Rotor short circuit protection technology

[Abstract]:

This is the method of some wind power manufacturers use more, it is equipped with a crowbar circuit in the rotor side of the generator, provides a bypass for the rotor side circuit, detected in power

This is the method of some wind power manufacturers use more, it is equipped with a crowbar circuit in the rotor side of the generator, provides a bypass for the rotor side circuit, detected in power system fault voltage sag, doubly fed induction generator excitation converter locking, and input bypass circuits (energy release resistance) to protection device. Limit the overvoltage by excitation converter current and rotor winding function. In order to maintain the generator operation (when the doubly fed induction generator according to induction motor operation).

At present, there are several typical crowbar circuits as follows:

(1) a hybrid bridge type crowbar circuit [9], as shown in Figure 1, each arm of the bridge is connected in series with a controller and a diode.

(2) the IGBT type crowbar circuit [9], as shown in Figure 2, each bridge arm is connected by two diodes, the DC side is strung into a IGBT device and an absorption resistance.

(3) crowbar [10] with bypass circuit resistance, as shown in Figure 3, occurs when the grid voltage drops, the shunt resistance connected to the rotor circuit through the power switch device, high current which is generated during the grid fault provides a bypass, limiting current protection so as to achieve the effect of excitation converter.

Operation analysis of AC excitation wind power system based on Crowbar protection control