Method for detection of upcoming pole slip

1. A method for detecting an imminent pole slip of a synchronous generator electrically connected to a power supply network, wherein a signal characteristic of a power fault is detected and an imminent pole slip is determined based on a pre-defined value when a load angle of the synchronous generator increases, comprising the following steps:

determining a first load angle during operation of the synchronous generator without a power fault,

determining a synchronous generator frequency as a function of time when a power fault occurs, and

precalculating a second value of a load angle resulting from the power fault by adding the first value of the load angle to a load angle difference occurring during the power fault, wherein this load angle difference is caused by a deviation of the synchronous generator frequency relative to a power frequency of a power grid, wherein the power fault comprises a power outage of the synchronous generator, wherein, on exceeding a second predefinable value for the second load angle resulting from the power fault, the synchronous generator is disconnected from the power supply network.

2. The method according to claim 1 , wherein after detecting a signal characteristic of a power fault, the load angle difference is determined between a polar wheel voltage and a synchronous generator voltage, wherein the load angle difference is caused by a deviation of the synchronous generator frequency relative to the power frequency.

3. The method according to claim 1 , wherein the first load angle in the operation without a power fault is determined by measuring a synchronous generator voltage, and a synchronous generator current.

4. The method according to claim 1 , wherein, from the calculated second value of the load angle resulting from the power fault, a decision is derived as to whether the synchronous generator should remain connected to the power supply network.

5. The method according to claim 1 , wherein, on exceeding a first predefinable value for the second load angle resulting from the power fault, at least one measure is taken to reduce the load angle.

6. A device for determining a load angle of a synchronous generator with a rotor electrically connected to a power supply network, comprising

at least one measuring device used to determine a frequency of a synchronous generator voltage and/or a synchronous generator current of the synchronous generator,

at least one rotary speed measuring device for determining a rotary speed,

and at least one controller designed to perform the following steps:

determine a first load angle during operation of the synchronous generator without a power fault,

determine a synchronous generator frequency as a function of time when a power fault occurs, and

precalculate a second value of a load angle resulting from the power fault by adding the first value of the load angle to a load angle difference occurring during the power fault, wherein this load angle difference is caused by a deviation of the synchronous generator frequency relative to a power frequency of a power grid, wherein the power fault comprises a power outage of the synchronous generator, wherein, on exceeding a second predefinable value for the second load angle resulting from the power fault, the synchronous generator is disconnected from the power supply network.

7. The device according to claim 6 , wherein the device further consists of a mechanical power source that is mechanically coupled to the synchronous generator.

8. The device according to claim 7 , wherein the mechanical power source is an internal combustion engine, in particular a stationary engine.

9. The device according to claim 7 , wherein the mechanical power source is a wind power plant, a hydroelectric power plant or a gas turbine.

10. A controller, configured to:

determine a first load angle during operation of a synchronous generator without a power fault,

determine a synchronous generator frequency as a function of time when a power fault occurs, and

precalculate a second value of a load angle resulting from the power fault by adding the first value of the load angle to a load angle difference occurring during the power fault, wherein this load angle difference is caused by a deviation of the synchronous generator frequency relative to a power frequency of a power grid, wherein the power fault comprises a power outage of the synchronous generator, wherein, on exceeding a second predefinable value for the second load angle resulting from the power fault, the synchronous generator is disconnected from a power supply network.

11. The controller of claim 10 , wherein after detecting a signal characteristic of a power fault, the load angle difference is determined between a polar wheel voltage and a synchronous generator voltage, wherein the load angle difference is caused by a deviation of the synchronous generator frequency relative to the power frequency.

12. The controller of claim 10 , wherein the first load angle is determined by measuring a synchronous generator voltage and a synchronous generator current.

13. The controller of claim 10 , wherein, from the calculated second value of the load angle resulting from the power fault, a decision is derived as to whether the synchronous generator should remain connected to the power supply network.

14. The controller of claim 10 , wherein, on exceeding a first predefinable value for the second load angle resulting from the power fault, at least one measure is taken to reduce the first load angle.