A control method implemented in a variable speed drive for starting a synchronous electric motor, said method including the application, as input, of a reference speed according to a predefined speed profile, the determination of a reference position based on the reference speed that is applied as input, the determination of a voltage in a rotating frame of reference, based on the reference speed that is applied as input, the determination of control voltages to be applied to each output phase depending, on the one hand, on the determined reference position and, on the other hand, on said voltage determined in the rotating frame of reference, and the application of the control voltages to each output phase to obtain an alignment of the position of the rotor of said motor with the reference position.

A system and method for starting electric motors. A controller attempts to start a motor without applying a brake to the rotor. If the motor fails to start, the controller applies a strength of braking and then again attempts to start the motor. If the motor still fails to start, the controller iteratively increases the strength of braking and attempts to start the motor until a maximum strength of braking and/or a maximum number of attempts to start the motor is reached. Alternatively, a sensing system first determines whether the rotor is rotating. If the rotor is rotating, the sensing system determines the speed of rotation, the controller determines a strength of braking that will halt the rotation based on the speed of rotation, applies that strength of braking to halt the rotation of the rotor, and then attempts to start the motor.

A system and method for starting electric motors. A controller attempts to start a motor without applying a brake to the rotor. If the motor fails to start, the controller applies a strength of braking and then again attempts to start the motor. If the motor still fails to start, the controller iteratively increases the strength of braking and attempts to start the motor until a maximum strength of braking and/or a maximum number of attempts to start the motor is reached. Alternatively, a sensing system first determines whether the rotor is rotating. If the rotor is rotating, the sensing system determines the speed of rotation, the controller determines a strength of braking that will halt the rotation based on the speed of rotation, applies that strength of braking to halt the rotation of the rotor, and then attempts to start the motor.

Provided is a wire connecting structure of coils of a three-phase motor, a wire connecting method and three-phase motor, which is capable of reducing a size of a short circuit terminal for a neutral point. The wire connecting structure is a wire connecting structure of coils which are wound to each salient-pole in a three-phase motor having respective salient-pole of a U phase, a V phase and a W phase, the coils of the salient-poles belonging to any two phases among the U phase, the V phase and the W phase are formed by a single continuous first conducting wire, and the coil of the salient-pole belonging to the rest one phase is formed by a single continuous second conducting wire.

Provided is a wire connecting structure of coils of a three-phase motor, a wire connecting method and three-phase motor, which is capable of reducing a size of a short circuit terminal for a neutral point. The wire connecting structure is a wire connecting structure of coils which are wound to each salient-pole in a three-phase motor having respective salient-pole of a U phase, a V phase and a W phase, the coils of the salient-poles belonging to any two phases among the U phase, the V phase and the W phase are formed by a single continuous first conducting wire, and the coil of the salient-pole belonging to the rest one phase is formed by a single continuous second conducting wire.

An air conditioner and a startup control method and system for an outdoor fan of the air conditioner. While in a process of charging a bootstrap capacitor in an actuator of a motor of the outdoor fan, an initial rotation state of the motor is detected in real time, and, when charging of the bootstrap capacitor is completed, startup of the motor is correspondingly controlled on the basis of the detected initial rotation state. This allows real time initial startup work state to be acquired when charging of the bootstrap capacitor is completed, thus allowing the motor to be started smoothly, increasing the success rate in starting the motor, and solving the problem of low success rate in starting the motor of an outdoor fan.

An air conditioner and a startup control method and system for an outdoor fan of the air conditioner. While in a process of charging a bootstrap capacitor in an actuator of a motor of the outdoor fan, an initial rotation state of the motor is detected in real time, and, when charging of the bootstrap capacitor is completed, startup of the motor is correspondingly controlled on the basis of the detected initial rotation state. This allows real time initial startup work state to be acquired when charging of the bootstrap capacitor is completed, thus allowing the motor to be started smoothly, increasing the success rate in starting the motor, and solving the problem of low success rate in starting the motor of an outdoor fan.

Disclosed is a motor. The motor is electrically connected to a control module. The motor includes a stator and a rotor. The stator includes a first stator module and a second stator module. The first stator module is configured beside the second stator module. A mechanical phase converting line is defined as a center position between the first stator module and the second stator module. The rotor is configured around the stator. The first phase detector is configured at one side of the mechanical phase converting line, and the first phase detector and the first stator module are configured at the same side of the mechanical phase converting line.

A controller for a sensorless permanent magnet synchronous motor having a rotor using a permanent magnet, the rotor rotating by a rotating magnetic field caused by a current flowing through an armature is provided. The controller is configured to apply a pulse voltage for generating a magnetic field vector for searching for the initial position to each of search sections obtained by dividing a target range, narrow down a target range in such a manner that a search section in which a largest amount of current flows through the armature by application of the pulse voltage is selected as a subsequent target range, and repeat the application processing and the narrow-down processing to estimate the initial position.

A system may include a prime mover configured to provide mechanical energy to the system by spinning a shaft. The system further includes a synchronous AC generator mechanically coupled to the shaft, and an exciter mechanically coupled to the shaft and configured to output a field current for exciting the synchronous AC generator. The system also includes a number of synchronous electric motors electrically coupled to the AC generator and configured to drive one or more mechanical loads. A controller of the system is configured to establish and maintain a magnetic coupling between the synchronous AC generator and the synchronous electric motors by controlling a level of the field current during a ramped increase in rotation of the synchronous AC generator from zero rotational speed. The motors accelerate synchronously with the generator due to the magnetic coupling as the rotational speed of the generator increases.