what is a variable frequency drive? how does it save · pdf filewhat is a variable frequency...
TRANSCRIPT
What is a Variable Frequency Drive?
How does it save energy?
Jason Fahey
EnSync Inc
10-12-2016
How does a VFD Work How does a VFD Work
Fixed Voltage
Fixed Frequency
Line
Voltage
AC/DC
DC Bus
DC/PWM
Motor
Drive Block Diagram
AC AC (PWM) DC
CONVERTER INVERTER
Variable Voltage
Variable Frequency
B+
B-
The VFD first CONVERTS AC to DC This is done in the “Converter Section”
B+
B-
DC is then INVERTED to Pulse Width Modulation (PWM) This is done in the “Inverter Section”
B+
B-
Today's VFDs are PWM style drives
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
+650VDC
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
0VDC
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
-650VDC
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
0VDC
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
RECTIFIER
Positive
DC Bus
Negative
DC Bus
+
-
INVERTER
Area Under The Square-Wave Pulses
Approximates The Area Under A Sine Wave
Frequency
Vo
lta
ge
“Electric motors and the systems they drive are the single largest electrical
end‐use, consuming more than twice as much as lighting, the next largest
end‐use. It is estimated that EDMS account for between 43% and 46% of all
global electricity consumption…” Paul WaIde and Conrad U. Brunner, International Energy Agency, 2011
A centrifugal fan is a mechanical device
for moving air or gases. It has a fan
wheel composed of a number of fan
blades mounted around a hub.
A centrifugal pump is a rotodynamic
pump that uses a rotating impeller to
increase the pressure of a fluid.
100% Supplied 70% Needed
70% Supplied 70% Needed
100% Supplied 70% Needed
70% Supplied
70% Needed
Q N flow rate proportional to
rotary speed
H N2 head (pressure) proportional to
rotary speed squared
P N3 power proportional to
rotary speed cubed
Large decrease in power
requirement for relatively
small decrease in flow
The opportunity is significant
“In the United States, an estimated 60-65% of
electrical energy is used to supply motors,
75% of which are variable-torque fan, pump
and compressor loads.” ~Wikipedia
Ameren Illinois Energy Efficiency Program Incentives:
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• Variable Frequency Drives
• Pumps and Fans up to 500hp
• $115/hp controlled
• Visit Actonenergy.com/vfd-incentives
Ameren Illinois Energy Efficiency
Program Energy Advisors
Call 1.866.800.0747
to request a consultation with an
Energy Advisor
1. Chad Whitehead [email protected] 309.620.6333 2. Steven Smith [email protected] 309.212.5831 3. Rod Rhoads [email protected] 217.649.8897 4. Mark Steinmetz [email protected] 217.670.9606 5. John Strode [email protected] 309.370.0062 6. Fred Joshu [email protected] 309.433.4316 7. Larry Erwin [email protected] 309.838.2340
Questions?
26
Jason Fahey
Vice President
En-Sync Group, Inc.
www.ensyncinc.com
