Modeling a power grid

Hierarchical and Recursive Queries in SQL Server

Jasmin Ludolf

Content Developer

The power grid

An example image of an electrical grid structure

Modeling a power grid

You need three ID values:

ID of the power line: EquipmentID
ID of the first connected power line: EquipmentID_From
ID of the second connected power line: EquipmentID_To

Simplified representation how a power grid is modeled.

Characteristics of power lines

Voltage Level

HV - high Voltage, MV - medium voltage, LV - low voltage

Description
```
Cable, Overhead Line, Transformer
```
Construction Year: Year of construction
Inspection Year: Year of the last inspection
Condition Assessment:

good,bad,repair,exchange

Common task for grid maintenance

Find the power lines to be replaced

Find the power lines that are connected to each other: use recursion to find the connected power lines
Find power lines with bad, exchange or repair condition

+-----------------+---------------------------+
| Line            | Condition                 |
|-----------------|---------------------------|
| 1               | exchange                  |
|-----------------|---------------------------|
| 2               | repair                    |
|-----------------|---------------------------|
| 3               | bad                       |
+-----------------+---------------------------+

Power grid maintenance engineers on their daily work

Let's find the power lines to be maintained!

Hierarchical and Recursive Queries in SQL Server