# US 2014/0191694 A1 · Electronically commutated electric motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191694 A1 - Document ID: US20140191694A1 - Status: Published application - Kind: A1 - Application number: 14/342,827 - Filed: 2012-08-31 - Published: 2014-07-10 - Earliest claimed: 2011-09-05 - Assignees: Robert Bosch GmbH - Inventors: Mattias Hallor; Ulrich Ulrich - Web page: https://patentgrep.com/patent/US20140191694A1 ## CPC - H02P 6/18: without separate position detecting elements - 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 The invention relates to an electronically commutated electric motor. The electronically commutated electric motor has a power output stage connected to a stator of the electric motor, and a processing unit connected to the power output stage. The processing unit is designed to drive the power output stage to produce at least one stator current. The electric motor has a current sensor which is designed to record the stator current produced by the power output stage and to generate a current signal representing the stator current. The processing unit is designed to use the current sensor to record at least one current value of the current at a recording time within an interval of time and to determine a current profile of the current in the interval of time at least on the basis of the current value and to drive the power output stage to energize the stator on the basis of the current profile determined. ## Claims ### Claim 1 An electronically commutated electric motor, having a stator and a rotor, wherein the electric motor has a processing unit connected to a power output stage of the electric motor, wherein the processing unit is designed to drive the power output stage to generate at least one stator current, wherein the electric motor has a current sensor connected to the processing unit, said current sensor being designed to detect the stator current generated by the power output stage and to generate a current signal representing the stator current and the processing unit is designed to detect, by means of the current sensor, at least one current value of the current at a detection instant within a time interval and to determine a current profile of the current in the time interval, at least on the basis of the current value and to drive the power output stage to energize the stator on the basis of the determined current profile. ### Claim 2 (depends on 1) The electric motor as claimed in claim 1, wherein the processing unit is designed to form, from the current profile, an average value of the current in the time interval composed of currents determined during time periods of the time interval and to drive the power output stage on the basis of the average value, wherein a voltage connected from the power output stage to the stator is constant during the time period. ### Claim 3 (depends on 1) The electric motor as claimed in claim 1, wherein the processing unit is configured to determine an electric charge flowing during a time period and to determine the average value of the current on the basis of a sum of the electric charges flowing during the time periods in the time interval. ### Claim 4 (depends on 2) The electric motor as claimed in claim 2, wherein the number of time periods corresponds to a number of possible switching states, which are different from one another, of a voltage connected to the stator coils of the stator. ### Claim 5 (depends on 1) The electric motor as claimed in claim 1, wherein the electric motor has a temperature sensor connected to the processing unit, said temperature sensor being designed to detect a temperature of at least one part of the electric motor (1), and to generate a temperature signal representing the temperature, and the processing unit is designed to detect the current value for determining the current profile on the basis of the temperature signal. ### Claim 6 (depends on 1) The electric motor as claimed in claim 1, wherein the current sensor is formed by a resistor connected to the power output stage. ### Claim 7 A method for operating an electronically commutated electric motor, in which stator coils of an electric motor for generating a rotating magnetic field are wired in a pulse-width-modulated manner to a voltage, wherein a current value of a current flowing through the stator coils at a detection instant in a time interval is detected and a current profile of the current in the time interval is determined and the stator coils are wired on the basis of the determined current profile. ### Claim 8 (depends on 7) The method as claimed in claim 7, in which an average value of the current in the time interval composed of currents determined during time periods of the time interval is formed from the current profile and the stator coils are driven on the basis of the average value, wherein switching states of the stator coils during the time period are unchanged in each case. ### Claim 9 (depends on 7) The method as claimed in claim 7, in which an electric charge flowing during a time period is determined and the average value of the current is determined on the basis of a sum of the charges flowing during the time periods in the time interval. ### Claim 10 (depends on 7) The method as claimed in claim 7, in which a temperature of at least one part of the electric motor is detected and a temperature signal representing the temperature is generated, and the current value for determining the current profile on the basis of the temperature signal.