DERATING CONTROL OF A POWER INVERTER MODULE

摘要

A system includes a DC battery pack, an inverter coolant loop, first and second temperature sensors, a polyphase electric machine, and a power inverter module (PIM) connected to the battery pack and electric machine. The PIM includes a plurality of semiconductor switches. The controller is operable to selectively derate the PIM and thus reduce a commanded torque to the electric machine. The controller is programmed to execute a method and thereby receive a coolant temperature from the first temperature sensor and a PIM temperature from the second temperature sensor, and to determine a set of electrical values of the electric machine. The controller estimates a junction temperature of the semiconductor switches using the temperature of the coolant, the temperature of the PIM, and the set of electrical values. The controller selectively derates the PIM using the estimated junction temperature when the temperature of the PIM exceeds a calibrated maximum temperature.

主权项

1. A system comprising: a direct current (DC) battery pack;
a polyphase electric machine; a power inverter module (PIM) that is electrically connected to the DC battery pack and to the polyphase electric machine, wherein the PIM includes a plurality of semiconductor switches; an inverter coolant loop operable to cool the PIM via a circulation of coolant; a first temperature sensor configured to measure a temperature of the coolant in the inverter coolant loop; a second temperature sensor configured to measure a temperature of the PIM; and a controller in communication with the PIM that is operable to selectively derate the PIM and thereby reduce a commanded torque to the electric machine, wherein the controller is programmed to:
receive the temperature of the coolant from the first temperature sensor and the temperature of the PIM from the second temperature sensor;determine a set of electrical values of the electric machine;estimate a junction temperature of the semiconductor switches using the temperature of the coolant, the temperature of the PIM, and the set of electrical values;selectively derate the PIM using the estimated junction temperature when the temperature of the PIM exceeds a calibrated maximum temperature by limiting a torque command to and available torque from the polyphase electric machine, including:calculating a numeric usage factor indicative of an age of the semiconductor switches; andreducing the calibrated maximum temperature using the calculated numeric usage factor.