Electronic control circuit comprising power transistors and method for monitoring the service life of the power transistors

US9529038B2 · kind B2 · utility

Assignee

• ebm-papst Mulfingen GmbH & Co. KG · DE

Inventors

• Helmut Lipp · Assamstadt, DE
• Günter Haas · Aalen, DE
• Martin Bürkert · Wendischenhof, DE

Key dates

• Filing date: Nov 21, 2011
• Grant date: Dec 27, 2016
• Expiry date: Jul 18, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02M7/53875
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An electronic control circuit for an electronically commutated motor (ECM) is disclosed. A plurality of power transistors controls the ECM, and a reference transistor is formed together with the power transistors on a common support. A control unit is configured to, in a test mode: apply a test current to the reference transistor and one of the power transistors respectively; measure a saturation voltage of the reference transistor and one of the power transistors; evaluate a saturation voltage difference between the measured saturation voltages of the reference transistor and the respective power transistor; evaluate a rate of change of saturation voltage differences between a first iteration of the test mode and a second iteration of the test mode; and determine an expected remaining service life of the power transistors based on the temperature of the support during the test mode and the rate of change of the saturation voltage differences.