# US 11,078,049 B2 · Elevator system including a permanent magnet (PM) synchronous motor drive system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,049 B2 - Document ID: US11078049B2 - Status: Granted - Kind: B2 - Application number: 15/750,964 - Filed: 2016-08-04 - Published: 2018-08-09 - Granted: 2021-08-03 - Earliest claimed: 2015-08-07 - Assignees: Otis Elevator Company - Applicants: Otis Elevator Company - Inventors: Edward D. Piedra - Web page: https://patentgrep.com/patent/US11078049B2 ## CPC - B66B 11/043: {actuated by rotating motor; Details, e.g. ventilation (roping on drum, sheave, winch or pulley B66B11/0065; power supply or control B66B1/28, H02P; motor construction H02K)} - B66B 1/308: {with AC powered elevator drive} - B66B 1/32: effective on braking devices {, e.g. acting on electrically controlled brakes (brake control H02P, lift brakes per se B66B5/02)} - H02P 21/09: Field phase angle calculation based on rotor voltage equation by adding slip frequency and speed proportional frequency - H02P 21/22: Current control, e.g. using a current control loop - H02P 21/36: Arrangements for braking or slowing; Four quadrant control - B66B 2201/00: Aspects of control systems of elevators - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract An elevator drive system (40) includes a permanent magnet (PM) synchronous electric motor (34) including a plurality of phases and a plurality of motor drives (55, 58) electrically connected to the PM synchronous electric motor. Each of the plurality of motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases. ## Claims ### Claim 1 An elevator drive system comprising: a permanent magnet (PM) synchronous electric motor including a plurality of phases; and a plurality of motor drives electrically connected to the PM synchronous electric motor, each of the plurality of motor drives being operatively connected to a corresponding one of the plurality of phases, the plurality of motor drives being configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases; wherein one of the plurality of motor drives is designated as a primary motor drive and remaining ones of the plurality of motor drives are designated as secondary motor drives. ### Claim 2 (depends on 1) The elevator drive system according to claim 1, wherein the primary motor drive is configured and disposed to establish a field orientation angle for each of the secondary motor drives. ### Claim 3 (depends on 1) The elevator drive system according to claim 1, wherein the primary motor drive is solely responsible for controlling velocity of the PM synchronous electric motor. ### Claim 4 (depends on 1) The elevator drive system according to claim 1, wherein the primary motor drive is solely responsible for controlling braking of the PM synchronous electric motor. ### Claim 5 (depends on 1) The elevator drive system according to claim 1, wherein the primary motor drive and one or more secondary motor drives are responsible for controlling braking of the PM synchronous electric motor. ### Claim 6 (depends on 1) The elevator drive system according to claim 1, wherein the PM synchronous electric motor includes at least three (3) phases. ### Claim 7 (depends on 6) The elevator drive system according to claim 6, wherein the PM synchronous electric motor includes at least six (6) phases. ### Claim 8 (depends on 7) The elevator drive system according to claim 7, wherein the PM synchronous electric motor includes at least nine (9) phases. ### Claim 9 An elevator drive system comprising: a permanent magnet (PM) synchronous electric motor including a plurality of phases; and a plurality of motor drives electrically connected to the PM synchronous electric motor, each of the plurality of motor drives being operatively connected to a corresponding one of the plurality of phases, the plurality of motor drives being configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases; wherein the PM synchronous electric motor includes at least twelve (12) phases. ### Claim 10 (depends on 1) The elevator drive system according to claim 1, wherein each of the plurality of phases is independent of others of the plurality of phases. ### Claim 11 (depends on 10) The elevator drive system according to claim 10, wherein each of the plurality of phases includes an independent ground. ### Claim 12 An elevator system comprising: a hoistway; a car movably arranged with the hoistway; and an elevator drive system operatively connected to the car, the drive system comprising: a permanent magnet (PM) synchronous electric motor operatively connected to the car, the PM synchronous electric motor including a plurality of phases; and a plurality of motor drives electrically connected to the PM synchronous electric motor, each of the plurality of motor drives being operatively connected to a corresponding one of the plurality of phases, the plurality of motor drives being configured and disposed to equally deliver torque current to each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases; wherein one of the plurality of motor drives is designated as a primary motor drive and remaining ones of the plurality of motor drives are designated as secondary motor drives. ### Claim 13 (depends on 12) The elevator system according to claim 12, wherein the primary motor drive is configured and disposed to establish a field orientation angle for each of the secondary motor drives. ### Claim 14 (depends on 12) The elevator system according to claim 12, wherein the primary motor drive is solely responsible for controlling velocity of the PM synchronous electric motor. ### Claim 15 (depends on 12) The elevator system according to claim 12, wherein the primary motor drive is solely responsible for controlling braking of the PM synchronous electric motor. ### Claim 16 (depends on 12) The elevator system according to claim 12, wherein the primary motor drive and one or more secondary motor drives are responsible for controlling braking of the PM synchronous electric motor. ### Claim 17 (depends on 12) The elevator system according to claim 12, wherein the PM synchronous electric motor includes at least three (3) phases. ### Claim 18 (depends on 17) The elevator system according to claim 17, wherein the PM synchronous electric motor includes at least six (6) phases. ### Claim 19 (depends on 18) The elevator system according to claim 18, wherein the PM synchronous electric motor includes at least nine (9) phases. ### Claim 20 (depends on 19) The elevator system according to claim 19, wherein the PM synchronous electric motor includes at least twelve (12) phases. ### Claim 21 (depends on 12) The elevator system according to claim 12, wherein each of the plurality of phases is independent of others of the plurality of phases. ### Claim 22 (depends on 21) The elevator system according to claim 21, wherein each of the plurality of phases includes an independent ground.