# Variable-slip wind turbine generator (Type 2)

Canonical URL: https://eloragrid.ai/symbols/type-2-variable-slip-wind-turbine-generator
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: WTG T2
Drawing use: SLD, Schematic
Reference families: IEC, IEEE / ANSI

A wind turbine using a wound-rotor induction generator with controlled external rotor resistance to widen the slip range.

## In plain English

### What does Variable-slip wind turbine generator (Type 2) mean?

A Type 2 wind turbine uses a wound-rotor induction generator whose rotor circuit is connected to a variable resistance, usually switched by power electronics mounted on the rotor. Raising the rotor resistance lets the slip increase to around ten per cent, which softens torque peaks from gusts while the stator stays connected directly to the network.

### A simple example

Drawings show the generator circle with rotor slip-ring or rotor-winding marks and a resistor element with a variable arrow attached to the rotor side. The stator side follows the same path as a Type 1 machine: soft starter, capacitor compensation and step-up transformer.

### What the drawings help you do

Energy dissipated in the rotor resistance is lost as heat, so the symbol says nothing about efficiency or about any capability to deliver reactive power. Fault ride-through behaviour and resistor ratings must be read from the turbine model data.

### This particular reference

A wind turbine using a wound-rotor induction generator with controlled external rotor resistance to widen the slip range. A Type 2 turbine dissipates rotor energy in resistance; a doubly-fed generator returns rotor power to the network through a converter.

### Terms

- Winding: A coil of conductor inside an electrical machine or transformer.
- Rating: A value stating the conditions for which equipment is specified.
- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [AutoCAD Electrical: Power station and substation concepts](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-74EF80E8-018D-4A57-88BD-FF973F1B8185.htm)
- [Resistors and heater-element symbols](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1D071951-D38E-4B15-8B9E-C30ECBD55C19.htm)


## What it represents

A Type 2 wind turbine uses a wound-rotor induction generator whose rotor circuit is connected to a variable resistance, usually switched by power electronics mounted on the rotor. Raising the rotor resistance lets the slip increase to around ten per cent, which softens torque peaks from gusts while the stator stays connected directly to the network.
Drawings show the generator circle with rotor slip-ring or rotor-winding marks and a resistor element with a variable arrow attached to the rotor side. The stator side follows the same path as a Type 1 machine: soft starter, capacitor compensation and step-up transformer.
Energy dissipated in the rotor resistance is lost as heat, so the symbol says nothing about efficiency or about any capability to deliver reactive power. Fault ride-through behaviour and resistor ratings must be read from the turbine model data.

## How to read it

- The variable resistor on the rotor side is a slip control element, not a braking resistor or a load.
- Stator-side compensation capacitors are still normally present.

## Information to show or reference

- State rotor resistance control range.
- Show stator connection and compensation.
- Reference turbine model data for dynamic studies.

## Important distinction

A Type 2 turbine dissipates rotor energy in resistance; a doubly-fed generator returns rotor power to the network through a converter.

## Facts

- Generator type: Wound-rotor induction
- Speed control: Rotor resistance, limited slip range
- Converter in power path: None in stator path
- Preview: Independent educational illustration; consult the applicable standard and project legend for the exact graphic

## Public references

- [AutoCAD Electrical: Power station and substation concepts](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-74EF80E8-018D-4A57-88BD-FF973F1B8185.htm) — Autodesk. Wind station representation used as site-level context.
- [Resistors and heater-element symbols](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1D071951-D38E-4B15-8B9E-C30ECBD55C19.htm) — Autodesk. Public variable-resistor symbol context for the rotor resistance element.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.