Apparatus and method for detecting abnormal conditions of a motor

• Main Authors: SEO BYUNGEOK, SERIZAWA AKIRA
• Format: Patent
• Language: English
• Published: 06.03.2008
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS

The present invention provides an apparatus and a method for accurately detecting abnormal conditions of a motor. A DeltaTc/Tj detector detects a difference (DeltaTc) between an environment temperature and a temperature of a field-effect transistor (FET) which turns on and off electric power supplied to a DC motor. A diagnosis control unit detects abnormal conditions such as a motor lock and a short circuit of the DC motor based upon the obtained difference. When the motor lock has been detected, the diagnosis control unit controls a pulse width modulation (PWM) control unit and a PWM oscillator (PWMOSC) and makes a frequency and duty cycle of a PWM signal lower. When the short circuit has been detected, the diagnosis control unit controls a gate driver and turns off the FET.