An inverter for driving a motor that has a switchable connection of windings and drives a load element having a periodically varying load torque is provided. The inverter is controlled so that an output torque of the motor follows the periodic variation of the load torque. The inverter is controlled so that a current flowing through the motor is zero during a period including a minimum torque phase at which the load torque is at or near a minimum value. The connection is switched while the current flowing through the motor is zero. It is possible to switch the connection of the windings while the motor is rotating, and avoid an increase in apparatus size.

The torque of a permanent magnet motor is increased. There is provided a permanent magnet type motor with concentrated windings, in which each stator pole has a circumferential pitch of 185° or more in an electric angle. In this motor, the circumferential distribution of the magnetic flux density in an air gap surface of the rotor poles PR of the permanent magnet type has an approximately trapezoidal shape. Moreover, the induced voltages of the concentrated windings of the stator have an approximately trapezoidal waveform. An approximately trapezoidal-shaped waveform current is energized in the concentrated winding of each phase. Even if the magnetic flux density is close to the maximum flux density of the soft magnetic member of the stator, large slot cross-sectional areas of the stator can be secured, thus outputting a large torque.

The torque of a permanent magnet motor is increased. There is provided a permanent magnet type motor with concentrated windings, in which each stator pole has a circumferential pitch of 185° or more in an electric angle. In this motor, the circumferential distribution of the magnetic flux density in an air gap surface of the rotor poles PR of the permanent magnet type has an approximately trapezoidal shape. Moreover, the induced voltages of the concentrated windings of the stator have an approximately trapezoidal waveform. An approximately trapezoidal-shaped waveform current is energized in the concentrated winding of each phase. Even if the magnetic flux density is close to the maximum flux density of the soft magnetic member of the stator, large slot cross-sectional areas of the stator can be secured, thus outputting a large torque.

A direct power conversion device includes a control unit. tb=1/|fdc−n×fL|. fdc is a frequency twice as high as a frequency of an AC power supply, fL is a frequency of periodic load fluctuations, and n is a positive integer that maximizes tb. In a half period of power supply during a period of tb, the half period including a timing at which peaks of a fundamental wave of load torque and an absolute value of a power supply voltage substantially coincide with each other, the control unit being configured to control the switching elements so that two or more local maximum points appear in the half period of power supply, in a waveform obtained by combining a second harmonic, a fourth harmonic, and a sixth harmonic of a power supply frequency contained in a waveform of an absolute value of a motor current vector.

This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

This three-phase AC motor drive device is provided with: a load; an inverter device 1 for driving the load; an MCOK_A_4 connected between the inverter device 1 and the load and electrically connecting or disconnecting the inverter device 1 to or from the load; a voltage detector 21a having terminals respectively connected to the circuits of at least two phases to detect the voltages between the three phases; and a current detector 11 for detecting the currents of the three phases. In the connection from the inverter device 1 to the load, the inverter device 1, the MCOK_A_4, the voltage detector 21a, the current detector 11, and the load are aligned in this order.

A motor driving device for driving a motor is provided. The motor driving device includes: a driver outputting a drive signal for driving the motor to the motor; and a controller controlling a duty ratio of the drive signal based on three control parameters which are an initial duty ratio, a duty ratio increasing speed, and a target duty ratio. The controller has a normal control mode in which each of the three control parameters is a predetermined value, and a cryogenic control mode in which at least one of the three control parameters is a smaller value than in the normal control mode.

A drive device for an AC motor includes: an adaptive observation unit that adaptively estimates an angular velocity of a rotor of an AC motor; a speed control unit that determines a first torque command with which an angular velocity command matches an average value of an estimated angular velocity; a phase lead amount calculation unit that calculates, based on a disturbance frequency, a phase lead amount of a transfer function from a true angular velocity to a model deviation; a vibration suppression control unit that determines, based on a frequency of load torque pulsations, the model deviation, and the phase lead amount, a second torque command with which speed pulsations in the AC motor are suppressed; and a torque control unit that controls a torque of the AC motor based on the first torque command and the second torque command.

The invention relates to a vehicle drive train and to a method for operating a drive train with an electromotive drive (4), wherein a rotational speed and a drive torque of the drive (4), which are convertible via a toothed transmission stage (12) for an output (19), and the drive (4) is controlled by means of a control signal (40), wherein the control signal (40) has superimposed thereon a periodic torque change signal (5), which is in phase with a tooth stiffness change of the toothed transmission stage (12), wherein a signal strength of the torque change signal (5) is lower with decreasing tooth stiffness than with increasing tooth stiffness.

A system for controlling a motor includes a controller module comprising a controller portion, a regulator portion and an integrator portion. The regulator portion includes a set of regulator modules communicatively coupled in a sequence. Each regulator module configured to receive a respective input signal, indicative of a target or selected value, from the controller portion or the immediately preceding regulator module in the sequence, determine a respective selectable value; select one of the respective selectable value and the value indicated by the received input signal; and provide the selected value as an output signal to the next regulator module in the sequence or the integrator module. The integrator module is configured to receive the output signal from the last regulator module in the sequence, calculate a final demand value based on the received signal, and provide an output signal indicative of the final demand value.