# US 2019/0165387 A1 · Partial derivative based feedback controls for pid

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- Number: US 2019/0165387 A1
- Document ID: US20190165387A1
- Status: Published application
- Kind: A1
- Application number: 15/824,904
- Filed: 2017-11-28
- Published: 2019-05-30
- Earliest claimed: 2017-11-28
- Assignees: Toyota Motor Engineering & Manufacturing North America, Inc.
- Applicants: Toyota Motor Engineering & Manufacturing North America, Inc.
- Inventors: Jared Farnsworth; Daniel Folick; Naoki Tomi; Shigeki Hasegawa; Kentaro Fukuda
- Web page: https://patentgrep.com/patent/US20190165387A1

## CPC

- H01M 8/04029: Heat exchange using liquids
- B60L 1/003: {to auxiliary motors, e.g. for pumps, compressors}
- B60L 50/72: Constructional details of fuel cells specially adapted for electric vehicles
- B60L 58/33: by cooling
- B60L 58/34: by heating
- H01M 8/04007: related to heat exchange
- H01M 8/04082: Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M 8/04134: {by coolants}
- H01M 8/0432: Temperature; Ambient temperature
- H01M 8/04358: {of the coolant}
- B60L 2240/36: Temperature of vehicle components or parts
- B60L 2260/44: by parameter estimation
- H01M 8/04723: {of the coolant}
- H01M 8/04955: Shut-off or shut-down of fuel cells
- H01M 2008/1095: {Fuel cells with polymeric electrolytes}
- H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane
- Y02E 60/50: Fuel cells
- Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A system includes a fuel cell stack having a plurality of fuel cells and designed to receive a fluid and to heat the fluid. The system also includes an actuator to increase or decrease a fluid temperature of the fluid and an ECU. The ECU can determine a temperature control signal corresponding to a desired temperature of the fluid and perform a feedforward control of the actuator to increase or decrease the fluid temperature towards the desired temperature. The ECU can also determine a temperature difference between the fluid temperature and the desired temperature, and can determine a sensitivity that corresponds a change in a parameter value or the actuator position to a change in the fluid temperature. The ECU can also apply the sensitivity to the temperature difference to determine an error signal, and control the actuator based on the error signal.

## Claims

### Claim 1

A system for heating or cooling a fuel cell circuit of a vehicle comprising:
a fuel cell stack having a plurality of fuel cells and configured to receive a fluid and to heat the fluid;
an actuator having an actuator position and configured to increase or decrease a fluid temperature of the fluid; and
an electronic control unit (ECU) coupled to the actuator and configured to:
determine a temperature control signal corresponding to a desired temperature of the fluid,
perform a feedforward control of the actuator to cause the actuator to increase or decrease the fluid temperature towards the desired temperature of the fluid,
determine a temperature difference between the fluid temperature of the fluid and the desired temperature of the fluid,
determine a sensitivity that corresponds a change in a parameter value or the actuator position to a change in the fluid temperature,
apply the sensitivity to the temperature difference to determine an error signal that corresponds to an additional change in the actuator position to cause the fluid temperature to increase or decrease to reduce the temperature difference, and
control the actuator based on the error signal.

### Claim 2 (depends on 1)

The system of claim 1 wherein the actuator is a three-way valve and the desired temperature of the fluid and the fluid temperature correspond to the fluid at an inlet of the fuel cell stack.

### Claim 3 (depends on 2)

The system of claim 2 further comprising:
a radiator configured to reduce the fluid temperature;
a bypass branch configured to cause the fluid to bypass the radiator; and
a pump configured to pump the fluid through the fuel cell circuit;
wherein:
the three-way valve is configured to split the fluid between the radiator and the bypass branch, and
the sensitivity is determined based on a pump fluid temperature corresponding to a pump inlet of the pump, a bypass fluid temperature corresponding to the bypass branch, and a radiator temperature corresponding to an outlet of the radiator.

### Claim 4 (depends on 1)

The system of claim 1 wherein the actuator is a pump configured to pump the fluid through the fuel cell circuit, and the desired temperature of the fluid and the fluid temperature correspond to the fluid at an outlet of the fuel cell stack.

### Claim 5 (depends on 4)

The system of claim 4 further comprising:
a radiator configured to reduce the fluid temperature;
a bypass branch configured to cause the fluid to bypass the radiator; and
a three-way valve configured to split the fluid between the radiator and the bypass branch, wherein:
the sensitivity is determined based on an amount of heat generated by the fuel cell stack, a specific heat of the fluid, the fluid temperature at the outlet of the fuel cell stack, and an inlet fuel cell temperature corresponding to an inlet of the fuel cell stack.

### Claim 6 (depends on 1)

The system of claim 1 wherein:
the ECU includes a proportional-integral-derivative (PID) controller configured to receive the error signal and to generate a feedback control signal by accounting for present error values, past error values, and potential future errors of the error signal; and
the ECU is configured to control the actuator based on the feedback control signal.

### Claim 7 (depends on 6)

The system of claim 6 wherein the ECU is further configured to control the actuator based on a sum of the feedforward control and the feedback control signal.

### Claim 8

A system for heating or cooling a fuel cell circuit of a vehicle comprising:
a fuel cell stack having a plurality of fuel cells and configured to receive a fluid and to heat the fluid;
an actuator configured to increase or decrease a fluid temperature of the fluid;
a radiator configured to receive the fluid and remove heat from the fluid; and
an electronic control unit (ECU) coupled to the actuator and configured to:
estimate an estimated parameter that affects an amount of the heat removed from the fluid by the radiator,
determine an actuator control signal corresponding to control of the actuator to increase or decrease the fluid temperature towards a desired temperature of the fluid based on the estimated parameter,
determine a temperature difference between the fluid temperature of the fluid and an estimated temperature of the fluid,
adjust the estimated parameter based on the temperature difference in order to decrease the temperature difference,
determine an updated actuator control signal based on the adjusted estimated parameter, and
control the actuator based on the updated actuator control signal.

### Claim 9 (depends on 8)

The system of claim 8 wherein the fluid temperature of the fluid is measured at an outlet of the radiator and the estimated temperature of the fluid is calculated for the outlet of the radiator.

### Claim 10 (depends on 8)

The system of claim 8 wherein the parameter corresponds to a velocity of air flowing over the radiator.

### Claim 11 (depends on 8)

The system of claim 8 wherein the ECU is further configured to determine a sensitivity that corresponds a change in the parameter to a change in the fluid temperature, and to adjust the estimated parameter by applying the sensitivity to the temperature difference.

### Claim 12 (depends on 11)

The system of claim 11 wherein:
the actuator includes a fan configured to direct air over the radiator; and
the sensitivity is determined based on a fan speed of the fan, a velocity of ambient air flowing over the radiator, a volume of the fluid in the radiator, a temperature of the fluid in the radiator, and a temperature of the air.

### Claim 13 (depends on 8)

The system of claim 8 further comprising a bypass branch configured to cause the fluid to bypass the radiator, wherein the actuator includes at least one of a pump configured to pump the fluid through the fuel cell circuit, a fan configured to direct air over the radiator, or a three-way valve configured to split the fluid between the radiator and the bypass branch.

### Claim 14 (depends on 8)

The system of claim 8 wherein:
the ECU includes a proportional-integral-derivative (PID) controller configured to receive the adjusted estimated parameter and to generate an updated estimated parameter by accounting for present error values, past error values, and potential future errors of the adjusted estimated parameter; and
the ECU is configured to determine an updated actuator control signal based on the updated adjusted estimated parameter.

### Claim 15 (depends on 8)

The system of claim 8 further comprising a temperature sensor configured to detect the fluid temperature of the fluid.

### Claim 16

A method for heating or cooling a fuel cell circuit of a vehicle comprising:
determining, by an electronic control unit (ECU), a temperature control signal corresponding to a desired temperature of a fluid of the fuel cell circuit;
performing, by the ECU, a feedforward control of an actuator of the fuel cell circuit to cause the actuator to increase or decrease a fluid temperature of the fluid towards the desired temperature of the fluid;
determining, by the ECU, a temperature difference between the fluid temperature of the fluid and the desired temperature of the fluid;
determining, by the ECU, a sensitivity that corresponds a change in a parameter value or an actuator position of the actuator to a change in the fluid temperature;
applying, by the ECU, the sensitivity to the temperature difference to determine an error signal that corresponds to an additional change in the actuator position to cause the fluid temperature to increase or decrease to reduce the temperature difference; and
controlling, by the ECU, the actuator based on the error signal.

### Claim 17 (depends on 16)

The method of claim 16 wherein the actuator is a three-way valve and the desired temperature of the fluid and the fluid temperature correspond to the fluid at an inlet of the fuel cell stack.

### Claim 18 (depends on 17)

The method of claim 17 wherein the three-way valve is configured to split the fluid between a radiator for cooling the temperature and a bypass branch for causing the fluid to bypass the radiator, and determining, by the ECU, the sensitivity includes determining the sensitivity based on a pump fluid temperature corresponding to a pump inlet of a pump of the fuel cell circuit, a bypass fluid temperature corresponding to the bypass branch, and a radiator temperature corresponding to an outlet of the radiator.

### Claim 19 (depends on 16)

The method of claim 16 wherein the actuator is a pump configured to pump the fluid through the fuel cell circuit, and the desired temperature of the fluid and the fluid temperature correspond to the fluid at an outlet of the fuel cell stack.

### Claim 20 (depends on 19)

The method of claim 19 wherein determining, by the ECU, the sensitivity includes determining the sensitivity based on an amount of heat generated by a fuel cell stack of the fuel cell circuit, a specific heat of the fluid, the fluid temperature at the outlet of the fuel cell stack, and an inlet fuel cell temperature corresponding to an inlet of the fuel cell stack.