Patent ID: 8335081

Claim:
A power electronic system, comprising: a cooling air duct that, in operation, channels a flow of cooling air; first, second, and third power electronic switching modules that, in operation, perform controlled switching of respective first, second, and third phases of AC power, the power electronic switching modules being disposed adjacent to the cooling air duct; first, second, and third heat sink sections disposed adjacent to the first, second, and third power electronic switching modules and extending into the cooling air duct in a sequential configuration wherein the second heat sink section receives cooling air from the first heat sink section, and the third heat sink section receives cooling air from the second heat sink section, each of the first, second, and third heat sink sections being physically configured differently from the other heat sink sections to reduce a working temperature of the respective power electronic switching module and to reduce working temperature differences between the power electronic switching modules, wherein the first, second, and third heat sink sections comprise respective first, second, and third sets of fins having first, second, and third lengths, respectively, the third length being greater than the first and second lengths; and means for moving the cooling air through the cooling air duct and across the first, second, and third heat sink sections.