Low Speed and High Speed Controller Architecture for Electric Motors
AssigneeTexas Instruments Incorporated
InventorDavid Patrick Magee
Life of this patent
Estimating the term…
Abstract
A motor controller architecture and method of operating the same. The motor controller includes a function for estimating the low speed operation of the motor, for example by evaluating the response to a periodic excitation signal injected into the control loop of the controller architecture. A periodic excitation signal in the form of a square wave allows for analysis of the response of the motor without requiring demodulation, which allows the frequency of the excitation signal to be above the audible range. Control logic for controlling the motor at transitional speeds between low speed control and high speed (back emf) control is provided in some embodiments.
Claims18
A controller for a rotating AC electric machine, comprising:
- drive circuitry, for driving a multiphase electric machine responsive to at least one control signal;
- feedback circuitry for producing feedback signals responsive to electrical values received from at least one sensor at the machine;
- a control loop, for producing the at least one control signal to the drive circuitry responsive to the feedback signals;
- and
- a low speed state estimator, having inputs coupled to receive the feedback signals, for injecting at least one excitation signal into the control loop, and for estimating a velocity of the machine from a response of the machine to the excitation signal and communicating a control signal corresponding to the estimated velocity to the control loop.
A method of controlling the operation of a multiphase electric machine, comprising:
- driving the electric machine, comprising:
- generating multiphase drive signals responsive to direct and quadrature phase control signals;
- applying the drive signals to the machine;
- sensing electrical parameters corresponding to rotation of the machine;
- transforming the sensed parameters into direct and quadrature phase feedback signals;
- generating the direct and quadrature phase control signals responsive to a comparison of the direct and quadrature phase feedback signals to reference signals;
- and
- repeating the generating, sensing, transforming, and generating steps;
- and
- during the driving step:
- combining a excitation signal with one or both of the direct and quadrature phase feedback signals;
- responsive to the direct and quadrature phase feedback signals, estimating a velocity of the machine corresponding to a response of the machine to the excitation signal;
- and
- producing a quadrature phase reference signal from a combination of the estimated velocity and a received velocity signal;
- wherein the step of generating the direct and quadrature phase control signals comprises:
- determining a quadrature phase error signal corresponding to a difference between the quadrature phase reference signal and the quadrature phase error signal;
- determining a direct phase error signal corresponding to a difference between a received direct phase reference signal and the direct phase error signal;
- and
- applying the direct phase error signal and the quadrature phase error signal to direct phase and quadrature phase controller functions, respectively, to produce the direct and quadrature phase control signals, respectively.
Dependencies are inferred from the claim text.