Reliability Standard MOD-025-2

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability
A. Introduction
1.

Title:
Verification and Data Reporting of Generator Real and Reactive Power
Capability and Synchronous Condenser Reactive Power Capability

2.

Number:

3.

Purpose: To ensure that accurate information on generator gross and net Real and
Reactive Power capability and synchronous condenser Reactive Power capability is
available for planning models used to assess Bulk Electric System (BES) reliability.

4.

Applicability:

MOD-025-2

4.1. Functional entities

4.1.1

Generator Owner

4.1.2

Transmission Owner that owns synchronous condenser(s)

4.2. Facilities:

For the purpose of this standard, the term, “applicable Facility” shall mean any one of
the following:

5.

4.2.1

Individual generating unit greater than 20 MVA (gross nameplate rating)
directly connected to the Bulk Electric System.

4.2.2

Synchronous condenser greater than 20 MVA (gross nameplate rating)
directly connected to the Bulk Electric System.

4.2.3

Generating plant/Facility greater than 75 MVA (gross aggregate
nameplate rating) directly connected to the Bulk Electric System.

Effective Date:
5.1. In those jurisdictions where regulatory approval is required1:

5.1.1

By the first day of the first calendar quarter, two calendar years following
applicable regulatory approval, or as otherwise made effective pursuant to
the laws applicable to such ERO governmental authorities, each Generator
Owner and Transmission Owner shall have verified at least 40 percent of
its applicable Facilities.

5.1.2

By the first day of the first calendar quarter, three calendar years following
applicable regulatory approval, or as otherwise made effective pursuant to
the laws applicable to such ERO governmental authorities, each Generator
Owner and Transmission Owner shall have verified at least 60 percent of
its applicable Facilities.

5.1.3

By the first day of the first calendar quarter, four calendar years following
applicable regulatory approval, or as otherwise made effective pursuant to

1

Wind Farm Verification - If an entity has two wind sites, and verification of one site is complete, the entity is 50%
complete regardless of the number of turbines at each site. A wind site is a group of wind turbines connected at a
common point of interconnection or utilizing a common aggregate control system.
Page 1 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

the laws applicable to such ERO governmental authorities, each Generator
Owner and Transmission Owner shall have verified at least 80 percent of
its applicable Facilities.
5.1.4

By the first day of the first calendar quarter, five calendar years following
applicable regulatory approval, or as otherwise made effective pursuant to
the laws applicable to such ERO governmental authorities, each Generator
Owner and Transmission Owner shall have verified 100 percent of its
applicable Facilities.

5.2. In those jurisdictions where regulatory approval is not required2:

5.2.1

By the first day of the first calendar quarter, two calendar years following
Board of Trustees approval, each Generator Owner and Transmission
Owner shall have verified at least 40 percent of its applicable Facilities.

5.2.2

By the first day of the first calendar quarter, three calendar years following
Board of Trustees approval, each Generator Owner and Transmission
Owner shall have verified at least 60 percent of its applicable Facilities.

5.2.3

By the first day of the first calendar quarter, four calendar years following
Board of Trustees approval, each Generator Owner and Transmission
Owner shall have verified at least 80 percent of its applicable Facilities.

5.2.4

By the first day of the first calendar quarter, five calendar years following
Board of Trustees approval, each Generator Owner and Transmission
Owner shall have verified 100 percent of its applicable Facilities.

Note: The verification percentage above is based on the number of applicable units owned.

2

Wind farm verification - If an entity has two wind sites, and verification of one site is complete, the entity is 50%
complete regardless of the number of turbines at each site. A wind site is a group of wind turbines connected at a
common point of interconnection or utilizing a common aggregate control system.
Page 2 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

Requirements
R1.

Each Generator Owner shall provide its Transmission Planner with verification of the
Real Power capability of its applicable Facilities as follows: [Violation Risk Factor:
Medium] [Time Horizon: Long-term Planning]
1.1. Verify the Real Power capability of its generating units in accordance with

Attachment 1.
1.2. Submit a completed Attachment 2 (or a form containing the same information as

identified in Attachment 2) to its Transmission Planner within 90 calendar days of
either (i) the date the data is recorded for a staged test; or (ii) the date the data is
selected for verification using historical operational data.
R2.

Each Generator Owner shall provide its Transmission Planner with verification of the
Reactive Power capability of its applicable Facilities as follows: [Violation Risk
Factor: Medium] [Time Horizon: Long-term Planning]
2.1. Verify, in accordance with Attachment 1, (i) the Reactive Power capability of its

generating units and (ii) the Reactive Power capability of its synchronous
condenser units.
2.2. Submit a completed Attachment 2 (or a form containing the same information as

identified in Attachment 2) to its Transmission Planner within 90 calendar days of
either (i) the date the data is recorded for a staged test; or (ii) the date the data is
selected for verification using historical operational data.
R3.

Each Transmission Owner shall provide its Transmission Planner with verification of
the Reactive Power capability of its applicable Facilities as follows: [Violation Risk
Factor: Medium] [Time Horizon: Long-term Planning]
3.1. Verify, in accordance with Attachment 1, the Reactive Power capability of its

synchronous condenser units.
3.2. Submit a completed Attachment 2 (or a form containing the same information as

identified in Attachment 2) to its Transmission Planner within 90 calendar days of
either (i) the date the data is recorded for a staged test; or (ii) the date the data is
selected for verification using historical operational data.
B. Measures
M1. Each Generator Owner will have evidence that it performed the verification, such as a

completed Attachment 2 or the Generator Owner form with the same information or
dated information collected and used to complete attachments, and will have evidence
that it submitted the information within 90 days to its Transmission Planner; such as
dated electronic mail messages or mail receipts in accordance with Requirement R1.
M2. Each Generator Owner will have evidence that it performed the verification, such as a

completed Attachment 2 or the Generator Owner form with the same information, or
dated information collected and used to complete attachments and will have evidence
that it submitted the information within 90 days to its Transmission Planner; such as
dated electronic mail messages or mail receipts in accordance with Requirement R2.
Page 3 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability
M3. Each Transmission Owner will have evidence that it performed the verification, such as

a completed Attachment 2 or the Transmission Owner form with equivalent
information or dated information collected and used to complete attachments, and will
have evidence that it submitted the information within 90 days to its Transmission
Planner; such as dated electronic mail messages or mail receipts in accordance with
Requirement R3.
C. Compliance
1.

Compliance Monitoring Process
1.1. Compliance Enforcement Authority

The Regional Entity shall serve as the Compliance enforcement authority unless
the applicable entity is owned, operated, or controlled by the Regional Entity. In
such cases the ERO or a Regional entity approved by FERC or other applicable
governmental authority shall serve as the CEA.
1.2. Evidence Retention

The following evidence retention periods identify a period of time an entity is
required to retain specific evidence to demonstrate compliance. For instances
where the evidence retention specified below is shorter than the time since the last
compliance audit, the Compliance Enforcement Authority may ask an entity to
provide other evidence to show that it was compliant for the full time period since
the last audit.
The Generator Owner and Transmission Owner shall each keep the data or
evidence to show compliance as identified below, unless directed by its
Compliance Enforcement Authority to retain specific evidence for a longer period
of time as part of an investigation:


The Generator Owner shall retain the latest MOD-025 Attachment 2 and
the data behind Attachment 2 or Generator Owner form with equivalent
information and submittal evidence for Requirements R1 and R2,
Measures M1 and M2 for the time period since the last compliance
audit.



The Transmission Owner shall retain the latest MOD-025 Attachment 2
and the data behind Attachment 2 or Transmission Owner form with
equivalent information and submittal evidence for Requirement R3,
Measure M3 for the time period since the last compliance audit.

If a Generator Owner or Transmission Owner is found noncompliant, it shall keep
information related to the noncompliance until mitigation is complete or for the
time specified above, whichever is longer.
The Compliance Enforcement Authority shall keep the last audit records and all
requested and submitted subsequent audit records.

Page 4 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability
1.3. Compliance Monitoring and Assessment Processes

Compliance Audit
Self-Certification
Spot Checking
Compliance Investigation
Self-Reporting
Complaint
1.4. Additional Compliance Information

None

Page 5 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

2.

Violation Severity Levels

R#
R1

Lower VSL
The Generator Owner
verified and recorded the
Real Power capability of
its applicable generating
unit, but submitted the data
to its Transmission Planner
more than 90 calendar
days, but within 120
calendar days, of the date
the data is recorded for a
staged test or the date the
data is selected for
verification using historical
operational data.
OR
The Generator Owner
verified the Real Power
capability, per Attachment
1 and submitted the data
but was missing 1 to less
than or equal to 33 percent
of the data.

Moderate VSL
The Generator Owner
verified and recorded the
Real Power capability of its
applicable generating unit,
but submitted the data to its
Transmission Planner more
than 120 calendar days, but
within 150 calendar days, of
the date the data is recorded
for a staged test or the date
the data is selected for
verification using historical
operational data.

OR
The Generator Owner
verified the Real Power
capability, per Attachment 1
and submitted the data but
was missing more than 33 to
66 percent of the data.

High VSL

Severe VSL

The Generator Owner verified
and recorded the Real Power
capability of its applicable
generating unit, but submitted
the data to its Transmission
Planner more than 150
calendar days, but within 180
calendar days, of the date the
data is recorded for a staged
test or the date the data is
selected for verification using
historical operational data.

The Generator Owner verified and
recorded the Real Power capability
of its applicable generating unit, but
submitted the data to its
Transmission Planner more than 180
calendar days of the date the data is
recorded for a staged test or the date
the data is selected for verification
using historical operational data.

OR

The Generator Owner failed to
verify the Real Power capability, per
Attachment 1 of an applicable
generating unit.

The Generator Owner verified
the Real Power capability, per
Attachment 1 and submitted
the data but was missing from
67 to 99 percent of the data.

OR

OR
The Generator Owner performed the
Real Power verification per
Attachment 1, “Periodicity for
conducting a new verification” item

OR

Page 6 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

R2

OR

OR

The Generator Owner
performed the Real Power
verification per Attachment
1, “Periodicity for
conducting a new
verification” item 1 or item
2 (5 year requirement) but
did so in more than 66
calendar months but less
than or equal to 69 months.

The Generator Owner
performed the Real Power
verification per Attachment
1, “Periodicity for
conducting a new
verification” item 1 or item 2
(5 year requirement) but did
so in more than 69 calendar
months but less than or equal
to 72 months.

OR

OR

The Generator Owner
performed the Real Power
verification per Attachment
1, “Periodicity for
conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 12 calendar
months but less than or
equal to 13 calendar
months.

The Generator Owner
performed the Real Power
verification per Attachment
1, “Periodicity for
conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 13 calendar
months but less than or equal
to 14 calendar months.

The Generator Owner
verified and recorded the

The Generator Owner
verified and recorded the

The Generator Owner
performed the Real Power
verification per Attachment 1,
“Periodicity for conducting a
new verification” item 1 or
item 2 (5 year requirement) but
did so in more than 72
calendar months but less than
or equal to 75 months.
OR
The Generator Owner
performed the Real Power
verification per Attachment 1,
“Periodicity for conducting a
new verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 14 calendar months
but less than or equal to 15
calendar months.

The Generator Owner verified
and recorded the Reactive
Page 7 of 20

1 or item 2 (5 year requirement) but
did so in more than 75 calendar
months.
OR
The Generator Owner performed the
Real Power verification per
Attachment 1, “Periodicity for
conducting a new verification” item
1, 2 or 3 (12 calendar month
requirement) but did so in more than
15 calendar months.

The Generator Owner verified and
recorded the Reactive Power

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

Reactive Power capability
of its applicable generating
unit or applicable
synchronous condenser,
but submitted the data to its
Transmission Planner more
than 90 calendar days, but
within 120 calendar days,
of the date the data is
recorded for a staged test
or the date the data is
selected for verification
using historical operational
data.

Reactive Power capability of
its applicable generating unit
or applicable synchronous
condenser, but submitted the
data to its Transmission
Planner more than 120
calendar days, but within 150
calendar days, of the date the
data is recorded for a staged
test or the date the data is
selected for verification
using historical operational
data.

Power capability of its
applicable generating unit or
applicable synchronous
condenser, but submitted the
data to its Transmission
Planner more than 150
calendar days, but within 180
calendar days, of the date the
data is recorded for a staged
test or the date the data is
selected for verification using
historical operational data.
OR

OR
OR
The Generator Owner
verified the Reactive
Power capability, per
Attachment 1 and
submitted the data but was
missing 1 to up to and
including 33 percent of the
data.
OR
The Generator Owner
performed the Reactive
Power verification per

The Generator Owner
verified the Reactive Power
capability, per Attachment 1
and submitted the data but
was missing 34 to 66 percent
of the data.

The Generator Owner verified
the Reactive Power capability,
per Attachment 1 and
submitted the data but was
missing 67 to 99 percent of the
data.
OR

OR
The Generator Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1 or item 2

capability of its applicable
generating unit or applicable
synchronous condenser, but
submitted the data to its
Transmission Planner more than 180
calendar days of the date the data is
recorded for a staged test or the date
the data is selected for verification
using historical operational data.
OR
The Generator Owner failed to
verify the Reactive Power
capability, per Attachment 1 of an
applicable generating unit or
synchronous condenser unit.
OR
The Generator Owner performed the
Reactive Power verification per
Attachment 1, “Periodicity for
conducting a new verification” item
1 or item 2 (5 year requirement) but
did so in more than 75 calendar
months.

The Generator Owner
performed the Reactive Power
verification per Attachment 1,
“Periodicity for conducting a
OR
new verification” item 1 or
item 2 (5 year requirement) but
did so in more than 72
Page 8 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

Attachment 1, “Periodicity
for conducting a new
verification” item 1 or item
2 (5 year requirement) but
did so in more than 66
calendar months but less
than or equal to 69 months.

(5 year requirement) but did
so in more than 69 calendar
months but less than or equal
to 72 months.

OR

The Generator Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 13 calendar
months but less than or equal
to 14 calendar months.

The Generator Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 12 calendar
months but less than or
equal to 13 calendar
months.
R3

The Transmission Owner
verified and recorded the
Reactive Power capability
of its applicable
synchronous condenser,
but submitted the data to its
Transmission Planner more

calendar months but less than
or equal to 75 months.
OR

OR

The Transmission Owner
verified and recorded the
Reactive Power capability of
its applicable synchronous
condenser, but submitted the
data to its Transmission
Planner more than 120

The Generator Owner
performed the Reactive Power
verification per Attachment 1,
“Periodicity for conducting a
new verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 14 calendar months
but less than or equal to 15
calendar months.

The Transmission Owner
verified and recorded the
Reactive Power capability of
an applicable synchronous
condenser unit, but submitted
the data to its Transmission
Planner more than 150
Page 9 of 20

The Generator Owner performed the
Reactive Power verification per
Attachment 1, “Periodicity for
conducting a new verification” item
1, 2 or 3 (12 calendar month
requirement) but did so in more than
15 calendar months.

The Transmission Owner verified
and recorded the Reactive Power
capability of its applicable
synchronous condenser, but
submitted the data to its
Transmission Planner more than 180
calendar days of the date the data is

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

than 90 calendar days, but
within 120 calendar days,
of the date the data is
recorded for a staged test
or the date the data is
selected for verification
using historical operational
data.

calendar days, but within 150
calendar days, of the date the
data is recorded for a staged
test or the date the data is
selected for verification
using historical operational
data.

calendar days, but within 180
calendar days, of the date the
data is recorded for a staged
test or the date the data is
selected for verification using
historical operational data.
OR

OR
OR
The Transmission Owner
verified the Reactive
Power capability, per
Attachment 1 and
submitted the data but was
missing 1 to up to and
including 33 percent of the
data.

The Transmission Owner
verified the Reactive Power
capability, per Attachment 1
and submitted the data but
was missing 34 to 66 percent
of the data.

OR

OR
The Transmission Owner failed to
verify the Reactive Power
capability, per Attachment 1 of an
applicable synchronous condenser
unit.
OR
The Transmission Owner performed
the verification per Attachment 1,
“Periodicity for conducting a new
verification” item 1 or item 2 (5 year
requirement) but did so in more than
75 calendar months.

OR

OR
The Transmission Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1 or item
2 (5 year requirement) but
did so in more than 66
calendar months but less

The Transmission Owner
verified the Reactive Power
capability, per Attachment 1
and submitted the data but was
missing 67 to 99 percent of the
data.

recorded for a staged test or the date
the data is selected for verification
using historical operational data.

The Transmission Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1 or item 2
(5 year requirement) but did
so in more than 69 calendar
months but less than or equal
to 72 months.

The Transmission Owner
performed the Reactive Power
verification per Attachment 1,
“Periodicity for conducting a
new verification” item 1 or
item 2 (5 year requirement) but
did so in more than 72
calendar months but less than
or equal to 75 months.

Page 10 of 20

OR
The Transmission Owner performed
the Reactive Power verification per
Attachment 1, “Periodicity for
conducting a new verification” item
1, 2 or 3 (12 calendar month
requirement) but did so in more than
15calendar months.

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive Power Capability and Synchronous
Condenser Reactive Power Capability

than or equal to 69 months.

OR
OR

OR
The Transmission Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 12 calendar
months but less than or
equal to 13 calendar
months.

The Transmission Owner
performed the Reactive
Power verification per
Attachment 1, “Periodicity
for conducting a new
verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 13 calendar
months but less than or equal
to 14 calendar months.

The Transmission Owner
performed the Reactive Power
verification per Attachment 1,
“Periodicity for conducting a
new verification” item 1, 2 or 3
(12 calendar month
requirement) but did so in
more than 14 calendar months
but less than or equal to 15
calendar months.

Page 11 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

D. Regional Variances

None
E. Associated Documents

Version History
Version

Date

Action

Change Tracking

1

12/1/2005

1. Changed tabs in footer.
2. Removed comma after 2004 in
“Development Steps Completed,” #1.
3. Changed incorrect use of certain
hyphens (-) to “en dash” (–) and “em
dash (—).”
4. Added “periods” to items where
appropriate.
5. Changed apostrophes to “smart”
symbols.
6. Changed “Timeframe” to “Time
Frame” in item D, 1.2.
7. Lower cased all instances of
“regional” in section D.3.
8. Removed the word “less” after 94%
in section 3.4. Level 4.

01/20/06

2

February 7, 2013

Adopted by NERC Board of Trustees

Revised per SAR for
Project 2007-09 and
combined with MOD024-1

2

March 20, 2014

FERC Order issued approving MOD025-2. (Order becomes effective on
7/1/16.)

Page 12 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

MOD-025 Attachment 1 – Verification of Generator Real and Reactive Power Capability
and Synchronous Condenser Reactive Power Capability
Periodicity for conducting a new verification:
The periodicity for performing Real and Reactive Power capability verification is as follows:
1. For staged verification; verify each applicable Facility at least every five years (with no
more than 66 calendar months between verifications), or within 12 calendar months of
the discovery of a change that affects its Real Power or Reactive Power capability by
more than 10 percent of the last reported verified capability and is expected to last more
than six months. The first verification for each applicable Facility under this standard
must be a staged test.
2. For verification using operational data; verify each applicable Facility at least every five
years (with no more than 66 calendar months between verifications), or within 12
calendar months following the discovery that its Real Power or Reactive Power capability
has changed by more than 10 percent of the last reported verified capability and is
expected to last more than six months. If data for different points is recorded on different
days, designate the earliest of those dates as the verification date, and report that date as
the verification date on MOD-025, Attachment 2 for periodicity purposes.
3. For either verification method, verify each new applicable Facility within 12 calendar
months of its commercial operation date. Existing units that have been in long term shut
down and have not been tested for more than five years shall be verified within 12
calendar months.
It is intended that Real Power testing be performed at the same time as full load Reactive Power
testing, however separate testing is allowed for this standard. For synchronous condensers,
perform only the Reactive Power capability verifications as specified below.
If the Reactive Power capability is verified through test, it is to be scheduled at a time
advantageous for the unit being verified to demonstrate its Reactive Power capabilities while the
Transmission Operator takes measures to maintain the plant's system bus voltage at the
scheduled value or within acceptable tolerance of the scheduled value.
Verification specifications for applicable Facilities:
1.

For generating units of 20 MVA or less that are part of a plant greater than 75 MVA in
aggregate, record data either on an individual unit basis or as a group. Perform
verification individually for every generating unit or synchronous condenser greater
than 20 MVA (gross nameplate rating).

2.

Verify with all auxiliary equipment needed for expected normal operation in service for
both the Real Power and Reactive Power capability verification. Perform verification
with the automatic voltage regulator in service for the Reactive Power capability
Page 13 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

verification. Operational data from within the two years prior to the verification date is
acceptable for the verification of either the Real Power or the Reactive Power
capability, as long as a) that operational data meets the criteria in 2.1 through 2.4 below
and b) the operational data demonstrates at least 90 percent of a previously staged test
that demonstrated at least 50 percent of the Reactive capability shown on the associated
thermal capability curve (D-curve). If the previously staged test was unduly restricted
(so that it did not demonstrate at least 50 percent of the associated thermal capability
curve) by unusual generation or equipment limitations (e.g., capacitor or reactor banks
out of service), then the next verification will be by another staged test, not operational
data:
2.1. Verify Real Power capability and Reactive Power capability over-excited

(lagging) of all applicable Facilities at the applicable Facilities’ normal (not
emergency) expected maximum Real Power output at the time of the
verifications.
2.1.1

Verify synchronous generating unit’s maximum real power and lagging
reactive power for a minimum of one hour.

2.1.2

Verify variable generating units, such as wind, solar, and run of river
hydro, at the maximum Real Power output the variable resource can
provide at the time of the verification. Perform verification of Reactive
Power capability of wind turbines and photovoltaic inverters with at least
90 percent of the wind turbines or photovoltaic inverters at a site on-line.
If verification of wind turbines or photovoltaic inverter Facility cannot be
accomplished meeting the 90 percent threshold, document the reasons the
threshold was not met and test to the full capability at the time of the test.
Reschedule the test of the facility within six months of being able to reach
the 90 percent threshold. Maintain, as steady as practical, Real and
Reactive Power output during verifications.

2.2. Verify Reactive Power capability of all applicable Facilities, other than wind and

photovoltaic, for maximum overexcited (lagging) and under-excited (leading)
reactive capability for the following conditions:
2.2.1

At the minimum Real Power output at which they are normally expected
to operate collect maximum leading and lagging reactive values as soon as
a limit is reached.

2.2.2

At maximum Real Power output collect maximum leading reactive values
as soon as a limit is reached.

2.2.3

Nuclear Units are not required to perform Reactive Power verification at
minimum Real Power output.

2.3. For hydrogen-cooled generators, perform the verification at normal operating

hydrogen pressure.
2.4. Calculate the Generator Step-Up (GSU) transformer losses if the verification

measurements are taken from the high side of the GSU transformer. GSU
Page 14 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

transformer real and reactive losses may be estimated, based on the GSU
impedance, if necessary.
3.

Record the following data for the verifications specified above:
3.1. The value of the gross Real and Reactive Power generating capabilities at the end

of the verification period.
3.2. The voltage schedule provided by the Transmission Operator, if applicable.
3.3. The voltage at the high and low side of the GSU and/or system interconnection

transformer(s) at the end of the verification period. If only one of these values is
metered, the other may be calculated.
3.4. The ambient conditions, if applicable, at the end of the verification period that the

Generator Owner requires to perform corrections to Real Power for different
ambient conditions such as:


Ambient air temperature



Relative humidity



Cooling water temperature



Other data as determined to be applicable by the Generator Owner to perform
corrections for ambient conditions.

3.5. The date and time of the verification period, including start and end time in hours

and minutes.
3.6. The existing GSU and/or system interconnection transformer(s) voltage ratio and

tap setting.
3.7. The GSU transformer losses (real or reactive) if the verification measurements

were taken from the high side of the GSU transformer.
3.8. Whether the test data is a result of a staged test or if it is operational data.
4.

Develop a simplified key one-line diagram (refer to MOD-025, Attachment 2) showing
sources of auxiliary Real and Reactive Power and associated system connections for
each unit verified. Include GSU and/or system Interconnection and auxiliary
transformers. Show Reactive Power flows, with directional arrows.
4.1. If metering does not exist to measure specific Reactive auxiliary load(s), provide

an engineering estimate and associated calculations. Transformer Real and
Reactive Power losses will also be estimates or calculations. Only output data are
required when using a computer program to calculate losses or loads.
5.

If an adjustment is requested by the Transmission Planner, then develop the
relationships between test conditions and generator output so that the amount of Real
Power that can be expected to be delivered from a generator can be determined at
different conditions, such as peak summer conditions. Adjust MW values tested to the
ambient conditions specified by the Transmission Planner upon request and submit
them to the Transmission Planner within 90 days of the request or the date the data was
recorded/selected whichever is later.
Page 15 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

Note 1:

Under some transmission system conditions, the data points obtained by the Mvar
verification required by the standard will not duplicate the manufacturer supplied
thermal capability curve (D-curve). However, the verification required by the
standard, even when conducted under these transmission system conditions, may
uncover applicable Facility limitations; such as rotor thermal instability, improper tap
settings or voltage ratios, inaccurate AVR operation, etc., which could be further
analyzed for resolution. The Mvar limit level(s) achieved during a staged test or from
operational data may not be representative of the unit’s reactive capability for
extreme system conditions. See Note 2.

Note 2:

While not required by the standard, it is desirable to perform engineering analyses to
determine expected applicable Facility capabilities under less restrictive system
voltages than those encountered during the verification. Even though this analysis
will not verify the complete thermal capability curve (D-curve), it provides a
reasonable estimate of applicable Facility capability that the Transmission Planner
can use for modeling.

Note 3:

The Reactive Power verification is intended to define the limits of the unit’s Reactive
Power capabilities. If a unit has no leading capability, then it should be reported with
no leading capability; or the minimum lagging capability at which it can operate.

Note 4:

Synchronous Condensers only need to be tested at two points (one over-excited point
and one under-excited point) since they have no Real Power output.

Page 16 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

MOD-025 Attachment 2
One-line Diagram, Table, and Summary for Verification Information Reporting
Note: If the configuration of the applicable Facility does not lend itself to the use of the diagram,
tables, or summaries for reporting the required information, changes may be made to this form,
provided that all required information (identified in MOD-025, Attachment 1) is reported.
Company:

Reported By (name):

Plant:

Unit No.:

Date of Report:

Check all that apply:
Over-excited Full Load Reactive Power Verification
Under-excited Full Load Reactive Power Verification
Over-excited Minimum Load Reactive Power Verification
Under-excited Minimum Load Reactive Power Verification
Real Power Verification
Staged Test Data
Operational Data

Simplified one-line diagram showing plant auxiliary Load connections and verification data:
Point of
interconnection
C

*

*

*
*

F

flow in direction of arrow; negative
numbers indicate power flow in

D

opposite direction of arrow.

Generator Step Up

*

*
A

Auxiliary or
Station Service
Transformer(s)

Other point(s) of
interconnection

B
Unit Auxiliary
Transformer(s)

E

Generator(s)
Aux bus

Positive numbers indicate power

*

Auxiliary or
Station Service
Transformer(s)

Aux bus

Page 17 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability
Point

A

Voltage

Real Power

kV

Reactive Power

Comment

MW

Mvar

Sum multiple generators that are verified together
or are part of the same unit. Report individual unit
values separately whenever the verification
measurements were taken at the individual unit.
Individual values are required for units or
synchronous condensers > 20 MVA.

MW

Mvar

Sum multiple unit auxiliary transformers.

MW

Mvar

Sum multiple tertiary Loads, if any.

MW

Mvar

Sum multiple auxiliary and station service
transformers.

Identify calculated values, if any:
B

kV

Identify calculated values, if any:
C

kV

Identify calculated values, if any:
D

kV

Identify calculated values, if any:
E

kV

MW

Mvar

If multiple points of Interconnection, describe
these for accurate modeling; report points
individually (sum multiple auxiliary transformers).

F

kV

MW

Mvar

Net unit capability

Identify calculated values, if any:

Page 18 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability

MOD-025 -Attachment 2 (continued)
Verification Data
Provide data by unit or Facility, as appropriate
Data Type

Data Recorded

Last Verification
(Previous Data;
will be blank for
the initial
verification)

Gross Reactive Power Capability (*Mvar)
Aux Reactive Power (*Mvar)
Net Reactive Power Capability (*Mvar) equals Gross
Reactive Power Capability (*Mvar) minus Aux
Reactive Power connected at the same bus (*Mvar)
minus tertiary Reactive Power connected at the same
bus(*Mvar)
Gross Real Power Capability (*MW)
Aux Real Power (*MW)
Net Real Power Capability (*MW) equals Gross Real
Power Capability (*MW) minus Aux Real Power
connected at the same bus (*MW) minus tertiary Real
Power connected at the same bus(*MW)
* Note: Enter values at the end of the verification period.

GSU losses (only required if verification measurements
are taken on the high side of the GSU - Mvar)
Summary of Verification


Date of Verification _________,Verification Start Time _____, Verification End Time ______



Scheduled Voltage ______________



Transformer Voltage Ratio: GSU ______, Unit Aux _____, Station Aux _____, Other Aux
_____



Transformer Tap Setting: GSU ______, Unit Aux _____, Station Aux _____, Other Aux _____



Ambient conditions at the end of the verification period:
Air temperature: _________
Humidity: _________
Cooling water temperature: _________
Other data as applicable: _________
Page 19 of 20

Standard MOD-025-2 — Verification and Data Reporting of Generator Real and Reactive
Power Capability and Synchronous Condenser Reactive Power Capability


Generator hydrogen pressure at time of test (if applicable) _____________

Date that data shown in last verification column in table above was taken _____________
Remarks :

Note: If the verification value did not reach the thermal capability curve (D-curve), describe the reason.

Page 20 of 20