Control unit for controlling an inverter inverter and method for operating an inverter

摘要

Provided is a control unit (4) for controlling an inverter (1) with a plurality of half bridges (11a-c). Each of the half bridges (11a-c) has a first switching element (12a-c) connected to a potential (13) of a DC link (3) and a second switching element (14a-c) connected to another potential (15) of the DC link (3). The control unit (4) is configured to provide first signals (41) to the first switching elements (12a-c) such that the first switching elements (12a-c) are turned off upon receiving a request signal (38), to provide second signals (45a-c) to the second switching elements (14a-c) such that the second switching elements (14a-c) are turned on upon receiving the request signal (38), and to perform a comparison of a measured electric parameter of the inverter (1) with a predefined threshold value. The control unit (4) is also configured to provide a second signal (45a) so that the second switching element (14a) controlled by the second signal (45a) is turned off for a predefined time span, if a switching criterion is fulfilled, which includes a condition that the comparison results in that the measured electric parameter reaches or crosses the threshold value. According to the present invention, structural difficulty of the control unit is reduced.