# US 2018/0026559 A1 · Rotation angle estimation apparatus for rotating electric machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0026559 A1 - Document ID: US20180026559A1 - Status: Published application - Kind: A1 - Application number: 15/653,992 - Filed: 2017-07-19 - Published: 2018-01-25 - Earliest claimed: 2016-07-22 - Assignees: Denso Corporation - Applicants: Denso Corporation - Inventors: Kiyoshi FUJII; Atsuyuki HIRUMA - Web page: https://patentgrep.com/patent/US20180026559A1 ## CPC - H02P 6/185: using inductance sensing, e.g. pulse excitation - H02P 6/18: without separate position detecting elements - H02P 21/26: Rotor flux based control - H02P 25/22: Multiple windings; Windings for more than three phases - G05B 2219/37523: Reduce noise by combination of digital filter and estimator - G05B 2219/42148: Position references as function of time, correlated noise, temperature in memory - G05B 2219/50191: Against noise - H02P 25/03: with brushless excitation - H02P 2203/11: Determination or estimation of the rotor position or other motor parameters based on the analysis of high-frequency signals - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A rotation angle estimation apparatus includes: a high-frequency voltage setting unit that sets high-frequency voltages; a circuit operating unit that operates an electric power conversion circuit to apply each of the high-frequency voltages to a corresponding one of winding groups of a rotating electric machine; and a rotation angle estimating unit that estimates a rotation angle of the rotating electric machine based on at least one of high-frequency currents that flow in the winding groups upon application of the high-frequency voltages to the winding groups. Moreover, the high-frequency voltage setting unit sets the high-frequency voltages based on the spatial phase difference between the winding groups so that in a fixed coordinate system of the rotating electric machine, the magnitude of a resultant vector of a plurality of high-frequency voltage vectors, which are respectively applied to the winding groups, becomes smaller than the magnitude of each of the high-frequency voltage vectors. ## Claims ### Claim 1 A rotation angle estimation apparatus for a rotating electric machine, the rotation angle estimation apparatus being applied to a system which includes the rotating electric machine and an electric power conversion circuit, the rotating electric machine including a stator having a plurality of winding groups wound therein, each of the winding groups being offset from another of the winding groups to have a spatial phase difference therebetween, the electric power conversion circuit being electrically connected with the winding groups to apply voltages to the winding groups, the rotation angle estimation apparatus comprising: a high-frequency voltage setting unit that sets a plurality of high-frequency voltages which change at an angular velocity higher than an electrical angular velocity of the rotating electric machine; a circuit operating unit that operates the electric power conversion circuit to apply each of the high-frequency voltages set by the high-frequency voltage setting unit to a corresponding one of the winding groups; and a rotation angle estimating unit that estimates a rotation angle of the rotating electric machine based on at least one of high-frequency currents that flow in the winding groups upon application of the high-frequency voltages to the winding groups, wherein the high-frequency voltage setting unit sets the high-frequency voltages based on the spatial phase difference between the winding groups so that in a fixed coordinate system of the rotating electric machine, the magnitude of a resultant vector of a plurality of high-frequency voltage vectors, which are respectively applied to the winding groups, becomes smaller than the magnitude of each of the high-frequency voltage vectors. ### Claim 2 (depends on 1) The rotation angle estimation apparatus as set forth in claim 1, wherein the winding groups comprise a reference winding group and at least one remaining winding group, the high-frequency voltage setting unit comprises: a reference high-frequency voltage setting unit that sets the high-frequency voltages applied to the reference winding group; and a phase operating unit that sets the high-frequency voltages applied to the at least one remaining winding group by offsetting, based on the spatial phase difference between the reference winding group and the at least one remaining winding group, the phases of the high-frequency voltages set by the reference high-frequency voltage setting unit, and the circuit operating unit operates the electric power conversion circuit to apply the high-frequency voltages set by the reference high-frequency voltage setting unit to the reference winding group and the high-frequency voltages set by the phase operating unit to the at least one remaining winding group. ### Claim 3 (depends on 2) The rotation angle estimation apparatus as set forth in claim 2, wherein the phase operating unit sets the high-frequency voltages applied to the at least one remaining winding group by offsetting, based on the spatial phase difference between the reference winding group and the at least one remaining winding group and the quotient of one cycle in electrical angle of the rotating electric machine divided by the number of the winding groups, the phases of the high-frequency voltages set by the reference high-frequency voltage setting unit. ### Claim 4 (depends on 2) The rotation angle estimation apparatus as set forth in claim 2, wherein each of the high-frequency voltages set by the phase operating unit has the same amplitude and frequency as a corresponding one of the high-frequency voltages set by the reference high-frequency voltage setting unit. ### Claim 5 (depends on 1) The rotation angle estimation apparatus as set forth in claim 1, wherein the high-frequency voltage setting unit sets the high-frequency voltages based on the spatial phase difference between the winding groups so that in the fixed coordinate system, the magnitude of the resultant vector of the high-frequency voltage vectors becomes zero. ### Claim 6 (depends on 1) The rotation angle estimation apparatus as set forth in claim 1, wherein the winding groups comprise a reference winding group and at least one remaining winding group, the high-frequency voltage setting unit sets: frequencies of the high-frequency voltages so that the frequencies of those of the high-frequency voltages which are applied to the reference winding group are higher than the frequencies of those of the high-frequency voltages which are applied to the at least one remaining winding group; and amplitudes of the high-frequency voltages so that the lower the frequencies of those of the high-frequency voltages which are applied to the at least one remaining winding group with respect to the frequencies of those of the high-frequency voltages which are applied to the reference winding group, the smaller the amplitudes of those of the high-frequency voltages which are applied to the at least one remaining winding group with respect to the amplitudes of those of the high-frequency voltages which are applied to the reference winding group.