Protection system for a power converter connected to a doubly fed induction generator

摘要

Protection system for a power converter connected to a doubly fed induction generator having a rotor and a stator. The power converter includes a grid-side-converter, a machine-side-converter, a DC link between both converters, a chopper connected to the DC link, and a hardware protection system connected to the rotor of the generator. The protection system includes a first control unit for controlling the hardware protection system depending on the voltage in the DC link, a second control unit for controlling the chopper depending on the DC link voltage, and a third control unit for controlling both converters.

主权项

1. Protection system for a power converter connected to a doubly fed induction generator, the system comprising:
a doubly-fed induction machine with a stator and a rotor, the stator of said doubly-fed induction machine being connected to a grid and the rotor of said doubly-fed induction machine being connected to the grid via a converter unit, said converter unit having a machine side converter, a grid side converter and a DC link connecting the machine side converter and the grid side converter;
a hardware protection system connected to the rotor of the doubly-fed induction machine;a chopper connected to the DC link;a first control unit for controlling the hardware protection system;a second control unit for controlling the chopper; anda third control unit for controlling the machine side converter and the grid side converter, wherein each of the first control unit, the second control unit and the third control unit comprises a respective processor, the first control unit, the second control unit and the third control unit being configured to operate independent of each other for controlling the hardware protection system, the chopper and the machine and grid side converters, respectively, a state signal from each of the first control unit and the second control unit is sent to the third control unit when the first control unit and the second control unit are operative; and, using said third control unit, it is determined that the first control unit and the second control unit are operative in response to receiving the corresponding state signal from the first control unit and the second control unit and that the first control unit and the second control unit are not operative in response to not receiving the corresponding state signal.