© ABB Group May 23, 2013 | Slide 1
Energy Savings attainable by the implementation of Variable Speed Drives Daniel Mancin, Market Development Manager, HVAC & Energy
AIRAH VICTORIA PRESENTATION, MAY 2013
THE ENERGY DILEMMA If the World demand for non-renewable fossil fuels continues at the current rate,
our existing resources will be exhausted in a relatively short time.
Increasing levels of Carbon Dioxide are leading to atmospheric warming and associated changes to our environment.
Although new, clean sources of energy are being investigated, they will not be viable for some time.
TAKING ACTION
In the short to mid term, Industry, commerce and society in general needs to consider current products and technologies that can reduce our energy usage quickly and cost effectively.
Variable Speed Drives (VSD) are a device that can dramatically reduce absorbed energy on given applications with minimal “cutting in” and downtime.
© ABB Group May 23, 2013 | Slide 3
THE ABB AC VARIABLE SPEED DRIVE RANGE
STANDARD DRIVES
ACS550
0.75 to 355 KW COMPONENT DRIVES
ACS55 – ACS150
0.18 to 4 KW
MACHINERY DRIVES
ACS350 – ACSM1
0.37 to 45 KW
INDUSTRIAL DRIVES
ACS800
0.55 to 5,600 KW
- LV & MV
- LOW HARMONIC DRIVES
- REGENERATIVE DRIVES
- DRIVE MODULES,
- SINGLE DRIVES,
- MULTI-DRIVES
HVAC DEDICATED
DRIVES
ACH550
0.75 – 355 KW
MV INDUSTRIAL DRIVES
ACS1000 ACS5000 ACS6000 LCI. SO / ST
0.3 to 5.0 MW 1.7 to 24.0 MW 3.0 to 27.0 MW 4.0 to 100.0 MW
ENERGY OPTIMIZATION LOAD TYPES
It is necessary to determine the “type of load” ie load characteristic
thereby confirming likely energy saving potential!
The two basic load types are:
- Constant Torque
- Variable Torque (Quadratic Load)
- Laws of Affinity applicable
- Q = Flow
- Q1/Q2 = N1/N2 H1/H2 = (N1/N2)2 P1/P2 = (N1/N2)3 N = Speed
P = Power
H = Pressure
LOAD PROFILES
Variable / Quadratic Torque
Constant Torque
P = T x w
SYSTEMS KNOWLEDGE
A clear and full understanding of existing system / plant operation is of paramount importance, governing factors include:
What are the operating pressures of the system? (Industrial boiler feed systems)
Is the system inheritantly quadratic / constant torque or something in between?
Is the system suitable for VSD control? An example of this would be is the design intent
of system based on static pressure or velocity pressure!
Are the losses in system frictional or head (lift) or combination of both?
Is the system an “open” or “closed” system
Is the reduced running speed (and hence energy saving) known or can it be determined
by a trial?
Is there a single pump in system or varying multiples in parallel?
Will equipment resonance occur within desired speed regulation range?
Ramifications of incorporating VSDs into system, i.e. DX systems, oil lubrication,
minimum motor speeds etc?
CONTROL METHODS
To enable and maximise the energy savings attainable through the use of VSDs to be realized, it is of equal importance to carefully consider the VSD control method(s) used, considerations include:
What do we want to measure? Flow, pressure,
temperature, parts per million(ppm), velocity etc.
OR a combination.
Location of sensor(s) in system.
Number of sensors in system.
Utilization of full bore flowmeters.
Will preset speed drop offs (digital) suffice OR
will infinite (analogue) speed adjustment be required.
Set and forget.
Local manual speed adjustment via keypad on VSD
FACTORS INFLUENCING ENERGY SAVING POTENTIAL
Load type
Overdesign / parallel pumping /
load profile
Running hours
Cost of electricity
Motor size / running current
PRIMARY PUMPING
PRIMARY / SECONDARY SYSTEMS
Constant Air Volume System (CAV)
Typical centrifugal pump curve
VSD operation overlay
VSD operation overlay
VSD IMPLEMENTATION CONSIDERATIONS
EMC (Electromagnetic compatibility) also known as
RFI (Radio Frequency Interference) AS61800-3-2005
Harmonics AS61000
Motor windings insulation quality
Motor minimum operating speed
Bearing Currents
Motor cable length / Sinusoidal filters
IP ratings
Starting Current – load
Running current Vs motor nameplate current
Hardwired Interface / High Level Interface
Multiple Motors
© ABB Group May 23, 2013 | Slide 16
Summary
As we have seen, there is a diverse range of applications where the many benefits of implementing Variable Speed Drives can be realized.
Should you wish to discuss / ascertain likely benefits to your specific plant, feel free to contact:
Daniel Mancin
Market Development Manager HVAC, Water and Energy
Mobile: 0408 960 812
Phone: 03 85777102
Fax: 03 85777004
Email: [email protected]
