Reliability Standard BAL-005-1, for RM16-13 NOPR

Exhibit A
Proposed Reliability Standard BAL-005-1

BAL-005-1 Clean Version

BAL-005-1 – Balancing Authority Control

A. Introduction
1.

Title:

Balancing Authority Control

2.

Number:

BAL-005-1

3.

Purpose: This standard establishes requirements for acquiring data necessary to
calculate Reporting Area Control Error (Reporting ACE). The standard also specifies a
minimum periodicity, accuracy, and availability requirement for acquisition of the
data and for providing the information to the System Operator.

4.

Applicability:
4.1. Functional Entities:
4.1.1. Balancing Authority
Effective Date: See Implementation Plan for BAL-005-1

B. Requirements and Measures
R1.

The Balancing Authority shall use a design scan rate of no more than six seconds in
acquiring data necessary to calculate Reporting ACE. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]

M1. Each Balancing Authority will have dated documentation demonstrating that the data
necessary to calculate Reporting ACE was designed to be scanned at a rate of no more
than six seconds. Acceptable evidence may include historical data, dated archive files;
or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R2.

A Balancing Authority that is unable to calculate Reporting ACE for more than 30consecutive minutes shall notify its Reliability Coordinator within 45 minutes of the
beginning of the inability to calculate Reporting ACE. [Violation Risk Factor: Medium]
[Time Horizon: Real-time Operations]

M2. Each Balancing Authority will have dated records to show when it was unable to
calculate Reporting ACE for more than 30 consecutive minutes and that it notified its
Reliability Coordinator within 45 minutes of the beginning of the inability to calculate
Reporting ACE. Such evidence may include, but is not limited to, dated voice
recordings, operating logs, or other communication documentation.
R3.

Each Balancing Authority shall use frequency metering equipment for the calculation
of Reporting ACE: [Violation Risk Factor: Medium] [Time Horizon: Real-time
Operations]
3.1. that is available a minimum of 99.95% for each calendar year; and,
3.2. with a minimum accuracy of 0.001 Hz.

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BAL-005-1 – Balancing Authority Control

M3. The Balancing Authority shall have evidence such as dated documents or other
evidence in hard copy or electronic format showing the frequency metering
equipment used for the calculation of Reporting ACE had a minimum availability of
99.95% for each calendar year and had a minimum accuracy of 0.001 Hz to
demonstrate compliance with Requirement R3.
R4.

The Balancing Authority shall make available to the operator information associated
with Reporting ACE including, but not limited to, quality flags indicating missing or
invalid data. [Violation Risk Factor: Medium] [Time Horizon: Real-time Operations]

M4. Each Balancing Authority Area shall have evidence such as a graphical display or dated
alarm log that provides indication of data validity for the real-time Reporting ACE
based on both the calculated result and all of the associated inputs therein.
R5.

Each Balancing Authority’s system used to calculate Reporting ACE shall be available a
minimum of 99.5% of each calendar year. [Violation Risk Factor: Medium] [Time
Horizon: Operations Assessment]

M5. Each Balancing Authority will have dated documentation demonstrating that the
system necessary to calculate Reporting ACE has a minimum availability of 99.5% for
each calendar year. Acceptable evidence may include historical data, dated archive
files; or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R6.

Each Balancing Authority that is within a multiple Balancing Authority Interconnection
shall implement an Operating Process to identify and mitigate errors affecting the
accuracy of scan rate data used in the calculation of Reporting ACE for each Balancing
Authority Area. [Violation Risk Factor: Medium] [Time Horizon: Same-day Operations]

M6. Each Balancing Authority shall have a current Operating Process meeting the
provisions of Requirement R6 and evidence to show that the process was
implemented, such as dated communications or incorporation in System Operator
task verification.
R7.

Each Balancing Authority shall ensure that each Tie-Line, Pseudo-Tie, and Dynamic
Schedule with an Adjacent Balancing Authority is equipped with: [Violation Risk
Factor: Medium] [Time Horizon: Operations Planning]
7.1. a common source to provide information to both Balancing Authorities for the
scan rate values used in the calculation of Reporting ACE; and,
7.2. a time synchronized common source to determine hourly megawatt-hour values
agreed-upon to aid in the identification and mitigation of errors.

M7. The Balancing Authority shall have dated evidence such as voice recordings or
transcripts, operator logs, electronic communications, or other equivalent evidence
that will be used to demonstratea common source for the components used in the
calculation of Reporting ACE with its Adjacent Balancing Authority.

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BAL-005-1 – Balancing Authority Control

C. Compliance
1.

Compliance Monitoring Process
1.1. Compliance Enforcement Authority
As defined in the NERC Rules of Procedure, “Compliance Enforcement
Authority” means NERC or the Regional Entity in their respective roles of
monitoring and enforcing compliance with the NERC Reliability Standards.
1.2. Evidence Retention
The following evidence retention period(s) identify the period of time an
entity is required to retain specific evidence to demonstrate compliance. For
instances where the evidence retention period specified below is shorter than
the time since the last audit, the Compliance Enforcement Authority may ask
an entity to provide other evidence to show that it was compliant for the fulltime period since the last audit.
The applicable entity shall keep 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 applicable entity shall keep data or evidence to show compliance for
the current year, plus three previous calendar years.

1.3. Compliance Monitoring and Assessment Processes:
As defined in the NERC Rules of Procedure, “Compliance Monitoring and
Assessment Processes” refers to the identification of the processes that will
be used to evaluate data or information for the purpose of assessing
performance or outcomes with the associated Reliability Standard.
1.4. Additional Compliance Information
None

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BAL-005-1 – Balancing Authority Control

Table of Compliance Elements
R#

Time
Horizon

VRF

R1.

Real-time
Operations

R2.

Real-time
Operations

Violation Severity Levels
Lower VSL

Moderate VSL

High VSL

Severe VSL

Medium

N/A

N/A

N/A

Balancing Authority
was using a design
scan rate of greater
than six seconds to
acquire the data
necessary to calculate
Reporting ACE.

Medium

The Balancing
Authority failed to
notify its Reliability
Coordinator within
45 minutes of the
beginning of the
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 50
minutes from the
beginning of the

The Balancing
Authority failed to
notify its Reliability
Coordinator within 50
minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 55
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within
55 minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 60
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within 60
minutes of the
beginning of an
inability to calculate
Reporting ACE.

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BAL-005-1 – Balancing Authority Control

R3.

R4.

Real-time
Operations

Real-time
Operations

Medium

Medium

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.95% of the
calendar year but
was available greater
than or equal to
99.94 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.94% of the
calendar year but was
available greater than
or equal to 99.93 % of
the calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.93% of the
calendar year but
was available greater
than or equal to
99.92 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.92% of the
calendar year

N/A

N/A

N/A

The Balancing
Authority failed to
make available
information
indicating missing or
invalid data
associated with

Or
The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE failed
to have a minimum
accuracy of 0.001 Hz.

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BAL-005-1 – Balancing Authority Control

Reporting ACE to its
operators.
R5.

Operations
Assessment

Medium

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.5% of the calendar
year but was
available greater
than or equal to 99.4
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.4% of the calendar
year but was
available greater than
or equal to 99.3 % of
the calendar year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.3% of the calendar
year but was
available greater
than or equal to 99.2
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.2% of the calendar
year.

R6.

Same-day
Operations

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
implement an
Operating Process to
identify and mitigate
errors affecting the
scan-rate accuracy of
data used in the
calculation of
Reporting ACE.

R7.

Operations
Planning

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
use a common source
for Tie-Lines, Pseudoties and Dynamic
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BAL-005-1 – Balancing Authority Control

Schedules with its
Adjacent Balancing
Authorities
Or
The Balancing
Authority failed to
use a time
synchronized
common source for
hourly megawatt
hour values that are
agreed-upon to aid in
the identification and
mitigation of errors.
D. Regional Variances
None.
E. Interpretations
None.
F. Associated Documents
None.

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BAL-005-1 – Balancing Authority Control

Version History
Version

Date

Action

Change Tracking

0

February 8,
2005

Adopted by NERC Board of Trustees

New

0

April 1, 2005

Effective Date

New

0

August 8, 2005

Removed “Proposed” from Effective Date

Errata

0a

December 19,
2007

Added Appendix 1 – Interpretation of R17 approved
by BOT on May 2, 2007

Addition

0a

January 16,
2008

Section F: added “1.”; changed hyphen to “en dash.”
Changed font style for “Appendix 1” to Arial

Errata

0b

February 12,
2008

Replaced Appendix 1 – Interpretation of R17
approved by BOT on February 12, 2008 (BOT
approved retirement of Interpretation included in
BAL-005-0a)

Replacement

0.1b

October 29,
2008

BOT approved errata changes; updated version
number to “0.1b”

Errata

0.1b

May 13, 2009

FERC approved – Updated Effective Date

Addition

0.2b

March 8, 2012

Errata adopted by Standards Committee; (replaced
Appendix 1 with the FERC-approved revised
interpretation of R17 and corrected standard version
referenced in Interpretation by changing from “BAL005-1” to “BAL-005-0)

Errata

0.2b

September 13,
2012

FERC approved – Updated Effective Date

Addition

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BAL-005-1 – Balancing Authority Control

0.2b

February 7,
2013

R2 and associated elements approved by NERC
Board of Trustees for retirement as part of the
Paragraph 81 project (Project 2013-02) pending
applicable regulatory approval.

0.2b

November 21,
2013

R2 and associated elements approved by FERC for
retirement as part of the Paragraph 81 project
(Project 2013-02) effective January 21, 2014.

February 11,
2016

Adopted by NERC Board of Trustees

1

Complete re-write of standard

Page 9 of 11

Supplemental Material
Rationale
During development of this standard, text boxes were embedded within the standard to explain
the rationale for various parts of the standard. Upon Board approval, the text from the
rationale boxes will be moved to this section.
Rationale for Requirement R1: Real-time operation of a Balancing Authority requires real-time
information. A sufficient scan rate is key to an Operator’s trust in real-time information.
Without a sufficient scan rate, an operator may question the accuracy of data during events,
which would degrade the operator’s ability to maintain reliability.
Rationale for Requirement R2: The RC is responsible for coordinating the reliability of bulk
electric systems for member BA’s. When a BA is unable to calculate its ACE for an extended
period of time, this information must be communicated to the RC within 15 minutes thereafter
so that the RC has sufficient knowledge of system conditions to assess any unintended
reliability consequences that may occur on the wide area.
Rationale for Requirement R3: Frequency is the basic measurement for interconnection health,
and a critical component for calculating Reporting ACE. Without sufficient available frequency
data the BA operator will lack situational awareness and will be unable to make correct
decisions when maintaining reliability.
Rationale for Requirement R4: System operators utilize Reporting ACE as a primary metric to
determine operating actions or instructions. When data inputs into the ACE calculation are
incorrect, the operator should be made aware through visual display. When an operator
questions the validity of data, actions are delayed and the probability of adverse events
occurring can increase.
Rationale for Requirement R5: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Since Reporting ACE is a measure of the
BA’s reliability performance for BAL-001, and BAL-002, it is critical that Reporting ACE be
sufficiently available to assure reliability.
Rationale for Requirement R6: Reporting ACE is a measure of the BA’s reliability performance
for BAL-001, and BAL-002. Without a process to address persistent errors in the ACE calculation,
the operator can lose trust in the validity of Reporting ACE resulting in delayed or incorrect
decisions regarding the reliability of the bulk electric system.
Rationale for Requirement R7: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Common source data is critical to
calculating Reporting ACE that is consistent between Balancing Authorities. When data sources
are not common, confusion can be created between BAs resulting in delayed or incorrect
operator action.

Page 10 of 11

Supplemental Material
The intent of Requirement R7 Part 7.1 is to provide accuracy in the measurement and
calculations used in Reporting ACE. It specifies the need for common metering points for
instantaneous values for the tie-line megawatt flow values between Balancing Authority Areas.
Common data source requirements also apply to instantaneous values for pseudo-ties and
dynamic schedules, and can extend to more than two Balancing Authorities that participate in
allocating shares of a generation resource in supplementary regulation, for example.
The intent of Requirement R7 Part 7.2 is to enable accuracy in the measurements and
calculations used in Reporting ACE. It specifies the need for common metering points for
hourly accumulated values for the time synchronized tie line MWh values agreed-upon
between Balancing Authority Areas. These time synchronized agreed-upon values are
necessary for use in the Operating Process required in R6 to identify and mitigate errors in the
scan-rate values used in Reporting ACE.

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BAL-005-1 Redline Version

BAL-005-1 – Balancing Authority Control

A. Introduction
1.

Title:

Automatic Generation Balancing Authority Control

2.

Number:

BAL-005-0.2b1

3.

Purpose: This standard establishes requirements for Balancing Authority
Automatic Generation Control (AGC)acquiring data necessary to calculate Reporting
Area Control Error (Reporting ACE) and to routinely deploy the Regulating Reserve.).
The standard also ensures that all facilitiesspecifies a minimum periodicity, accuracy,
and availability requirement for acquisition of the data and load electrically
synchronized tofor providing the Interconnection are included within information to
the metered boundary of a Balancing Area so that balancing of resources and demand
can be achievedSystem Operator.

4.

Applicability:
4.1. Balancing Authorities
4.2.

Generator Operators

4.3.

Transmission Operators

4.4.4.1.

Load ServingFunctional Entities:

4.1.1. Balancing Authority
5.

Effective Date:

May 13, 2009 See Implementation Plan for BAL-

005-1
B.

Requirements

R1.B.

All generation, transmission, and load operating within an
Interconnection must be included within the metered boundaries of a
Balancing Authority Area.Measures
R1.1. The Balancing Each Generator Operator with generation facilities operating in

an Interconnection shall ensure that those generation facilities are included
within the metered boundaries of a Balancing Authority Area.
R1.2. Each Transmission Operator with transmission facilities operating in an

Interconnection shall ensure that those transmission facilities are included
within the metered boundaries of a Balancing Authority Area.
R1.3. Each Load-Serving Entity with load operating in an Interconnection shall

ensure that those loads are included within the metered boundaries of a
Balancing Authority Area.
R2. Each Balancing Authority shall maintain Regulating Reserve that can be controlled by

AGC to meet the Control Performance Standard. (Retirement approved by FERC
effective January 21, 2014.)

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BAL-005-1 – Balancing Authority Control

R1.

Authority shall use a design scan rate of no more than six seconds in acquiring data
necessary to calculate Reporting ACE. [Violation Risk Factor: Medium] [Time Horizon:
Real-time Operations]

M1. Each Balancing Authority will have dated documentation demonstrating that the data
necessary to calculate Reporting ACE was designed to be scanned at a rate of no more
than six seconds. Acceptable evidence may include historical data, dated archive files;
or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R3. A Balancing Authority providing Regulation Service shall ensure that adequate
metering, communications, and control equipment are employed to prevent such
service from becoming a Burden on the Interconnection or other Balancing Authority
Areas.
R4. A Balancing Authority providing Regulation Service shall notify the Host Balancing

Authority for whom it is controlling if it that is unable to provide the service, as well
as any Intermediate Balancing Authorities.
R5.

A Balancing Authority receiving Regulation Service shall ensure that backup plans are
in place to provide replacement Regulation Service should the supplying Balancing
Authority no longer be able to provide this service.calculate Reporting ACE for more
than 30-consecutive

R6.R2.

The Balancing Authority’s AGC shall compare total Net Actual Interchange to
total Net Scheduled Interchange plus Frequency Bias obligation to determine the
Balancing Authority’s ACE. Single Balancing Authorities operating asynchronously
may employ alternative ACE calculations such as (but not limited to) flat frequency
control. If a Balancing Authority is unable to calculate ACE for more than 30 minutes
it shall notify its Reliability Coordinator. within 45 minutes of the beginning of the
inability to calculate Reporting ACE. [Violation Risk Factor: Medium] [Time Horizon:
Real-time Operations]

M2. Each Balancing Authority will have dated records to show when it was unable to
calculate Reporting ACE for more than 30 consecutive minutes and that it notified its
Reliability Coordinator within 45 minutes of the beginning of the inability to calculate
Reporting ACE. Such evidence may include, but is not limited to, dated voice
recordings, operating logs, or other communication documentation.
R3.

Each Balancing Authority shall use frequency metering equipment for the calculation
of Reporting ACE: [Violation Risk Factor: Medium] [Time Horizon: Real-time
Operations]
3.1. that is available a minimum of 99.95% for each calendar year; and,
3.2. with a minimum accuracy of 0.001 Hz.

R7. The Balancing Authority shall operate AGC continuously unless such operation

adversely impacts the reliability of the Interconnection. If AGC has become

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BAL-005-1 – Balancing Authority Control

inoperative, the Balancing Authority shall use manual control to adjust generation to
maintain the Net Scheduled Interchange.
R8. The Balancing Authority shall ensure that data acquisition for and calculation of ACE

occur at least every six seconds.
R8.1.M3. Each Balancing Authority shall provide redundant and independent have

evidence such as dated documents or other evidence in hard copy or electronic
format showing the frequency metering equipment that shall automatically activate
upon detection of failure of the primary source. This overall installation shall
provideused for the calculation of Reporting ACE had a minimum availability of
99.95%.% for each calendar year and had a minimum accuracy of 0.001 Hz to
demonstrate compliance with Requirement R3.

R4.

The Balancing Authority shall make available to the operator information associated
with Reporting ACE including, but not limited to, quality flags indicating missing or
invalid data. [Violation Risk Factor: Medium] [Time Horizon: Real-time Operations]

M4. Each Balancing Authority Area shall have evidence such as a graphical display or dated
alarm log that provides indication of data validity for the real-time Reporting ACE
based on both the calculated result and all of the associated inputs therein.
R5.

Each Balancing Authority’s system used to calculate Reporting ACE shall be available a
minimum of 99.5% of each calendar year. [Violation Risk Factor: Medium] [Time
Horizon: Operations Assessment]

M5. Each Balancing Authority will have dated documentation demonstrating that the
system necessary to calculate Reporting ACE has a minimum availability of 99.5% for
each calendar year. Acceptable evidence may include historical data, dated archive
files; or data from other databases, spreadsheets, or displays that demonstrate
compliance.
R6.

Each Balancing Authority that is within a multiple Balancing Authority Interconnection
shall implement an Operating Process to identify and mitigate errors affecting the
accuracy of scan rate data used in the calculation of Reporting ACE for each Balancing
Authority Area. [Violation Risk Factor: Medium] [Time Horizon: Same-day Operations]

M6. Each Balancing Authority shall have a current Operating Process meeting the
provisions of Requirement R6 and evidence to show that the process was
implemented, such as dated communications or incorporation in System Operator
task verification.
R7.

Each Balancing Authority shall ensure that each Tie-Line, Pseudo-Tie, and Dynamic
Schedule with an Adjacent Balancing Authority is equipped with: [Violation Risk
Factor: Medium] [Time Horizon: Operations Planning]
7.1. a common source to provide information to both Balancing Authorities for the
scan rate values used in the calculation of Reporting ACE; and,
7.2. a time synchronized common source to determine hourly megawatt-hour values
agreed-upon to aid in the identification and mitigation of errors.

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BAL-005-1 – Balancing Authority Control
R9. The Balancing Authority shall include all Interchange Schedules with Adjacent

Balancing Authorities in the calculation of Net Scheduled Interchange for the ACE
equation.
R9.1. Balancing Authorities with a high voltage direct current (HVDC) link to

another Balancing Authority connected asynchronously to their Interconnection
may choose to omit the Interchange Schedule related to the HVDC link from
the ACE equation if it is modeledhave dated evidence such as internal
generation or load.
R10. The Balancing Authority shall include all Dynamic Schedules in the calculation of Net

Scheduled Interchange for the ACE equation.
R11. Balancing Authorities shall include the effect of ramp rates, which shall be identical

and agreed to between affected Balancing Authorities,voice recordings or transcripts,
operator logs, electronic communications, or other equivalent evidence that will be
used to demonstrate a common source for the components used in the Scheduled
Interchange values to calculate ACE.
R12.M7.

Each Balancing Authority shall include all Tie Line flowscalculation of Reporting
ACE with its Adjacent Balancing Authority Areas in the ACE calculation.
R12.1. Balancing Authorities that share a tie shall ensure Tie Line MW metering is

telemetered to both control centers, and emanates from a common, agreed-upon
source using common primary metering equipment. Balancing Authorities
shall ensure that megawatt-hour data is telemetered or reported at the end of
each hour.
R12.2. Balancing Authorities shall ensure the power flow and ACE signals that are

utilized for calculating Balancing Authority performance or that are transmitted
for Regulation Service are not filtered prior to transmission, except for the Antialiasing Filters of Tie Lines.
R12.3. Balancing Authorities shall install common metering equipment where

Dynamic Schedules or Pseudo-Ties are implemented between two or more
Balancing Authorities to deliver the output of Jointly Owned Units or to serve
remote load.
R13. Each Balancing Authority shall perform hourly error checks using Tie Line megawatt-

hour meters with common time synchronization to determine the accuracy of its
control equipment. The Balancing Authority shall adjust the component (e.g., Tie
Line meter) of ACE that is in error (if known) or use the interchange meter error (IME)
term of the ACE equation to compensate for any equipment error until repairs can be
made.
R14. The Balancing Authority shall provide its operating personnel with sufficient

instrumentation and data recording equipment to facilitate monitoring of control
performance, generation response, and after-the-fact analysis of area performance. As
a minimum, the Balancing Authority shall provide its operating personnel with realtime values for ACE, Interconnection frequency and Net Actual Interchange with each
Adjacent Balancing Authority Area.

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BAL-005-1 – Balancing Authority Control
R15. The Balancing Authority shall provide adequate and reliable backup power supplies

and shall periodically test these supplies at the Balancing Authority’s control center
and other critical locations to ensure continuous operation of AGC and vital data
recording equipment during loss of the normal power supply.
R16. The Balancing Authority shall sample data at least at the same periodicity with which

ACE is calculated. The Balancing Authority shall flag missing or bad data for
operator display and archival purposes. The Balancing Authority shall collect
coincident data to the greatest practical extent, i.e., ACE, Interconnection frequency,
Net Actual Interchange, and other data shall all be sampled at the same time.
R17. Each Balancing Authority shall at least annually check and calibrate its time error and

frequency devices against a common reference. The Balancing Authority shall adhere
to the minimum values for measuring devices as listed below:

C.

Device

Accuracy

Digital frequency transducer

≤ 0.001

MW, MVAR, and voltage transducer

≤ 0.25 % of full scale

Remote terminal unit

≤ 0.25 % of full scale

Potential transformer

≤ 0.30 % of full scale

Current transformer

≤ 0.50 % of full scale

Hz

Measures
Not specified.

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BAL-005-1 – Balancing Authority Control
D.C.

1.

Compliance
Compliance Monitoring Process
1.1. Compliance Monitoring ResponsibilityEnforcement Authority
Balancing Authorities shall be prepared to supply data to NERC in the format
defined below:
1.1.1.

Within one week upon request, Balancing Authorities shall provide As
defined in the NERC Rules of Procedure, “Compliance Enforcement
Authority” means NERC or the Regional Reliability Organization CPS
source data Entity in daily CSV filestheir respective roles of
monitoring and enforcing compliance with time stamped one minute
averages of: 1) ACE and 2) Frequency Error.

Within one week upon request, Balancing Authorities shall provide
the NERC or the Regional Reliability Organization DCS source data in CSV
files with time stamped scan rate values for: 1) ACE and 2) Frequency Error
for a time period of two minutes prior to thirty minutes after the identified
DisturbanceReliability Standards.
1.1.2.

1.2.

Compliance Monitoring Period and Reset Timeframe
Not specified.

1.3.1.2. DataEvidence Retention
1.3.1. Each Balancing Authority shall retain its ACE, actual frequency,

Scheduled Frequency, Net Actual Interchange, Net Scheduled
Interchange, Tie Line meter error correction and Frequency Bias
Setting data in digital format at the same scan rate at which the data is
collected for at least one year.
1.3.2.

Each Balancing Authority or Reserve Sharing Group shall retain
documentation of the magnitude of each Reportable Disturbance as
well as the ACE charts and/or samples used to calculate Balancing
Authority or Reserve Sharing Group disturbance recovery values. The
data shall be retained for one year following the reporting quarter for
which the data was recorded.

The following evidence retention period(s) identify the period of time an
entity is required to retain specific evidence to demonstrate compliance. For
instances where the evidence retention period specified below is shorter than
the time since the last audit, the Compliance Enforcement Authority may ask
an entity to provide other evidence to show that it was compliant for the fulltime period since the last audit.
The applicable entity shall keep 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.

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BAL-005-1 – Balancing Authority Control

•

The applicable entity shall keep data or evidence to show compliance for
the current year, plus three previous calendar years.

1.3. Compliance Monitoring and Assessment Processes:
As defined in the NERC Rules of Procedure, “Compliance Monitoring and
Assessment Processes” refers to the identification of the processes that will
be used to evaluate data or information for the purpose of assessing
performance or outcomes with the associated Reliability Standard.
1.4. Additional Compliance Information
Not specified.
LevelsNone

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BAL-005-1 – Balancing Authority Control

Table of Non-Compliance Elements

2.

Not specified.
R#

Time
Horizon

VRF

R1.

Real-time
Operations

R2.

Real-time
Operations

Violation Severity Levels
Lower VSL

Moderate VSL

High VSL

Severe VSL

Medium

N/A

N/A

N/A

Balancing Authority
was using a design
scan rate of greater
than six seconds to
acquire the data
necessary to calculate
Reporting ACE.

Medium

The Balancing
Authority failed to
notify its Reliability
Coordinator within
45 minutes of the
beginning of the
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 50
minutes from the
beginning of the

The Balancing
Authority failed to
notify its Reliability
Coordinator within 50
minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 55
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within
55 minutes of the
beginning of an
inability to calculate
Reporting ACE but
notified its Reliability
Coordinator in less
than or equal to 60
minutes from the
beginning of an

The Balancing
Authority failed to
notify its Reliability
Coordinator within 60
minutes of the
beginning of an
inability to calculate
Reporting ACE.

Page 8 of 17

BAL-005-1 – Balancing Authority Control

R3.

R4.

Real-time
Operations

Real-time
Operations

Medium

Medium

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

inability to calculate
Reporting ACE.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.95% of the
calendar year but
was available greater
than or equal to
99.94 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.94% of the
calendar year but was
available greater than
or equal to 99.93 % of
the calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.93% of the
calendar year but
was available greater
than or equal to
99.92 % of the
calendar year.

The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE was
available less than
99.92% of the
calendar year

N/A

N/A

N/A

The Balancing
Authority failed to
make available
information
indicating missing or
invalid data
associated with

Or
The Balancing
Authority’s frequency
metering equipment
used for the
calculation of
Reporting ACE failed
to have a minimum
accuracy of 0.001 Hz.

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BAL-005-1 – Balancing Authority Control

Reporting ACE to its
operators.
R5.

Operations
Assessment

Medium

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.5% of the calendar
year but was
available greater
than or equal to 99.4
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.4% of the calendar
year but was
available greater than
or equal to 99.3 % of
the calendar year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.3% of the calendar
year but was
available greater
than or equal to 99.2
% of the calendar
year.

The Balancing
Authority’s system
used for the
calculation of
Reporting ACE was
available less than
99.2% of the calendar
year.

R6.

Same-day
Operations

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
implement an
Operating Process to
identify and mitigate
errors affecting the
scan-rate accuracy of
data used in the
calculation of
Reporting ACE.

R7.

Operations
Planning

Medium

N/A

N/A

N/A

The Balancing
Authority failed to
use a common source
for Tie-Lines, Pseudoties and Dynamic
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BAL-005-1 – Balancing Authority Control

Schedules with its
Adjacent Balancing
Authorities
Or
The Balancing
Authority failed to
use a time
synchronized
common source for
hourly megawatt
hour values that are
agreed-upon to aid in
the identification and
mitigation of errors.
E.D.

Regional DifferencesVariances

None.
E. Interpretations
NoneNone identified.
F. Associated Documents
1.

Appendix 1  Interpretation of Requirement R17 (February 12, 2008).

None.

Page 11 of 17

BAL-005-1 – Balancing Authority Control

Version History
Version

Date

Action

Change Tracking

0

February 8,
2005

Adopted by NERC Board of Trustees

New

0

April 1, 2005

Effective Date

New

0

August 8, 2005

Removed “Proposed” from Effective Date

Errata

0a

December 19,
2007

Added Appendix 1 – Interpretation of R17 approved
by BOT on May 2, 2007

Addition

0a

January 16,
2008

Section F: added “1.”; changed hyphen to “en dash.”
Changed font style for “Appendix 1” to Arial

Errata

0b

February 12,
2008

Replaced Appendix 1 – Interpretation of R17
approved by BOT on February 12, 2008 (BOT
approved retirement of Interpretation included in
BAL-005-0a)

Replacement

0.1b

October 29,
2008

BOT approved errata changes; updated version
number to “0.1b”

Errata

0.1b

May 13, 2009

FERC approved – Updated Effective Date

Addition

0.2b

March 8, 2012

Errata adopted by Standards Committee; (replaced
Appendix 1 with the FERC-approved revised
interpretation of R17 and corrected standard version
referenced in Interpretation by changing from “BAL005-1” to “BAL-005-0)

Errata

0.2b

September 13,
2012

FERC approved – Updated Effective Date

Addition

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BAL-005-1 – Balancing Authority Control

0.2b

February 7,
2013

R2 and associated elements approved by NERC
Board of Trustees for retirement as part of the
Paragraph 81 project (Project 2013-02) pending
applicable regulatory approval.

0.2b

November 21,
2013

R2 and associated elements approved by FERC for
retirement as part of the Paragraph 81 project
(Project 2013-02) effective January 21, 2014.

February 11,
2016

Adopted by NERC Board of Trustees

1

Complete re-write of standard

Appendix 1
Effective Date: August 27, 2008 (U.S.)
Interpretation of BAL-005-0 Automatic Generation Control, R17
Request for Clarification received from PGE on July 31, 2007

PGE requests clarification regarding the measuring devices for which the requirement applies, specifically clarification if the
requirement applies to the following measuring devices:
•
•
•
•
•
•

Only equipment within the operations control room
Only equipment that provides values used to calculate AGC ACE
Only equipment that provides values to its SCADA system
Only equipment owned or operated by the BA
Only to new or replacement equipment
To all equipment that a BA owns or operates

BAL-005-0

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BAL-005-1 – Balancing Authority Control

R17. Each Balancing Authority shall at least annually check and calibrate its time error and
frequency devices against a common reference. The Balancing Authority shall adhere to the
minimum values for measuring devices as listed below:
Device

Accuracy

Digital frequency transducer

≤ 0.001 Hz

MW, MVAR, and voltage transducer

≤ 0.25% of full scale

Remote terminal unit

≤ 0.25% of full scale

Potential transformer

≤ 0.30% of full scale

Current transformer

≤ 0.50% of full scale

Existing Interpretation Approved by Board of Trustees May 2, 2007

BAL-005-0, Requirement 17 requires that the Balancing Authority check and calibrate its control
room time error and frequency devices against a common reference at least annually. The
requirement to “annually check and calibrate” does not address any devices outside of the
operations control room.
The table represents the design accuracy of the listed devices. There is no requirement within the
standard to “annually check and calibrate” the devices listed in the table, unless they are included
in the control center time error and frequency devices.
Interpretation provided by NERC Frequency Task Force on September 7, 2007 and Revised on November 16, 2007

As noted in the existing interpretation, BAL-005-0 Requirement 17 applies only to the time error and frequency devices that provide,
or in the case of back-up equipment may provide, input into the reporting or compliance ACE equation or provide real-time time error
or frequency information to the system operator. Frequency inputs from other sources that are for reference only are excluded. The
time error and frequency measurement devices may not necessarily be located in the system operations control room or owned by the
Balancing Authority; however the Balancing Authority has the responsibility for the accuracy of the frequency and time error
measurement devices. No other devices are included in R 17. The other devices listed in the table at the end of R17 are for reference
only and do not have any mandatory calibration or accuracy requirements.
New or replacement equipment that provides the same functions noted above requires the same calibrations. Some devices used for
time error and frequency measurement cannot be calibrated as such. In this case, these devices should be cross-checked against other
properly calibrated equipment and replaced if the devices do not meet the required level of accuracy.
Page 14 of 17

BAL-005-1 – Balancing Authority Control

Page 15 of 17

Standard BAL-005-0.2b — Automatic Generation ControlSupplemental Material

Rationale
During development of this standard, text boxes were embedded within the standard to explain
the rationale for various parts of the standard. Upon Board approval, the text from the
rationale boxes will be moved to this section.
Rationale for Requirement R1: Real-time operation of a Balancing Authority requires real-time
information. A sufficient scan rate is key to an Operator’s trust in real-time information.
Without a sufficient scan rate, an operator may question the accuracy of data during events,
which would degrade the operator’s ability to maintain reliability.
Rationale for Requirement R2: The RC is responsible for coordinating the reliability of bulk
electric systems for member BA’s. When a BA is unable to calculate its ACE for an extended
period of time, this information must be communicated to the RC within 15 minutes thereafter
so that the RC has sufficient knowledge of system conditions to assess any unintended
reliability consequences that may occur on the wide area.
Rationale for Requirement R3: Frequency is the basic measurement for interconnection health,
and a critical component for calculating Reporting ACE. Without sufficient available frequency
data the BA operator will lack situational awareness and will be unable to make correct
decisions when maintaining reliability.
Rationale for Requirement R4: System operators utilize Reporting ACE as a primary metric to
determine operating actions or instructions. When data inputs into the ACE calculation are
incorrect, the operator should be made aware through visual display. When an operator
questions the validity of data, actions are delayed and the probability of adverse events
occurring can increase.
Rationale for Requirement R5: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Since Reporting ACE is a measure of the
BA’s reliability performance for BAL-001, and BAL-002, it is critical that Reporting ACE be
sufficiently available to assure reliability.
Rationale for Requirement R6: Reporting ACE is a measure of the BA’s reliability performance
for BAL-001, and BAL-002. Without a process to address persistent errors in the ACE calculation,
the operator can lose trust in the validity of Reporting ACE resulting in delayed or incorrect
decisions regarding the reliability of the bulk electric system.
Rationale for Requirement R7: Reporting ACE is an essential measurement of the BA’s
contribution to the reliability of the Interconnection. Common source data is critical to
calculating Reporting ACE that is consistent between Balancing Authorities. When data sources
are not common, confusion can be created between BAs resulting in delayed or incorrect
operator action.
Page 16 of 17

Standard BAL-005-0.2b — Automatic Generation ControlSupplemental Material

The intent of Requirement R7 Part 7.1 is to provide accuracy in the measurement and
calculations used in Reporting ACE. It specifies the need for common metering points for
instantaneous values for the tie-line megawatt flow values between Balancing Authority Areas.
Common data source requirements also apply to instantaneous values for pseudo-ties and
dynamic schedules, and can extend to more than two Balancing Authorities that participate in
allocating shares of a generation resource in supplementary regulation, for example.
The intent of Requirement R7 Part 7.2 is to enable accuracy in the measurements and
calculations used in Reporting ACE. It specifies the need for common metering points for
hourly accumulated values for the time synchronized tie line MWh values agreed-upon
between Balancing Authority Areas. These time synchronized agreed-upon values are
necessary for use in the Operating Process required in R6 to identify and mitigate errors in the
scan-rate values used in Reporting ACE.

Page 17 of 17