# US 10,768,234 B2 · Method for estimating power consumption of motor in fuel cell system

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- Number: US 10,768,234 B2
- Document ID: US10768234B2
- Status: Granted
- Kind: B2
- Application number: 15/782,679
- Filed: 2017-10-12
- Published: 2018-06-14
- Granted: 2020-09-08
- Earliest claimed: 2016-12-13
- Assignees: Hyundai Motor Company; Kia Motors Corporation
- Applicants: Hyundai Motor Company; Kia Motors Corporation
- Inventors: Dong Hun Lee; Chang Seok You; Min Su Kang; Sung Do Kim
- Web page: https://patentgrep.com/patent/US10768234B2

## CPC

- G01R 31/343: {in operation}
- B60L 15/025: {using field orientation; Vector control; Direct Torque Control [DTC]}
- B60L 50/72: Constructional details of fuel cells specially adapted for electric vehicles
- B60L 58/30: for monitoring or controlling fuel cells
- H01M 8/04544: {Voltage}
- H01M 8/04992: characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
- B60L 2240/423: Torque
- B60L 2240/427: Voltage
- B60L 2240/429: Current
- B60L 2240/527: Voltage
- B60L 2240/529: Current
- B60L 2260/44: by parameter estimation
- H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane
- H02P 6/08: Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence)
- H02P 31/00: Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00
- Y02E 60/50: Fuel cells
- Y02T 10/64: Electric machine technologies in electromobility
- Y02T 90/00: Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- 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
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A method for estimating power consumption of a motor includes steps of: determining an error voltage for a terminal voltage of each of multiple phases of the motor, the terminal voltage being supplied from an inverter to the motor; generating a compensation terminal voltage for each of the multiple phases of the motor by applying the error voltage to a prediction value of the terminal voltage that is derived in a preset manner during operation of the motor; and calculating power consumption of the motor by using the compensation terminal voltage and a current value obtained by detecting a current that flows in each of the multiple phases of the motor.

## Claims

### Claim 1

A method for estimating power consumption of a motor in a fuel cell system, the method comprising steps of:
supplying, by a controller, a terminal voltage command for each of multiple phases of the motor to an inverter;
driving, by the controller, switching elements included in the inverter based on the terminal voltage command;
detecting, by a current sensor, a current of each of the multiple phases of the motor depending on a change in the terminal voltage command;
extending, by the controller, a line of a region where the current is linearly changed in a voltage-current graph showing a relationship between the terminal voltage command and the detected current, and determining, by the controller, a voltage value of a point where the line meets a voltage axis of the voltage-current graph to be an error voltage for each of the multiple phases;
generating, by the controller, a compensation terminal voltage for each of the multiple phases of the motor by applying the error voltage to a prediction value of the terminal voltage that is derived in a preset manner during operation of the motor;
calculating, by the controller, power consumption of the motor by using the compensation terminal voltage and a current value obtained by detecting a current that flows in each of the multiple phases of the motor; and
controlling, by the controller, power output from the fuel cell system to be restricted based on the calculated power consumption of the motor.

### Claim 2 (depends on 1)

The method of claim 1, wherein:
the step of supplying a terminal voltage command comprises: supplying a positive terminal voltage command and a negative terminal voltage command to each of the multiple phases of the motor, and
the step of determining an error voltage further comprises steps of: determining a first error voltage for each of the multiple phases by using a positive current that is detected when the positive terminal voltage command is supplied; and determining a second error voltage for each of the multiple phases by using a negative current that is detected when the negative terminal voltage command is supplied.

### Claim 3 (depends on 1)

The method of claim 1, wherein the step of generating a compensation terminal voltage comprises:
generating the compensation terminal voltage for each of the multiple phases by subtracting the error voltage from the prediction value of the terminal voltage when the current of each of the multiple phases is a positive value during operation of the motor, and by adding the error voltage to the prediction value of the terminal voltage when the current of each of the multiple phases is a negative value during operation of the motor.

### Claim 4 (depends on 3)

The method of claim 3, wherein the step of generating a compensation terminal voltage comprises:
generating the compensation terminal voltage for each of the multiple phases by subtracting the first error voltage from the prediction value of the terminal voltage when the current of each of the multiple phases is a positive value during operation of the motor, and by subtracting the second error voltage from the prediction value of the terminal voltage when the current of each of the multiple phases is a negative value during operation of the motor.

### Claim 5 (depends on 1)

The method of claim 1, wherein the step of generating a compensation terminal voltage comprises:
subtracting the error voltage from the prediction value of the terminal voltage when the current of each of the multiple phases is greater than a preset reference current α (positive value);
adding the error voltage to the prediction value of the terminal voltage when the current of each of the multiple phases is less than a; and
changing the error voltage linearly and applying the changed error voltage to the prediction value of the terminal voltage when the current of each of the multiple phases is a value ranging from α to −α.

### Claim 6 (depends on 5)

The method of claim 5, wherein when the current of each of the multiple phases is a value ranging from α to −α, the error voltage is changed and applied to the prediction value of the terminal voltage by using formulas
V
n_Out
⁢
_real
=
V
n
-
V
Comp
⁢
⁢
and
⁢
⁢
V
Comp
=
V
ref
×
I
α
(Vn_out_real: the compensation terminal voltage for each of the multiple phases, Vn: the prediction value of the terminal voltage for each of the multiple phases, Vref: the error voltage, α: the reference current, I: the detected current of each of the multiple phases).

### Claim 7 (depends on 1)

The method of claim 1, wherein the prediction value of the terminal voltage is a voltage value estimated based on a duty value of a PWM signal applied to a gate of a switching element of the inverter, or is a terminal voltage command value of each of the multiple phases generated by performing coordinate transformation on both a D-axis voltage command and a Q-axis voltage command that are generated at a current controller included in a motor controller for controlling the motor.

### Claim 8 (depends on 1)

The method of claim 1, wherein the step of calculating power consumption comprises:
converting the compensation terminal voltage into D-axis and Q-axis voltages of a stationary reference frame, and converting the current value obtained by detecting the current that flows in each of the multiple phases of the motor into D-axis and Q-axis currents of the stationary reference frame; and calculating the power consumption of the motor by using the converted voltages and currents.

### Claim 9 (depends on 8)

The method of claim 8, wherein the step of calculating power consumption further comprises:
calculating the power consumption of the motor by using formula Pmot=1.5×(IDfix×VDfix+IQfix×VQfix) (IDfix: the D-axis current of the stationary reference frame generated by converting the current value, IQfix: the Q-axis current of the stationary reference frame generated by converting the current value, VD_out_real: the D-axis voltage of the stationary reference frame generated by converting the compensation terminal voltage, VQ_out_real: the Q-axis voltage of the stationary reference frame generated by converting the compensation terminal voltage).

### Claim 10 (depends on 1)

The method of claim 1, further comprising a step of:
calculating power of the inverter based on both the calculated power consumption of the motor obtained in the calculating of the power consumption and inverter efficiency preset for the inverter.

### Claim 11 (depends on 10)

The method of claim 10, wherein the step of calculating power of the inverter comprises:
calculating the power of the inverter by using formula Pinf=Pnot×ηinv (Piny: the power of the inverter, Pmot: the calculated power consumption of the motor obtained in the calculating of the power consumption, ηinv: the inverter efficiency) in a motoring state where the inverter applies a torque in a rotation direction of the motor, and
calculating the power of the inverter by using formula
P
inv
=
P
mot
η
inv
in a regenerative braking state where the inverter applies a torque in a direction opposite to the rotation direction of the motor.