Patent ID: 8487461

Claim:
A method for operating a wind energy plant having a double-fed asynchronous machine, at least one inverter and at least one control device, wherein electrical energy is at least partly supplied to a grid via the inverter, wherein the inverter comprises per phase at least one power semi-conductor module having at least two transistor circuits and at least two free-wheeling diodes as components, and wherein the control device actuates the inverter at least at times via a pulse width modulation (PWM), the method comprising: altering, at frequencies of currents to be impressed by the inverter on a machine side of less than 10 Hz, the switching frequency of the transistor circuits and/or of the free-wheeling diodes of the inverter via the control device depending upon the thermal heating of the respective components such that the number of switching operations in the power semi-conductor module is reduced.