A PWM control part rotationally drives a motor based on a PWM control value. A rotation speed control part controls a rotation speed of the motor. A rotation angle detection part detects a rotation angle of the motor. A reference position learning part controls the motor to rotate at a constant rotation speed until a detent plate stops at a limit position of a movable range and learns a reference position of the motor. A current detection circuit detects a current value corresponding to a driving current. A current limitation part limits a current supplied to the motor. A PWM control value limitation part controls the PMW control value to be equal to or smaller than a PWM limitation value, which is a predetermined value. A relation check part checks whether a relation between a current value detected by the current detection circuit and the PWM control value is inappropriate.

According to some embodiments, AC chopping circuit includes a switching circuit, a synchronizing signal generating circuit, a switch driving circuit and an auxiliary power supplying circuit. In some examples, the switching circuit are coupled to an AC power source and a load. In certain examples, the synchronizing signal generating circuit provides a synchronizing signal which is related to a polarity of the AC power source. In some examples, the switching circuit is controlled based at least in part on the synchronizing signal.

A method for protecting a permanent magnet generator of a wind turbine with a multiphase generator, and n number of isolated converters, the multiphase generator including a rotor carrying permanent magnets and n number of independent multiphase sub-stators comprising a plurality of windings, each converter being connected to an independent multiphase sub-stator and configured to control the plurality of windings of the multiphase sub-stator comprises determining an asymmetrical short circuit current in one of the sub-stators, which generates a first oscillating torque, disconnecting the converter linked to the sub-stator with an asymmetrically short circuited group of windings, and injecting an asymmetrical current with the remaining connected converters, wherein said injected asymmetrical current generates a second oscillating torque that is substantially opposed in phase to the first oscillating torque so that the first oscillating torque is at least partly compensated is disclosed. Permanent magnet generators are also disclosed.

A drive control device of a motor includes a comparison unit for comparing a first voltage value, which increases or decreases depending on a current value obtained in an inverter unit of the motor, with a reference voltage value, and an arithmetic processing unit for determining presence or absence of an overcurrent based on a comparison result of the comparison unit. The arithmetic processing unit includes a first terminal and a second terminal. The comparison result of the comparison unit is inputted to the first terminal. The second terminal receives the input of the first voltage value and outputs an operation confirmation signal to the comparison unit at predetermined timings. The arithmetic processing unit determines an overcurrent state based on the first voltage value and determines a state of the first terminal based on an output timing of the operation confirmation signal from the second terminal.

A converter including a converter control for a wind turbine and a chopper, wherein the converter control includes a dynamic limit value which is allowable for a first tolerance time and a static limit value of the converter. Furthermore, an overcurrent module is provided which includes a limit value expander which is designed to increase the static limit value by a portion of the difference from the dynamic limit value as additional current, and a dynamic module which interacts with the limit value expander in such a way that overcurrents between the static limit value which is increased by the additional current and the dynamic limit value are routed in a first stage to the converter and in a second stage at least partially to the chopper, wherein a switch is made to the second stage after a second tolerance time.

A voltage comparator and a programmable counter coupled to a high-speed clock are used to provide a near constant delay time for use in a closed-loop system. The voltage comparator input-output time delay is characterized at a certain temperature and operating voltage then variances in the voltage comparator delay times over a range of operating temperatures and voltages are measured and/or extrapolated. A number of clock pulses used for a delay time count are programmed into the programmable counter to provide for a near constant delay time from a change at the input of the voltage comparator to a change at the output of the programmable counter.

Provided is a power supply control device for controlling power supply to a motor installed in a vehicle, including: a switching element configured to turn on and off the power supply to the motor; a current detection circuit configured to detect a current flowing to the motor; and a control unit configured to determine whether or not the motor is in a locked state based on the current detected by the current detection circuit, and control turning on and off the power supply to the motor at a duty cycle that corresponds to the current detected by the current detection circuit, if it is determined that the motor is in the locked state.

A deposit detection device for an exhaust pump is provided, which can be easily put into operation without the burdens of, for example, installing equipment for flowing a gas, or adding or changing operation modes in apparatuses. The device is configured to include: a means for detecting motor current values a motor that rotates a rotating body; a current value storage portion that stores only motor current values that are equal to or greater than a preset value from among detected motor current values; an average value calculation portion that calculates an average value per unit time of the stored motor current values; an average value storage portion that stores the calculated average value; an approximation calculation portion that determines a linear approximation of the stored chronologically ordered average values; and a difference value calculation portion that determines a difference value between a predicted motor current value calculated by using the linear approximation and an initial motor current value at a start of use of the exhaust pump. A time when the difference value exceeds a predetermined threshold is determined as a time for maintenance of the exhaust pump.

An axial flux permanent magnet machine including a pair of axially spaced first components. A second component positioned axially between and equidistant from the first components. Either the pair of first components or the second component is arranged to rotate about a shaft. A translation mechanism coupled to each of the first components. The translation mechanism configured to translate the first components axially away from the second component. Also a method of controlling an axial flux permanent magnet machine.

A motor control apparatus controlling current feeding and a rotational direction of a motor includes: four bridge-circuit switches between a high and low potential lines; two current feeding line switches connected through the motor between a first and second nodes in series to arrange two parasitic diodes facing each other; a pull-up resistor between the high potential line and a third node; a pull-down resistor between the low potential line and a fourth node to interpose the motor between the third and fourth nodes; a protective diode blocking current; and a fault diagnostic device having: a driver turning on or off the switches; and a voltage determinator determining suitability of a first and second voltages and performing initial fault diagnosis for at least one of the switches.