A failure in the activation, of a motor, caused by external noise superimposed on an induced voltage is reduced. A detection circuit is connected to a connection node provided between an upper-arm switching element and a lower-arm switching element, and detects the induced voltage of a fan motor before activation. The switching controller activates the fan motor in accordance with a result of detection by the detection circuit. While the detection circuit detects the induced voltage, the switching controller performs switching control which involves alternately turning ON and OFF of the lower-arm switching element.

The present invention provides a motor driving device for easily and accurately detecting an abnormal status of a motor. The motor driving device (21) includes a control circuit (100) for generating a driver control signal (S10); a driving circuit (200) for generating a motor driving signal (S3) according to the driver control signal (S10); an initial position detecting circuit (300) for detecting an initial position of a motor (22); and a rotation detecting circuit (400) for detecting a rotation status of the motor (22). Before the motor (22) starts to rotate normally, the control circuit (100) repeatedly performs a serial activation processing including detecting an initial position; applying an initial torque and detecting a motor rotation, and when the repetition number reaches a threshold value m (for example, m=5), the motor (22) is forced stop.

An apparatus for delay angle compensation for flying start function in a medium-voltage inverter is disclosed. The apparatus generates generate a phase angle () by converting a three-phase voltage of an inverter output terminal to dq-axis voltages (Vd, Vq), and calculate a compensation phase angle by a predetermined delay time. In addition, the apparatus generates an initial angle for the flying start by aggregating the compensation phase angle with the phase angle (). The apparatus may drive a high-voltage motor more stably, because an error between a command voltage phase angle and an actual output voltage phase angle may be reduced, when electric power of the medium voltage inverter is restored after a trip or an instantaneous blackout occurs.

A method of controlling a brushless permanent-magnet motor having a phase winding and a rotor, includes applying voltages of first and second opposing polarities to the phase winding when the rotor is oscillating about a parking position, measuring a plurality of first times, each first time including a time taken for current flowing through the phase winding in response to an applied voltage of the first polarity to exceed a threshold and measuring a plurality of second times, each second time including a time taken for current flowing through the phase winding in response to an applied voltage of the second polarity to exceed the threshold. The method includes determining which of an average magnitude of the plurality of first times and an average magnitude of the plurality of second times has the smaller average magnitude, and determining an amplitude peak of the plurality of times having the smaller average magnitude. The method includes using the amplitude peak to calculate a time window, setting a timer corresponding to the time window at a subsequent determined amplitude peak, and applying a drive voltage to the phase winding during the time window.

A sensorless electric motor control device is provided that completes a phase detection of a rotor before an activation signal is received, so as to shorten a time period from when the activation signal is received to when the rotor reaches a target number of rotations. The control device for a sensorless electric motor 10 includes an inverter 11 that drives the electric motor 10 and a first processor 18 that serves as a phase detection unit that causes the inverter 11 to perform a phase detection before the inverter 11 receives an activation signal that activates the electric motor 10, wherein the phase detection aligns a magnetic pole of a rotor of the electric motor 10 with a predetermined position with respect to a stator.

A method for electrically connecting a converter to an electrical machine supplied with current by the converter by closing a separate electrical connection between the converter and the machine. The connection includes multiple phases. In order to close the electrical connection without causing undue wear to the material, at least two phases of the connection are closed at different times.

A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. The frequency regulator limits decrease of the frequency when a bus voltage of a bus exceeds a first threshold in the frequency decrease mode. The bus supplies DC power to an inverter to drive the motor. A mode changer alternatively changes the voltage increase mode and the frequency decrease mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. The determinator determines whether the voltage and the frequency satisfy the relationship.

A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. When a current through the motor exceeds a first threshold in the voltage increase mode, a mode changer changes the mode to the frequency decrease mode. When the current through the motor becomes smaller than a second threshold in the frequency decrease mode, the mode changer changes the mode to the voltage increase mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. A determinator determines whether the voltage and the frequency satisfy the relationship.

Disclosed embodiments relate to apparatuses, methods, and systems for restarting an induction machine. In some embodiments, a method includes estimating a position of a rotor and a speed thereof in a position and speed estimation Operation, resetting a speed reference to correspond to the speed of the rotor in a speed reference resetting Operation, generating a control voltage corresponding to the speed reference to regulate a voltage magnitude using the control voltage in a voltage magnitude regulation Operation, and re-accelerating the induction machine up to a target speed after the regulation of the voltage magnitude in a re-acceleration Operation.

A method for controlling a direct drive transmission system and related devices. The method includes: S1: starting direct drive transmission system for overall zero returning; S2: reading a zero signal of the first incremental position feedback means identified by a corresponding second incremental position feedback means; S3: determining whether any actuator reads two zero signals; if yes, performing step S4; otherwise, returning to step S1; S4: determining according to a distance between two zero signals fed back by the actuator that the corresponding mover has completed zero returning, and further completing zero returning of the direct drive transmission system; and S5: acquiring, by the controller based on the direct drive transmission system after zero returning, position information of the movers, and driving the movers to move. Compared with the related art, the present disclosure has good position feedback effect, high positioning accuracy, and good drive control effect.