A METHOD FOR PROTECT INVERTER POWER DEVICE FROM OVERHEATING WHEN A MOTOR STALLED

摘要

A method for protecting a power device of an inverter when stalling a motor is provided to improve power performance by outputting the maximum torque in an allowable temperature range when driving the motor. A method for protecting a power device of an inverter when stalling a motor includes the steps of: detecting and calculating the maximum allowable temperature of a junction unit of the power device of the inverter and a case temperature between the power device and a heat radiating plate according to the driving of the motor, outputting an absolute value of driving speed of the motor according to the driving of the motor, and applying differently a pattern gain according to the absolute value(S102-S108); calculating the loss of the inverter according to the driving of the motor by using a motor torque command and a motor speed(S112); outputting the temperature difference between the junction unit of the power device of the inverter and the case temperature of the power device and the heat radiating plate by calculating the result of the first step and the second step(S118); limiting the output of a PI controller which receives the difference of the temperature outputted from the third step(S122); and limiting the motor driving torque output according to the motor torque command applied by using the output of the PI controller in the fourth step(S124).