Simplified VO M&V Protocols
Approved May 4th, 2010
1. Simplified VO M&V Protocol can be applied to distribution
systems with Residential and Small Commercial Loads to
verify energy savings from reduced voltage operation.
2. Protocol makes use of historical data, system modeling, 7day M&V ‘on’ and 7-day ‘off’ hourly measurements, and
“Deemed” end-use VO Factors determined from NEEA DEI
Study 2007 results.
3. Protocol can be used with three Voltage Regulation
Techniques, VFR, LDC, and AVFC.
1
Three Voltage Regulation Techniques
1. Voltage Fixed Reduction (VFR)
• Fixes the voltage level at the substation source and the
voltage level at the end of the feeder varies with load
Volts
126
• Old voltage setting Vset = 125V, R and X settings = 0
• New voltage setting Vset = 122V, R and X settings = 0
120
114
Feeder Length
2
Three Voltage Regulation Techniques
2. Line Drop Compensation (LDC)
– Fixes the voltage level at the end of the feeder and the
voltage level varies at the substation source with load
Volts
126
• Old voltage setting Vset = 125V, R and X settings = 0
• New voltage setting Vset = 120V, R and X settings = 3 to 5
120
114
Feeder Length
3
Three Voltage Regulation Techniques
3. Automatic Voltage Feedback Control (AVFC)
– Fixes the voltage level at the substation source based on
real-time voltage feedback sign from the end of the feeder
(s)
4
Three Voltage Regulation Techniques
3. Automatic Voltage Feedback Control (AVFC)
– Fixes the voltage level at the substation source based on
real-time voltage feedback sign from the end of the feeder
Volts
126
• Old voltage setting Vset = 125V, R and X settings = 0
• New voltage setting Vset = 119V, R and X settings = 0
120
114
Feeder Length
5
Voltage Control Zones
Primary
Voltage Zone
VCZ for
LTC
Transformer
Feeder
Secondary
Voltage
Zone
Load Tap
Changer
(LTC)
Feeder Breaker
6
Voltage Control Zones
VCZ for LTC
Transformer
VCZ for V-Reg
Feeder
V-Reg
Load Tap
Changer
(LTC)
Feeder Breaker
7
Four Stages to Simplified VO M&V Protocol
1.
Existing Performance
Assessment and
VO Implementation Plan
2.
System Improvements
Baseline Pre-VO
measurements
3.
VO Implementation
Post-VO Measurements
and Verification
4.
Persistence Measurements
Historical Load Data:
kWh-annual, Volt_Drop-max,
kWpeak-demand
Distr _Line Modeling
Load_Flow Analysis
Threshold Analysis
Determine end-use VO Factor
Estimate Potential Savings
Install VO and SI Improvements
7-day measurements ‘OFF’
Veol, Vset, Esub
Calculate Vpre-annual average
7-day measurements ‘ON’
Veol, Vset, Esub
Calculate Vpost-annual average
Determine Verified Savings
8
Performance Thresholds
• Power Factor
 Power Factor on average > 98% (period)
 Power Factor minimum > 96% (period)
• Phase Unbalance
 Must be < 0.15pu, or < 40 amps
• Voltage Drop (Vd) for each voltage control zone
 Must be < 3.3% on primary at feeder peak loads
9
Performance Thresholds (continued)
• Maximum Voltage Drop Variance (Vdv) between feeders
within the same voltage control zone (during period)
 Must be < 0.25 p.u. or < 2.0V
• Maximum Voltage Drop (Vd) for secondary
– Must be < 4.0%, based on design standards and criteria
• Voltage level must be > (114V+1/2 Bandwidth) and less than
(126V-1/2 Bandwidth)
10
Why Performance Threshold are Critical
Establishing thresholds helps to resolve key issue found
in the pilot NEEA projects that did not perform well.
• Reduces voltage fluctuation due to changing
loads/conditions
• Reduces losses in the distribution system
• Allows recording periods to be minimized (1 week to
establish daily load shapes and weekend/weekday
load shapes)
11
VO Factor Determination
• Uses Results from the NEEA DEI study to determine
– Heating and cooling zones
– Residential and commercial load
– End-use load characteristics
• Electric heating
• Air conditioning
395
12
NEEA DEI Study VOf Sensitivity
Minor impacts due to AC End-Use Load
VOf with Heating Zone = 2 Cooling Zone = 2
Each Curve Represents % of Homes with Airconditioning
0.8
0
10
20
30
40
50
60
70
80
90
100
VOf Residental Homes
0.7
0.6
0.5
0.4
16% Variation
0.3
0.2
0.1
0
0
10
20
30
40
50
60
70
80
90
100
% Non-Electric
13
Voltage Reduction Calculation
• Calculate ΔV for each voltage control zone
• Dependant on which voltage control method
– VFR
Adjusted Average Voltage for VFR =
[Regulator_Set_Point_Voltage_Setting – ½ * A *
Annual_Load_Factor]
– LDC/AVFC
Adjusted Average Voltage for LDC =
[Regulator_Set_Point_Voltage_Setting + Annual_Load_Factor
*[B - 1/2 *A]]
Where:
A is the maximum voltage drop at peak load, and
B is the Calculated Regulator Maximum Annual Volt-Rise
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Method of Calculating Energy Savings (Delta V)
Energy Saved =
Change in voltage x Voltage Optimization Factor x Annual Energy +
Energy Saved from System Improvements
From proposed protocols
E Saved = ΔV x VOf x E Annual + ΔE SI
From NEEA’s DEI research and pilot
VO calculation method already “approved” by RTF
• ΔV - determined from this program
• VOf - derived from NEEA load research study and confirmed by
EPRI studies, and other industry pilots and research
• E Annual – Metered Data from Utility
• ΔE - Energy Saved from System Improvements
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