Guangdong Fullde Electrical Technology Co., Ltd |
|
20KW Wind Inverter High Power Variable Crowbar Braking Resistor
Introduction of the Crowbar Braking Resistor:
Crowbar resistors are three phase resistance banks which are connected to the rotor windings of the DFIG (Doubly-Feed Induction Generator) such as wind power generator.
They are used to prevent damage to the inverter circuits attached
to rotor side when a fault occurs in the grid. DFIG power
converter, which has a restricted over-current limit, needs special
attention during faults in the grid. If the rotor current or DC
link voltage reaches the threshold value, crowbar resistors
disconnect the converter in order to prevent the generator turning
into a squirrel cage induction machine. By crowbar resistors, the
DFIG could stay connected to the grid and continue its operation.
The crowbar resistors should be high enough to limit the short circuit rotor current and also they should be low enough to avoid too high voltage in the rotor circuit. The crowbar resistor should be designed with low inductance and capable of handling very high currents for short periods.
Detailed pictures of the products: