TSDOS 2020 - Battery Testing Standards and Best Practices...NETA ATS & MTS NERC PRC-005 Reliability...
Transcript of TSDOS 2020 - Battery Testing Standards and Best Practices...NETA ATS & MTS NERC PRC-005 Reliability...
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Battery Testing Standards and Best PracticesVolney Naranjo, Senior Applications Engineer
Daniel Carreno, Applications EngineerMegger
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Introduction• Electrical substations require ESS to operate under outage
conditions• Lead Acid and Nickel Cadmium are the main technologies• Regulations and recommended practices to guarantee
safety, reliability and durability• Installation design, installation, maintenance and testing
practices are scattered in different documents• Navigating guide for substation designers and operators
through the documents from NFPA, IEEE, NETA and NERC
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Agenda• Stationary Battery Types• Standards and Regulations• Inspections and Testing• Load Testing• Ohmic Testing
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STATIONARY BATTERY TYPES
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Battery Types: Construction
VLA VRLA Vented NiCd
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Battery Types: ApplicationFeature Long duration General Purpose Short durationPlate characteristic Thick positive plates Moderately thick plates Thin positive platesApplication Telecommunications Switchgear and control
Suitable for UPSUPS
Type of load Constant and low current Constant and switching loads High current loadsMinimum supply time 3 hours 1 to 3 hours 1 hour or lessNominal discharge rate 8 hours 8 hours 15 minutesCycles per year Less than 10 2 to 5 10-20Performance under high discharge/short time rates
Poor Good Good
Performance under low discharge/long time rates
Good Good Poor
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STANDARDS AND REGULATIONS
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Standards and RegulationsStationary Storage
Systems
Safety
NFPA 1 Chapter
52
NFPA 855 Chapters
4 & 9
IEEE C2 Section
14
Design and installation
Sizing of LA
IEEE 485
VLA Installation
IEEE 484
VRLA Installation IEEE 1187
NiCdInstallationIEEE 1106
Maintenance and Testing
VLAIEEE 450
VRLAIEEE 1188
NETA ATS & MTS
NERC PRC-005
Reliability
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Standards and Regulations
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Safety Standards
NFPA 1 Chapter 52NFPA 70 Non-utility –
Articles 90 and 480
NFPA 855 Chapters 4 and 9IEEE C2 Section 14
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Design and Installation Standards
NFPA 855 Chapters 4 and 9IEEE C2 Section 14IEEE 485 Sizing of LA IEEE 484 VLA InstallationIEEE 1187 VRLA InstallationIEEE 1106 NiCd
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Maintenance and Testing
IEEE 1106 NiCdIEEE 450 VLAIEEE 1188 VRLANETA ATS & MTS VLA, VRLA, NiCdNERC PRC-005 VLA, VRLA, NiCd
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Reliability
NERC PRC-005 VLA, VRLA, NiCd
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VLA/VRLA: INSPECTIONS AND TESTING
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VLA/VRLA: Monthly RecommendationsInspection Type Activity
Monthly
VLA VRLAVisual General appearance and cleanliness of the whole installation I N I N
Visual Crack in cells (evidence of electrolyte leakage) I I
Visual Evidence of corrosion at terminals, connectors, racks or cabinets I N I N
Visual Electrolyte levels I N
Visual Verify presence of flame arresters N
Visual Verify existence of suitable eyewash equipment N N
Mechanical Ambient temperature and ventilation I N I N
Mechanical Perform a thermographic survey under load7 N6 N6
Mechanical Structural Integrity of the battery rack N N
Mechanical Verify tightness of accessible bolted electrical connections 5 N6 N6
Electrical Float voltage measured at the battery terminals I I
Electrical Pilot cells (If used) voltage and electrolyte temperature I
Electrical Cell-to-cell and terminal connection resistance N6 N6
Electrical Charger output current and voltage I I
Electrical Unintentional battery grounds I N N
Electrical Battery float charging current or pilot cell specific gravity I
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VLA/VRLA: Quarterly/Tri-annualRecommendations
Add to Monthly
Inspection Type ActivityQuarterly/ Tri-annual*
VLA VRLAVisual Electrolyte levels P
Mechanical Temperature of at least 10% of cells I
Mechanical Temperature of the negative terminal of each cell I
Mechanical Specific Gravity of 10% of the cells of the battery I2
Electrical Float voltage measured at the battery terminals PElectrical Voltage of each cell I IElectrical Cell/unit internal ohmic values I P10
Electrical Charger output current and voltage PElectrical Unintentional battery grounds P P
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VLA/VRLA: Yearly/18-months Recommendations
Add to Quarterly/Tri-annual
Inspection Type ActivityYearly/18-months*
VLA VRLA1
Visual Cell condition I PMechanical Measure negative post temperature NMechanical Specific Gravity of all cells I2
Mechanical Structural Integrity of the battery rack I P PElectrical Float voltage measured at the battery terminals N P N PElectrical Voltage of each cell N NElectrical Cell/unit internal ohmic values N P4 N PElectrical Cell-to-cell and terminal connection resistance I N P3 I N PElectrical AC ripple current and/or voltage imposed on the battery IElectrical Performance or modified performance capacity test of entire bank I8 N8 P4 I9 N9 P10
SettingsVerify Equalizing Voltage Setting is in accordance to Battery's Manufacturer recommendation N N
Settings Verify all charger functions and alarms N N
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NICD: INSPECTIONS AND TESTING
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NiCd: Quarterly/Tri-annual Recommendations
NiCd
Inspection Type
ActivityQuarterly/ Tri-annual*
Visual General appearance and cleanliness of the whole installation IVisual Electrolyte levels I PVisual Crack in cells (evidence of electrolyte leakage) IVisual Evidence of corrosion at terminals, connectors, racks or cabinets IMechanical Ambient temperature and ventilation IElectrical Pilot cells (If used) voltage and electrolyte temperature IElectrical Float current I
ElectricalMeasure battery system voltage from positive-to-ground and negative-to-ground (check for unintentional battery grounds) P
Electrical Float voltage measured at the battery terminals IElectrical Verify Station DC supply voltage PSettings Charger output and voltage ISettings Adequacy of ventilation I7
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NiCd: Semi-annually Recommendations
NiCd
Add to Quarterly/Tri-annual
Inspection Type
Activity Semi-annually
Electrical Voltage of each cell I
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NiCd: Yearly/18-months RecommendationsNiCd
Add to Semi-annually
Inspection Type
ActivityYearly1 / 18
months*Visual General appearance and cleanliness of the whole installation N PVisual Verify existence of suitable eyewash equipment NVisual Verify application of an oxide inhibitor on battery terminal connections NMechanical Ambient temperature and ventilation NMechanical Perform thermographic survey4 N2
Mechanical Intercell connection torque I
Mechanical Verify tightness of accessible bolted electrical connections by calibrated torque-wrench3 N2
Mechanical Structural Integrity of the battery rack I N PElectrical Pilot cells (If used) voltage and electrolyte temperature NElectrical Voltage of each cell N5
Electrical Perform internal ohmic measurements NElectrical Condition and resistance of cable connections I N2 P
Electrical Measure battery system voltage from positive-to-ground and negative-to-ground (check for unintentional battery grounds) N
Electrical Float voltage measured at the battery terminals NElectrical Perform load test N6
Settings Charger output and voltage P
Settings Charger float and equalizing voltage levels. Adjust to manufacturer’s recommended settings N P
Settings Verify all charger functions and alarms N
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NiCd: 6-years Recommendations
NiCd
Add to Yearly
Inspection Type Activity 6 YearsElectrical Performance or modified performance capacity test of entire bank P
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Corrective Actions
• Electrolyte levels should be maintained above the low-level line and up to the full-level line using either distilled or approved-qualitywater.
• Remove any corrosion in posts or terminals.• When inter-cell connection resistance values are not acceptable, even after retorque, connections should be disassembled, cleaned,
reassembled, and retested.• If individual cell temperatures deviate more than 3 ˚C from each other, the problem should be investigated and corrected. For multi-tier
installations, 3 ˚C might not be achievable and the battery manufacturer should be consulted.• Equalizing charge – for applicable battery types, when:
o Individual float voltages deviate from the average value recommended by manufacturero Undercharge condition is suspected and confirmed by lower than expected specific-gravity measurementso Plate sulfationo Immediately if any cell voltage is below the manufacturer’s recommended minimum cell voltage
• Hydration: a battery in this condition should be replaced as soon as possible
IEEE recommends some corrective actions for common issues that can be found duringmaintenance activities.
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LOAD AND OHMIC TESTING
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LOAD TESTING
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Load Testing• Load testing is the only proven
method to determine– Capacity of the battery– True State of Health (SOH)
• Load testing is a time and resource demanding test– Proper understanding of
procedures– Adequate tools
https://www.radiology.ca/article/how-does-exercise-stress-test-work
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Load Testing
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Type of Tests:
Acceptance Test
@ Factory or Upon
Installation
Specific constant discharge
rate & duration
Measures %C, ≥ 90% of
rated Capacity
Capacity may rise after use
Acceptance based on the
Time-Adjusted Method
Baseline for trending
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Type of Tests:
Performance Test
Measures the %C
Constant current or
power
Similar in duration to duty cycle
Test periodically. Every 25%
of Life
For trending:
Prepare the battery
To reflect maintenance
, do not prepare the
battery
https://www.radiology.ca/article/how-does-exercise-stress-test-work
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Type of Tests:
Service Test
Ability to meet a specific
application
Ability to meet the duty cycle
As found, no preparation,
no temperature
correctionAt discretion in between
performance tests
Discharge rate as close as practical
to duty cycle
If fails: review sizing,
maintain & equalize
IEEE485
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Type of Tests:
Modified Performance Test (MPT)
Constant current
modified to include duty
cycle
Tests ability to meet the duty cycle
Measures %C, uses
T correction
Initial conditions
same as Service test
Three types of MPT
described in IEEE450 (Annex I)
Aging factor needed to calculate
minimum test duration
https://www.radiology.ca/article/how-does-exercise-stress-test-work
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Analysis & Replacement Criteria• If at 85% of service life, delivers
100% capacity or greater of the manufacturer’s rated capacity, and has shown no signs of degradation:
– performance testing at two-year intervals instead of 1-year intervals
– Until the battery shows signs of degradation
• Degradation:– Capacity drop>10% from
previous performance test
– Below 90% of the manufacturer’s rating
• Replacement: at 80% Capacity
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OHMIC TESTING
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Test MethodsInternal Ohmic Measurements
─ Ohmic testing can be accomplished using one of three techniques:
– Resistance – Measures only the resistive value of a battery, The battery has capacitive and inductive values as well.
– Conductance – (Actually Admittance) This is the reciprocal of impedance.
– Impedance Testing – Measures the resistive, capacitive and inductive qualities of the battery.
NOTE: Ohmic testing is a relative test NOT an absolute test. We do not test against an absolute value. We test and compare data to a previous test result.
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• Impedance testing has a distinct advantage over resistive type testing. When we look at a schematic representation of a battery there are more than just resistive components to that battery. There are also capacitive and inductive characteristics.
• This means that impedance testing will be able to detect certain problems that resistive measurements can miss; these include negative lug rot as well as negative plate corrosion. These failures will show themselves as changes in inductance and capacitance, not in resistance. In addition many chemical changes in a battery will be seen as impedance changes before they are seen as resistive changes.
Test Methods
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Battery Impedance Test• The following factors will affect the readings (per IEEE 450):
– Cell type and construction– Battery Charge– Electrolyte temperature– Specific Gravity– String length and configuration (Parallel)– Load– Charger (Ripple and other noise) – Make and model of instrument being used– Probe Type– Where the measurement is taken on the battery
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Battery Impedance Test
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Ohm
ic V
alue
(moh
ms)
Cell
Ohmic Results From Two Different Signals
Instrument A Instrument B
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Battery Impedance Test
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0.2
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0.6
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Ohm
ic V
alue
(moh
ms)
Cell
Impedance before and after charging
Discharged Charged
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Additional Measurements
• Voltage of each cell• Float Current• Ripple Current• Strap Resistances
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Impedance Data Analysis
Type of Battery Single Test Trending
% change from average (short-
term)
% change from last test (mid-
term)
Overall % change (long-
term)VLA 15 5 30VRLA 10 5 20NiCd 10 5 15
Recommended impedance warning limits
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Impedance Data Analysis
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Summary
Design, Installation,
Maintenance and Testing
Construction
Application
VLA
VRLA
NiCd
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SummaryFire & Life
Safety
NFPA 1
NFPA70
NFPA855
Design & Installation
NFPA 1
NFPA70
NFPA855
IEEE C2
IEEE 485
IEEE 484
IEEE 1187
IEEE 1106
Maintenance & Testing
IEEE 450
IEEE 1188
NETA ATS & MTS
NERC PRC-005
Reliability
NERC PRC-005
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Summary
Fire & Life Safety
NFPA 1
NFPA70
NFPA855
Design & Installation
NFPA 1
NFPA70
NFPA855
IEEE C2
IEEE 485
IEEE 484
IEEE 1187
IEEE 1106
Reliability
NERC PRC-005
Maintenance & Testing
IEEE 450
IEEE 1188
NETA ATS & MTS
NERC PRC-005
Load Testing
Ohmic Testing
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QUESTIONS?