Glossary - Terms & Definitions

Owned by magnus
Last updated: Jul 22, 2024
2 min read

Dynamic Line Ratings

Dynamic Line Ratings come in many shapes and sizes. This list contains all our definitions of DLRs, including AARs. Any rating that varies using a dynamic variable is considered a DLR. All AARs are DLRs but not all DLRs are AARs.

Rating Standards

Industry ratings standards. Used only for benchmarking internally. These are the widely used and accepted methodologies for calculating DLR as described in published standards

Rating Standards

Industry ratings standards. Used only for benchmarking internally. These are the widely used and accepted methodologies for calculating DLR as described in published standards

DLR (CIGRE)

DLR calculation as defined by CIGRE TB 601 with no additional modifications.

DLR (IEEE)

DLR Calculation as defined by the IEEE 738-2012 standard with no additional modifications.

Default Ratings

How our customers lines are currently rated. Used as reference & for benchmarking of Heimdall DLR models.

Static Line Rating

A static number based on CIGRE or IEEE standard and fixed values for weather.

Seasonal Line Rating

A rating that changes based on the date. Each rating reflects changes to the fixed values for weather.

Ambient Line Rating

A rating that changes based on different ambient intervals, i.e every 10 deg C. Can be stepwise or interpolated based on the latest ambient temperature.

Facility Ratings

 

 

Heimdall DLR Models

All lines have a main DLR model which is considered to be ‘valid’ for this line. This can only be one of the following DLR models.

Heimdall DLR Models

All lines have a main DLR model which is considered to be ‘valid’ for this line. This can only be one of the following DLR models.

 

Heimdall DLR

Real-time: The average value of a five minute sliding window for all neurons/virtual neurons on the line.

Forecasting: Uses the most limiting forecast for the respective physical and virtual neurons on a given line.

 

Heimdall AAR

Real-time: Ambient Adjusted Ratings are based on the standard CIGRE TB 601 equation. In this method, only the ambient temperature changes. Wind speed, wind direction, and solar heating are set to static values chosen by the customer.

Forecasting: Takes into account the forecasting error in ambient temperature to make sure the predictions provide ratings with high confidence, given the provided static weather assumptions for wind and solar irradiation.

 

Heimdall Circuit Rating

Either Dynamic Circuit Rating or Ambient Circuit Rating

Real-time: Circuit Ratings are not a rating type in itself. It is designed to reflect any other limitations in the system beyond the conductor.

This rating always uses either DLR or AAR of the transmission line as its input. In addition, any component ratings defined by the user are reflected.

Forecasting: Circuit ratings apply to forecasting by reflecting any component ratings in the DLR or AAR forecast.

Â