Battery health aware thermal management system

A vehicle comprising:

• a powertrain including an electric motor and a rechargeable battery coupled to the electric motor to provide drive power for the vehicle, the rechargeable battery including a first temperature sensor configured to sense a temperature of the rechargeable battery;
• a thermal management system for the rechargeable battery using a circulating fluid to control temperature of the rechargeable battery, the thermal management system including a chiller for cooling the circulating fluid;
• and
• a reference tracking controller coupled to the thermal management system and configured to use a set of references to control operation of the thermal management system;
• a non-linear optimizing controller configured to calculate and communicate the set of references to the reference tracking controller by:
• obtaining a set of temperatures from the thermal management system, including at least one temperature of the circulating fluid, and a battery temperature;
• estimating a state of charge (SOC) of the battery;
• using a battery thermal model to estimate heat transfer between the circulating fluid and the battery, and a chiller model to estimate heat transfer in the chiller;
• predicting, over a time horizon having a duration of the time horizon, a future battery current profile as a disturbance input to the battery thermal model;
• classifying, within the time horizon, portions in which the future battery current profile is predicted (i) to be below a nominal threshold, (ii) to be issued from the battery to the powertrain, and (iii) to be injected to the battery at a level that exceeds the nominal threshold;
• applying a cost function minimization to determine the set of references for controlling the thermal management system by minimizing a sum of economic costs of battery health effects in the time horizon, the sum of economic costs varying with SOC of the battery, and economic costs of operation of the thermal management system in the time horizon, including:
• using a first battery deterioration model due to aging for first portions of the time horizon classified as having the future battery current profile predicted to be below the nominal threshold,
• using a second battery deterioration model during battery discharge for second portions of the time horizon classified as having the future battery current profile predicted to be issued from the battery to the powertrain, and
• using a third battery deterioration model during battery charging for third portions of the time horizon classified as having the future battery current profile predicted to be injected to the battery at the level that exceeds the nominal threshold;
• and
• issuing the set of references to the reference tracking controller.

A method of controlling battery temperature in a vehicle, the vehicle including a powertrain including an electric motor and a battery coupled to the electric motor to provide drive power for the vehicle, the rechargeable battery including a first temperature sensor configured to sense a temperature of the battery, and a thermal management system for the battery using a circulating fluid to control temperature of the battery, the thermal management system including a chiller for cooling the circulating fluid;

• the method comprising:
• issuing control signals from a reference tracking controller to control operation of the thermal management system using a set of references;
• issuing the set of references to the reference tracking controller from a non-linear optimizing controller;
• calculating the set of references at the reference tracking controller by:
• obtaining a set of temperatures from the thermal management system, including at least one temperature of the circulating fluid, and a battery temperature;
• estimating a state of charge (SOC) of the battery;
• using a battery thermal model to estimate heat transfer between the circulating fluid and the battery, and a chiller model to estimate heat transfer in the chiller;
• predicting, over a time horizon having a duration of the time horizon, a battery current profile as a disturbance input to the battery thermal model;
• and
• classifying, within the time horizon, portions in which the battery current profile is predicted (i) to be below a nominal threshold, (ii) to be issued from the battery to the powertrain, and (iii) to be injected to the battery at a level that exceeds the nominal threshold;
• and
• applying a cost function minimization to determine the set of references for controlling the thermal management system by minimizing a sum of economic costs of battery health effects in the time horizon, the sum of economic costs varying with SOC of the battery, and economic costs of operation of the thermal management system in the time horizon, including:
• using a first battery deterioration model due to aging for first portions of the time horizon classified as having the battery current profile predicted to be below the nominal threshold,
• using a second battery deterioration model during battery discharge for second portions of the time horizon classified as having the battery current profile predicted to be issued from the battery to the powertrain, and
• using a third battery deterioration model during battery charging for third portions of the time horizon classified as having the battery current profile predicted to be injected to the battery at the level that exceeds the nominal threshold.