# US 2008/0185986 A1 · Low noise heating, ventilating and/or air conditioning (HVAC) systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0185986 A1 - Document ID: US20080185986A1 - Status: Published application - Kind: A1 - Application number: 11/701,350 - Filed: 2007-02-01 - Published: 2008-08-07 - Earliest claimed: 2007-02-01 - Assignees: Emerson Electric Co. - Inventors: Joseph G. Marcinkiewicz; Arthur E. Woodward; Prakash B. Shahi; Mark E. Carrier; Michael I. Henderson - Web page: https://patentgrep.com/patent/US20080185986A1 ## CPC - H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A heating, ventilating and/or air conditioning (HVAC) system includes a system controller, a motor controller, an air-moving component, and a permanent magnet motor having a stationary assembly, a rotatable assembly in magnetic coupling relation to the stationary assembly, and a shaft coupled to the air-moving component. The motor controller is configured for performing sinewave commutation in response to one or more control signals received from the system controller to produce continuous phase currents in the permanent magnet motor for driving the air-moving component. By using sinewave commutation (in contrast to square wave commutation), the noise and vibration produced by the HVAC system is markedly reduced. ## Claims ### Claim 1 A heating, ventilating and/or air conditioning (HVAC) system comprising a system controller, a motor controller, an air-moving component, and a permanent magnet motor having a stationary assembly, a rotatable assembly in magnetic coupling relation to the stationary assembly, and a shaft coupled to the air-moving component, wherein the motor controller is configured for performing sinewave commutation in response to one or more control signals received from the system controller to produce continuous phase currents in the permanent magnet motor for driving the air-moving component. ### Claim 2 (depends on 1) The HVAC system of claim 1 wherein the stationary assembly includes a plurality of phase windings and the motor controller is configured for energizing all of the phase windings at the same time. ### Claim 3 (depends on 2) The HVAC system of claim 2 wherein the continuous phase currents are substantially sinusoidal. ### Claim 4 (depends on 3) The HVAC system of claim 3 wherein the rotatable assembly is coupled to the shaft without using a damping material. ### Claim 5 (depends on 3) The HVAC system of claim 3 wherein the air-moving component is a blower. ### Claim 6 (depends on 3) The HVAC system of claim 3 wherein the air-moving component is a draft inducer. ### Claim 7 (depends on 3) The HVAC system of claim 3 wherein the air-moving component is a condenser fan. ### Claim 8 (depends on 3) The HVAC system of claim 3 wherein the permanent magnet motor is a brushless permanent magnet (BPM) motor. ### Claim 9 (depends on 8) The HVAC system of claim 8 wherein the BPM motor is a back-emf BPM motor. ### Claim 10 (depends on 3) The HVAC system of claim 3 wherein the system controller includes a thermostat. ### Claim 11 (depends on 3) The HVAC system of claim 3 wherein the at least one control signal from the system controller represents a desired airflow for the air-moving component. ### Claim 12 (depends on 3) The HVAC system of claim 3 wherein the at least one control signal from the system controller represents a desired torque or speed of the permanent magnet motor. ### Claim 13 (depends on 3) The HVAC system of claim 3 wherein the motor controller is configured for performing sinewave commutation using vector control. ### Claim 14 (depends on 13) The HVAC system of claim 13 wherein the motor controller is configured for performing sinewave commutation using sensorless vector control. ### Claim 15 (depends on 3) The HVAC system of claim 3 wherein the motor controller is configured to produce continuous phase currents that cancel effects of harmonic content in the permanent magnet motor's back emf. ### Claim 16 A blower assembly for a heating, ventilating and/or air conditioning (HVAC) system, the blower assembly comprising a motor controller, a blower, and a permanent magnet motor having a stationary assembly, a rotatable assembly in magnetic coupling relation to the stationary assembly, and a shaft coupled to the blower, wherein the motor controller is configured for performing sinewave commutation in response to one or more control signals received from a system controller to produce continuous phase currents in the permanent magnet motor for driving the blower. ### Claim 17 (depends on 16) The blower assembly of claim 16 wherein the motor controller is configured for performing sinewave commutation using sensorless vector control. ### Claim 18 (depends on 17) The blower assembly of claim 17 wherein the motor controller is configured to produce continuous phase currents that cancel harmonic content in the permanent magnet motor's back emf. ### Claim 19 A method for driving an air-moving component of a heating, ventilating and/or air conditioning (HVAC) system in response to a control signal, the HVAC system including a permanent magnet motor having a stationary assembly and a rotatable assembly in magnetic coupling relation to the stationary assembly, said rotatable assembly coupled in driving relation to the air-moving component, the method comprising receiving at least one control signal from a system controller, and performing sinewave commutation in response to the at least one control signal received from the system controller to produce continuous currents in the permanent magnet motor for driving said air-moving component. ### Claim 20 (depends on 19) The method of claim 19 wherein the air-moving component is a blower, and wherein receiving includes receiving at least one control signal representing a desired airflow for the blower, a desired torque of the permanent magnet motor, or a desired speed of the permanent magnet motor.