1. Energy Saving Concepts with Variable Speed Drives
Automation and Drives
Energy Saving Concepts with
Variable Speed Drives
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2. Presentation of Lenze
Solutions for drives and automation technologies for manufacturing machines and logistics facilities with:
Frequency inverters
Servo drives
Geared motors
Decentralized drives
Automation
3.200 employees worldwide, thereof approx in Germany
Revenue of 505 mEUR in 2008/09
Established in 1947 in Hameln
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3. Overview Presentation of Lenze Motivation for higher energy efficiency
The role of drive technology
Three ways to increase energy efficiency in drives
Evaluation by life cycle costs
Path breaking drive solutions to save energy
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4. Lenze‘s markets Machine building with focus on: Conveyor techniques
Robotics/Automotive
Material Handling
Packaging
Printing
Highly automated manufacturing and logistics systems
especially for consumer goods
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5. Motivation for higher energy efficiency
Two motivations for a higher energy efficiency
reduction of CO2 emissions due to the climate change
rising energy costs due to limited resources and worldwide rising energy consumption (industrialization of emerging countries)
Energy production from renewable sources (wind, solar, biofuel) needs high invests and political decisions
Compared to this, saved (not-used) energy is the most cost effective energy source
Actions towards a higher energy efficiency can be adopted by everyone, products and concepts are already available
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6. The role of drive technology
Drives convert two thirds of electrical energy in industry
A reduction of >20 percent can be achieved by energy saving solutions
Here, the whole drive system must be considered
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7. Three ways to increase energy efficiency in drives
Designing and dimensioning drive systems
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8. 1. Intelligently using energy
Energy efficiency = as little energy as necessary
Ways to increase energy efficiency
dimensioning as required
inverter controlled operation
energy saving motion control and control systems
An exact analysis of the application is required to intelligently use energy
The intelligent use of energy in a drive application has the highest energy savings potential by far
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9. 1.1 Exact dimensioning saves money and energy
Today‘s usual practice: over dimensioning for fear of malfunctioning
This happens although engineers ought to develop solutions in a cost-efficient way
In partial load operation, drives often have a low level of efficiency. Example:
0,75 • PN → η = 75%
0,35 • PN → η = 45%
Therefore, dimensioning as required saves money and energy from the first moment
Lenze’s Drive Solution Designer and its “Energy Performance Certificate” result in an exact drive dimensioning
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10. 1.2 Inverter controlled operation
The energy consumption of most processes depends on the current ambient and operating conditions
e.g. cooling/heat requirements is dependent on the ambient temperature
e.g. conveying speed is dependent on the rate of production
An uncontrolled motor can only adjust its torque
A speed controlled drive including an inverter can adjust speed and torque (= power)
An inverter can optimize the operating point and the motion profile of the drive
Almost every process benefits from using an inverter
In 10 to 15 years from now, every drive will be driven by inverters
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11. 1.3 Energy efficient control and motion
The use of an inverter offers further savings potential:
Voltage reduction under partial load operation
Acceleration adjustment to the required dynamics
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12. 2. Convert energy at a high level of efficiency
Inverters already have a high level of efficiency of 94% to 97%
Level of efficiency of standard three-phase AC motors of the EFF2 efficiency class (IE1): 75% to 85% at 1…10 kW
Losses can be reduced by one third by using motors of the EFF1 efficiency class (IE2)
Useful in applications with long operating times and high continuous loads
Motor output in kW
Degree of efficiency in %
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13. 2.1 New standard for efficiency classes for electric motors
A world-wide standard for efficiency classes for motors was created (including CEMEP, EPAct, NEMA)
Standard IEC , valid since 2009
Efficiency classes and measurement methods have been harmonized
IE1≈eff2
IE2≈eff1
IE3≈Premium (EPAct)
Scope of the standard:
2-/4-/6-pole standard induction motors, 50 und 60 Hz operation
0,75…375 kW
continuous duty cycle (S1)
also valid for geared motors
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14. 2.2 Minimum efficiency classes for motors
Implementation of EUP directive
Will get pre-condition for CE marking for electric motors
Minimum efficiency class IE2 from for 0,75 … 375 kW
Minimum efficiency class IE3 or IE2 + inverter operation from for 7,5 kW … 375 kW
Minimum efficiency class IE3 or IE2 + inverter operation from for 0,75 kW … 375 kW
From 2015/2017 IE2 motors are only allowed to be operated by frequency inverters
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15. 2.3 Components with a high level of efficiency
Synchronous motors instead of asynchronous motors
No magnetizing current required
Lower currents and losses
A smaller inverter can be selected
Particularly useful in servo drives
Bevel gearboxes instead of worm gearboxes
Worm gearboxes have a very low level of efficiency
Due to the higher level of efficiency of the bevel gearbox, smaller motors and inverters can be selected
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16. 3. Using the feedback of braking energy
Many drives are moving material:
Accelerating and braking
Lifting and lowering
If a lot of braking energy is generated, it is worth while using the feedback of the braking energy
Frequent acceleration/braking of large masses
Lifting and lowering of large masses
Drives that are permanently operated in generator mode (e.g. unwinders, load drives)
Using braking energy by:
Power regeneration to the mains
Exchange of energy between two drives by DC link
Storing energy in a capacitor
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17. Evaluation by life cycle costs (LCC)
After a few years, the energy costs will be equal to the acquisition costs
Concepts with a higher level of energy efficiency are often amortized after two or three years
Evaluation by life cycle costs (LCC) is necessary
The following must act jointly
Component suppliers
Machine manufacturers
Machine operators
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18. The 12 drive solutions…
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19. …path breaking solutions to increase energy efficiency
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20. Flyer „Energy saving drive solutions“
Motivation for higher energy efficiency
The role of drive technology
Three ways to increase energy efficiency in drives
Evaluation by life cycle costs
The 12 drive solutions as path breaking solutions to increase energy efficiency (Chart with 12 solutions and 3 ways to increase energy efficiency)
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21. Summary Energy efficiency is the most cost effective energy source
Electrical drives are the most important consumers of electrical energy in manufacturing. A high energy saving potential of >20% can be achieved
There are three ways to increase energy efficiency in drives
Using electrical energy intelligently (75%)
Converting energy with a high degree of efficiency (15%)
Using the recovered braking energy (10%)
The evaluation of concepts with a higher level of energy efficiency is being carried out by life cycle costs
The 12 drive solutions are path breaking solutions to increase energy efficiency
Intelligent drive concepts can treat both environment and budget with care
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22. Thank you for your attention.
Fabio Trindade Paes
São Paulo – Brasil
11/16/2018