# US 12,000,638 B2 · Controlling systems with motor drives using pulse width modulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,638 B2 - Document ID: US12000638B2 - Status: Granted - Kind: B2 - Application number: 18/319,608 - Filed: 2023-05-18 - Published: 2023-09-14 - Granted: 2024-06-04 - Earliest claimed: 2017-06-12 - Assignees: Lennox Industries Inc. - Applicants: Lennox Industries Inc. - Inventors: Palanivel Subramaniam - Web page: https://patentgrep.com/patent/US12000638B2 ## CPC - F25B 49/025: {Motor control arrangements} - H02M 5/4585: {having a rectifier with controlled elements} - H02P 27/085: {wherein the PWM mode is adapted on the running conditions of the motor, e.g. the switching frequency} - F25B 2500/13: Vibrations - F25B 2600/024: by controlling the electric parameters, e.g. current or voltage - F25B 2600/11: Fan speed control - H03K 7/08: Duration or width modulation {; Duty cycle modulation} - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A system includes an electronic power converter and a controller. The electronic power converter supplies power to one or more motor drives of an HVAC system. The controller obtains a plurality of pulse width modulation (PWM) algorithms. Each PWM algorithm has an associated spectrum of frequencies. The controller further determines one or more resonance frequencies associated with the HVAC system. The controller also selects a first PWM algorithm from the plurality of PWM algorithms wherein the spectrum of frequencies of the first PWM algorithm lacks frequency peaks that overlap with the one or more resonance frequencies associated with the HVAC system. The controller further operates the electronic power converter according to the first PWM algorithm. ## Claims ### Claim 1 A system, comprising: a heating ventilation and air conditioning (HVAC) system; an electronic power converter configured to supply power to one or more motor drives of the HVAC system; and a controller communicatively coupled to the HVAC system and the electronic power converter, the controller configured to: obtain a plurality of pulse width modulation (PWM) algorithms, each PWM algorithm having an associated spectrum of frequencies; determine one or more resonance frequencies associated with the HVAC system; select a first PWM algorithm from the plurality of PWM algorithms, wherein the spectrum of frequencies of the first PWM algorithm lacks frequency peaks that overlap with the one or more resonance frequencies associated with the HVAC system; and operate the electronic power converter operable to supply power to the one or more motor drives of the HVAC system according to the first PWM algorithm. ### Claim 2 (depends on 1) The system of claim 1, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; determine a second amount of vibration associated with operating the HVAC system according to a second PWM algorithm of the plurality of PWM algorithms; and control the electronic power converter according to the second PWM algorithm in response to a determination that the second amount of vibration is less than the first amount of vibration. ### Claim 3 (depends on 1) The system of claim 1, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; compare the determined first amount of vibration to a vibration threshold; and based on the comparison, control the electronic power converter according to a second PWM algorithm of the plurality of PWM algorithms. ### Claim 4 (depends on 1) The system of claim 1, wherein the one or more motors drives drive one or more of a fan, a condenser, and a compressor, each comprising a mechanical assembly. ### Claim 5 (depends on 1) The system of claim 1, wherein the controller is further configured to measure the one or more resonance frequencies associated with the HVAC system and select the first PWM algorithm during operation of the HVAC system. ### Claim 6 (depends on 1) The system claim 1, wherein selecting a first PWM algorithm comprises: comparing the one or more resonance frequencies associated with the HVAC system to the associated spectrum of frequencies of each of the plurality of PWM algorithms; and based on the comparisons, selecting the PWM algorithm that most mitigates the one or more resonance frequencies associated with the HVAC system as the first PWM algorithm. ### Claim 7 (depends on 1) The system of claim 1, wherein determining the one or more resonance frequencies associated with the HVAC system comprises: obtaining current values in the one or more motor drives of the HVAC system; based on the obtained current values, calculating torque in the one or more motors drives of the HVAC system; and detecting one or more modal peaks in the calculated torque. ### Claim 8 (depends on 1) The system of claim 1, wherein the one or more resonance frequencies associated with the HVAC system are predetermined values associated with one or more components of the HVAC system. ### Claim 9 A system, comprising: a heating ventilation and air conditioning (HVAC) system; an electronic power converter configured to supply power to one or more motor drives of the HVAC system; and a controller communicatively coupled to the HVAC system and the electronic power converter, the controller configured to: obtain a plurality of pulse width modulation (PWM) algorithms, each PWM algorithm having an associated spectrum of frequencies; determine one or more resonance frequencies associated with an HVAC system; select a first PWM algorithm from the plurality of PWM algorithms, wherein the spectrum of frequencies of the first PWM algorithm lacks frequency peaks that overlap with the one or more resonance frequencies associated with the HVAC system; and operate an electronic power converter operable to supply power to the one or more motor drives of the HVAC system according to the first PWM algorithm; wherein selecting a first PWM algorithm comprises: comparing the one or more resonance frequencies associated with the HVAC system to the associated spectrum of frequencies of each of the plurality of PWM algorithms; based on the comparisons, selecting the PWM algorithm that most mitigates the one or more resonance frequencies associated with the HVAC system as the first PWM algorithm; and the one or more resonance frequencies associated with the HVAC system are predetermined values associated with one or more components of the HVAC system. ### Claim 10 (depends on 9) The system of claim 9, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; determine a second amount of vibration associated with operating the HVAC system according to a second PWM algorithm of the plurality of PWM algorithms; and control the electronic power converter according to the second PWM algorithm in response to a determination that the second amount of vibration is less than the first amount of vibration. ### Claim 11 (depends on 9) The system of claim 9, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; compare the determined first amount of vibration to a vibration threshold; and based on the comparison, control the electronic power converter according to a second PWM algorithm of the plurality of PWM algorithms. ### Claim 12 (depends on 9) The system of claim 9, wherein the one or more motors drives drive one or more of a fan, a condenser, and a compressor, each comprising a mechanical assembly. ### Claim 13 (depends on 9) The system of claim 9, wherein the controller is further configured to measure the one or more resonance frequencies associated with the HVAC system and select the first PWM algorithm during operation of the HVAC system. ### Claim 14 (depends on 9) The system of claim 9, wherein determining the one or more resonance frequencies associated with the HVAC system comprises: obtaining current values in the one or more motor drives of the HVAC system; based on the obtained current values, calculating torque in the one or more motors drives of the HVAC system; and detecting one or more modal peaks in the calculated torque. ### Claim 15 A system, comprising: a heating ventilation and air conditioning (HVAC) system; an electronic power converter configured to supply power to one or more motor drives of the HVAC system; and a controller communicatively coupled to the HVAC system and the electronic power converter, the controller configured to: obtain a plurality of pulse width modulation (PWM) algorithms, each PWM algorithm having an associated spectrum of frequencies; determine one or more resonance frequencies associated with an HVAC system; select a first PWM algorithm from the plurality of PWM algorithms, wherein the spectrum of frequencies of the first PWM algorithm lacks frequency peaks that overlap with the one or more resonance frequencies associated with the HVAC system; and operate an electronic power converter operable to supply power to the one or more motor drives of the HVAC system according to the first PWM algorithm; wherein determining the one or more resonance frequencies associated with the HVAC system comprises: obtaining current values in the one or more motor drives of the HVAC system; based on the obtained current values, calculating torque in the one or more motors drives of the HVAC system; detecting one or more modal peaks in the calculated torque; and the one or more resonance frequencies associated with the HVAC system are predetermined values associated with one or more components of the HVAC system. ### Claim 16 (depends on 15) The system of claim 15, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; determine a second amount of vibration associated with operating the HVAC system according to a second PWM algorithm of the plurality of PWM algorithms; and control the electronic power converter according to the second PWM algorithm in response to a determination that the second amount of vibration is less than the first amount of vibration. ### Claim 17 (depends on 15) The system of claim 15, wherein the controller is further configured to: determine a first amount of vibration associated with operating the HVAC system according to the first PWM algorithm; compare the determined first amount of vibration to a vibration threshold; and based on the comparison, control the electronic power converter according to a second PWM algorithm of the plurality of PWM algorithms. ### Claim 18 (depends on 15) The system of claim 15, wherein the one or more motors drives drive one or more of a fan, a condenser, and a compressor, each comprising a mechanical assembly. ### Claim 19 (depends on 15) The system of claim 15, wherein the controller is further configured to measure the one or more resonance frequencies associated with the HVAC system and select the first PWM algorithm during operation of the HVAC system. ### Claim 20 (depends on 15) The system claim 15, wherein selecting a first PWM algorithm comprises: comparing the one or more resonance frequencies associated with the HVAC system to the associated harmonic signature of each of the plurality of PWM algorithms; and based on the comparisons, selecting the PWM algorithm that most mitigates the one or more resonance frequencies associated with the HVAC system as the first PWM algorithm.