Speed control device for an electronically commutated multiphase electric motor
AssigneeSiemens Aktiengesellschaft
InventorsMartin Meschik, Markus Schermann
Life of this patent
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Abstract
A speed control device, whereby individual motor phases of an electronically commutated multiphase electric motor are supplied via corresponding individual phase shifters from a constant voltage supply unidirectionally and unpulsed during time blocks which are derived from stored time block pulse patterns specific to certain speeds. The speed control device permits setting a variety of speeds with relatively little expense and with low operating losses. The speed control device further provides a simple device for setting intermediate speeds by means of low-frequency switching between at least two time block pulse patterns.
Claims18
A speed control device for use with an electronically commutated multiphase electric motor, comprising:
- a plurality of phase shifters;
- a sensor signal evaluation device, evaluating rotor position sensor signals;
- a time block pulse pattern source, providing at least two distinct time block pulse patterns, each assigned to a specific motor speed;
- a switching frequency source, providing at least one switching frequency that is below the audible frequency range;
- and
- a controller,
- wherein the phase shifters control delivery of unidirectional and unpulsed power during definable time blocks to motor phases of the electric motor from a constant voltage supply, thereby creating torque, and
- wherein the controller controls the phase shifters in accordance with the evaluated rotor position sensor signals and the time block pulse patterns and alternately switches between the time block pulse patterns at the switching frequency.
A speed control device, for use with an electronically commutated electric motor having five motor phases on a stator side and three pairs of poles on a rotor side, the speed control device comprising:
- five phase shifters, each corresponding to one of the motor phases;
- a sensor signal evaluation device, evaluating five rotor position sensor signals;
- a time block pulse pattern source, providing at least two distinct time block pulse patterns, each assigned to a specific motor speed;
- a switching frequency source, providing at least one switching frequency that is below the audible frequency range;
- and
- a controller,
- wherein the phase shifters control delivery of unidirectional and unpulsed power during definable time blocks to the motor phases from a constant voltage supply, thereby creating torque, and
- wherein the controller controls the five phase shifters in accordance with the evaluated five rotor position sensor signals and the time block pulse patterns and alternately switches between the time block pulse patterns at the switching frequency.
An electronically commutated electric motor comprising:
- a permanent magnet excited rotor;
- a stator having a plurality of motor phases;
- a power source;
- and
- a speed control device comprising:
- a plurality of phase shifters;
- a sensor signal evaluation device, evaluating rotor position sensor signals;
- a time block pulse pattern source, providing at least two distinct time block pulse patterns, each assigned to a specific motor speed;
- a switching frequency source, providing at least one switching frequency that is below the audible frequency range;
- and
- a controller,
- wherein the phase shifters control delivery of unidirectional and unpulsed power during definable time blocks to the motor phases from the power source, thereby creating torque, and
- wherein the controller controls the phase shifters in accordance with the evaluated rotor position sensor signals and the time block pulse patterns and alternately switches between the time block pulse patterns at the switching frequency.
A method of achieving an intermediate speed, for an electronically commutated electric motor, comprising the steps of:
- evaluating rotor position sensor signals;
- delivering unidirectional and unpulsed power during definable time blocks to motor phases of the electric motor via phase shifters, thereby creating torque;
- controlling the phase shifters in response to the evaluated rotor position sensor signals and in accordance with distinct time block pulse patterns, each assigned to a specific motor speed;
- and
- further controlling the phase shifters by alternately switching between the time block pulse patterns at a switching frequency, that is below the audible frequency range, thereby providing the intermediate speed.
Dependencies are inferred from the claim text.