A method and a system for detecting a logic level of a rotor of a motor, and a motor are disclosed. The method comprises: obtaining an analog voltage output by a position sensor for a winding of the motor; setting a first commutation voltage and a second commutation voltage; generating a logic level according to the analog voltage, the first commutation voltage and the second commutation voltage; and performing angle correction on the logic level according to a first angle corresponding to the first commutation voltage and a second angle corresponding to the second commutation voltage. The first commutation voltage is a commutation voltage for triggering a rising edge, and the second commutation voltage is a commutation voltage for triggering a falling edge. This method may accurately identify the logic level corresponding to the motor rotor, improve uniformity of a commutation voltage and prevent fluctuations in motor speed.

A method and a system for detecting a logic level of a rotor of a motor, and a motor are disclosed. The method comprises: obtaining an analog voltage output by a position sensor for a winding of the motor; setting a first commutation voltage and a second commutation voltage; generating a logic level according to the analog voltage, the first commutation voltage and the second commutation voltage; and performing angle correction on the logic level according to a first angle corresponding to the first commutation voltage and a second angle corresponding to the second commutation voltage. The first commutation voltage is a commutation voltage for triggering a rising edge, and the second commutation voltage is a commutation voltage for triggering a falling edge. This method may accurately identify the logic level corresponding to the motor rotor, improve uniformity of a commutation voltage and prevent fluctuations in motor speed.

In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

A swing/rotating gas metal arc welding torch, include a hollow shaft motor and a feeder panel. An upper extending shaft of the feeder panel penetrates through a brush mechanism, and is fixedly connected to a lower extension shaft of the hollow shaft by means of a coupling, and a lower extending shaft of the feeder panel penetrates through a support bearing mounted in a brush base and is then connected to an eccentric or bent conductive rod mechanism; the motor base is fixedly connected to the brush base by means of connecting screws, and a welding shielding gas is provided and welding torch cooling is achieved by means of inner holes of the connecting screws as well as a built-in gas passage and a cooling water passage of the brush base; the length of the conductive rod mechanism is adjusted by means of modulation or extension and retraction.

A swing/rotating gas metal arc welding torch, include a hollow shaft motor and a feeder panel. An upper extending shaft of the feeder panel penetrates through a brush mechanism, and is fixedly connected to a lower extension shaft of the hollow shaft by means of a coupling, and a lower extending shaft of the feeder panel penetrates through a support bearing mounted in a brush base and is then connected to an eccentric or bent conductive rod mechanism; the motor base is fixedly connected to the brush base by means of connecting screws, and a welding shielding gas is provided and welding torch cooling is achieved by means of inner holes of the connecting screws as well as a built-in gas passage and a cooling water passage of the brush base; the length of the conductive rod mechanism is adjusted by means of modulation or extension and retraction.

A motor controller for controlling a drive of a motor having plural phase windings includes upper and lower arm circuits and a control unit. The control unit switchingly controls ON/OFF of switches of the upper and lower arm circuits, for sequentially switching an energized phase of the motor. Then, from among the plural switches, a switch forming an energization path to the energized phase is designated as an energized phase switch with the others of the plural switches being designated as non-energized phase switches. Further, from among the non-energized phase switches, a switch forming a path of a reflux current that accompanies the switching of the energized phase is designated as a reflux switch. Then, the control unit performs an ON control of the energized phase switch in addition to performing an ON control of the reflux switch.

A motor controller for controlling a drive of a motor having plural phase windings includes upper and lower arm circuits and a control unit. The control unit switchingly controls ON/OFF of switches of the upper and lower arm circuits, for sequentially switching an energized phase of the motor. Then, from among the plural switches, a switch forming an energization path to the energized phase is designated as an energized phase switch with the others of the plural switches being designated as non-energized phase switches. Further, from among the non-energized phase switches, a switch forming a path of a reflux current that accompanies the switching of the energized phase is designated as a reflux switch. Then, the control unit performs an ON control of the energized phase switch in addition to performing an ON control of the reflux switch.

A motor controller comprises a switch circuit and a control unit. The motor controller is used for driving a motor, where the motor has a coil. The switch circuit is configured to supply a coil current to the coil. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller enables a floating phase time to be a variable value, where the floating phase time has a stable interval and a detecting interval. The motor controller enables a zero point of the coil current to appear in the stable interval, so as to detect a phase switching time point in a stable way and avoid a noise problem. The motor controller detects a zero crossing point of a back electromotive force in the detecting interval.

A motor controller comprises a switch circuit, a control unit, and a pulse width modulation signal, where the pulse width modulation signal has a duty cycle. The motor controller is used for driving a motor, where the motor has a coil. The switch circuit is configured to supply a coil current to the coil. The control unit is configured to generate a plurality of control signals to control the switch circuit. When the motor controller enters an early alignment state, the motor controller enables the coil current to achieve a predetermined value within one electric period. When the coil current achieves the predetermined value, the control unit records the duty cycle. The motor controller is configured to increase a success rate of starting the motor.