Boosted converter for pulsed electric machine control
AssigneeTula eTechnology, Inc.
InventorsBabak Mazda, Adya S. Tripathi, Paul Carvell
Life of this patent
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Abstract
A boost circuit is arranged to reduce rise and fall times of pulsed power used for pulsed control operation of electric machines. Magnetic energy present in the electric machine at the end of a pulse is extracted by the boost circuit to reduce the pulse fall time. The energy is stored by the boost circuit and then applied at the beginning of a subsequent pulse to reduce the rise time. By reducing rise and fall times compared to not using such a boost circuit, machine efficiency is improved.
Claims41
An apparatus, comprising:
- a power supply;
- an electric machine having windings with magnetic energy stored in the windings;
- an electric machine controller configured to selectively operate the electric machine in a pulsed mode;
- and
- a power converter coupled between the power supply and the electric machine, the power converter arranged to deliver pulsed power to or receive pulsed power from the windings of the electric machine in response to the machine controller;
- wherein the power converter includes a boost circuit arranged to extract at least some of the magnetic energy present in the electric machine at the end of a pulse to reduce the pulse fall time, store at least some of the energy, and apply at least some of the energy at the beginning of a subsequent pulse, thereby reducing rise and fall times of the pulsed power relative to the rise and fall times of the pulsed power without the boost circuit.
A method of operating an electric machine, comprising:
- operating the electric machine in a pulsed manner, such that a power applied to or taken from the electric machine consists of a series of pulses separated by periods of reduced power, wherein a duty cycle of the series of pulses is determined so as to deliver a desired torque magnitude;
- extracting at least some of a magnetic energy present in the electric machine at the end of a pulse to reduce the pulse fall time;
- storing at least some of the energy;
- and
- applying at least some of the energy at the beginning of a subsequent pulse thereby reducing rise and fall times of the pulsed power.
A method of operating an electric machine, comprising:
- operating the electric machine in a pulsed manner, such that a power applied to or taken from the electric machine consists of a series of pulses separated by periods of reduced power, wherein a duty cycle of the series of pulses is determined so as to deliver a desired torque magnitude;
- and
- increasing the electrical potential difference between a positive voltage bus and a negative voltage bus so as to reduce transition times of the series of pulses respectively.
A system, comprising:
- an electric motor;
- a torque modulation module arranged to:
- (a) receive a torque demand;
- (b) ascertain if the received torque demand is less than a peak efficiency torque of the motor;
- and
- (c) generate a modulated waveform if the torque demand is less than the peak efficiency of the motor;
- a power convertor arranged to receive the modulated waveform, the power converter arranged to generate a series of energy pulses in response to the modulated waveform, the series of energy pulses driving the electric motor to generate torque at a peak efficiency of the electric motor and a lower torque respectively, the average of which is substantially equal to the received torque demand;
- and
- a boost circuit coupled to the power converter, the boost circuit causing a reduction of transition times of the series of energy pulses relative to transition times without the boost circuit.
Dependencies are inferred from the claim text.