Texas Instruments Corporation

Microchip Technology Inc.

Prasad Kulkarni

Venkata Pavan Mahankali

Ganapathi Hegde

Sameer Pradeep Kulkarni

Ramesh Kankanala

Debraj Deb

Krushal Shah

Sivabalan Mohan

A motor control system operable to control a motor includes a motor control circuit and an inverter circuit connected to the motor control circuit and configured to connect to the motor at phase output terminals. The inverter circuit, in response to one or more output control signals indicating a deceleration instruction from the motor control circuit, implements a multi-state deceleration sequence for at least one commutation state of a commutation scheme of the motor.

Fast deceleration of PMSM and BLDC motors using recirculation braking

A motor controller that is operable to control a motor includes drive current generation circuitry having an output coupled to the motor. The motor controller further includes a velocity control path. The velocity control path includes angular velocity estimation circuitry having an input adapted to be coupled to the motor, a velocity comparator having first input coupled to a target velocity input and a second input coupled to an output of the angular velocity estimation circuitry, and an adaptive velocity controller having a first input coupled to an output of the velocity comparator and having an output coupled to a first input of the drive current generation circuitry. The motor controller further includes controller parameter determination circuitry having a first input coupled to the output of the angular velocity estimation circuitry and having an output coupled to a second input of the adaptive velocity controller.

Motor controller and a method for controlling a motor

Described examples include a method that includes setting a reference isignal in a field-oriented control of a motor such that the field-oriented control modulates power from a power supply using a modulator to apply a torque on the motor that is opposite to a kinetic energy applied to the motor. The method also includes setting a reference isignal in the field-oriented control such that the motor current provided to the power supply is reduced.

Motor control with reduced back current during braking

A method for determining a position of a rotor of a brushless direct current (BLDC) motor at standstill. The method includes providing a plurality of current pulses to a plurality of windings of the BLDC motor while the rotor of the BLDC motor is at a standstill position. The method further includes measuring a plurality of times that it takes for the plurality of current pulses to reach a threshold for respective ones of the plurality of windings. A first position corresponding to a shortest time of the plurality of times is determined. A position detection value is determined based on the shortest time and based on times corresponding to positions that are adjacent to the first position. A position of the rotor at the standstill position is determined based on the position detection value and an interpolation function.

Method for determining a position of a rotor at standstill

A motor controller is operable to control a motor. The motor has a first terminal and the motor controller includes an angular velocity transmission path having an input and an output. A current generator includes a velocity-torque input, an angular position input, and a motor drive output. The velocity-torque input is coupled to the output of the angular velocity transmission path. An angular velocity feedback path is coupled between a first terminal and a first location on the angular velocity transmission path. The first location is between the input and the output of the angular velocity transmission path. A current feedback path is coupled between the first terminal and a second location on the angular velocity transmission path. The second location is disposed between the first location on the angular velocity transmission path and the velocity-torque input of the current generator.

Example systems and processes use three-phase vector mutual inductance analysis to detect zero-crossing (ZC) locations of back-electromotive force (BEMF) of an electric motor and to detect its commutation points during start-up or low-speed operation. For each sector of rotation of the rotor, two pairs of three-phase vectors are applied, along with current for the corresponding driving phase. The first pair is alternately applied to move the rotor, and the mutual inductances resulting from such application are compared to detect the zero-crossing (ZC) location in the BEMF of the electric motor in that sector. The second pair is then alternately applied within the same sector to continue to move the rotor, and the mutual inductances from such application are compared to detect the commutation point of the electric motor in that sector. The process may be repeated for each successive sector, changing the driving current at each new sector.

Inductance-based, high-torque start up of electric motor

A motor controller integrated circuit (IC) includes a storage device containing software. The IC also includes a processor core coupled to the storage device. The processor core has an output adapted to be coupled to a motor. The processor core is configured to execute the software to implement a resonant controller at a frequency that is a harmonic of a speed of a motor.

Motor controller including resonant controllers

In some examples, an apparatus operable to drive a motor includes driver circuitry adapted to be coupled to the motor and processing logic coupled to the driver circuitry. The processing logic is operable to determine an expected current for controlling the motor, reduce a reference current upon which the motor is controlled from a first value to a second value at an exponential rate, determine that a measured current of the motor is approximately equal to the expected current, and responsive to determining that the measured current of the motor is approximately equal to the expected current, provide a control signal to the driver circuitry based on the expected current to the motor to control the motor to operate according to closed loop control.

Brushless motor control

A motor controller integrated circuit (IC) includes a storage device containing software, and a processor core. The processor core has an output adapted to be coupled to a motor. The processor core is configured to execute the software to operate the motor in an open-loop control, calculate first and second orthogonal components of a back electromotive force (BEMF), calculate a total BEMF value, and determine that the first orthogonal component is within a threshold of the total BEMF value. The processor core is further configured to, responsive to the first orthogonal component being within the threshold of the total BEMF value, operate the motor in a closed-loop control.

Automatic transition of motor controller from open-loop control to closed-loop control

A controller is adapted to be coupled to a brushless direct current (DC) motor and includes an analog-to-digital converter (ADC), a computing device, and a driver. The ADC is configured to receive an analog back electromotive force (BEMF) waveform from the brushless DC motor and sample the analog BEMF waveform to produce a digital BEMF waveform. The computing device is coupled to the ADC and is configured to receive the digital BEMF waveform and determine a position and a speed of the rotor based on the digital BEMF waveform. The driver is coupled to the ADC and the computing device and is configured to receive the position and the speed of the rotor and provide a drive signal based on the position and the speed of the rotor of the brushless DC motor.

Resynchronization of brushless DC motors

Embodiments of the present disclosure include a motor controller with a processor and a machine readable medium. The medium includes instructions that, when loaded and executed by the processor, cause the processor to receive an estimated or sensed speed of a motor, extract a mechanical frequency component from the estimated or sensed speed, transform the mechanical frequency into direct quadrature (DQ) domain at the mechanical frequency, control the mechanical frequency to zero, and generate a dampening signal for torque based upon the controlled mechanical frequency.

Closed loop torque compensation for compressor applications

Example systems and processes control transition of an electric motor from open-loop operation to closed-loop operation by detecting zero-crossing (ZC) locations of the back-electromotive force (BEMF). The rotor angle of the electric motor is changed, e.g., by changing acceleration of the electric motor to correct a phase difference based on the detected ZC locations and an open-loop profile of the electric motor. Detected ZC locations may be used to identify ZC-detected-based commutation points, and each detected ZC location may be used to update a next commutation point. During the control process the open-loop profile is updated. Transition may occur when a set number of ZC-detection-based commutation points are sufficiently aligned with corresponding updated commutation points, or such alignment is maintained for at least one electrical cycle.

Operational transition control of a motor

A closed loop flux weakening method and apparatus are provided. The closed loop flux weakening apparatus may include a difference circuit that obtains a difference between a q-axis reference voltage and a q-axis voltage, a controller that converts the difference between the q-axis reference voltage and the q-axis voltage into a d-axis current of a stator of the motor, and a summation circuit that obtains a d-axis reference current by adding the d-axis current of the stator of the motor and a feed forward d-axis current of the stator of the motor.

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Bengaluru, India

Prasad Kulkarni