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