Switching frequency modulation utilizing rotor position
AssigneeCaterpillar Inc.
InventorsBrett Nee, Joshua Williams
Life of this patent
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Abstract
A control system (128) for controlling a switched reluctance (SR) machine (110) having a rotor (116) and a stator (118) is provided. The control system (128) may include a converter circuit (122) operatively coupled to the stator (118) and including a plurality of switches (132) in selective communication with each phase of the stator (118) and a controller (130) in communication with each of the stator (118) and the converter circuit (122). The controller (130) may be configured to determine a position of the rotor (116) relative to the stator (118), and generate a modulated switching frequency (152) based on the rotor position.
Claims20
A control system for controlling a switched reluctance (SR) machine having a rotor and a stator, the control system comprising:
- a converter circuit operatively coupled to the stator and including a plurality of switches in selective communication with each phase of the stator;
- and
- a controller in communication with each of the stator and the converter circuit, the controller being configured to determine a position of the rotor relative to the stator, and generate a modulated switching frequency based on the rotor position, the modulated switching frequency being modulated by increasing or decreasing the modulated switching frequency based on the rotor position.
A method of controlling a switching frequency of a switched reluctance (SR) machine having a rotor and a stator, the method comprising the steps of:
- determining a position of the rotor relative to the stator, the rotor position being indicative of machine inductance for a given machine flux value;
- and
- modulating the switching frequency by increasing or decreasing the switching frequency based on the rotor position such that the switching frequency decreases when machine inductance increases and increases when machine inductance decreases.
A method of controlling a switched reluctance (SR) machine having a rotor and a stator, the method comprising the steps of:
- determining a position of the rotor relative to the stator;
- generating a switching frequency based on the rotor position, the switching frequency being modulated by increasing or decreasing the modulated switching frequency based on the rotor position;
- generating a pulse width modulated (PWM) phase current signal based on the switching frequency and a current reference signal;
- and
- controlling at least one phase of the stator based on the PWM phase current signal.
Dependencies are inferred from the claim text.