drive basics
DESCRIPTION
LV Drive basics & beyondTRANSCRIPT
LV Drives – Basics & beyond
Rockwell Automation
Presented by
What is a VFD
• Diode rectifier converts AC line voltage to fixed voltage DC.
• DC voltage is filtered to reduce current ripple from rectification.
• Inverter changes fixed voltage DC to adjustable PWM AC voltage.
• Diode rectifier converts AC line voltage to fixed voltage DC.
• DC voltage is filtered to reduce current ripple from rectification.
• Inverter changes fixed voltage DC to adjustable PWM AC voltage.
What is VFD ?
� Save substantial energy costs (due to direct speed control)
� Improves Process by smooth speed control
� Save Energy costs by reducing maximum utility demand charges
� Reduce Motor stress & Increase Life of mechanical equipment due to ‘soft starting’ (lower heat, vibration, and transient torques)
� Lower chances of System disruptions (by lowering current inrush from 600% to 100-150%)
� Complete Motor Protection in build
� Automatic Energy Saving Feature
� Substantially brings down – Down time & Maintenance costs
How Drives Can HelpHow Drives Can Help
Basic Control Classes for AC drives
Volts/Hertz
Control
(V/Hz)
Volts/Hertz
Control
(V/Hz)
Sensorless Vector
Control with
slip comp.
Sensorless Vector
Control with
slip comp.
Flux Vector or
Field Oriented
Control
w/ out Encoder
Flux Vector or
Field Oriented
Control
w/ out Encoder
Flux Vector or
Field Oriented
Control
w/ Encoder Fdbk
Flux Vector or
Field Oriented
Control
w/ Encoder Fdbk
Basic Volts/Hertz Sensorless Vector Vector Control
Vector Control vs Flux Vector
Vector Control
– Acknowledges that motor current is the vector sum of the
torque and flux currents and uses this information to provide
better control of motor speed/torque.
Flux Vector Control
– The ability to independently control the flux and torque in a
motor for the purpose of accurate torque and power control.
standard Duty classes IEC-146( converter)
100% continuous, 150% for 2 hours,300 % for 60 sec 6
100% continuous.125% for 2 hours, 200% for 60 sec5
100% continuous.125% for 2 hours, 200% for 10 sec4
100% continuous,150% for 1min in 5 mins3
100% continuous,150% for 1min in 10 mins2
100% continuous 1
Rated current values for converters& test conditions for
assemblies
Duty Class
A,B,C of Sizing & selection
Sizing & selection
� Application ( Types of load ):CT,VT, CHP
� Braking: DC, Resistance, Regeneration
� Communication: Devicenet, control net , Modbus, Ether Net
� Cable Length: Choke, Terminator, Sin Filter
� Feedback: Tacho, Encoder
� Power: As per Duty class
� Temperature: 45 or 50 degree centigrade
�Fans, pumps, blowers etc where the load vary depending upon
the flow rate demanded by process.
�Applications where mechanical methods / eddy current drives
are being used to limit the rated flow.
The most popular applications which result in energy savings are
fans and pumps.
ENERGY CONSERVATION USING VARIABLE SPEED DRIVES
WHERE CAN ENERGY BE SAVED USING DRIVES ?
Application Fan and Pump
Fans, pumps, blowers load vary depending upon the flow rate demand.
•Requirement of application.
•Characteristics of Fan and Pump.
•Principle diagram of Adjusting the flow rate.
•Advantage of Using Drives
“ENERGY” Saving by Variable Speed Drives
PROCESS-Flow Rate, Load Cycle.
FAN SIDE -Torque, Speed & Power.
DRIVES SIDE -Torque, Speed, Current, Power & Motor Details.
FANS & PUMPS -THE CHRACTERISTICS
TORQUE α(Speed)2
POWER CONSUMED α (Speed)3
If speed decreases, the power consumption decreases in a cubic
manner.
THE PARAMETERS INVOLVED :
Drive Advantages
� High motor power factor even at partial load
� Smooth start / stop reduces shock loading on pipelines, reduced torque on motor and peak KVA demand is reduced .
� Efficient fluid flow , better energy management during non-peak demand
� Accurate flow control as per process needs improves product quality (metering, mixing applications)
� Optimum sizing of pumps , low running cost.
� Multiple motor starts and stops are permitted.
� Pipeline leakages are better controlled.
� Throttling Valve, additional piping and friction avoided
� Remote and easy control of Drive and integration with higher level automation is possible.
To reduce the flow from 100%
to 60% , input power
requirements are reduced from
100 % to 62 %
Variable Inlet Vane ID Fan application
Saves 38%
Variable Torque
To reduce the flow from 100%
to 60% , input power
requirements are reduced only
from
100 % to 86 %
Outlet Damper
Saves 14%
ID Fan application
Variable Torque
Reduction of flow from 100% to
60% , results into Input power
requirements reduction from
100% to 22%
Variable Speed Drive
Energy
Saved
Saves 78% of Energy
ID Fan application
Variable Torque
Power α (Speed)
Torque is ConstantP = 2 X Π X N X T
Constant Torque
Food processing equipment
Machine tools
Conveyor equipment
Packaging machinery
Wood working machinery
Press and stamping
Winder
Some Applications
20 % REDUCTION IN SPEED REDUCES 20 % ENERGY CONSUMPTION
Wagon Tippler
Screw Feeder
Press and stamping
Crane/Hoists
Lifts
Compressors
Etc…….
� Crusher
� Screw Pumps
� Coal Feeders
� Conveyor
P = 2 X Π X N X T
Constant Power
P
NO Energy Saving
Example:
Blower
Spindle
Mixer etc..
Constant Power
Zone
Mine cooling fan - AC drive instead of damper
Mine submersible pump - AC drive instead of throttling
Clay workshop ID fan - AC drive instead of damper
Mine ore conveyor - AC cage motor + drive instead of slip-ring motor
Cement factory ID fan - AC drive instead of damper
Minerals, Mining and Cement,
Power plant ID fan - AC drive instead of fluid coupling
Power plant FD fan - AC drive instead of inlet guide vanes
Power plant fans - AC drive instead of inlet guide vanes
Power plant booster fan - AC drive instead of inlet guide vanes
Boiler extract fans - AC drive instead of dampers
Boiler feed pump - AC drive instead of fluid coupling
District heating pump - AC drive instead of throttling
Power Generation
Metal industry ID fans - AC drive instead of damper
Metal industry scrubber pump - AC drive instead of throttling
Steel melting plant fan - AC drive instead of damper
Steel mill roller table - AC drive instead of fixed speed
Wastewater pumping - AC drive instead of on-off control
Water booster pump - AC drive instead of throttling
Water treatment pump - AC drive instead of on-off
Metal and Manufacturing
Rockwell Automation
?
Line Transients
Harmonics
Grounding
&
Bonding
Common Mode&
Capacitive Coupling
Reflected Wave
A little protection
and good
technique
go a long way to
insure a good
drive installation
Tell me again
why I’m using
drives?
AC Drive and Motor Installation Practices
Selection of Motor
� Standard Motor( Insulation level ???) or Inverter Grade Motor
� Forced cooled or self cooled
� Operating Area: safe or hazardous
� Bearing Insulation
Motor Insulation & Choke insulation
24
Design Review Checklist – Line Side
• Distribution System
– Grounding
– Cable type
• Transients and Harmonics
– Converter type
– Line impedance
• Common Mode Noise
– EMI noise
– Cable type
– Cable configuration
25
Design Review Checklist – Load Side
• Reflected wave– Motor insulation
– Cable type
• dV/dt– Motor insulation
– Motor CIV
– Cable charging
• Common Mode Noise– EMI noise
– Bearing currents
– Cable type
– Cable configuration
26
Drive System
Transformer AC Drive Motor
M
27
Drive System
Transformer AC Drive Motor
Reflected Waves
M
Copyrig
Reflected Wave Result
Copyrig
• Output Reactor with and without resistor between drive & motor– Slopes off the waveform (lengthens rise time)
– Reduces destructive force for same amplitude
– Allows longer lead lengths
– With resistor even longer lead lengths
– Reactor does create voltage drop
• Output Filters– dV/dt limiters
• 1204-RWR2, 1204-RWC-17A
• 1204-TFA1, TFB2 “terminator”
– Sine Wave
• Filters
Protect the Motor
30
Transformer AC Drive Motor
Line Current Harmonics
M
Drive System
31
Root Cause of Problems with Other Equipment
Current HarmonicsCurrent HarmonicsCurrent HarmonicsCurrent Harmonics
createcreatecreatecreate
Voltage DistortionVoltage DistortionVoltage DistortionVoltage Distortion
What problems do HARMONICS cause?
• Increased Utility current requirement inability to expand or utilize equipment
• Component overheating distribution transformers & wires
• Nuisance tripping causing lost productivity sensitive equipment
• Equipment malfunction due to multiple or loss of zero crossing
• Noise transfer to other loads possibly even other utility customers
• Incorrect meter readings, relays malfunction maintenance time
• Communication or Telephone Interference problems
• Excitation of Power System Resonance's creating over-voltage’s
• Voltage Flat Topping Problem
How can we reduce the harmonic current?
• DC link choke within the drive
• line reactor
• passive filter
• active filter
• phase shifting loads
• harmonic mitigating transformers
• multi-pulse converters
• active front-end
Guidelines to be taken care during installation of Drive system
• Drives to be installed in clean dry and corrosion free environment
• Keep panel door closed.
• Use suction type vacuum cleaner to clean dust. (No blower)
• Room A.C should have humidity control.
• Use antistatic protection while handling electronic parts. (Self grounding).
• Cable from drive to motor should be 3 core. (Not 3.5 core)
• Never run control or drive input wires in the same conduit as the drive output
wires.
• Keep the distance from the drive to the motor as short as possible to maximize
motor life.
• Never connect incoming supply to drive output terminal.
• Do not conduct insulation test on motor terminal with cables connected to drive
output.
Guidelines to be taken care during installation of Drive system
• Dedicated earth connection from drive P.E terminal to motor P.E terminal is recommended. (No welding using this earth permitted)
• Earth conductor of drive panel, motor, transformer should have at least 50 % cross section of input phase conductor.
• Earth strip of panel should not be used for any other purpose including welding which may lead to electronic component failure.
• All 24V/ 10 V (4-20 mA) control signal cables should be twisted pair screen cables, screen to be grounded at receiving end.
• Do not store the drive more than twelve month without charging. • Set Lower Drive carrier frequency
• Add suppression to all inductive loads (electric brakes, relay coils, solenoids)
Rockwell Offer
PowerFlex Family of Drives
• Power ratings from 0.2kW (0.25 Hp) single phase to 25MW (34,000 Hp) at medium voltage
• Seamless control system integration –maximize uptime
• Decrease development time by as much as 70% with Premier Integration —RSLogix 5000 Software with PowerFlex drives add-on-profiles
• Increase productivity and flexibility with integrated safe speed control technology and safe torque off options
• Flexible control – simplifies operation, reduces training & costs
– Common operator interface & integration capabilities
– Consistent programming structure
– Consistent software tools
– Variety of packaging designs
0.2 kW (0.25 Hp) to 25.4 MW (34,000 Hp)
PowerFlex Family of Low Voltage Drives
PowerFlex drives meet worldwide standards out of-the-box, achieving EMC, global voltage and safety requirements. All PowerFlex
drives offer commonality in networks, operator interface and programming — factors that significantly contribute to ease-of-use and
faster application start-up.
• PowerFlex Component Class AC drives offer you cost-effective motor control for machine-level and stand-alone applications
(PowerFlex 4, 4M, 40, 40P and 400)
• PowerFlex Architecture Class AC drives are designed for advanced application flexibility and control system integration
(PowerFlex 70, 700, 700L, 700H, 755, 700S)
• PowerFlex DC drives are designed for coordinated drive control and drive system applications (PowerFlex DC)
Power
Performance
Component Class
Architecture Class
PowerFlex DC
DSI Communication Products
22-SCM-232
RS-232 DF1
22-COMM-D
DeviceNet
22-COMM-E
EtherNet/IP
22-COMM-P
Profibus DP
22-XCOMM
Ext. DSI Kit
AK-U0-RJ45-*
Cable Accessories
22-COMM-C
ControlNet
22-WIM-Nx
Bluetooth
1769-SM2
Compact I/O
22-COMM-B
BACnet MS/TP
22-COMM-L
LonWorks
1203-USB
USB Converter
PowerFlex 750-Series AC Drives
• The PowerFlex 750-Series of AC drives offers more standard features and selection for control, safety and supporting hardware options than any other drive in its class – Standard embedded Ethernet
– Standard embedded I/O
– Predictive diagnostics
– Real Time Clock
– Safety - Safe Speed and Safe Stop(EN-954)
– DeviceLogix -
– Features:
– Positioning Functions -- I/O Slot Options
– Feedback Options -- RoHS Compliant
– I/O Slot Options
Instruction Types include:
-- Boolean -- Process
-- Filter -- Select / Limit
-- Statistical -- Timer / Counter
-- Comparison -- Compute
-- Move -- PID
PowerFlex755 Drive Awarded
Control Engineering 2010 Engineers’ Choice Award for drives, motion control and motors category
Performance Improvement - Load Sharing
In the world of DRIVES Load Sharing: Involves multiple drives/motors powering the same process
• Each drive contribute a fair share of torque to do work proportional to its own capacity
• When uncoupled roller must not run away - use min torque/speed comparator feature.
• Perfect Speed Synchronization and accurate Torque control
Compressors - Concept - Conventional Control
Time
Upper Limit
Lower Limit - Reqd. Pr.
Average Pr.
Pressure
Ksc
6.5
6.0
7.0
� No loading / Unloading Cycles
� Less Leakages
�Constant Lower Pressure
�Process Feedback
� Better Motor Efficiency�Higher Power Factor
�Controlled Accel / decel Time�Lower Starting Torque�Lower Starting Current
VFD Advantages In Compressors
� Energy Saving
Lifting applications can now be solved
easily using the TorqProveTM feature in the
PowerFlex 700.
Lifting applications can now be solved
easily using the TorqProveTM feature in the
PowerFlex 700.
Benefits include:
– Assured control of the load.
• TorqProveTM assures that the mechanical brake has control of the load when stopping the drive, and the drive has control of the load when releasing the brake during a move command
• TorqProveTM and Force TechnologyTM helps eliminate concerns with brake timing and environment changes inherent in V/Hz drives
– Reduced set-up time
• Very easy to set-up – only a few parameters
• No PLC programming required for function (brake control is performed by drive)
Perfect Hoist Load Control
Can Hold Full Load in air Without
Mechanical Brakes ?.............
Can Hold Full Load in air Without
Mechanical Brakes ?.............
References :
Bhutan Ferro Alloys Ltd on Hot Metal Bucket
BALCO Korba for Bucket Pick and drop
Bhushan Steel Orissa
LMW Foundary Shop
Hindustan Zinc etc….
Confidential -- For Internal Use Only. Copyright © 2008 Rockwell Automation, Inc. All rights reserved.
Auto-Economizer - Extra Saving
“Idle Mode” Energy Saver
Reduced Load
Automatically fold back Voltage to reduce motor flux
Auto Energy Saving Feature
A key in Press like Applications
Performance Improvement - Premier Integration with Powerflex Drives
Controller-based Automatic Device Configuration (ADC)
Controller will automatically detect a node replacement, flash it if necessary, and download the configuration settings
EtherNet/IP
ControlNetFlashConfiguration
Incident at 2:00 AM!!
Benefits Using RA Drive with RA Controllers – Pre.Intg.
• Reduce drive system development time by as much as 70%*:
– Use one software tool to configure the entire Logix / drive system
– Controller and drive network connections are configured at the same time
• eliminates I/O mismatch errors
– Auto-generation of descriptive tag names
– Auto-generation of respective tag data types
– All drive configurations are saved in the RSLogix
project file and in the Logix controller
Competitor’s Drive PowerFlex Drive~25 minutes ~3.5 minutes
Key Differences Programming the 1st Drive
Readymade PowerFlex Global Objects
Key Differences Programming Ten Additional Drives
Competitor’s Drive ~42 minutes PowerFlex Drive ~7 minutes
� Ambient Temperature of 50 Degree C.
� Flexible performance with ForceTM Like Technology.
� Seamless Integration
� Built in DC Chokes to abate input Current Harmonics (Obeys IEEE 519 -1992 Standards) with 97.5% Efficiency
� Power Devices having PIV of 1700V and Transient Protection of 6KV
� Built in Software to control the effect of reflected wave
� Built in EMC Filters and common mode core to address noise related issues. Conformity to EMC directives and european Standards.
� Excellent Feature of Zero Stacking
� PTC input to the Drive
� Internal family of communications and HIM modules
� 7th IGBT – Chopper is internally Provided
� Over Load Capacity as per Application.
� Complete Output Short Circuit Protection
� Compact Size
What makes RA Drives More Reliable
50
Thanks For your Patient Listening
Lakhbir Singh
Area Manager( East) – Drives
Rockwell Automation
+91-9874624151