Fundamentals & Application of Medium Voltage Adjustable...
Transcript of Fundamentals & Application of Medium Voltage Adjustable...
Slide #1
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 1Page 1
Lunch & Learn Meeting
Fundamentals & Application of Medium
Voltage Adjustable Speed Drives (ASD)
Manish
VermaSenior Member IEEE
TMEIC
IEEE IAS Atlanta Chapter
November 21st 2016, Noon – 1:15PM
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 2Page 2
Safety Moment - Petextrians
After decades of decline,
pedestrian fatalities are once
again on the rise.
“Petextrians” — people who
text while walking — may be
partly to blame, according to
the report.”
(ABC News Report)
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Quality Moment
Quality means doing it right when no one
is looking.
- Henry Ford
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Parameter Description
Service typesRotating machinery such as pumps,
compressors, extruders, fans, blowers, etc.
Power Level (HP) 500HP – 130,000HP
Voltage range(kV) Medium Voltage, > 1.0 kV
Applicable dimension
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0.0
01
.00
2.0
03
.00
4.0
05
.00
6.0
07
.00
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
MOTOR SPEED – PER UNIT
MO
TO
R C
UR
RE
NT
-P
U
MOTOR CURRENT
MOTOR TORQUE
TO
RQ
UE
-PU
0.0
00
.50
1.0
01
.50
2.0
02
.50
3.0
03
.50
Typical Motor Starting Characteristics
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Why is starting large motors stressful?
• Highest current is seen when shaft is still
• Starting currents create stresses and torques that can
damage motor and attached load
• The motor and the load must breakaway and accelerate
• Remember current equals heat !
• Balance allowed inrush amps with Voltage drop
• Balance power system effects with torque demand of load
Power System Challenge
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Motor Speed Control Strategies
Large
Motor
Large
Motor
ASD
Available Motor Speed Control Methods
Direct-On-Line
(DOL)
Adjustable Speed
Drives (ASD)
Other
Mech. Methods
Constant Utility Frequency
(50 or 60Hz)Adjust Frequency
Large
MotorPony
Motor
Good Reference: Larabee, J.; Pellegrino, B.; Flick, B., "Induction motor starting methods and
issues," Petroleum and Chemical Industry Conference, 2005. Industry Applications Society
52nd Annual , vol., no., pp.217,222, 12-14 Sept. 2005
Nevelsteen, J.; Aragon, H., "Starting of large motors-methods and economics," Petroleum and
Chemical Industry Conference, 1988, Record of Conference Papers., Industrial Applications
Society 35th Annual , vol., no., pp.91,96, 12-14 Sep 1988
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 8
Transformation
Utility
Supply
Conversion
Load
Utilization
AC
MOTOR
CONVERTER
RECTIFICATION
AC TO DC
OROR
ENERGY
STORAGE
OR
INVERTER
SWITCHING
DC TO AC
OR
What is an ASD?
Util
ity M
ains
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
Fixed Voltage
Fixed Frequency
Var. Voltage
Var. Frequency
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 9
Transformation
Utility
Supply
Conversion
Load
Utilization
AC
MOTOR
CONVERTER
RECTIFICATION
AC TO DC
OROR
ENERGY
STORAGE
OR
INVERTER
SWITCHING
DC TO AC
OR
What is an ASD? – Other common terminology
Pulses (DFE)
Harmonic performance
equivalent (AFE)
Output Voltage Levels / Steps
(higher the better, min 5-level from 0-
Peak)
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What is an ASD?
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What is an ASD?
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What is an ASD?
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What does an ASD mean for the motor?
0
Motor In rush
Current (650% FLA)
Full LoadTo
rqu
e, A
mp
s
Frequency, RPM
Motor Full
Load Current
AC Utility
Line Amps
Starting
Torque
Direct-on-line / Fixed Frequency Variable Frequency
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 14
What does an ASD mean for the motor?
Motor Starting
Reduced inrush current
High Torque Loads
Close to unity power factor
Process Control
Energy Savings
Speed Control
Torque Control
Motor size optimization (eg: large
inertia loads)
Motor Running
Power factor improvement
Unstable voltage supply
Quick stopping (Regeneration)
Reduced Mech. Wear /
Tear
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 15
• Medium Voltage drives range from 2300V – 13800V.
• Voltage defined at output.
• Input voltage to the VFD between 2.3kV – 138kV
• ASD = VFD = EVFD = VVVF (can be used interchangeably)
What do we mean by “Medium Voltage ASD”
Sm
all A
ir-C
oo
led
AS
D
La
rge
Wa
ter-
Co
ole
d A
SD
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2,000
4,000
6,000
8,000
10,000
12,000
0100 10,000 50,000 100,000
AS
D O
utp
ut V
olta
ge
(V
)
Water Cooled
Air Cooled
Motor Horsepower (HP)
Typical Range of ASDs
14,000
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Single VFD / single motor
Motor
Compressor
Bypass
VFD
Utilit
y
Motor
Compressor
Bypass
VFD
Utilit
y
Motor
Bypass
VFD Compressor
XFMRUtilit
y
Utility = VFD
VFD = Motor
Utility = VFD
VFD ≠ Motor
Utility > VFD
VFD = Motor
Voltage Level
ScenarioSimple Electrical One-line
$
$$
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 18
Multi drive – Multi Motor
Utility Voltage bus 4.16kV
Byp
ass B
us
6000HP
VFD Bus
DB-5i
PLC Coordination
& Interface
Incoming
Switch
MPRAuxct
MPRAuxct
MPRAuxct
MPRAuxct
Syn
ch
ron
ize
d B
yp
ass
Syn
ch
ron
ize
d B
yp
ass
Syn
ch
ron
ize
d B
yp
ass
Syn
ch
ron
ize
d B
yp
ass
DB-5i
Incoming
Switch
75
00
HP
7500HP 7500HP7500HP 7500HP
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 19
Historical Overview
1955 1965 1975 1985 1995 2005
Gate TurnoffThyristor
GTO
Bipolar Power Transistor
(BPT )
Silicon Controlled
Rectifier (SCR )Thyristor
Family
Diode ( D)
Low Voltage InsulatedGate Bipolar
Transistor (LV IGBT )
Integrated Gate Commutated Thyristor
(IGCT )
Symmetric Gate Commutated. Thyristor
(SGCT )
Medium Voltage InsulatedGate Bipolar Transistor
(MV IGBT )
Injection EnhancedGate Transistor
(IEGT )Transistor
Family
DC Motor
Drives
Synchronous
Motor drives
Induction Motor
Drives
Time Line of Adjustable Speed Drives
1955 1965 1975 1985 1995 2005
Ind/Synch Motor
Drives
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 20
A map-like diagram showing the elements of an AC drive and the relationships between them.
• AC Drive Topology:
ASD Topologies
• The Common Threads:
All AC Drives rectify AC to DC.
All AC Drives use switches to create AC from DC.
• Drive topologies were created as power rectifiers and switches grew in ratings and capabilities.
• Each new or uprated device opens up new applications
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 21
Major ASD Topologies
Current Source Inverters
(CSI)
Voltage Source Inverters
(VSI)
Load Commutated
Inverters (LCI)
Pulse Width
Modulated (PWM)
• Energy
storage/DC
Link is
Capacitor
• Energy
storage/DC
Link is
Inductor
• Maintains constant Voltage at
DC Link
• Maintains constant current at
DC Link
• Converter (AC/DC) is either
Passive (using diodes) or
Active (using PWM)
• Converter (AC/DC) is Active (using
phase control or PWM)
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 22
Comparing Drives of All Topologies
• Current Source Drives
• LCI – Load Commutated Inverter
• GTO/SGCT Current Source Induction Motor Drive
• Voltage Source Drives
• LV IGBT “Paice” Multilevel PWM
• MV IGCT PWM – Diode or Active Source/Converter
• MV IGBT PWM – Integrated package
• MV IEGT PWM – Active or Diode Source/Converter
Good Reference for more details: Lockley B, Paes, R. “What’s new with MV Drives” http://sites.ieee.org/northern-canada-
pesias/files/2014/02/Whats-New-with-MV-Drives-IEEE-NCS-2014-Final.pdf , Pages: 43 – 58.
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 23
ASD System Considerations
Must consider the whole system in which the ASD will work
• From Utility to finished product or process
• Consider environment
• Consider effects on utility
• Consider the needs of the load
• Consider the effect of ASD on the motor and drive train
Utilit
y M
ain
s
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 24
ASD Overall Success Factors
• Minimum first cost, including installation
• Maximum long-term payback.
• Good match to process & loads.
• Long equipment life.
• Ease of use for operators & technicians.
• Minimum impact on nearby equipment.
• Easy to maintain & repair.
• Smallest foot print
Application considerations can divided into the following:
Electrical/Load Application Factors
Installation Factors (E-house integration/Cabling)
ASD Protection & Cooling methodology
ASD standards and Factory Testing
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 25
Electrical/Power Application Factors
• Continuous kW or HP & duty cycle
• Torque & Power Overload requirements
• Load factors: CT, VT, CHP, regenerative, non-regenerative.
• Drive and Motor Voltage
• Power system compatibility
Utilit
y M
ain
s
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
#1 - Define the
process loads
and duty cycle
#2 - Define the
power system
requirements
#3 – Determine
best drive
solution!
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 26
Load Type Examples
Constant Torque
• Conveyors
• Grinding Mills
• Kilns
• Reciprocating Compressors
• Positive Displacement
[Screw Type] pumps,
compressors
Variable Torque
• ID / FD Fans
• Centrifugal Pumps
• Centrifugal Compressors
• Pipeline booster pumps
• Axial Compressors
To
rqu
e (
%)
Speed (%) Speed (%)
To
rqu
e (
%)
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 27
Keep In Mind
Drives are sized & priced based on Motor Full
Load Current AND Operating Envelope
Example:
1. 7000 HP, 1800 rpm,
4000V, FLA 910A
= 6300 kVA
2. 7000 HP, 450 rpm,
4000V, FLA 1240A
= 8600 kVA
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 28
Lets take an example
0
2.0
1.0
0
1.0
0.5
60
Torque
Speed [RPM]
Horsepower
0
1.0
0.5
120 180 240240 300 360
TIME IN SECONDS >
One duty cycle >
Power = Speed x Torque
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Drive Ratings and Torques
• Variable Torque (VT) ratings usually include 110 -115% OL
rating for 60 seconds when starting from rated Temp
• Constant Torque (CT) rating usually includes 150% OL
rating for 60 seconds when starting from rated Temp.
On Constant Torque applications, take a close look at the
Speed Torque Curve for selecting the correct ASD size
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 30
Power System Compatibility
• Power distribution (available
utilization voltages)
• Protection.
• Harmonics limits.
• Power factor control.
• Efficiency.
• Breakers, transformers, and cable must be rated to carry full kVA &
harmonics.
• Transformers need to be “drive isolation” rated with proper considerations
for the drive type.
Utilit
y M
ain
s
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 31
Power system compatibility - Keep In Mind
• Always provide and electrical one-line diagram
• Some tips for ASD voltage level selection
• 250HP – 5000HP
• 5000HP – 10,000HP
• >10,000HP
Motor Power ASD Input Voltage Motor Voltage
2.3, 4.16, 3.3, 6.6, 10,
11, 13.8 kV
4.16, 6.6, 10, 11, 13.8,
25, 34, 66 kV
10, 11, 13.8, 25, 34, 66,
110, 138 kV
2.3, 4.16, 3.3, 6.6, 10,
11 kV
Matched to ASD
output voltage
Matched to ASD
output voltage
Note: if ASD is used for starting ONLY, then
Motor Voltage = Utility Voltage (Max 13.8kV)
Slide #32
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 32
• MV drive $ / HP decreases with HP
• Installed cost must be considered including:-
- Harmonic mitigation requirements
- Cabling costs
- Installation costs
- Reliability
MV vs LV AC Drives
Budgetary $ per HP
vs HP
0.0
110.0
220.0
330.0
440.0
500.0
0 500 1000 1500
Horsepower
Bu
dg
etar
y
$ p
er H
ors
epo
wer
LV 6-Pulse w/o Transformer
MV 4160 v 24-Pulse
LV 6-Pulse w/8% Filter
LV 18 pulse incl transf
Medium voltage versus low voltage – what to use??
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 33
Drive Output Voltage & Motor Application
• Why Pick LV [<690v] Drive & Motor?
- LV drives are lower cost / HP than MV
- Reduces some safety & MV training concerns
- HP range is small enough
- Individual preference
• Why pick MV over LV?
- Lower cost wiring, smaller cables
- Lower power system harmonic impact
- High HP LV require dual winding motors
- Individual preference
Recent Trend: Some users select MV >250 HPMany users select MV > 500 HP.
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 34
Some MV vs. LV Conclusions
• For drives > 1000 HP, MV makes sense
• For long cable runs, MV makes sense
• For drives < 500 HP, LV makes sense.
• If low power system harmonics are required, LV filter or
multi-pulse cost adders can favor MV over LV.
• In the range 500 to 1000 HP the various application &
installation factors apply.
• Final choice may boil down to user preference.
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 35
Power Line Harmonics
• “Harmonics” are voltages and currents at frequencies that are multiples of utility power frequency.
• Harmonic currents are drawn by loads such as drives, computers and ballasts that take their power in non-sine-wave format. These are so-called non-linear loads.
-1.5
-1
-0.5
0
0.5
1
1.5
0 120 240 360
Fundamental, 5th and 7th Harmonics
Sum
Fundamental
7th5th
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IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 36
IEEE 519-2014 Table 10.3 ITDD Limits
Maximum Harmonic Curent Distortion in % of I-Load
Isc to I-load
Ratio h < 11
h = 11
to <17
h = 17
to <23
h = 23
to <35
h = 35
& up
TDD
%
< 20 4.0 2.0 1.5 0.6 0.3 5.0
20 < 50 7.0 3.5 2.5 1.0 0.5 8.0
50 < 100 10.0 4.5 4.0 1.5 0.7 12.0
100 < 1000 12.0 5.5 5.0 2.0 1.0 15.0
>1000 15.0 7.0 6.0 2.5 1.4 20.0
Notes: Even Harmonics limited to 25% of the harmonic level
TDD = Total Demand Disortion %, based on maximum demand current
at the point of common coupling [PCC].
Isc = Maximum Short Circuit current or kVA at the PCC
I-load = Fundamental freqency load current or kVA at the PCC
I-Load[fund]
PCC Isc Available
I-harm
Vpcc
D
M
Specifying a min. 24-Pulse VSI VFDs or Active Front End VFD is safest option for harmonic mitigation
Slide #37
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 37
Power System & Drive Efficiency
• Drive itself is typically 98% or more efficient
With all fans, transformers, pumps, etc, efficiencies of
96-97% are common
Efficiency impact of drive varies with speed
• Efficiency effect of the drive can be eliminated at full speed
by synchronous bypass.
For Air-cooled Versus Water-cooled Overall system efficiency use:
92% for air-cooled (Includes VFD and E-house HVAC)96% for water-cooled (Includes VFD and E-House HVAC)
Slide #38
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 38
Speed & Torque Control Requirements
• Each application is unique
- Simple, free-standing pumps
- Complex – e.g. sync to utility, multiple motors per drive, multiple drives on same load
• Process control – usually 4-20 mA for speed
• Go Tachless if possible
- Precise speed control rare with MV drives and high kW level drives
- High load torques (>150% OL) may require tachometer
Slide #39
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 39
Operator Control and Communication
• Interface with larger process
- Controls for operator –• Simple start-stop contacts
• More complex HMI
- Process equipment controls –system PLC
• LAN communication of drive status if/as needed to plant PLC or DCS
• Plan for remote diagnostics capability
Slide #40
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 40
Drive Design For Reliability
• Minimum parts – fewest power components, and simplest firing circuits
• No “Weak links” like marginally rated capacitors, switching devices, etc
• Conservatively rated, fully qualified components
- Quality built in not “burn-in tested”
- Quality tracked
Utilit
y M
ain
s
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
Slide #41
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 41
ASD Operational / Environmental limitations
• Altitude: De-rate current rating 2-3% per 1000 ft above 3000 feet. May have to de-rate voltage for very high altitudes.
• Temperature De-rate: 1.5% per degree C above base rating (usually 40C) up to max (usually 50 C).
• Drives put out heat – must be removed or vented to outside
• ASDs are designed to be installed in a relatively clean, dry environment
Operation
• 0 to 40 or 50 C with a relative humidity of 95% maximum, non-
condensing.
Storage
• Equipment is generally designed for a non-operating (storage)
temperature range of –25 C to 70 C.
Slide #42
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 42
Specifying E-houses – Key to reliability
• Good standard to use is PIP ELSSG11, Electrical power
center specification
If End User / EPC / OEM is
supplying the ASD building
ASD Vendor to supply:-
Heat Dissipation in kW
Max. ASD Operating Temp.
ASD Humidity & Air Quality Req.
Weights & Dimensions
Air flow requirement
Outline ultimate responsibility of the entire system
If End User / EPC / OEM splits the scope of building
and ASD
ASD Vendor Building Vendor
Heat Dissipation in kW
Max. ASD Operating Temp.
ASD Humidity & Air Quality Req.
Weights & Dimensions
Air flow requirementsClarify responsibility ASD hook-up, plumbing, wiring, check-out
Slide #43
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 43
E-house requirements
• Minimum requirements for ASD E-houses are:-
• E-House NEMA rating, Typically 3R
• Fire/Smoke detection
• Note: Fire suppression is usually not provided and is
optional (like FM200 waterless suppression)
• N+1 HVAC based on ASD heat loss
• 480V, 120V Panel boards for lights, control, ASD Aux
• Bus Ducts or cable trays
• PE stamp, certifications (if any), access restrictions
• Local codes. Default is NEC
• Location of E-house final destination – For E-house
estimating shipping splits
Slide #44
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 44
Sample E-house layouts
Slide #45
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 45
Sample E-house layouts
VFD# 1
8,000HP
VFD# 2
33,000HP
Preferable for ASD vendor to take responsibility of E-house
specially for large ASDs
Switchgear Room ASD Room ASD Aux/LV Room
Slide #46
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 46
Cables From ASD to Motors
• Drives themselves are usually tolerant of most cable types & methods
• BUT, Cabling affects EMI radiation or motor.
• Cables > 500 meters need special attention [cable capacitance]
Utilit
y M
ain
s
Motor
Driven
EquipmentVFD
Input
Breaker
Step-Down
Drive Isolation
Transformer
Cooling System
Industrial Control Building
Slide #47
IEEE IAS Atlanta Chapter Lunch & Learn For Reference ONLY Page 47
Motor-Drive Cable Methods And Tradeoffs
IEEE IAS PCIC 2014, Tutorial B For Reference ONLY Page 48
Questions?
The Curse of Knowledge