“It’s What’s Inside that Counts”
Drive Basics
© ABB Inc. - slide 2
Product Overview
Adjustable Frequency Drive Description:
„
Solid State Device
„
Controls the Frequency and Voltage
„
Speed Range Depends on the Motor
„
HP Range - Fractional to 10,000
Drive Basics
© ABB Inc. - slide 3
Product Overview
Why Use Adjustable Speed Drives?
„
Soft Start Capability
„
Allows for Process Changes
„
Improves Product Quality
Drive Basics
Adjustable Frequency Drive Definition (AFD):
© ABB Inc. - slide 4
Product Overview
„
An Adjustable Frequency Drive controls an AC motor. It
converts the incoming line constant voltage and
frequency to an adjustable voltage and frequency. The
adjustable voltage and frequency is applied to a squirrel
cage induction motor.
Drive Basics
© ABB Inc. - slide 5
Product Overview
AFD Capabilities:
„
Controllable Acceleration
„
Controllable Deceleration
„
Controllable Speed
„
Torque Limiting
„
Inrush Current Limiting
Drive Basics
© ABB Inc. - slide 6
Product Overview
AFD Capabilities (Continued)
„
Controlled Jog / Thread
„
Electronic Overload
„
Programmable Settings
„
Output Contacts and Signals
„
Multiple Control Methods
Drive Basics
© ABB Inc. - slide 7
Product Overview
How Do Induction Motors Work With Drives?
„
Control of Speed and Torque
„
Control of Frequency and Voltage
Drive Basics
© ABB Inc. - slide 8
Product Overview
Advantages:
„
Uses Squirrel Cage Motor
„
High Input Power Factor
„
Low Operating Cost
„
Soft Start and Stop
„
Easy to Retrofit
Drive Basics
© ABB Inc. - slide 9
Product Overview
Advantages (continued):
„
Multiple Motor Capability
„
Electronic Reversing
„
Master Reference Capability
„
Closed Loop Capability
„
Bypass Capability
Drive Basics
© ABB Inc. - slide 10
Product Overview
„
Why Use Adjustable Speed Drives?
„
Reduced Energy Consumption
„
Improved Process Control / Efficiency
„
Increased Product Quality
„
Expanded Automation / Integration
„
Broader Equipment Flexibility / Versatility
„
Increased Reliability / Availability
„
Reduced Maintenance
$
Drive Basics
Typical Adjustable Speed Drive Configuration
Variable
Power
(AC or DC)
Utility
Power
Adjustable
Speed Drive
Variable
Speed
Motor(s)
Appropriate Feedbacks
© ABB Inc. - slide 11
Product Overview
Process
Reference
Variable speed is used to replace
inefficient mechanical regulator devices
such as valves, dampers, clutches, etc.
Process
Output
Process
Equipment
© ABB Inc. - slide 12
Product Overview
VS Drives Process Advantages
„
Speed vs. mechanical control ⇒
Increased process efficiency,
Reduced energy usage,
Lower operating costs
„
Accurate speed regulation ⇒
Increased flow / volume accuracy,
Product quality improvement
„
Dynamic Speed Response ⇒
Minimized process disturbances,
Product quality improvement
„
Higher input power factor ⇒
Lower operating costs
Applications, Types
© ABB Inc. - slide 13
Product Overview
Primary
Focus
„
Constant Torque
„
Constant Horsepower
„
Variable Torque
Applications, Types
© ABB Inc. - slide 14
Product Overview
Variable Torque Loads
„
Fans
„
Centrifugal Pumps
„
Centrifugal Blowers
„
Mixers (material dependent)
Applications, Types
Variable Torque
100%
Flow varies linearly
with speed
90%
% Flow, % Torque, % Power
80%
70%
60%
Torque requirement varies
as the square of speed
50%
40%
30%
20%
Power requirement varies
as the cube of speed
© ABB Inc. - slide 15
Product Overview
10%
0%
0
10
20
30
Frequency (Hz)
40
50
60
Applications, Types
© ABB Inc. - slide 16
Product Overview
Conventional Flow Control
Bypass
Outlet
Inlet
Inlet Vane
Applications, Fans and Blowers
Outlet Control - Operating Points
140
Throttled System Curves
120
Operating Points
100
%
Pressure
80
Fan Curve
60
40
Design System Curve
© ABB Inc. - slide 17
Product Overview
20
0
20
40
60
80
% Flow
100
120
140
160
Applications, Fans and Blowers
Outlet Control - Power Requirement
100
80
%
Input
Power
60
40
Relatively small decrease
in power requirement for
large decrease in flow
20
© ABB Inc. - slide 18
Product Overview
0
20
40
60
% Flow
80
100
120
Applications, Fans and Blowers
Variable Speed - Operating Points
140
120
Operating Points
Design System Curve
100
80
%
Pressure
Rated Speed
Fan Curve
60
40
Reduced Speed
Fan Curves
© ABB Inc. - slide 19
Product Overview
20
0
20
40
60
80
% Flow
100
120
140
160
Applications, Fans and Blowers
Variable Speed - Power Requirement
100
80
%
Input
Power
60
Large decrease in power
requirement for relatively
small decrease in flow
40
20
© ABB Inc. - slide 20
Product Overview
0
20
40
60
% Flow
80
100
120
Applications, Fans and Blowers
Power Requirement Comparisons
100
Outlet
80
%
Input
Power
Inlet Vane
60
Variable Speed
40
20
© ABB Inc. - slide 21
Product Overview
0
20
40
60
80
% Flow
100
120
Applications, Economic Justification
Representative Sample:
„
Fan, Variable Speed vs. Damper Control
© ABB Inc. - slide 22
Product Overview
Three Criteria:
„
Energy Usage
„
Efficiency Improvement
„
Annual Savings
Applications, Economic Justification
© ABB Inc. - slide 23
Product Overview
Base Assumptions :
„
Full rated flow = 178,000 CFM @ 3 “H2O
„
Fan / blower efficiency = 85%
„
Motor efficiency = 94%
„
Drive efficiency = 98%
„
Rated shaft power = 100 hp
„
Cost per kWh = $ 0.10
Applications, Economic Justification
Fan Energy Usage
Variable Speed vs. Damper Control
800
700
Energy Usage (MWh)
600
500
Variable Speed
Damper
400
300
200
© ABB Inc. - slide 24
Product Overview
100
0
30%
40%
50%
60%
70%
Flow
80%
90%
100%
Applications, Economic Justification
Fan Efficiency Improvement
Variable Speed vs. Damper Control
70%
60%
Efficiency Improvement
50%
40%
30%
20%
10%
© ABB Inc. - slide 25
Product Overview
0%
30%
40%
50%
60%
70%
(10%)
Flow
80%
90%
100%
Applications, Economic Justification
Fan Annual Savings
Variable Speed vs. Damper Control
$35,000
$30,000
$25,000
Savings
$20,000
$15,000
$10,000
$5,000
© ABB Inc. - slide 26
Product Overview
$0
30%
40%
50%
60%
70%
($5,000)
Flow
80%
90%
100%
“It’s What’s Inside that Counts”