Current source converter-based wind energy system

A switch control system for providing pulse width modulated switching control signals with firing angle control for controlling a current source converter (CSC) in a power conversion system providing electrical power to a power grid, the switch control system comprising:

• a feedback system operative to sense a grid voltage and to provide a fault mode signal when a grid fault is detected;
• at least one resistor;
• and
• at least one switch selectively operable according to the fault mode signal to couple the at least one resistor to one of an intermediate circuit and an input of the CSC to dissipate excess power in a fault mode.

A method for controlling a power conversion system providing electrical power to a power grid, the method comprising:

• detecting a grid fault condition based on a sensed grid voltage;
• selectively dissipating excess power of the power conversion system through at least one resistor when a grid fault condition is detected;
• and
• controlling an output current of the power conversion system to a leading angle relative to the sensed grid voltage when a grid fault condition is detected.