# US 8,786,221 B2 · Method for controlling permanent magnet synchronous motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,221 B2 - Document ID: US8786221B2 - Status: Granted - Kind: B2 - Application number: 12/829,638 - Filed: 2010-07-02 - Published: 2011-10-06 - Granted: 2014-07-22 - Earliest claimed: 2010-03-31 - Assignees: Hyundai Motor Company; Kia Motors Corporation - Applicants: Bum Sik Kim; Young Kook Lee; Jin Hwan Jung - Inventors: Bum Sik Kim; Young Kook Lee; Jin Hwan Jung - Web page: https://patentgrep.com/patent/US8786221B2 ## CPC - H02P 21/14: Estimation or adaptation of machine parameters, e.g. flux, current or voltage - B60L 3/12: Recording operating variables {; Monitoring of operating variables} - B60L 15/025: {using field orientation; Vector control; Direct Torque Control [DTC]} - B60L 50/13: using AC generators and AC motors - B60L 2220/14: Synchronous machines - B60L 2240/421: Speed - 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 - 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 - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - 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 A method for controlling a permanent magnet synchronous motor includes detecting an absolute angular position and using the angular position to calculate a rotational speed of the motor; detecting a voltage of a battery as a power source; calculating a compensated speed from a rotational speed of the permanent magnet synchronous motor based on a torque command, the rotational speed of the permanent magnet synchronous motor, and the battery voltage; generating a d-axis current command and a q-axis current command corresponding to the torque command and the compensated speed; calculating a d-axis voltage command and a q-axis voltage command based on the d-axis current command and the q-axis current command; converting the d-axis voltage command and the q-axis voltage command into three-phase voltage commands based on the detected absolute angular position; and controlling the operation of the permanent magnet synchronous motor based on the three-phase voltage commands. ## Claims ### Claim 1 A method for controlling a permanent magnet synchronous motor, the method comprising: detecting an absolute angular position of a permanent magnet synchronous motor; calculating a rotational speed of the permanent magnet synchronous motor based on the detected absolute angular position; detecting a voltage of a battery as a power source; calculating a compensated speed, for which a battery voltage variation is compensated, from the rotational speed of the permanent magnet synchronous motor based on a torque command, the rotational speed of the permanent magnet synchronous motor, and the battery voltage; generating a d-axis current command and a q-axis current command corresponding to the torque command and the compensated speed using a predetermined current command map; converting three-phase currents flowing into the permanent magnet synchronous motor into a d-axis feedback current and a q-axis feedback current based on the detected absolute angular position; calculating a d-axis voltage command and a q-axis voltage command based on the d-axis current command, the q-axis current command, the d-axis feedback current, and the q-axis feedback current; converting the d-axis voltage command and the q-axis voltage command into three-phase voltage commands based on the detected absolute angular position; and controlling the operation of the permanent magnet synchronous motor based on the three-phase voltage commands, wherein the calculating the compensated speed comprises: determining whether the rotational speed of the permanent magnet synchronous motor is greater than a predetermined weight application speed; calculating an operating weight factor by applying a weight to the rotational speed and the torque command, if the rotational speed of the permanent magnet synchronous motor is greater than the weight application speed; and calculating the compensated speed, for which a battery voltage variation is compensated, from the rotational speed of the permanent magnet synchronous motor based on the operating weight factor and a reference voltage used when the current command map is set. ### Claim 2 (depends on 1) The method of claim 1, wherein the operating weight factor is calculated by the following equation E1 based on predetermined speed weightweight factor of speed and weight factor of torque command weight: KN=Kω(ωrpm−ω0 )+KT|Te*| E1: wherein KN represents the operating weight factor, Kω represents the speed weightweight factor of speed, ωrpm represents the motor rotational speed, ω0 represents the weight factor of application start speed, KT represents the weight factor of torque command weight, and Te* represents the torque command. ### Claim 3 (depends on 1) The method of claim 1, wherein the operating weight factor is zero if the rotational speed of the permanent magnet synchronous motor is smaller than the weight application speed. ### Claim 4 (depends on 1) The method of claim 1, wherein the calculation the compensated speed further comprises determining whether the battery voltage is greater than a predetermined compensation starting voltage, wherein if the battery voltage is greater than the compensation starting voltage, the compensated speed is calculated and used as an input of the current command map data, and if the battery voltage is smaller than the compensation starting voltage, the rotational speed of the permanent magnet synchronous motor is used as an input of the current command map data instead of the compensated speed. ### Claim 5 (depends on 1) The method of claim 1, wherein the compensated speed is calculated by a motor speed normalization formula in which the operating weight factor, the battery voltage, and the rotational speed of the permanent magnet synchronous motor are used as input variables. ### Claim 6 (depends on 5) The method of claim 5, wherein the compensated speed is a normalized motor speed calculated by the motor speed normalization formula represented by the following equation E2: ω rpm , Nom = [ 1 + F ⁢ { ( 1 + K N ) ⁢ V DC , MAP V DC - 1 } ] ⁢ ω rpm E2 wherein ωrpm,Nom represents the normalized motor speed, KN represents the operating weight factor, VDC,MAP represents the reference voltage used when the map is set, VDC represents the battery voltage, and F is equal to 1(VDC≧V0) or 0(VDC