31.4 : 暂态稳定性和系统控制

There are four types of wind turbines. Types 1 and 2 are induction machine models, where stator windings induce AC rotor currents via relative motion between the magnetic field and rotor.

The difference between per unit synchronous and rotor speeds is quantified as slip.

This model includes equivalent voltage behind stator resistance and transient reactance.

Transient stability initial conditions are determined by setting two differential equations to zero and using power flow real power injection and terminal voltage as inputs.

The negative reactive power produced indicates power consumption by the induction machines.

Type 1 turbines feature a squirrel cage rotor with fixed resistance, while Type 2 employs wound rotor induction machines with a control system to adjust rotor resistance.

Type 3 wind turbines, also known as Doubly-Fed Asynchronous Generators, use wound rotor induction machines.

The rotor windings connect to the AC network via an AC-DC-AC converter, allowing separate control of real and reactive power.

Type 4 turbines use a fully asynchronous design where the machine's output connects to the AC network through an AC-DC-AC converter.