A propulsion system for a device includes an electric motor configured to generate torque to propel the device. The electric motor includes a stator and a rotor with one or more permanent magnets. A controller is in communication with the electric motor and has recorded instructions for a method for minimizing demagnetization in the one or more permanent magnets. The controller is adapted to select a starting point and an intermediate point on a current trajectory in a stator current graph. The controller is adapted to obtain a final point on the stator current trajectory based on a comparison of the intermediate point and a predetermined voltage limit. A demagnetized torque capability is generated based on the final point on the current trajectory.

A method includes calculating, for a motor, a voltage constraint and calculating, for the motor, a supply current constraint and a regenerative current constraint. The method also includes calculating, for the motor, a motor current constraint and determining, for the motor, a first operating torque based on the voltage constraint, the supply current constraint, and the motor current constraint. The method also includes at least one of selectively controlling the motor based on the first operating torque and generating information associated with the first operating torque.

A method for determining zero crossing occurrence in an alternating current (AC) signal with constant frequency of a permanent magnet synchronous motor (PMSM) includes: sampling the AC signal to obtain a plurality of data points; starting to count a number of consecutive data points that have sampled values with a same sign in a detection range, to generate a count value, wherein the consecutive data points are included in the plurality of data points; determining whether the count value is equal to a zero crossing determination value; and in response to the count value being equal to the zero crossing determination value, determining that a zero crossing occurs at a last data point of the consecutive data points.

A transient current planning method for an ultra-high-speed permanent magnet synchronous motor for improving speed regulation response capabilities is provided. A transient current planning module uses a voltage model considering transient current changes to calculate current instruction values of an ultra-high-speed permanent magnet synchronous motor under MTPA control, general flux-weakening control, and MTPV control; a mode switching condition judgment subsystem judges whether a control mode is MTPA control or general flux-weakening control, or MTPV control, and sends d- and q-axis current instruction values in the corresponding control mode to a voltage decoupling control module; and the voltage decoupling control module calculates d- and q-axis voltage instruction values for controlling the motor, so as to realize control over the ultra-high-speed permanent magnet synchronous motor.

A driving device is used with a compressor including a motor including coils. The driving device drives the motor. The driving device includes an inverter connected to the coils, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state, a controller to control the inverter and the connection switching unit, and a compressor state detection unit to detect a state of the compressor. When the connection state of the coils is the first connection state, the controller controls the motor based on a first detection value detected by the compressor state detection unit and a first threshold. When the connection state of the coils is the second connection state, the controller controls the motor based on a second detection value detected by the compressor state detection unit and a second threshold.

A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

A motor drive control device includes a drive circuit configured to drive a motor with a drive control signal for driving the motor, and a control circuit configured to perform a vector control arithmetic operation based on a detection result of drive currents of coils of the motor, to generate the drive control signal and supply the drive control signal to the drive circuit. When generating the drive control signal, the control circuit estimates a rotation angle of a rotor of the motor and a rotation speed of the rotor with a q-axis current value of a two-phase rotating coordinate system calculated with a detection result of the drive current, and a q-axis voltage command value of the two-phase rotating coordinate system, by using a linear Kalman filter including a prediction step and an update step, using a stationary Kalman filter with the prediction step expressed linearly and time-invariantly.

A method for detecting an obstacle opposing the movement of a screen in a home automation closure or sun protection system includes an electromechanical actuator driving movement of the screen. The electromechanical actuator includes a torque support, a housing, an output shaft, and an electric motor including a stator and a rotor. The system includes a winding shaft rotating the screen and a connecting accessory between the electromechanical actuator's output shaft and the winding shaft. The method includes: determining an angular displacement value of the rotor with respect to the stator; determining angular displacement of the winding shaft relative to the housing or torque support of the electromechanical actuator; determining angular deformation of the kinematic chain between the electric motor and the winding shaft by comparing these two angular displacements; and determining the presence of an obstacle to screen movement from an angular deformation exceeding a predefined value.

A stator defines multiple stator poles with associated electrical windings. A rotor includes multiple rotor poles. The rotor is movable with respect to the stator and defines, together with the stator, a nominal gap between the stator poles and the rotor poles. The rotor poles includes a magnetically permeable pole material. The rotor also includes a series of frequency programmable flux channels (FPFCs). Each FPFC includes a conductive loop surrounding an associated rotor pole. The stator and the rotor are arranged such that the electrical windings in the stator induce an excitement current within at least one of the FPFCs during start-up.

The present application provides a method for speed estimation, device, electronic device, and storage medium, and relates to the technical field of rotational speed estimation. The method for speed estimation is applied to a three-phase brushless motor: firstly, acquire voltages of three terminals of a three-phase brushless motor; secondly, take the voltage difference value of each two terminals as an equivalent line voltage; thirdly, determine a virtual Hall signal according to a zero-crossing point of the equivalent line voltage; and lastly, estimate the rotational speed of the three-phase brushless motor according to the virtual Hall signal. The method for speed estimation, device, electronic device, and storage medium provided in the present application have the advantage of being simpler for rotational speed estimation.