSDs generates labour cost savings by eliminating the need for manual labour. By investing in an automated system, you will have the ability to reduce your downtime, in comparison to the standard process to operate, in which it could take one person up to an hour to start a pumping station.
- Savings in capital expenditure
With a rapid reduction in electrical consumption, the total cost of ownership will be reduced, and the return on investment for the installation of a variable speed drive for pump and fan applications will be visible within months. By reducing the motor speed in an application by 25% or greater, you will lower your operating costs by more than 50%, potentially saving $10,000 annually depending on your application (Sustainability Victoria 2022)
- Savings in maintenance costs
Maintenance for your VSD is critical to your operations, as stress on the mechanical equipment during startup and operation will cause deterioration over time. Through regular maintenance, you will reduce your overall downtime and total cost of ownership, by increasing the lifecycle of the equipment.
To conclude, the use of ABB’s variable speed drives is an optimal solution to maximise energy efficiency to benefit not only business operations but also the external environment.