COOLING SYSTEM FOR A POWER ELECTRONIC UNIT FOR OPERATING AT LEAST ONE ELECTRICAL GROUP OF A MOTOR VEHICLE

摘要

The invention is directed to a cooling system for a power electronics module to drive at least one unit in a motor vehicle, in particular a starter motor/generator, with a pressure sealed compartment (2) for housing an electronic assembly (1) and a bath (3) of electrically isolating primary coolant surrounding this, boiling, at operating pressure, at a temperature which does not exceed the permissible operating temperature of the electronic assembly (1), and a heat exchanger (5), fitted above the meniscus of the primary coolant or linked to it by means of a connecting assembly (9), whereby the primary coolant vaporized in the electronic assembly (1) reaches the heat exchanger (5) as vapor, there condenses and returns to the bath (30, thus providing circulation of the primary coolant. A secondary cooling circuit with a secondary coolant, has a cooler (8) cooling the heat exchanger (5). The secondary cooling circuit (6) has at least one low point for the coolant below the level of the heat exchanger (5) and a pump (7) to force a circulating flow of the secondary coolant.