Wind turbine generator fault protection system

A method of fault protection in a wind turbine power generation system comprising a generator connected to a power converter by an electrical connection, a circuit breaker system controlling the connection between the generator and the power converter through the electrical connection, and a sensor system configured to sense operational parameters, wherein the generator is a permanent magnet generator, wherein the method comprises:

• storing a first data structure for a first operational mode and a second data structure for a second operational mode different from the first operational mode, wherein the first data structure comprises a first expected value for a generator voltage and a first expected value for a generator speed, and wherein the second data structure comprises a second expected values for the generator voltage and a second expected value for the generator speed;
• determining that the wind turbine is operating according to the first operational mode rather than the second operational mode by monitoring at least two parameters of:
• the generator speed, an operational status of the power converter, and an operational status of the circuit breaker system;
• selecting the first data structure rather than the second data structure in response to determining that the wind turbine is operating according to the first operational mode rather than the second operational mode;
• determining actual values for the generator voltage and the generator speed;
• identifying a fault condition in the event that at least one of the actual values for the generator voltage or the generator speed do not correspond to at least one of the first expected value for the generator voltage or the first expected value for the generator speed in the selected first data structure;
• and
• implementing a protection action based on the identified fault condition.

A computer program product comprising a non-transitory computer readable medium storing instructions that, when executed by a computer, cause the computer to perform an operation of fault protection in a wind turbine power generation system, the operation comprising:

• storing a first data structure for a first operational mode and a second data structure for a second operational mode different from the first operational mode, wherein the first data structure comprises a first expected value for a generator voltage and a first expected value for a generator speed, and wherein the second data structure comprises a second expected values for the generator voltage and a second expected value for the generator speed;
• determining that the wind turbine is operating according to the first operational mode rather than the second operational mode by monitoring at least two parameters of:
• the generator speed, an operational status of the power converter, and an operational status of a circuit breaker system;
• selecting the first data structure rather than the second data structure in response to determining that the wind turbine is operating according to the first operational mode rather than the second operational mode;
• determining actual values for the generator voltage and the generator speed;
• identifying a fault condition in the event that at least one of the actual values for the generator voltage or the generator speed do not correspond to at least one of the first expected value for the generator voltage or the first expected value for the generator speed in the selected first data structure;
• and
• implementing a protection action based on the identified fault condition.