Volt VAR Control Optimization Bob Uluski Quanta Technology

Volt ‐ VARControl & Optimization

Bob UluskiQuanta Technology

© 2010 Quanta Technology LLC

What is Volt‐VAR control?• Volt‐VAR control (VVC) is a fundamental operating requirement of all

electric distribution systems

• The prime purpose of VVC is to maintain acceptable voltage at all points along the distribution feeder under all loading conditions

LTC

Primary Feeder

SUBSTATION

Primary Feeder

Secondary

Distribution Transformer

Service Drop WiresFirst

Customer

Last Customer

Customer

Voltage

3 volts Primary

2 volts distribution transformer

1 volt secondary

1 volt service drop

122

119117116

First Customer


Distance

115 Last CustomerANSI C84.1 Lower Limit (114 volts)114

What is Volt‐VAR control?• Without VVC:

– Voltage might be okay during average load

Transformer T P i i

120V

126VTap Position

114V

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– voltage might droop below the minimum acceptable level for some customers during heavy load periods

Transformer T P i i

120V

126VTap Position

114VLow Voltage

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F�� C�� L�� C��


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– Could raise the manual tap setting on the substation transformer to correct the peak load problemcorrect the peak load problem

Transformer Tap Position

120V

126V

114V

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– But when feeder loading in light, high voltage could be a problem at the substation end of the feederproblem at the substation end of the feeder

Transformer Tap Position High Voltage

120V

126V

114V

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– But when feeder loading in light, high voltage could be a problem at the substation end of the feeder

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�� be a problem at the substation end of the feeder

Transformer Tap Position

120V

126V

114V

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VVC = Voltage Regulation + Reactive Power Compensation

• Use voltage regulators (Vregs) or transformers with load tap changers• Use voltage regulators (Vregs) or transformers with load tap changers (LTCs) that automatically raise or lower the voltage in response to changes in load

• Use capacitor banks to supply some of the reactive power that would• Use capacitor banks to supply some of the reactive power that would otherwise be drawn from the supply substations


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VVC in Today’s Operating Environment(and Tomorrow’s Operating Environment Too!)

• Maintaining the status quo no longer acceptable

• Utilities are seeking to do more with VVC than just keeping voltage within the allowable limits

S t ti i ti i i t t t f th l• System optimization is an important part of the normal operating strategy under smart grid

• As penetration of intermittent renewable generating As penetration of intermittent renewable generatingresources grows in future, high‐speed dynamic volt VAR control will play a significant role in maintaining power quality and voltage stability on the distribution feedersquality and voltage stability on the distribution feeders


Volt‐VAR Control in a Smart Grid World

• Expanded objectives for Volt‐VAR control include– Basic requirement – maintain acceptable voltageBasic requirement maintain acceptable voltage

– Support major “Smart Grid” objectives:• Accomplish energy conservation

ff ( d h l l )• Improve efficiency (reduce technical losses)

• Promote a “self healing” grid (VVC plays a role in maintaining voltage after “self healing” has occurred)

• Enable idespread deplo ment of Distrib ted generation Rene ables• Enable widespread deployment of Distributed generation, Renewables, Energy storage, and other distributed energy resources


Requirements for the “Ideal” Volt‐VAR System

• Maintain Acceptable Voltage Profile at all points along the distribution feeder under all loading conditions

• Maintain Acceptable Power Factor under all loading conditions

• Provide Self Monitoring – alert dispatcher when a volt‐VAR device f ilfails

• Allow Operator Override during system emergencies

• Work correctly following Feeder ReconfigurationWork correctly following Feeder Reconfiguration

• Accommodate Distributed Energy Resources

• Provide Optimal Coordinated Control of all Volt VAR devices

• Allow Selectable Operating Objectives as different needs arise


Approaches to Volt VAR ControlApproaches to Volt VAR Control

• Traditional ApproachTraditional Approach

DLA Master Station

Switched Capacitor Bank

• SCADA Volt VARDistribution

SCADA

Distribution Power Flow

p

• SCADA Volt VAR

• Integrated Volt VAR

IVVCApplication

Substation RTU

Line Regulator

• Integrated Volt VARSubstationCapacitor Bank

Substation TransformerWith Load

Tap Changer


Traditional Volt‐VAR Control

Current/VoltageSensor

CapacitorBank

Distribution Primary LineCurrent/Voltage

Sensor

Voltage R l tBank

"Local" Current/Voltage

Measurements On/Off Control Command

Regulator



Standalone Controller

CommandSignal Standalone

Controller

CommandSignal

• Volt‐VAR flows managed by individual, independent, standalone volt‐VAR regulating devices:

Substation transformer load tap changers (LTCs)– Substation transformer load tap changers (LTCs)– Line voltage regulators

– Fixed and switched capacitor banks


Limitations of Traditional ApproachLimitations of Traditional Approach

• Power factor correction/loss reductionPower factor correction/loss reduction– Many traditional cap bank controllers have voltage control (switch on when voltage is low)control (switch on when voltage is low)

• Reactive power controllers available, but expensive (need to add CT)

• Good at maintaining acceptable voltage

• Good at PF correction during peak load seasons may not come on at all• Good at PF correction during peak load seasons –may not come on at all during off peak seasons

• Result is that PF is usually great (near unity) during peak load periods and low during off peak seasons (higher electrical losses)g p ( g )


Monitoring of Switched Capacitor Bank fPerformance

• Switched capacitor banks are notorious forSwitched capacitor banks are notorious for being out of service due to blown fuses, etc.

• With traditional scheme switched capacitor• With traditional scheme, switched capacitor bank could be out of service for extended periods without operator knowingperiods without operator knowing– Losses higher if cap bank is out of service

R i i i d d?– Routine inspections needed?


Traditional Voltage Regulation Strategy

• “Line Drop Compensation” accounts for varying load

Wh l d th h ltLTC

– When load through voltage regulator is high, voltage dropalong the feeder will be high

LTC i lt t

SUBSTATION

Primary Feeder

Secondary

Distribution Transformer

Service Drop WiresFirst

– LTC raises voltage to “compensate”

• This approach works well when ll f d l d th h th

Last Customer

Customer

Voltage

all feeder load passes through the voltage regulator

3 volts Primary

2 volts distribution transformer

1 volt secondary

1 volt service drop

122

119117116115

First Customer

Last Customer

Distance

Last CustomerANSI C84.1 Lower Limit (114 volts)114


Voltage Regulation Problem When Large DG Unit is Introduced

• With a large DR out on the feeder load throughthe feeder, load through Vreg will be reduced

• Vreq thinks load is light on the feeder

• Vreg lowers tap setting to avoid “light load, high voltage” condition

• This action makes theThis action makes the actual “heavy load, low voltage” condition even worse

• DMS that accounts for• DMS that accounts for DG affects can make the proper raise/lower decision based on total feeder conditions


feeder conditions

Voltage Regulation During Alternate Feed Configuration

• Older style voltage regulators were often designed to handle a purely radial situation – power flow always from the same direction (from the substation)

• Older style Vregs may not work correctly if power flow is from the opposite direction (see example)

– Could raise voltage when during light load, creating high voltage situation– Could lower voltage when during heavy load, creating low voltage situation

• Feeder reconfiguration may become a more frequent occurrence due to– Load transferred to another feeder during service restoration (FLISR)g ( )

– Optimal network reconfiguration to reduce losses (DMS application)

Vreg not bi-directional


Incorrect Operation!

Use of “Bidirectional” Voltage Regulator

• Can Use “Bidirectional” voltage regulator controller to handle feeder reconfiguration

• These make the opposite tap position movement when flow is from the reverse directiondirection

Vreg bi-directional


Correct Operation!

Reverse Power Flow with DGReverse Power Flow with DG• A DG of sufficient size can reverse

power flow• Bidirectional Voltage Regulator

Vreg bi-directional

g gmay not work correctly

• DG does not typically provide a source strength stronger than the substation

Direction of Power Flow

1.0 1.0

Normal Load

DG

substation. – Substation side voltage does not

change, – DG side changesE ith Bidi ti l V

Direction of Power Flow

Normal Load

VsVl

Vl = Vs

• Even with Bidirectional Vreg, could wind up lowering the voltage on a portion or the feeder during heavy load

diti

.901.0Increased

Load

Vs VlVl = Vs x .90

DG

conditions• Conclusion: Need a more

sophisticated voltage control strategy when DG penetration is

Vl

Incorrect Operation!


large enough to reverse power flow

Limitations of Traditional Volt‐VAR Control

Current/VoltageSensor

CapacitorBank

Distribution Primary LineCurrent/Voltage

Sensor

Voltage R l tBank



Regulator



Standalone Controller

CommandSignal Standalone

Controller

CommandSignal

• The system is not continuously monitored• The system lacks flexibility to respond to changing conditions out on the

distribution feeders can misoperate following automatic reconfigurationdistribution feeders – can misoperate following automatic reconfiguration• System operation may not be “optimal” under all conditions

• Cannot override traditional operation during power system emergencies


• System may misoperate when modern grid devices (e.g., distributed generators) are present – reverse power flow from DG can “trick” standalone controller to believe feeder has been reconfigured

“Scorecard” for Traditional Volt VAR

V lt VAR R i t Traditional Volt-Volt VAR Requirements Traditional VoltVAR

Acceptable Voltage Profile XAcceptable Power Factor XSelf MonitoringOperator OverridepFeeder Reconfiguration SmartGrid DevicesOptimal Coordinated ControlOptimal Coordinated ControlSelectable Operating Objectives


“SCADA” Controlled Volt‐VARSCADA Controlled Volt VAR

• Volt‐VAR power apparatus monitored and controlled by p pp ySupervisory Control and Data Acquisition (SCADA)

• Volt‐VAR Control typically handled by two separate (i d d t) t(independent) systems:– VAR Dispatch – controls capacitor banks to improve power factor,

reduce electrical losses, etc

– Voltage Control – controls LTCs and/or voltage regulators to reduce demand and/or energy consumption (aka, Conservation Voltage Reduction)

• Operation of these systems is primarily based on a stored set of predetermined rules (e.g., “if power factor is less than 0 95 then switch capacitor bank #1 off”)


0.95, then switch capacitor bank #1 off )

Overall Objective of VAR dispatchOverall Objective of VAR dispatch

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VAR Dispatch Components

• Switched & fixed feeder capacitor banks

• Capacitor bank control interfacep

• Communications facility ‐ one‐way paging or load management communications is sufficient

• Means of monitoring 3‐phase var flow at the substation


substation

• Master station running VAR dispatch software

Monitoring Real and Reactive Power Flow


VAR Dispatch Rules Applied


Real and Reactive Load Increases


Reactive Power Flow Exceeds Threshold


Capacitor Switched On


Change in Reactive Power Detected


Change in Reactive Power Detected

Change detected by Substation

RTU


RTU

Benefits of VAR Dispatch vs Traditional

• Self Monitoring

• Operator override capability


• Some improvement in efficiency

Objectives for SCADA Voltage Control

• Maintain acceptable voltage at all locationsMaintain acceptable voltage at all locations under all loading conditions

• Operate at as low as voltage as possible to• Operate at as low as voltage as possible to reduce power consumption (aka Conservation Voltage Reduction)Voltage Reduction)


Conservation Voltage Reduction


Source: Tom Wilson PCS Utilidata

Benefits of Voltage Reduction for Various Types of Loads

• Constant impedance (power consumed is proportional to voltage squared)

– Incandescent lighting, resistive water heaters, stovetop and over cooking loads

• Constant power (demand is constant regardless of voltage)

– Electric motors, regulated power supplies

• Constant current (demand is proportional to voltage) (few of this type of load)

– Welding units, smelting, electroplating processes

• Feeder load is always a mix of the different load types

• Rules of thumb:• Rules of thumb:– 60/40 split (constant power/constant

impedance) for summer peak loads

– 40/60 split for winter peak loads

– 80/20 for industrial areas

– 70/30 for residential load in residential with summer peaking

– 30/70 for res load with winter peaking

– Commercial loads: 50/50 or 60/40

• Source: Power Distribution Planning


Source: Power Distribution Planning Reference Book”, H. Lee Willis

Benefits of Voltage Reduction

• Works best with resistive load (lighting and resistive heating) because power drawn decreases with the voltage squared .

P = V 2 ÷ RConstant

Impedance load

• Devices that operate using a thermostatgenerally do not reduce energy – the devices


just run longer

Benefits of Voltage Reduction

Efficiency improve for small voltage reduction

Incremental change in efficiency drops off and then turns negative as voltage is reduced

Negative effect occurs sooner for heavily loaded motors


Benefits of Voltage Reduction on motors• Motor loss reduction is a balancing act between magnetic

effects and electrical effects:– Magnetic losses (Iron Losses) are reduced when voltage is lowered

– Motor current increases as voltage is decreased (constant power effect) – but if motor loading is light, current increases gradually

– Initial effect is reduced energy assumption, but as voltage is deceased further, copper loss increases and motor becomes less efficient

“Power Savings Obtained from Supply VoltageVariation on Squirrel Cage Induction Motors”

C. D. Pitis, BC Hydro Power Smart, and M. W. Zeller, BC Hydro Power Smart


BC Hydro Power Smart

Emerging Load Characteristics• Digital Devices:

– Typically have a universal power supply covering a wide‐range of input voltage variations (e.g.: LCD/Plasma TV & VCRs = 80‐240 V)g ( g )

– Constant power behavior

• Electric Vehicle Chargers:C– Constant power

– Constant Voltage (regulated output, during maintenance charge)

– Constant current (Low state of charge and fast charging type) NiMH Charging Profile


Example charging curves for two EV chargers

Voltage Control ComponentsVoltage Control Components

EOF V ltEOF Voltage measurement126V

Actual

114V

116VCVR

Cutoff

Voltage

EOF = End of feeder


EOF Voltage Below Voltage Control Threshold (No Control Actions)(No Control Actions)

EOF V ltVoltage Control

ProcessorComm

Interface

EOF Voltage measurement126V

Actual

LTCSubstation

RTUVolt Meter

or AMRComm Interface

LTCController

Substation Transformer

114V

116VCVR

Cutoff

Voltage

OO

Reactive Power (MVAR)

Real Power (MW) End ofFeeder

OOOOOO

OO Voltage Transformer

Reactive Power (MVAR)EOF = End of feeder


EOF Voltage Above Voltage Control h h ldThreshold

EOF V ltVoltage Control

ProcessorComm

Interface


Actual Voltage

LTCSubstation

RTUVolt Meter


LTCController


114V

116VCVR

Cutoff

OOEnd ofFeeder

OOOOOO

OO

EOF = End of feeder


EOF Voltage Above Voltage Control Threshold (lower tap setting)(lower tap setting)

EOF V lt

Voltage Control Processor

Comm Interface

Lower Tap


Actual Voltage

LTCSubstation

RTUVolt Meter


LTCController


Setting

114V

116VCVR

Cutoff

OOEnd ofFeeder

OOOOOO

OOTransformer

EOF = End of feeder


EOF Voltage Above Voltage Control Threshold (lower tap setting)(lower tap setting)

EOF V lt

Voltage Control Processor

Comm Interface

Lower Tap


Actual Voltage

LTCSubstation

RTUVolt Meter


LTCController


Setting

114V

116VCVR

Cutoff

OOEnd ofFeeder

OOOOOO

OOTransformer

• Self Monitoring

• Operator override capability


• CVR function not available with traditional

CVR based on Voltage measurementsCVR based on Voltage measurements

• Hydro Quebec Results:– Simple but not fully effective. Demonstration project gained

only 30% of the estimated energy consumption.only 30% of the estimated energy consumption.• Volt meters not really at the end of the feeders. Volt meters installed only on 3 phases circuits. Targets need to cover also the worst case voltage drop of the single phase networks.

• Network topology during the demonstration project (1 year average) was not in its normal state 40% of the time.

Volt Meter

Communication network

Substation

End of Feeder

Regulationllcontroller

A local regulation controller monitors the end of feeder’s voltage and


Source: ”Volt-VAR Control Implementation at Hydro Québec”; Presented by Herve Delmas to IEEE Smart Distribution Volt Var

Task Force, January 2010

A local regulation controller monitors the end of feeder s voltage and sets the tap to maintain this voltage at 115V.

Lack of Coordination between Volt and lVAR control

• Switching a capacitor bank on raises theSwitching a capacitor bank on raises the voltage, which:– Increases no load losses in distribution– Increases no‐load losses in distribution transformers

– Increases energy consumption and possiblyIncreases energy consumption and possibly demand

• Lowering the voltage through CVR:Lowering the voltage through CVR:– Makes the capacitor banks less effective (lower voltage means less capacitive current delivered by


voltage means less capacitive current delivered by the cap banks)

SCADA Volt VAR Summaryy• Does not adapt to changing feeder configuration (rules are fixed in advance)configuration (rules are fixed in advance)

• Does not adapt to varying operating needs(rules are fixed in advance)(rules are fixed in advance)

• Overall efficiency is improved versus traditional approach but is not necessarilytraditional approach, but is not necessarily optimal under all conditions

• Operation of VAR and Volt devices is not• Operation of VAR and Volt devices is not coordinated

• Does not adapt well to presence of modern


• Does not adapt well to presence of modern grid devices such as DG

Sample Calc: kWh Loss Savings Due to VAR DispatchVAR Dispatch

Sample Calculation 2: Savings Due to kWh Reduction Input Values: Target power factor (TPF) = 1 00 usefulTarget power factor (TPF) = 1.00 Average power factor (AVGPF) = .95 Peak load on feeder (PKLOAD) = 8,000 kilowatts Distribution losses (% of peak load) = 4.0% Average cost to purchase one kilowatt-hour = 0.04 $/kWh

useful formula

g p $ Annual savings per feeder = 8760 x .456 x DLOSS x PKLOAD x (1 – AVGPF2 / TPF2) x .04 kWh per year = 8760 x 0.456 x 4% x 8000 x (1 - .952 / 1.02) * .04

$ f = $4,985 per year per feeder


Sample Calculation: Demand Reduction Due to VAR DispatchDue to VAR Dispatch

Sample Calculation 3: Savings in Energy Supplier Demand ChargesSample Calculation 3: Savings in Energy Supplier Demand Charges Input Values: Target power factor (TPF) = 1.00g p ( )Power factor at peak load (PKPF) = .98 Peak load on feeder (PKLOAD) = 8,000 kilowatts Energy supplier demand charge (DEMCHG) = 20 $/kW

useful formula

Annual savings per feeder = (1/PKPF - 1/TPF) x 100 % x PKLOAD x DMDCHG = (1 / 0.98 – 1 / 1.00) x 100% x 8,000 x 20

$3 265 f d = $3,265 per year per feeder


Volt VAR “Scorecard”Volt VAR Scorecard

Volt-VAR Approach

Volt VAR Requirements Traditional Volt-VAR

SCADA Volt- VAR

A t bl V lt P fil X X

pp

Acceptable Voltage Profile X XAcceptable Power Factor X XSelf Monitoring XOperator Override XOperator Override XFeeder Reconfiguration SmartGrid DevicesOptimal Coordinated ControlSelectable Operating Objectives


Volt VAR Optimization (Centralized Approach)

• Develops and executes a coordinated “optimal” switching plan for all voltage control devices

• Uses optimal power flow program to decide what to• Uses optimal power flow program to decide what to do

• Achieves utility‐specified objective functions:Achieves utility specified objective functions:– Minimize distribution system power loss– Minimize power demand (sum of distribution power loss and

customer demand)customer demand)– Maximize revenue (the difference between energy sales and energy

prime cost)– Combination of the above

• Can bias the results to minimize tap changermovement and other equipment control actions that

ddi i l “ d ” h h i l


put additional “wear and tear” on the physicalequipment

Modeling Load Voltage Sensitivity

• Accurate load model for IVVC:

• Determine appropriate values for coefficients on above formula using field experiments andabove formula using field experiments and regression analysis


Volt VAR Optimization (VVO) System fi iConfiguration

Temp Changes

MDMSAMI Line Switch

Distribution System Model

Geographic Information

System (GIS)

Perm Changes

Dynamic Changes

Switched Cap

Bank

Distribution SCADA

On-Line Power Flow (OLPF)

IVVC Optimizing

Engine

Line Voltage

RegulatorDevelops a coordinated

“optimal”Substation RTU

Substation Transformer with TCUL

Substation Capacitor

B k

optimal switching plan for all voltage control

devices and executes the plan


with TCUL Bankexecutes the plan

Volt VAR Optimization (VVO) System Operation

Voltage Feedback

Temp Changes

MDMSAMI Line Switch

Switch Status

Voltage Feedback, Accurate load data

Bank voltage & status, switch control



System (GIS)

Perm Changes

Dynamic Changes Switched

Cap Bank

switch control

Distribution SCADA

On-Line Power Flow (OLPF)IVVC requires real-

time monitoring & control of sub &

IVVC Optimizing

Engine

Line Voltage Regulator

Monitor & control tap

control of sub & feeder devices

Substation RTU



Bank Bank voltage & status

pposition, measure load

voltage and loadMonitor & control tap position, measure load

voltage and load


Bank voltage & status, switch control

Volt VAR Optimization (VVO) System Operation

Temp Changes

MDMSAMI Line Switch

Cuts, jumpers, manual switching

Real-Time Updates



System (GIS)

Perm Changes


Cap Bank

Distribution SCADA

On-Line Power Flow (OLPF)Permanent asset changes

(line extension, d t )

IVVC Optimizing

Engine


reconductor)

Substation RTU



Bank

IVVC requires an accurate, up-to date

electrical model


Bank

Volt VAR Optimization (VVO) System OperationOperation

Temp Changes

MDMSAMI Line Switch



System (GIS)

Perm Changes


Cap Bank

Distribution SCADA


OLPF calculates losses, voltage

profile, etc

IVVC Optimizing

Engine


PowerflowSubstation RTU



Bank

Powerflow Results


Bank


Temp Changes

MDMSAMI Line Switch



System (GIS)

Perm Changes


Cap Bank

Distribution SCADA


Determines optimal set of control

actions to achieve a desired objective

IVVC Optimizing

Engine


Powerflow

j

Substation RTU



Bank

Powerflow Results

Alternative Switching


BankSwitching Plan


Temp Changes

MDMSAMI Line Switch



System (GIS)

Perm Changes


Cap Bank

Distribution SCADA


Determines optimal set of control

actions to achieve a desired objective

IVVC Optimizing

Engine


j

Substation RTU



Bank

Optimal Switching


BankSwitching Plan

Impact of Voltage Reduction on Customers

• In most cases, voltage reduction does not impactIn most cases, voltage reduction does not impact customer equipment, but…..

• Some customers are aware of the principle of voltage p p greduction and gave already taken steps to lower their voltage via individual service voltage regulators (e.g. Smart motor controllers)

• When utility lowers the voltage on the feeder, h l d l hcustomers who are already lowering their own

voltage will go below the minimum


Voltage Reduction LimitationsVoltage Reduction Limitations• Feeders voltage limited?

– May not be able to reduce voltage at all

– May need to “flatten” the voltage profile (Progress energy, Georgia Power, etc)


Current Technologies, LLC


Time Decay of CVR Effects• The most reduction occurs right when the voltage is reduced and then some of the reduction is lost as some loads j st r n longersome loads just run longer


IVVC Benefits D i d l d t t ti ll h• Dynamic model updates automatically when reconfiguration occurs

• Volt – VAR control actions are coordinated

• System can model the effects of Distributed Generation and other modern grid elements

• Produces “optimal” results

• Accommodates varying operating objectives d di t d


depending on present need

Benefits of Volt VAR OptimizationBenefits of Volt VAR Optimization• CVR Factor = ΔP / ΔV basic on actual CVR experience:

BC H d CVR 0 7– BC Hydro CVRf = 0.7

– Progress Energy CVRf = 0.8

– Georgia Power CVRf = 0 8Georgia Power CVRf = 0.8

• Annual Energy Savings = Average Load x #Hours per year x % voltage reduction x CVRf x value of energy conservation ‐Lost revenue from kWh sales

• CVR performed during peak load period can be viewed as demand (capacity) reductiondemand (capacity) reduction


Final Volt‐VAR “Scorecard”Final Volt VAR Scorecard

Volt VAR Approach

Volt VAR Requirements Traditional Volt-VAR

SCADA Volt- VAR

Integrated Volt-VAR

A t bl V lt P fil X X X

Volt-VAR Approach

Acceptable Voltage Profile X X XAcceptable Power Factor X X XSelf Monitoring X XOperator Override X XF d R fi tiFeeder Reconfiguration XSmartGrid Devices XOptimal Coordinated Control XSelectable Operating Objectives X


Volt VAR Optimization – Next Steps

SUBSTATION

PV Inverter PV

Inverter

SUBSTATION

PV Inverter PV

Inverter

SUBSTATION

FEEDER

Supplementary Regulators


Rotating DG

SUBSTATION

FEEDER



Rotating DG

Rotating DG

Rotating

Capacitor ControlLTC Control

PF Rotating

Rotating DG

PV Inverter PV

Inverter

RotatingRotating

Capacitor ControlLTC Control

PF RotatingRotating

Rotating DG

Rotating DG

PV Inverter PV

Inverter

Rotating DG Capacit

or

Rotating DG

Rotating DG

Rotating DG Capacit

or

Rotating DG

Rotating DG

Voltage and VAR Regulation

Coordination Al ith

Manages tap changer settings, inverter and rotating machine VAR levels, and capacitors to regulate voltage, reduce l d

Communication Link

Voltage and VAR Regulation

Coordination Al ith

Manages tap changer settings, inverter and rotating machine VAR levels, and capacitors to regulate voltage, reduce l d

Communication Link


Algorithm losses, conserve energy, and system resources

Algorithm losses, conserve energy, and system resources

Feeder Flow and Resource Control (DG+ES)

ES

DR

Utility grid

DR

ΔPG

DG

RES

• Constant power flow or firming up ΔPW

rate of change at PCC– Eliminate adverse impact

Reduce reserve capacity requirement


– Reduce reserve capacity requirement

Volt VAR Control Optimization Bob Uluski Quanta Technology

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