# US 12,179,780 B2 · Method for online direct estimation and compensation of flux and torque errors in electric drives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,780 B2 - Document ID: US12179780B2 - Status: Granted - Kind: B2 - Application number: 17/723,094 - Filed: 2022-04-18 - Published: 2022-09-29 - Granted: 2024-12-31 - Earliest claimed: 2019-12-30 - Assignees: Karma Automotive LLC - Applicants: Karma Automotive LLC - Inventors: Parisa Mohammadalizadeh Shabestari; Younes Sangsefidi; Geng Niu - Web page: https://patentgrep.com/patent/US12179780B2 ## CPC - B60W 50/029: Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 50/0205: {Diagnosing or detecting failures; Failure detection models} - H02P 21/06: Rotor flux based control involving the use of rotor position or rotor speed sensors - H02P 21/13: Observer control, e.g. using Luenberger observers or Kalman filters - H02P 21/14: Estimation or adaptation of machine parameters, e.g. flux, current or voltage - H02P 21/141: {Flux estimation} - H02P 23/14: Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - B60W 2050/0026: {Lookup tables or parameter maps} - B60W 2050/0056: {Low-pass filters} - B60W 2510/087: Temperature - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract An online method of detecting and compensating for errors in flux estimation in operation of a motor system. The method includes determining a voltage compensation term by comparing an expected voltage and an actual voltage. The method also includes determining a flux compensation term by passing the voltage compensation term through a low-pass filter, and determining a corrected flux component value by comparing the flux compensation term with a flux value obtained from a look-up table, wherein the low-pass filter receives operating parameters based on data regarding an operating environment of the motor system. The method then further determines a corrected torque value based on the corrected flux component value. ## Claims ### Claim 1 A computer-implemented method when executed on a microprocessor causes the microprocessor to perform operations comprising: receiving a torque command for powering an electric motor drive system, the electric motor drive system comprising an electric motor and an inverter; determining a voltage compensation term based on an expected voltage and an actual voltage; determining, using a low-pass filter, a flux compensation term based on the voltage compensation term and operating parameters comprising at least one of a cutoff frequency or a period length, the operating parameters based on data regarding an operating environment of the electric motor drive system; determining a corrected flux compensation term by adding the flux compensation term to a look-up table flux value; correcting the torque command based on the corrected flux compensation term; and commanding the inverter to provide power to the electric motor to output an actual torque equal to the corrected torque command. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, wherein the microprocessor resides on a control board of the inverter. ### Claim 3 (depends on 1) The computer-implemented method of claim 1, wherein the electric motor comprises a rotor and a stator having a plurality of stator coils. ### Claim 4 (depends on 3) The computer-implemented method of claim 3, wherein each stator coil of the plurality of stator coils generates a magnetic field when the inverter provides the power to the electric motor. ### Claim 5 (depends on 3) The computer-implemented method of claim 3, wherein the rotor comprises a permanent magnet. ### Claim 6 (depends on 1) The computer-implemented method of claim 1, wherein determining the voltage compensation term comprises determining the voltage compensation term based on a difference between the expected voltage and the actual voltage. ### Claim 7 (depends on 1) The computer-implemented method of claim 1, wherein the low-pass filter comprises a specific time constant and a predetermined time constant, wherein the specific time constant and the predetermined time constant ensures control over a dynamic response of the corrected torque command. ### Claim 8 (depends on 1) The computer-implemented method of claim 1, wherein the data regarding the operating environment of the electric motor drive system comprises data regarding at least one of heat, aging, or saturation of at least one component of the electric motor drive system. ### Claim 9 (depends on 1) The computer-implemented method of claim 1, wherein correcting the torque command comprises adding the corrected flux compensation term to an uncorrected torque command. ### Claim 10 An electric motor drive system comprising: an electric motor configured to rotate a wheel of a vehicle; an inverter configured to power the electric motor; and a microprocessor executing instructions that cause the microprocessor to perform operations comprising: receiving a torque command for powering the electric motor drive system; determining a voltage compensation term based on an expected voltage and an actual voltage; determining, using a low-pass filter, a flux compensation term based on the voltage compensation term and operating parameters comprising at least one of a cutoff frequency or a period length, the operating parameters based on data regarding an operating environment of the electric motor drive system; determining a corrected flux compensation term by adding the flux compensation term to a look-up table flux value; correcting the torque command based on the corrected flux compensation term; and commanding the inverter to provide power to the electric motor to output an actual torque equal to the corrected torque command. ### Claim 11 (depends on 10) The electric motor drive system of claim 10, wherein the microprocessor resides on a control board of the inverter. ### Claim 12 (depends on 10) The electric motor drive system of claim 10, wherein the electric motor comprises a rotor and a stator having a plurality of stator coils. ### Claim 13 (depends on 12) The electric motor drive system of claim 12, wherein each stator coil of the plurality of stator coils generates a magnetic field when the inverter provides the power to the electric motor. ### Claim 14 (depends on 12) The electric motor drive system of claim 12, wherein the rotor comprises a permanent magnet. ### Claim 15 (depends on 10) The electric motor drive system of claim 10, wherein determining the voltage compensation term comprises determining the voltage compensation term based on a difference between the expected voltage and the actual voltage. ### Claim 16 (depends on 10) The electric motor drive system of claim 10, wherein the low-pass filter comprises a specific time constant and a predetermined time constant, wherein the specific time constant and the predetermined time constant ensures control over a dynamic response of the corrected torque command. ### Claim 17 (depends on 10) The electric motor drive system of claim 10, wherein the data regarding the operating environment of the electric motor drive system comprises data regarding at least one of heat, aging, or saturation of at least one component of the electric motor drive system. ### Claim 18 (depends on 10) The electric motor drive system of claim 10, wherein correcting the torque command comprises adding the corrected flux compensation term to an uncorrected torque command.