# US 7,746,023 B2 · Position detecting device and synchronous motor driving device using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,023 B2 - Document ID: US7746023B2 - Status: Granted - Kind: B2 - Application number: 12/610,397 - Filed: 2009-11-02 - Published: 2010-02-25 - Granted: 2010-06-29 - Earliest claimed: 2005-12-12 - Assignees: Hitachi, Ltd. - Inventors: Toshiyuki Ajima; Hideki Miyazaki; Masataka Sasaki; Bunji Furuyama; Tokihito Suwa - Web page: https://patentgrep.com/patent/US7746023B2 ## CPC - H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple - G01D 5/2046: {by a movable ferromagnetic element, e.g. a core} - H02P 6/16: Circuit arrangements for detecting position - H02P 2209/07: Trapezoidal waveform - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract A position detecting device which can increase accuracy in detecting the pole position of a motor used to perform quick acceleration and deceleration over the range from a zero speed to a high rotation speed, and a synchronous motor driving device using the position detecting device. A position detector detects basic-wave component signals in sensor signals and executes position calculation. A correcting unit calculates signal information representing at least one of a gain, an offset and a phase by a phase detector from the basic-wave component signals detected by an error calculator, and makes correction based on the calculated signal information such that a position detection error is zero. ## Claims ### Claim 1 A position detecting device for detecting a motor pole position by using at least two sensor signals, comprising: a position detector for executing position calculation by inputting basic-wave component signals in said sensor signals, a correcting means for correcting so as that a position detecting error is reduced, wherein said position detector extracts said sensor signals in a range between predetermined first and second determination values, thereby converting extracting signals, and said first determination value is larger than said second determination value and is smaller than a maximum value of said sensor signals, and said second determination value is larger than a minimum value of said sensor signals; and means for correcting to reduce a position detecting error by calculating signal information representing at least one of a gain, an offset and a phase by using a signal between said first determination value and said second determination value in said extracting signal and making a correction based on the signal information. ### Claim 2 (depends on 1) The position detecting device according to claim 1, wherein said sensor signals are three-phase signals of U-, V- and W-phases, and said signal between said first determination value and said second determination value in said extracting signal is a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, a signal from a cross point between the V-phase signal and the W-phase signal to a cross point between the U-phase signal and the V-phase, a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, and a signal from a cross point between the U-phase signal and the V-phase signal to a cross point between the U-phase signal and the W-phase. ### Claim 3 A motor driving device comprising: a semiconductor device for converting DC power to AC power or converting AC power to DC power; a position detecting device for detecting a motor pole position by using two or more sensor signals; a position detector calculator configured to execute position calculation by inputting basic-wave component signals in said sensor signals, wherein said position detector calculator is configured to extract said sensor signals in a range between predetermined first and second determination values, thereby converting extracting signals, and said first determination value is larger than said second determination value, and is smaller than a maximum value of said sensor signal, and said second determination value is larger than a minimum value of said sensor signal; and said means for correcting so as to reduce position detection error by calculating signal information representing at least one of gain, an offset and a phase by using a signal between said first determination value and said second determination value in said extracting signal and making correction based on the signal information. ### Claim 4 (depends on 3) The position detecting device according to claim 3, wherein said sensor signals are three-phase signals of U-, V- and W-phases, and said signal between said first determination value and said second determination value in said extracting signal is a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, a signal from a cross point between the V-phase signal and the W-phase signal to a cross point between the U-phase signal and the V-phase, a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, and a signal from a cross point between the U-phase signal and the V-phase signal to a cross point between the U-phase signal and the W-phase. ### Claim 5 A motor driving system comprising: a semiconductor device for converting from DC power to AC power or converting from AC power to DC power; a position detecting device for detecting a motor pole position by using two or more sensor signals; a sensor unit for generating said sensor signal; a position detector for executing position calculation by inputting basic-wave component signals in said sensor signals, wherein said position detector extracts said sensor signals in a range between predetermined first and second determination values, thereby converting extracting signals, and said first determination value is larger than said second determination value, and is smaller than a maximum value of said sensor signal, and said second determination value is larger than a minimum value of said sensor signal; and means for correcting to reduce position detecting error by calculating signal information representing at least one of a gain, an offset and a phase by using a signal between said first determination value and said second determination value in said extracting signal and making correction based on the signal information. ### Claim 6 (depends on 5) The position detecting system according to claim 5, wherein said sensor unit consists of Hall element at least. ### Claim 7 (depends on 5) The motor driving system according to claim 5, further comprising a sensor unit for generating said sensor signal, wherein said sensor unit includes a magnetic adjusting member for adjusting an amount of effective magnetic flux crossing a sensor. ### Claim 8 (depends on 7) The position detecting system according to claim 7, wherein said sensor unit consists of Hall element at least. ### Claim 9 (depends on 5) The position detecting system according to claim 5, further comprising a sensor unit for generating said sensor signal, said sensor unit having a magnetic shielding member oriented perpendicularly to a direction in which magnetic flux is sensed. ### Claim 10 (depends on 9) The position detecting system according to claim 9, wherein said sensor unit consists of Hall element at least. ### Claim 11 (depends on 5) The position detecting system according to claim 5, wherein said sensor unit includes a plurality of sensors attachable to a motor housing from the outside. ### Claim 12 (depends on 11) The position detecting system according to claim 11, wherein said sensor unit consists of Hall element at least. ### Claim 13 A permanent-magnet synchronous motor driving device comprising: a position detecting device for detecting a motor pole position by using two or more sensor signals; a motor controller for producing a PWM drive signal based on a position detected value detected by said position detecting device, and outputting the PWM drive signal to an inverter, thereby driving a permanent-magnet synchronous motor; a sensor unit for generating said sensor signal; a position detector for executing position calculation by inputting basic-wave component signals in said sensor signals, wherein said position detector extracts said sensor signals in a range between predetermined first and second determination values, thereby converting extracting signals and said first determination value is larger than said second determination value, and is smaller than a maximum value of said sensor signal, and said second determination value is larger than a minimum value of said sensor signal; and means for correcting to reduce position detection error by calculating signal information representing at least one of a gain, an offset and a phase by using a signal between said first determination value and said second determination value in said extracting signal and making correction based on the signal information. ### Claim 14 (depends on 13) The position detecting device according to claim 13, wherein said sensor signals are three-phase signals of U-, V- and W-phases, and said signal between said first determination value and said second determination value in said extracting signal is a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, a signal from a cross point between the V-phase signal and the W-phase signal to a cross point between the U-phase signal and the V-phase, a signal from a cross point between the U-phase signal and the W-phase signal to a cross point between the V-phase signal and the W-phase, and a signal from a cross point between the U-phase signal and the V-phase signal to a cross point between the U-phase signal and the W-phase.