Transcript VFD_Session - kishorekaruppaswamy

RESOLVING TRANSFORMER NOISE
AND ELECTRICAL HARMONICS
PROBLEMS ASSOCIATED WITH DEEP
WELL PUMPING SYSTEMS
Craig Patterson, Project Engineer, Meurer & Associates
Paul D. Goldfain, Associate Principal, Meurer & Associates
Robert Anderson, Electrical Engineer, The RMH Group
David Kaunisto, District Manager, East Cherry Creek Valley
Water & Sanitation District
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East Cherry Creek Valley
Water & Sanitation District
2
East Cherry Creek Valley
Water & Sanitation District
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
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Approximately 50,000 population
10-15 MGD yearly range
Water Supply
– Arapahoe aquifer (1,500’ - 1,800’ deep)
– Laramie-Fox Hills aquifer (1,800’ – 2,300’
deep)
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Deep Well Installation
Diagram
480 Volts
UTILITY
TRANSFORMER
(XFMR)
480 Volts
VARIABLE
FREQUENCY
DRIVE
(VFD)
2300 Volts
STEP-UP
TRANSFORMER
SUBMERSIBLE WELL
PUMP AND MOTOR
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Deep Well Installation
Diagram
480 Volts
480 Volts
2300 Volts
VFD
PUMPING WATER LEVEL (PWL)
PUMPING WATER LEVEL (PWL)
1-YEAR
10-YEAR
5
Variable Speed Pumps
Head
3000
70 Hz
60 Hz
2000
10 Year PWL
50 Hz
1 Year PWL
0
0
200
400
Gallons Per Minute
600
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Discussion of Problem
– Power Factor
Power Factor is the percentage
difference between apparent and
actual power.
 The Electric utility requires at least
95%.

 P.S. SA-8 was 84%.
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Discussion of Problem
– Power Factor
 The current lags the voltage because
of motor load.
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Discussion of Problem
– Transformer Noise

Complaints from neighbors
about transformer noise.
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Transformers
Stepup
Utility
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Physical Muffling of
Transformer Noise by Fence
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Goal
Equipment combination that will:
Provide adequate power factor
Reduce noise to acceptable level
Provide operating flexibility to
meet varying demands.
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Electrical Analysis


RMH Group analyzed the power
systems at several pump stations.
They determined that problem was
caused by voltage and current
harmonics generated in the VFDs.
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Variable-Frequency Drive
Accusine
Active Filter
VFDs
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Variable Frequency Drive
6-step VFD voltage source output
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Electrical Harmonics
Graph of harmonics
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Electrical Harmonics
Graph of harmonics
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Harmonic Current Distortion
Well SL-10 VFD operating without Accusine
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Transformer Vibration
Core
Base connected to box
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How Noisy Is It?
decibels (dB)
Whisper
30
Light Traffic
40-50
Vacuum Cleaner
70
Garbage Disposal 80
Circular Saw
100
Rock Concert
110-130
Threshold of Pain 108-130
Jet Takeoff
140
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Decibels vs. Audible Noise
Decibels (dB)
Equipment Tested
 12-step or Pulse-Width Modulated VFD
– More frequent pulsing reduces distortion.
 Southwest Electric “Quiet” Transformers
– Larger core, rubber supports, sound proofing
 MTE load filter
(for PWM drive)
– Converts VFD output to sinusoidal wave
 Accusine “Active” filter
– Senses current, then gates just the right amount
of power through the filter to correct distortion.
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Transformer Vibration
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Harmonic Current Distortion
Well SL-10 VFD operating without Accusine
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Harmonic Current Distortion
Well SL-10 VFD operating with Accusine
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Accusine Installation Diagram
480 Volts
UTILITY
TRANSFORMER
(XFMR)
480 Volts
ACCUSINE
ACTIVE
FILTER
480 Volts
6-STEP
VFD
2300 Volts
STEP-UP
TRANSFORMER
SUBMERSIBLE WELL
PUMP AND MOTOR
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MTE Load Filter
Installation Diagram
480 Volts
UTILITY
TRANSFORMER
(XFMR)
PWM
(VFD)
480 Volts
480 Volts
MTE
LOAD
FILTER
2300 Volts
STEP-UP
TRANSFORMER
SUBMERSIBLE WELL
PUMP AND MOTOR
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Equipment Tests – P.S. SA-8/SL-8
6-Pulse VFD
Utility Transformer 72 dB
Step-up Transformer 68 dB
SWE “Quiet” Step-up Transformer 60 dB
12-Pulse VFD with Phase-Shift Transformer
Utility Transformer 68 dB
SWE “Quiet” Step-up Transformer 60 dB
TAPS Phasor Step-up Transformer 63 dB
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Equipment Tests – P.S. SA-8/SL-8
Before:
Utility Transformer
72 dB
Step-up Transformer 68 dB
Utility Power Factor 84%
After adding Accusine Active Filter and Quiet Xfmrs:
Utility Transformer 66 dB
SWE Quiet Step-up Transformer 60 dB
Utility Power Factor 97%
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Equipment Tests – P.S. A-19/L-19
Well A-19 equipped with Toshiba PWM 12-pulse VFD
Well L-19 equipped with Toshiba PWM 6-pulse VFD
A-19 Step-up Transformer 81 dB
L-19 Step-up Transformer 82 dB
Utility Transformer 69 dB
Installed MTE Output (Load) Filters
A-19 Step-up Transformer 64 dB
L-19 Step-up Transformer 69 dB
Utility Transformer 62 dB, Power Factor 99%
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Equipment Tests – P.S. SA-1/SL-1
Both wells equipped with Centrilift 6-step VFDs and SWE
Quiet transformers.
Without Accusine operating:
SA-1 Step-up Transformer 57 dB
SL-1 Step-up Transformer 50 dB
Utility Transformer 66 dB, Power Factor 25%
With Accusine operating:
SA-1 Step-up Transformer 55 dB
SL-1 Step-up Transformer <50 dB
Utility Transformer 59 dB, Power Factor 95%
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$ Equipment Costs $



6-pulse drive $18,000 - $22,000
12-pulse drive $22,000 – $24,000
“Regular” Step-Up Xfmr SWE “Quiet” Xfmr
130 KVA $7,600
260 KVA $11,300
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130 KVA $13,000
260 KVA $17,600
PCS300 Accusine Active Filter $36,900
MTE Load Filter $4,500
Transportation and Installation – Add 20 - 30%
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Results
Installation of “Quiet” transformers generally
reduced transformer noise by 1/2.
Installation of Accusine “Active Filter” corrected
power factor to better than 95%, and reduced utility
transformer noise.
Installation of MTE load filter on PWM drives
reduced transformer noise by almost 1/2.
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Questions?
Craig Patterson, Project Engineer, Meurer & Associates
Paul D. Goldfain, Associate Principal, Meurer & Associates
Robert Anderson, Electrical Engineer, The RMH Group
David Kaunisto, District Manager, East Cherry Creek Valley Water
& Sanitation District
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PWM Wave
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PWM Output Wave Forms
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