Alternating current machine with increased torque above and below rated speed for hybrid/electric propulsion systems
OwnerEwald Franz Fuchsinventor
Life of this patent
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Abstract
The machine in accordance with the present disclosure is an AC machine whose pole numbers can be switched (from pole p1 to pole p2), and whose number of series turns per phase N can be switched say from N0=Nrated to N1=N0/2. Furthermore, it employs an inverter so that the frequency can be changed from a low value (e.g., 5 Hz) to a high value (e.g., 200 Hz). Due to the combination of pole number and number of series turns switching/reconfiguration, a high torque at low speed (e.g., 0 rpm) and a high torque at high speed (e.g., 5,000 rpm) can be achieved, making mechanical gears obsolete. In addition, the output power of the motor can be increased at high speed in direct proportion to the speed increase.
Claims20
A multiphase inductance-changing and pole-changing electric machine operable at above rated parameters comprising:
- a stator having a plurality of phase belts, wherein each phase belt comprises two or more coils, and wherein each of the two or more coils in a phase belt are initially connected in series;
- a rotor driven by currents in the stator;
- and
- a control system connected to the plurality of phase belts and configured to:
- (a) apply an alternating current to the plurality of phase belts at a first time and at a frequency equal to a first frequency, wherein the first frequency is below a rated frequency;
- (b) increase the frequency to a second frequency during a time period spanning the first time and a second time;
- (c) decrease a number of poles at a third time;
- and
- (d) increase the frequency to a third frequency during a time period spanning a fourth time and a fifth time.
A multiphase inductance-changing and pole-changing electric machine operable at above rated parameters comprising:
- a stator having a plurality of phase belts, wherein each phase belt comprises two or more coils, and wherein each of the two or more coils in a phase belt are initially connected in series;
- a rotor driven by currents in the stator;
- and
- a control system connected to the plurality of phase belts and configured to:
- (a) increase frequency of an alternating current applied to the plurality of phase belts during a first time period;
- (b) decrease a number of poles in the stator at a second time;
- (c) further increase the frequency of the alternating current applied to the plurality of phase belts during a second time period;
- and
- (d) decrease an inductance of the plurality of phase belts at a third time.
A method of operating an alternating current machine at above rated parameters, the method comprising:
- (a) increasing frequency of an alternating current applied to a plurality of stator phase belts during a first time period;
- (b) decreasing the number of poles in the stator at a second time;
- (c) further increasing the frequency of the alternating current applied to the plurality of stator phase belts during a second time period;
- and
- (d) decreasing the inductance of the plurality of stator phase belts at a third time.
Dependencies are inferred from the claim text.