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US 2021/0203257 A1Published application
Sensorless angle estimation for trapezoidal control
AssigneeTexas Instruments Incorporated
InventorsRAJAN LAKSHMI NARASIMHA, DAVID PATRICK MAGEE
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Abstract
Systems and methods for sensorless trapezoidal control of brushless DC motors provide effective high-torque startup and low speed operation without the use of Hall effect sensors or encoders during motor operation. The systems and methods also provide the ability to boost signal-to-noise ratio for motor startup and low speed operation via an augmenting supply voltage. Sampling architectures and current-dependent inductance modeling architectures for the control systems are also described.
Claims20
A method comprising:
- obtaining measurements of voltage signals and of a total current signal from a brushless direct-current (BLDC) motor having a rotor;
- with processing circuitry, determining an angular position of the rotor or a commutation state of the motor according to a nonlinear motor model responsive to the measurements, in which the nonlinear motor model provides voltage offsets and at least one of the following as a function of current level and current slope:
- voltage thresholds, or zero-crossing time intervals;
- and
- responsive to the angular position or the commutation state, controlling the motor during a startup of the motor.
2 more elements
A system comprising:
- measurement circuitry having first inputs and first outputs, the first inputs adapted to be coupled to a brushless direct-current (BLDC) motor having a rotor, and the measurement circuitry configured to:
- receive voltage signals and a total current signal at the first inputs;
- and provide measurements of the voltage signals and of the total current signal at the first outputs;
- processing circuitry having second inputs and second outputs, the second inputs coupled to the first outputs, the processing circuitry configured to determine an angular position of the rotor or a commutation state of the motor according to a nonlinear motor model responsive to the measurements, and to provide the angular position or the commutation state at the second outputs, in which the nonlinear motor model provides voltage offsets and at least one of the following as a function of current level and current slope:
- voltage thresholds, or zero-crossing time intervals;
- and
- control circuitry having third inputs and third outputs, the third inputs coupled to the second outputs, the third outputs adapted to be coupled to the motor, and the control circuitry configured to provide motor control signals at the third outputs during a startup of the motor, responsive to the angular position or the commutation state.
4 more elements
Dependencies are inferred from the claim text.