# US 7,746,064 B2 · Speed measurement for an electrical permanent-magnet synchronous machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,064 B2 - Document ID: US7746064B2 - Status: Granted - Kind: B2 - Application number: 11/576,025 - Filed: 2005-09-19 - Published: 2008-03-20 - Granted: 2010-06-29 - Earliest claimed: 2004-09-27 - Assignees: Siemens Aktiengesellschaft - Inventors: Markus Knorr; Zeljko Jajtic - Web page: https://patentgrep.com/patent/US7746064B2 ## CPC - H02K 41/031: {of the permanent magnet type} - G01P 3/487: delivered by rotating magnets - G01P 3/52: by measuring amplitude of generated current or voltage - G01P 3/54: by measuring frequency of generated current or voltage - H02K 11/215: Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements - H02K 21/16: having annular armature cores with salient poles (with homopolar co-operation H02K21/20) - H02K 41/0356: {moving along a straight path} - H02P 6/18: without separate position detecting elements - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract The invention relates to a speed measurement device (1, 2) for a permanently excited electric synchronous machine (5, 7) comprising a first part (11, 13) and a second part (15, 17). The invention also relates to a corresponding method for measuring speed. The second part (15, 17) of the permanently excited electric synchronous machine comprises permanent magnets (19). The speed measurement device (1, 2) comprises at least one first sensor (25) and a second sensor (31), wherein the first sensor (25) is provided with a sensor coil and the second sensor (31) is a Hall sensor and the sensors (25, 31) on the first part (11, 13) are arranged in such a way that the first sensor (25) and second sensor (31) are influenced by a magnetic field (33), which is generated by the permanent magnets (19), by means of a flow conducting device (43) having an integrated character. ## Claims ### Claim 1 A speed measurement device for an electrical machine, which has a primary part, a secondary part, and permanent magnets said speed measurement device comprising: a first sensor having a sensor coil which generates a first signal value having a position-dependent component and a speed-dependent component; a second sensor constructed as a Hall sensor to generate a position-dependent second signal value to eliminate the position-dependent component of the sensor coil; a flux guidance device for guidance of a magnetic flux, wherein at least one of the first and second sensors is arranged in an area of the flux guidance device and configured to measure the magnetic flux in the flux guidance device; and an evaluation device relating the first signal value to the second signal value, wherein a ratio between the first signal value and the second signal value is proportional to the speed of the machine. ### Claim 2 (depends on 1) The speed measurement device of claim 1, wherein the second sensor is arranged in another area of the flux guidance device. ### Claim 3 (depends on 2) The speed measurement device of claim 2, wherein the first and second sensors are positioned in the areas of the flux guidance device such that the first and second sensors can be influenced by a magnetic field produced by the permanent magnets. ### Claim 4 (depends on 1) The speed measurement device of claim 1, wherein the flux guidance device has teeth, with the magnetic flux generated by the permanent magnets of the electrical machine. ### Claim 5 (depends on 4) The speed measurement device of claim 4, wherein the permanent magnets are components of the secondary part of the electrical machine. ### Claim 6 (depends on 1) The speed measurement device of claim 1, wherein the flux guidance device is integrated in the primary part of the electrical machine. ### Claim 7 (depends on 1) The speed measurement device of claim 1, wherein at least one of the first and second sensors is arranged outside a magnetic circuit of the primary part. ### Claim 8 (depends on 1) The speed measurement device of claim 1, wherein at least one of the first and second sensors is arranged within a magnetic circuit of the primary part. ### Claim 9 (depends on 1) The speed measurement device of claim 1, wherein the first and second sensors are connectable to the evaluation device for determination of a speed of a permanent-magnet electrical synchronous machine. ### Claim 10 (depends on 1) The speed measurement device of claim 1, wherein the first sensor has an electrical phase offset from the second sensor. ### Claim 11 A speed measurement assembly for a permanent-magnet electrical synchronous machine which has a primary part and a secondary part, said speed measurement assembly comprising an evaluation device, and two speed measurement devices operatively connected to the evaluation device, each speed measurement device including a first sensor having a sensor coil which generates a first signal value having a position-dependent component and a speed-dependent component, a second sensor constructed as a Hall sensor to generate a position-dependent second signal value to eliminate the position-dependent component of the sensor coil, and a flux guidance device for guidance of a magnetic flux, wherein at least one of the first and second sensors is arranged in an area of the flux guidance device and configured to measure the magnetic flux in the flux guidance device, wherein one of the speed measurement devices is constructed for attachment in and/or to the primary part with an electrical phase offset from the other one of the speed measurement devices, wherein the evaluation device relates the first signal value to the second signal value of each of the speed measurement devices, wherein a ratio between the first signal value and the second signal value is proportional to the speed of the machine. ### Claim 12 A primary part of a permanent-magnet electrical synchronous machine, comprising: a first sensor having a sensor coil which generates a first signal value having a position-dependent component and a speed-dependent component; a second sensor constructed as a Hall sensor to generate a position-dependent second signal value to eliminate the position-dependent component of the sensor coil, wherein the first and second sensors are configured for measurement of a speed; a flux guidance device for guidance of a motor flux of the permanent-magnet electrical synchronous machine, with at least one of the first and second sensors being constructed for attachment to or adjacent to the flux guidance device, wherein the flux guidance device has teeth; and an evaluation device relating the first signal value to the second signal value, wherein a ratio between the first signal value and the second signal value is proportional to the speed of the machine. ### Claim 13 (depends on 12) The primary part of claim 12, wherein the first and second sensors are positioned in such a manner that the first and second sensors can be influenced by a magnetic field produced by permanent magnets of the permanent-magnet electrical synchronous machine. ### Claim 14 (depends on 13) The primary part of claim 13, wherein the permanent magnets are components of a secondary part of the permanent-magnet electrical synchronous machine. ### Claim 15 (depends on 12) The primary part of claim 12, wherein the first sensor has an electrical phase offset from the second sensor. ### Claim 16 (depends on 12) The primary part of claim 12, wherein the first and second sensors are components of a first speed measurement device, further comprising a second speed measurement device having a third sensor, and a fourth sensor, with the third sensor being a Hall sensor, and with the fourth sensor having a sensor coil. ### Claim 17 (depends on 12) The primary part of claim 12, wherein the Hall sensor is constructed for determining a rotor position. ### Claim 18 (depends on 12) The primary part of claim 12, wherein at least one of the first and second sensors is arranged outside a magnetic circuit of the primary part. ### Claim 19 (depends on 12) The primary part of claim 12, wherein at least one of the first and second sensors is arranged within a magnetic circuit of the primary part. ### Claim 20 A method for measurement of a speed of a machine, said method comprising the steps of: guiding a magnetic field produced by permanent magnets of the machine by a flux guidance device to a first sensor which measures a magnetic field to generate a first signal value having a position-dependent component and a speed-dependent component; guiding the magnetic field by means a further flux guidance device to a second sensor, which measures the magnetic field to generate a position-dependent second signal value to eliminate the position-dependent component of the first signal value; and relating the first signal value to the second signal value, wherein a ratio between the first signal value and the second signal value is proportional to the speed of the machine. ### Claim 21 (depends on 20) The method of claim 20, further comprising the step of constructing one of the flux guidance devices with teeth placed in opposition to the permanent magnets. ### Claim 22 (depends on 20) The method of claim 20, wherein signal disturbances of the first signal value and of the second signal value, caused by a current flowing in a primary part, and further comprising the step of compensating the signal disturbances by a compensation device.