EKK Control Unit and DC/AC Converter

The EKK control unit controls the speed of the air conditioning compressor depending on the requirements of the IHKA (integrated heater and air conditioner). In addition, it carries out the diagnostics for the EKK and communicates with other control units via PT-CAN. The DC/AC converter converts the direct current voltage into the alternating current that is required to operate the three-phase motor.

The control unit and the DC/AC converter are integrated into the aluminum housing of the entire air conditioning compressor and are cooled by the flow of gaseous refrigerant. If the temperature of the DC/AC converter exceeds 110°C, it is shut off by the EKK control unit. Various measures, such as increasing the speed for self-cooling, are implemented to prevent the temperature from reaching such a level where possible. The temperature is monitored by the EKK.