Heater and pump performance diagnostic for a hybrid battery thermal system

摘要

A system includes a controller, battery pack, fluid, heater, a pump that circulates the fluid to the battery pack through the heater, and a temperature sensor positioned between the heater and battery pack. The controller processes temperature signals from the sensor, diagnoses the pump and heater by turning on the pump in response to a received enabling signal, calculates an absolute value of a temperature gradient of the fluid while the pump remains on, and records a passing pump diagnostic code if the absolute value of the temperature gradient exceeds a calibrated rate. The controller executes a heater diagnostic, after calculating the absolute value of the temperature gradient, only when heating is requested or the absolute value of the temperature gradient does not exceed the calibrated rate. The heater diagnostic includes turning off the pump, cycling the heater on and off, and monitoring the temperature signals for a temperature rise.

主权项

1. A system comprising:
a battery pack; a supply of heat transfer fluid; a heater; a pump that circulates the fluid to the battery pack through the heater; a temperature sensor configured to measure a temperature of the fluid; and a controller in communication with the temperature sensor, the pump, the battery pack, and the heater, wherein the controller includes a processor and tangible, non-transitory memory on which is recorded instructions for diagnosing the performance of the heater and the pump; wherein the controller, via the processor, receives and processes temperature signals from the temperature sensor, and is configured to:
turn on the pump in response to a received enabling signal;calculate a temperature gradient of the coolant entering the battery pack using the temperature signals while the pump remains on;record a passing pump diagnostic code if the absolute value of the calculated temperature gradient exceeds a calibrated rate in the form of a calibrated temperature gradient value; andexecute a heater diagnostic, after calculating the temperature gradient, only when heating is requested or the absolute value of the calculated temperature gradient does not exceed the calibrated temperature gradient value, including turning off the pump, cycling the heater on and off, and monitoring the temperature signals for a calibrated temperature rise.