Summary
Under normal operating conditions, the voltage between the turns of the field winding of a hydro-generator with salient poles will hardly exceed a few volts and may lead to the wrong and dangerous conclusion that the turn insulation is of no concern. If this voltage is used to design the turn insulation and/or to test it to check and ensure its effectiveness, and/or periodic checks to detect any wear or damage to the insulation, the results may be (very) doubtful. The design will be inappropriate or poor, and tests may only detect a “solid” turn failure.
Read more Read lessThis paper develops an analytical calculation for the induced voltage during a short-circuit on the main leads and shows some examples of application demonstrating that the maximum value of the turn-to-turn voltage on the field winding during a stator failure can reach some dozen to some hundred volts.
The correct approach is to consider the maximum induced voltage between the turns of the field coils during transient phenomena - namely, the short circuit at the main leads - for both aspects, the design and the test.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | A1_10802_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Brazil |
| Study committees | |
| File size | 1 MB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
HILDINGER Thomas - Voith Hydro Brazil
Keywords
Turn-to-turn insulation, transient voltage, field winding, analytical calculation
