# US 9,518,570 B2 · Motor winding heater systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,570 B2 - Document ID: US9518570B2 - Status: Granted - Kind: B2 - Application number: 13/445,673 - Filed: 2012-04-12 - Published: 2013-10-17 - Granted: 2016-12-13 - Earliest claimed: 2012-04-12 - Assignees: Rockwell Automation Technologies, Inc. - Applicants: David Messersmith; Andrew Jaap - Inventors: David Messersmith; Andrew Jaap - Web page: https://patentgrep.com/patent/US9518570B2 ## CPC - F04B 17/00: Pumps characterised by combination with, or adaptation to, specific driving engines or motors - F04B 49/065: {and making use of computers} - H02K 15/125: Heating or drying of machines in operational state, e.g. standstill heating - H02P 29/62: for raising the temperature of the motor - H02P 2207/01: Asynchronous machines - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A motor controller includes a motor winding heater function. The motor controller applies a predefined current to one or more of the motor windings without the use of additional dedicated motor winding heater devices. The motor controller serves to control the operation of the motor, while the motor windings serve both as a heater at times and to produce torque at times. ## Claims ### Claim 1 A motor winding heater comprising: a motor controller configured to receive an alternating current (AC) power and transmit at least a portion of the AC power during a conduction interval of a cycle of the AC power to a motor, the motor including at least two motor windings; the motor controller including a processor configured to control operation of the motor controller in a first operation mode and a second operation mode; the motor controller further including a heating level input to the second operation mode, the heating level input to set at least one of a heating level and a heating period to control heating of the at least two motor windings, the heating level to control a level of heating current to the at least two motor windings; wherein in the first operation mode, the motor controller operates to transmit a first AC power derived from the AC power to all of the at least two motor windings to cause the motor to rotate; and wherein in the second operation mode, the motor controller operates to transmit a second AC power derived from the AC power to all of the motor windings, the second AC power transmitted at a lower frequency than the first AC power to heat the motor windings without causing the motor to rotate. ### Claim 2 (depends on 1) The motor winding heater according to claim 1, wherein the motor controller further comprises a silicon controlled rectifier (SCR) configured to conduct the AC power during the conduction interval. ### Claim 3 (depends on 1) The motor winding heater according to claim 1, wherein the motor is an induction motor. ### Claim 4 (depends on 1) The motor winding heater according to claim 1, wherein the input comprises a terminal block input. ### Claim 5 (depends on 4) The motor winding heater according to claim 4, wherein the second operation mode is enabled when the terminal block input is active. ### Claim 6 (depends on 1) The motor winding heater according to claim 1, wherein in the second operation mode, the motor controller transmits the second AC power to the motor windings to heat the motor windings only after a motor start command is issued to the motor controller. ### Claim 7 (depends on 1) The motor winding heater according to claim 1, wherein the second AC power transmitted to all of the at least two motor windings in the second operation mode is transmitted at a very low frequency in a range of 0 to 0.1 hertz to at least one of the at least two motor windings. ### Claim 8 (depends on 1) The motor winding heater according to claim 1, wherein the processor is configured to control operation of the motor controller in a third operation mode; and in the third operation mode, the motor controller operates to transmit a third AC power derived from the AC power to at least one of the at least two motor windings to heat the at least one of the at least two motor windings without causing the motor to rotate. ### Claim 9 (depends on 8) The motor winding heater according to claim 8, wherein in the third-operation mode, the motor controller transmits the third AC power to one of the at least two motor windings at a time. ### Claim 10 A motor controller comprising: a processor configured to control operation of the motor controller to rotate a motor having at least two motor windings, and when not rotating the motor, the processor is configured to control operation of the motor controller to heat the motor; the motor controller further including a heating level input to heat the motor, the heating level input to set at least one of a heating level and a heating period to control heating of the at least two motor windings, the heating level to control a level of heating current to the at least two motor windings; wherein when the processor controls operation of the motor controller to rotate the motor, the processor controls operation of the motor controller to transmit a first AC power to all of the at least two motor windings to cause the motor to rotate; wherein when the processor controls operation of the motor controller to heat the motor, the processor controls operation of the motor controller to transmit a second AC power to all of the motor windings having a frequency less than the first AC power, such that the frequency of the second AC power is sufficient to heat the motor without causing the motor to rotate; and an input to the motor controller, the input to control at least one of the level of the AC power to the motor and the duration of the AC power to the motor. ### Claim 11 (depends on 10) The motor controller according to claim 10, further comprising a first, second, and third SCR pairs, wherein each SCR pair is coupled to a first phase path, a second phase path, or a third phase path, respectively, the processor configured to energize at least one SCR in the SCR pairs according to a first reference voltage, a second reference voltage, or a third reference voltage, wherein the first reference voltage, the second reference voltage, and the third reference voltage vary generally sinusoidally. ### Claim 12 (depends on 10) The motor controller according to claim 10, wherein the motor is an induction motor, and the induction motor is coupled to the motor controller. ### Claim 13 A method for heating a motor having at least two motor windings, the method comprising: receiving an alternating current (AC) power and transmitting at least a portion of the AC power during a conduction interval of a cycle of the AC power to the at least two motor windings; providing a motor controller including a processor configured for controlling operation of the motor controller in a first operation mode and a second operation mode: the motor controller further including a heating level input to the second operation mode, the heating level input to set at least one of a heating level and a heating period to control heating of the at least two motor windings, the heating level to control a level of heating current to the at least two motor windings; controlling operation of the motor controller in the first operation mode, such that the motor controller is transmitting a first AC power derived from the AC power to all of the at least two motor windings and causing the motor to rotate; and controlling operation of the motor controller in the second operation mode, such that the motor controller is transmitting a second AC power derived from the AC power to all of the motor windings, the second AC power being transmitted at a lower frequency than the first AC power and heating the motor windings without causing the motor to rotate. ### Claim 14 (depends on 13) The method according to claim 13, wherein the motor controller further comprises a silicon controlled rectifier (SCR) configured for conducting the AC power during the conduction interval. ### Claim 15 (depends on 13) The method according to claim 13, further including inputting to the motor controller a duration of the AC power to the motor windings.