# US 2019/0168104 A1 · Control system for electric vehicles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0168104 A1 - Document ID: US20190168104A1 - Status: Published application - Kind: A1 - Application number: 16/208,485 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: Future Motion, Inc. - Applicants: Future Motion, Inc. - Inventors: Kyle Jonathan DOERKSEN; Daniel J. WOOD; Julian DE LA RUA - Web page: https://patentgrep.com/patent/US20190168104A1 ## CPC - A63C 17/12: with driving mechanisms - A63C 17/016: {with wheels arranged in one track} - A63C 17/08: single-wheel type {with single axis} - A63C 17/223: {Wheel hubs} - A63C 17/226: {Wheel mounting, i.e. arrangement connecting wheel and axle mount} - A63C 17/26: with special auxiliary arrangements, e.g. illuminating, marking, or push-off devices - B60K 7/0007: {the motor being electric} - B60L 15/025: {using field orientation; Vector control; Direct Torque Control [DTC]} - B60L 15/2018: {for braking on a slope} - B60L 53/00: Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles - A63C 2203/12: Electrically powered or heated - A63C 2203/14: Lighting means - A63C 2203/18: Measuring a physical parameter, e.g. speed, distance - A63C 2203/24: Processing or storing data, e.g. with electronic chip - B60L 2200/14: Vehicles with one wheel only - B60L 2220/44: Wheel Hub motors, i.e. integrated in the wheel hub - B60L 2220/46: Wheel motors, i.e. motor connected to only one wheel - B60L 2240/12: Speed - B60L 2240/22: Yaw angle - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 10/72: Electric energy management in electromobility - Y02T 90/14: Plug-in electric vehicles - A63C: SKATES; SKIS; ROLLER SKATES; DESIGN OR LAYOUT OF COURTS, RINKS OR THE LIKE (water skis B63B32/00, B63B34/00) - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract When an electric vehicle is traveling downhill, experiencing regenerative braking, or otherwise forcing the vehicle motor to turn faster than the commanded motor torque, the vehicle motor produces electrical energy that can be used to recharge a vehicle battery. However, if the vehicle battery is already nearly or fully charged, the excess electrical energy produced may damage the battery. Control systems described herein may reduce and/or dispose of the excess energy by manipulating the motor flux (i.e., direct) current and quadrature current independently. ## Claims ### Claim 1 A control system for an electric vehicle, the control system comprising: a power supply; an electric motor coupled to the power supply; and a motor controller having a field-oriented control (FOC) scheme configured to control the electric motor by manipulating a direct current aligned with a rotating rotor flux angle and a quadrature current defined at ninety degrees from the rotating rotor flux angle, wherein manipulation of the direct current is independent of manipulation of the quadrature current, and the motor controller includes processing logic configured to: determine whether a counter electromotive force (CEMF) of the electric motor exceeds a voltage of the power supply by comparing a bus voltage of the power supply to a voltage threshold; and in response to the bus voltage being greater than the voltage threshold, weakening a motor flux of the electric motor and reducing the CEMF by automatically increasing the direct current. ### Claim 2 (depends on 1) The control system of claim 1, wherein the processing logic of the motor controller is further configured to: while the bus voltage is greater than the voltage threshold, automatically continue to increase the direct current of the motor; and in response to the direct current reaching a direct current threshold, automatically stop increasing the direct current. ### Claim 3 (depends on 1) The control system of claim 1, wherein automatically increasing the direct current comprises: increasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to a higher of the existing flux command and the flux setpoint. ### Claim 4 (depends on 1) The control system of claim 1, wherein the processing logic of the motor controller is further configured to: in response to the bus voltage being less than the voltage threshold and the direct current being greater than zero, reducing inefficiency of the motor by automatically reducing the direct current. ### Claim 5 (depends on 4) The control system of claim 4, wherein automatically reducing the direct current comprises: decreasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to a higher of the existing flux command and the flux setpoint. ### Claim 6 (depends on 1) The control system of claim 1, wherein the power supply comprises a lithium ion battery. ### Claim 7 (depends on 1) The control system of claim 1, wherein the electric motor comprises a hub motor configured to rotate a wheel of a vehicle. ### Claim 8 An electric vehicle comprising: one or more wheels; an electric hub motor coupled to a power supply and configured to drive the one or more wheels; a motor controller having a field-oriented control (FOC) scheme configured to control the electric hub motor by manipulating a direct current aligned with a rotating rotor flux angle and a quadrature current defined at ninety degrees from the rotating rotor flux angle, wherein manipulation of the direct current is independent of manipulation of the quadrature current, and the motor controller includes processing logic configured to: determine whether a counter electromotive force (CEMF) of the electric motor exceeds a voltage of the power supply by comparing a bus voltage of the power supply to a voltage threshold; and in response to the bus voltage being greater than the voltage threshold, weakening a motor flux of the electric motor and reducing the CEMF by automatically increasing the direct current. ### Claim 9 (depends on 8) The vehicle of claim 8, wherein the vehicle has exactly one wheel. ### Claim 10 (depends on 9) The vehicle of claim 9, wherein the vehicle comprises a self-balancing electric skateboard, the skateboard comprising: a board including first and second deck portions each configured to receive a left or right foot of a rider oriented generally perpendicular to a direction of travel of the board; a wheel assembly including the exactly one wheel disposed between and extending above the first and second deck portions, wherein the electric hub motor is configured to rotate the wheel around an axle to propel the skateboard; and at least one sensor configured to measure orientation information of the board; wherein the motor controller is further configured to receive orientation information measured by the sensor and to cause the hub motor to propel the skateboard based on the orientation information. ### Claim 11 (depends on 8) The vehicle of claim 8, wherein the processing logic of the motor controller is further configured to: while the bus voltage is greater than the voltage threshold, automatically continue to increase the direct current of the motor; and in response to the direct current reaching a direct current threshold, automatically stop increasing the direct current. ### Claim 12 (depends on 8) The vehicle of claim 8, wherein automatically increasing the direct current comprises: increasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to the higher of the existing flux command and the flux setpoint. ### Claim 13 (depends on 8) The vehicle of claim 8, wherein the processing logic of the motor controller is further configured to: in response to the bus voltage being less than the voltage threshold and the direct current being greater than zero, reducing inefficiency of the motor by automatically reducing the direct current. ### Claim 14 (depends on 13) The vehicle of claim 13, wherein automatically reducing the direct current comprises: decreasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to a higher of the existing flux command and the flux setpoint. ### Claim 15 A method for preventing damage to a power supply of an electric vehicle during regenerative braking, the method comprising: controlling an electric motor using a motor controller having a field-oriented control (FOC) scheme configured to control the electric motor by manipulating a direct current aligned with a rotating rotor flux angle and a quadrature current defined at ninety degrees from the rotating rotor flux angle, wherein manipulation of the direct current is independent of manipulation of the quadrature current; using processing logic of the motor controller to determine whether a counter electromotive force (CEMF) of the electric motor exceeds a voltage of the power supply; and in response to the CEMF of the electric motor exceeding the voltage of the power supply, weakening a motor flux of the electric motor and reducing the CEMF by automatically increasing the direct current. ### Claim 16 (depends on 15) The method of claim 15, wherein determining whether the CEMF of the electric motor exceeds the voltage of the power supply comprises comparing a bus voltage of the power supply to a voltage threshold. ### Claim 17 (depends on 15) The method of claim 15, further comprising: while the CEMF of the electric motor exceeds the voltage of the power supply, automatically continuing to increase the direct current of the motor until the direct current reaches a direct current threshold. ### Claim 18 (depends on 15) The method of claim 15, wherein automatically increasing the direct current comprises: increasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to a higher of the existing flux command and the flux setpoint. ### Claim 19 (depends on 15) The method of claim 15, further comprising: in response to the CEMF of the electric motor being below the voltage of the power supply and the direct current being greater than zero, reducing inefficiency of the motor by automatically reducing the direct current. ### Claim 20 (depends on 19) The method of claim 19, wherein automatically reducing the direct current comprises: decreasing a flux setpoint of the motor controller by a selected amount; comparing an existing flux command to the flux setpoint; and adjusting direct current to a higher of the existing flux command and the flux setpoint.