Automated Modeling of power SYSTEM PROTECTIVE...

Texas A & M Conference For Protective Relay Engineers 2019 Slide 1

M a r c h 2 6 t h 2 0 1 9

AUTOMATED MODELING OF PROTECTIVE DEVICES

M o h a m e d M a r i a , H a d i K h a n i , S a m a n A l a e d d i n i

Overview Automated Modeling of Protective Devices


Why Model Protection?

NERC State of Reliability - 2018 NERC State of Reliability - 2013


Fault Study Process

1. Relay settings are modeled

2. Model is validated

3. Model is used for coordination studies

4. Results are reviewed

5. Changes are applied to model

6. Changes are verified using the model

7. Results are used to update relay settings

8. New settings are stored in repository

9. New settings are issued to field


Other Reasons to Model Protection

Easier to demonstrate compliance with standards (PRC-023, PRC-027, etc…)

Easier to determine interactions between newly issued settings with the rest of system

Accurately study the behavior of the protection system and catch hidden coordination issues

Allow engineer to study the pilot protection as well

Save significant amount of budget and time used for protection study


Manual Modeling

Keeping an up-to-date and accurate protection model for an entire utility’s worth of devices is a Sisyphean task!

Other Issues:• Huge burden on protection

engineers• Significant amount of time and

budget• Prone to human error, results in a

less accurate model


Automatic Modeling

Single-Line Diagrams

Utility Data Sources

Circuit Configuration

Equipment Data Communication Matrix Database

Protection Data Management Tool

Automation-based Data

Extraction Tools

Short Circuit Model

Grid Operating Diagrams

Relay Settings Database


Results

Equipment Time Saving Budget Saving

About 600 Lines 50% 40%

More than 600 Transformers 60% 40%

Data Extraction Process Automated Modeling of Protective Devices


System Topology Extraction• Involves the extraction and analysis

of the primary model used in a utility’s short circuit program of choice

• Requires:– An accurate and complete primary model

– That the short circuit program stores the primary model in an open format or provides an interoperability API

• Result:– A list of line and transformer ‘positions’

that require protection to be modeled

Data Extraction Process: Step 1

Real

Junction Point

Load Tap Point

Real

Junction PointAuto

Transformer

Load Tap Point

Load Tap Point Load Tap Point

Load Tap Point

Real

Real

Real Real

Real


Protection Scheme Extraction• Includes:

– Relay settings

– Pilot scheme information

– Anything else that would be required to create an accurate protection scheme model

• Requires that information be machine readable!

• Must maintain compliance with CIP procedures (See figure on right)


Relay Repository or

File Share

Extraction Script

Extracted Relay Settings

Remove CIP Information

Extracted Relay Settings without CIP Information

CIP Setting Tap Lookup



Matching Protection Data to System Topology• Difficulty is a function of have similar the identifiers are in the two

datasets (or if identifiers exist!)• Can either:

– Develop a rule-based algorithm to match the identifiers– Create a translation table (requires maintenance) to match the identifiers


Data Extraction Process: Result

At this point in the process you should be able to automatically generate:• A list of all equipment requiring protection in your model

• All protection data necessary to model protection on all equipment in your model

Highly recommend storing this information in a relational database to track modeling progress!

Even ignoring the rest of the presentation, this information would be useful if attempting to manually keep a protection model up to date!

Modeling Process Automated Modeling of Protective Devices


Modeling Process: Step 1

Parse Relay Settings• Requires relay setting be in a machine

readable format



Determine Appropriate Model• Based on parsed relay settings• Should balance accuracy and ability to maintain model

– Example:

–100 relays are device ‘A’, revision ’14’–5 relays are device ‘A’, revision ‘9’–3 relays are device ‘A’, revision ‘15’–Possible to model all devices as the same relay model to

reduce model complexity


Determine Enabled Elements• Requires reading the ‘enable’, ‘logic’,

and ‘output contact’ settings of relays• Requires algorithm to make the

decision on whether an element can trip the breaker




Determine Pilot Schemes• Requires determining pilot logic• Requires determining relay

elements used in pilot scheme• Requires determining

communication between terminals

Multi-Terminal Line

Terminal 2 Terminal 1

Terminal 3

Received Pilot Signal T1

T3

T2

T1

T2

T3

Legend:

Receiver

Transmitter

EXT_INPUT_1

EXT_INPUT_2

EXT_INPUT_3

EXT_INPUT_4

EXT_INPUT_5

EXT_INPUT_6

GND IOC FWD

GND IOC REV

Zone 2 GND

Zone 2 PH

Zone 3 GND

Zone 3 PH

Pilot Relay Local Elements Local Protective Elements

Pilot Relay Communication Eelements


Received Pilot Signal

Sent Pilot Signal

Received Pilot Signal T2

T3

T1



Sent Pilot Signal



Sent Pilot Signal


Add to Short Circuit Model• Requires the short circuit software

store protection information in an open format or provide an interoperability API



Modeling Process: Result

At this point you should have relays and pilot schemes modeled in your short circuit solution of choice!

Validation Automated Modeling of Protective Devices


Quality Assurance

To get all the benefits of having a protection model, it is necessary that the model is trusted


Holistic QA

Can use a short circuit program’s query language or API to perform some simple checks such as:

• Existence of protection• Conformance of objects to naming conventions• Conformance of enabled elements to protection philosophy


Multi-Terminal Line

Tap 1 Tap 2

Terminal 3 Terminal 1

Terminal 2

Operational QA

Involves using a short circuit program’s scripting interface to apply a few faults and measure the response of the modeled protection.

Incidentally, this can be used to find actual protection problems present in real life!

Challenges Automated Modeling of Protective Devices


Challenges

Modeling• Non-standard protection schemes make automation more difficult• Assumptions are usually used to compensate for missing information or reduce

model complexity. It is important that these assumptions are based in reality!

Data Management• Protection data sources must be aggregated, accurate, complete, and up-to-

date• The primary model in the short circuit model should be accurate, complete, and

up-to-date• Ideally the identifiers in both the protection data and primary model should be

similar!

Closing Remarks Automated Modeling of Protective Devices


Conclusion

Automation-based methods for modeling complex protection are feasible and can be preferable to traditional manual modeling

It is useful to have a complete, up-to-date protection model

It is possible to validate a protection model automatically

Challenges to implementing the automation-based solution exist


What can you do now?

Keep relay settings in a single place (database, or file share)

Keep protection scheme information in a single place

Make sure relay settings are easily identifiable as belonging to a certain substation and protecting a certain equipment

Model a few relays manually to identify possible challenges to automation


Thank you!

Automated Modeling of power SYSTEM PROTECTIVE...

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