power management
Post on 03-Jan-2016
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Power Management
Fred GibsonGibson Technologies cc
www.gibsontech.org.za
Basic Energy Concept
Energy Management
► What is energy management?▪ One meter at the main incomer.▪ Report at the end of the month.▪ Want to check up on the supplier.▪ Driven by an idea of a saving somewhere???▪ Closed demand control system.
• Black box sitting in the corner
• Dot matrix printer with the ink dried up years ago
• Cannot adjust. No control over fixed philosophy
Too LateAccounting Based Approach
LOAD PROFILE
Energy Management
► What comes next?▪ One meter at the main incomer.▪ Continuous updated data on a machine.▪ Ability to react in time.▪ Driven by a knowledge of achievable savings▪ Changeable demand control system.
• Computer with SCADA and real time info
• Trending showing fresh data
• Set Priorities, move limits….choice
• Ability to lock or limit freedom, but override on intelligent decision
▪ Write fixed philosophies with adjustable set points
Pro ActiveActive Approach
Demand Control
► Load Shedding▪ Turn non critical loads off
• Plant specific
Example :
Wheat Mill
Intake has bins as buffer and can be stopped at times with proper planning
Three Mills may be run individualy or together C-Mill Example
Shedding in Process
Two Flow Paths
Note the current drawn by each motor
Demand Control
► Load Shedding▪ Turn non critical loads off
• Plant specificExample :
▪ Adjustable control• Smooth
• Arc and Induction FurnacesExample :
Adjustable Load Shedding
Continuous Control
► Philosophy▪ Before:
• Furnace power controlled by POT
• POT adjusts 0-10V signal to controller
• Operator has full control. Example 0 – 3000KVA
▪ After• Read POT Voltage into Analog Input
• Write Analog output to Furnace controller
• When Shedding, read 100% of POT Value in
• Write only 90% to controller
• Shed 300KVA
Smooth Shedding
► With continuous control we can achieve almost perfectly smooth control of demand
► Maximum demand window runs for 30min► Calculate in PLC a 25min Window► Leaves 5min to shed progressively► Ease the power back up► Run your plant at peak power► Do not cross the maximum demand target
Actual Case
IT Furnace
AEG Furnace
Thermal
PLC Target
Shed Percentage limited to 40%
KVA Without Shedding
KVA With Shedding
Energy Management
► What are you missing?▪ All this is demand based control (KVA).▪ You need to save energy (kWh).▪ Then you need to know where your energy is going.▪ Use 80/20 Principle.▪ Cutting KWh can be very expensive.
• Screening windows
• Insulating heat sources
• Replacing inefficient machines
▪ Most savings to be had are mechanical.▪ We just pay for them on our electricity bill.▪ This is why we choose the right tool for the job
Plant / Mine Power System
G
Right Application
Fixed Power Quality Monitoring
Roaming Fault Analysis
Metering and Control
Fault Direction
Sags and Swells
RMS Analysis
TRANSIENT
Harmonics
Switch/Gateway/Meter
Ethernet Radio
Beckhoff
EtherCAT
The PLC solution
Build an Ethernet backbone
Plug a Power meter into the PLC
Plug in five if you need
No Communication Gateways, all Ethernet
Measure your transformer core temperature
Plug a PT100 Card into the PLC
Need to know CB Open or Closed Status
Plug an Input Card into the PLC
Need to open or close CB’s
Plug an output card into the PLC
Need a BUS TIE BUS Controller
Need a Power Factor Controller
Need a Generator Changeover Controller
Need a Safety interlocks on TIES and Rings
PROGRAM IT INTO THE PLC
Need a Power meter
Need to Look after the load on your Generator
The Power values are available in your PLC + The PLC Controls
Important Cards
PLC CODE
Makes it easier to calculate averages and complex mathematics
Brainstorm Valuable Ideas
G
Visualise your power system
Animate breaker statuses
Switch remotely,Keep personnel out of harms way
See and trend all your power meters in the control room
Make safe,informed switching decisions on rings and bus ties
Log all events in the system
Generate alarms onStatus and level,proactively
Read last trip data directly from your protection relay
Monitor your generator’s temperature, Diesel level and Battery voltageAnd make sure it will be ready when you need it.
Schedule Load shedding based onTime, Priority, Load, Trip ConditionsAnd Thermal feedback from yourTransformer.
Use trip counters, timers and loadData to schedule maintenance
Publish all info on Intranet
Send E-mails, SMS’s based onEvents. Call Artisans out.
Save all your power system details, specs, part numbers, procedures,Escalation procedures etc in one place
Build load and voltage history over many years. Know how much your Power system can take when you want to expand.
See the load flow, know if your equipment will hold
Understand where energy is used, focus on solutions, measure, compare
Calculate electricity cost as a percentageof production cost
Avoid crippling penalties, by stopping productionWhen your kWh budget is spent. Make a management decision.
Need power to expand? Eskom says no.Shift, schedule, save, shed and make a plan
Capacitor condition monitoring
Incorporate production schedules'In your energy management scheme
Why Wonderware ?
► Wonderware makes all the above possible► Tried and tested software which is scalable ► Start with your immediate needs► Upgrade tag base, Add software ► Install more power meters► Slide more PLC cards in easily► Connect to any commercial protocol► All as you need when you need► No Limits
Meyerton M1
Substation Automation
The Object Solution
► Use object orientated software▪ Build Power meter object
• Will gather data from field
• Will display all values available from meter
• Will handle functions like reset max registers, kWh etc.
• Will trend, log into database, alarm
▪ Build Circuit Breaker object• Will read status
• Will do operations counter
• Will log operations and times
▪ Build all objects once and us them all over▪ Update your object and your whole system will
be updated and deployed
How to start
► Brainstorm your immediate concerns, not wants► Choose a philosophy that will address these
concerns► Plan and engineer the solution to allow for
expansion and wants of the future► Plan how you will store the information► Think of who must see and react…..When?► Think of who will be the Energy Manager► When you have some data then Analyse► To get the backbone system running is the most
difficult, your wants later will be easier
Conclusions
► I hope I have given you some idees of what is achievable with energy management.
► The most difficult part is to define what your needs are.
► Don’t think you will not want the extras later.► If you plan the system with the end in mind, you
will be able to achieve a lot without much hassle.
QUESTIONS
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