Induction generator system with a grid-loss ride-through capability

1. A power generation system comprising:

a prime mover for transforming a first energy to a second energy;

an induction generator operatively coupled to the prime mover and configured to generate electrical power using the second energy, with the operatively coupled prime mover configured to shut down the induction generator by reducing speed of the induction generator at a predefined rate upon conditions during a grid-loss condition;

an inverter electrically coupled to the induction generator for controlling a terminal voltage of the induction generator during the grid-loss condition; and

a power dissipating device operatively coupled to the inverter for dissipating power generated by the induction generator during the grid-loss condition.

2. The system of claim 1 , wherein the prime mover comprises a gas turbine, a steam turbine, a combination of the gas turbine and the steam turbine, or a wind turbine.

3. The system of claim 1 , wherein the prime mover comprises an organic rankine cycle based power generation system.

4. The system of claim 1 , wherein the inverter comprises a static synchronous compensator.

5. The system of claim 1 , wherein the power dissipating device comprises a resistive element.

6. The system of claim 1 , further comprising a capacitor bank or a bank of switchable capacitors or a combination thereof operatively coupled to the induction generator.

7. The system of claim 6 , wherein the capacitor bank or the bank of switchable capacitors or the combination thereof is configured to provide reactive power to the induction generator.

8. The system of claim 1 , further comprising one or more auxiliary loads operatively coupled to the induction generator.

9. The system of claim 8 , wherein the one or more auxiliary loads receive power from the inverter during the grid-loss condition.

10. The system of claim 1 , further comprising a switch configured to connect or disconnect the induction generator from a power grid.

11. The system of claim 1 , wherein the conditions for shutting down the induction generator are non-initiation of a backup generator within a predetermined time.

12. The system of claim 11 , wherein the backup generator comprises a diesel generator.

13. A method comprising:

identifying a grid-loss condition in a power generation system having a prime mover and a backup generator;

disconnecting a power grid from an induction generator using a switch;

controlling an inverter to control a terminal voltage of the induction generator;

dissipating power generated by the induction generator using a power dissipating device; and

shutting down the induction generator by reducing speed of the induction generator at a predefined rate using the prime mover upon conditions during a grid-loss condition.

14. The method of claim 13 , further comprising using the inverter for synchronizing the induction generator with the backup generator upon activation of the backup generator.

15. The method of claim 13 , further comprising connecting the backup generator with the induction generator using the switch after synchronizing the induction generator with the backup generator.

16. The method of claim 13 , further comprising using the inverter to synchronize the induction generator with the power grid upon restoration of the power grid.

17. The method of claim 13 , further comprising controlling the inverter to provide reactive power to the induction generator upon restoration of the power grid.

18. The method of claim 13 , wherein the conditions for shutting down the induction generator are non-initiation of a backup generator within a predetermined time.

19. The method of claim 13 , further comprising providing reactive power to the induction generator using at least one of a capacitor bank or a bank of switchable capacitors.

20. A system comprising:

a retrofit unit for providing a grid-loss ride-through capability to an induction generator in a power generation system, wherein the retrofit unit comprises:

an inverter operatively coupled to the induction generator and configured to control a terminal voltage of the induction generator during a grid-loss condition;

a power dissipating device electrically coupled to the inverter and configured to dissipate power generated by the induction generator during the grid-loss condition; and

a prime mover operatively coupled to the induction generator, with the prime mover configured to shut down the induction generator by reducing speed of the induction generator at a predefined rate upon conditions during a grid-loss condition.