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.

The present disclosure discloses a method for measuring an initial position angle of a rotor of an electric machine, which solves the technical problem in the prior art that the requirement on the measurement conditions of the initial position angle of the rotor of the electric machine is high and the actual operation is not easy. The method comprises: Step 1, supplying an electric current i to an electric machine to be measured to cause the electric machine to run; Step 2, when the electric machine is running, reducing the electric current i to be zero; Step 3, measuring voltages of a d-axis and a q-axis of a stator of the electric machine at the moment, respectively as u.sub.d and u.sub.q; and Step 4, according to a trigonometric function relation between u.sub.d and u.sub.q, calculating to obtain an initial position angle deviation θ.sub.err of the rotor of the electric machine.

A motor control device according to an embodiment comprises a first signal generator, a second signal generator, a main controller, and a driver. The first signal generator is configured to generate, based on a clock signal indicating a stepping drive cycle of a motor, a first control signal. The second signal generator is configured to generate, based on a command phase indicating a target phase of a rotor of the motor, a second control signal. The main controller is configured to control the first signal generator and the second signal generator to output at least one of the first control signal and the second control signal. The driver is configured to drive the motor based on at least one of the first control signal and the second control signal.

A motor control device controls energization of a motor by interchangeably converting a direct current electric power of a power source and an alternating current electric power of the motor with a power conversion circuit according to a power running operation and a regeneration operation of the motor. A voltage instruction value calculation unit calculates a q-axis voltage instruction value and a d-axis voltage instruction value by feedback control of dq-axis currents. A voltage instruction value limit unit limits at least one of the q-axis voltage instruction value and the d-axis voltage instruction value. The voltage instruction value limit unit performs a q-axis voltage limit prioritize process for limiting the q-axis voltage instruction value over the d-axis voltage instruction value, or a d-axis voltage limit prioritize process for limiting the d-axis voltage instruction value over the q-axis voltage instruction value, during the regenerative operation of the motor.

A windshield wiper system includes a three-phase motor, the three-phase inverter, a brake circuit, and a controller. The controller transmits commutation signals to the three-phase inverter to drive the motor according to an inboard-to-outboard speed profile and to drive the motor according to an outboard-to-inboard speed profile. The controller activates the brake circuit based on the inboard-to outboard speed profile, or the outboard-to-inboard speed profile, and a direct current bus voltage.

In an electric motor control device which controls rotation of an AC electric motor having two sets of three-phase windings and provided with a resolver having two systems by calculating voltage command values on dq axes, dq conversion of currents of first three-phase windings is performed using a first angle calculated from output of the first system of the resolver, and dq conversion of currents of second three-phase windings is performed using a second angle calculated from output of the second system of the resolver. With both d-axis current command values set at the same value, respective voltage command values on dq axes are calculated and respectively converted into voltage command values for voltage application to the first three-phase windings, using the first angle, and converted into voltage command values for voltage application to the second three-phase windings, using the second angle.

In an electric motor control device which controls rotation of an AC electric motor having two sets of three-phase windings and provided with a resolver having two systems by calculating voltage command values on dq axes, dq conversion of currents of first three-phase windings is performed using a first angle calculated from output of the first system of the resolver, and dq conversion of currents of second three-phase windings is performed using a second angle calculated from output of the second system of the resolver. With both d-axis current command values set at the same value, respective voltage command values on dq axes are calculated and respectively converted into voltage command values for voltage application to the first three-phase windings, using the first angle, and converted into voltage command values for voltage application to the second three-phase windings, using the second angle.

A motor control system includes: a voltage command module configured to determine a target d-axis voltage for an electric motor and a target q-axis voltage for the electric motor; a target frequency module configured to: selectively set a target switching frequency to a first predetermined switching frequency; and selectively set the target switching frequency to a second predetermined switching frequency that is at least 2 kilohertz (kHz) greater than the first predetermined switching frequency; and a switching module configured to: based on the target d-axis voltage and the target q-axis voltage, determine target pulse width modulation (PWM) duty cycles for phases, respectively, of the electric motor; and switch switches of legs of an inverter module connected to the phases of the electric motor at the target PWM duty cycles, respectively, and the target switching frequency.

A method for driving an actuator of an HVAC system having a region of mechanical play is provided, and which comprises the steps of: a] monitoring a position of a movable member of the HVAC system or at least one rotatable element of the actuator to determine when the region of mechanical play has been entered or exited; and b] ramping a drive power to the actuator between a zero-velocity drive power and a steady-state-velocity drive power during the region of mechanical play. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.

A method for driving an actuator of an HVAC system having a region of mechanical play is provided, and which comprises the steps of: a] monitoring a position of a movable member of the HVAC system or at least one rotatable element of the actuator to determine when the region of mechanical play has been entered or exited; and b] ramping a drive power to the actuator between a zero-velocity drive power and a steady-state-velocity drive power during the region of mechanical play. The HVAC system implementing the above method is not only capable of reducing the noise produced by an HVAC system, but is also capable of reducing an over-powering of the actuator when there is a low load on the system.