Method and device for monitoring connection of semiconductor of power module

A device for monitoring connections of semiconductors of a power module, the semiconductors being connected in parallel and providing voltage and current to a load according to a pulse width modulation, the device comprising, for each semiconductor, a driver for driving a gate of the semiconductor in order to set the semiconductor in a conducting state or non-conducting state at each cycle of the pulse width modulation, characterized in that the semiconductors are grouped in plural groups comprising at least one semiconductor and in that the device comprises:

• determining circuitry to determine if a duration of the conducting state of the semiconductors in a first cycle of the pulse width modulation is upper than a predetermined duration,
• measuring circuitry to measure, during the conducting state of the semiconductors at a second cycle of the pulse width modulation, the voltage provided to the load by the semiconductors if the duration of the conducting state of the semiconductors in the first cycle of the pulse width modulation is upper than a predetermined value,
• first disabling circuitry to sequentially disable the conduction of each group of at least one semiconductor during a part of the duration of the conducting state of the semiconductors in a third cycle of the pulse width modulation and measuring circuitry to measure the voltage provided to the load each time the conduction of one group of at least one semiconductor is disabled,
• determining circuitry to determine differences between the voltage measured during the second cycle and each voltage measured during the third cycle,
• ordering circuitry to order the differences according to the values of the differences, checking circuitry to check if the determined order is identical to an order stored in a memory of the device,
• determining circuitry to determine that a connection of one semiconductor of one group of at least one semiconductor is deteriorated if the determined order is different from the order stored in the memory of the device.