Abstract: In a system for driving an electric motor by an engine generator, there is a possibility that oscillation and d-axis current are increased. In an engine generator system, a power converter (105) controls a generator (104) so that the phase of an oscillating component included in the d-axis current in the rotor magnetic flux direction of the generator (104) advances by 90 degrees or more with respect to the phase of an oscillating component of the identical frequency included in the rotating electric angular frequency of the generator (104), and further using q-axis voltage adjusting device (118) so that the phase of an oscillating component included in the q-axis current advances by 90 degrees or more with respect to the phase of an oscillating component of the identical frequency included in the rotating electric angular frequency of the generator (104).

Abstract: An electric motor drive device 1000 includes: an inverter 3 that drives a motor 4, a voltage division circuit 2 that serves as a neutral point potential detection unit that detects a neutral point potential of a stator winding of the motor 4; and a controller 1 that estimates a rotor position of the motor 4 based on the detected neutral point potential, and that controls the inverter 3 based on an estimation result. A ground potential of the controller 1 is set to a negative side potential or a positive side potential of a DC voltage that is supplied to the inverter 3. The voltage division circuit 2 detects the neutral point potential with reference to the negative side potential or the positive side potential.

Abstract: A linear motor is capable of miniaturization of a device, sharing of effective magnetic fluxes between the magnetic poles adjacent to each other, and decreasing a magnetic attractive force acting between a mover and an armature, and a linear motor drive system. The linear motor includes a mover, formed by lining up a plurality of pieces of permanent magnets or magnetic materials while inversing a magnetization direction thereof, and an armature. First and second magnetic pole teeth are disposed in such a way as to vertically tuck the permanent magnet or the magnetic material. A magnetic material links the first magnetic pole tooth to the second magnetic pole tooth, thereby forming a path for a magnetic flux, and windings are disposed on the first magnetic pole tooth and the second magnetic pole tooth, respectively. At least two units of the armatures are lined to be linked to each other.

Abstract: An electric motor drive device 1000 includes: an inverter 3 that drives a motor 4, a voltage division circuit 2 that serves as a neutral point potential detection unit that detects a neutral point potential of a stator winding of the motor 4; and a controller 1 that estimates a rotor position of the motor 4 based on the detected neutral point potential, and that controls the inverter 3 based on an estimation result. A ground potential of the controller 1 is set to a negative side potential or a positive side potential of a DC voltage that is supplied to the inverter 3. The voltage division circuit 2 detects the neutral point potential with reference to the negative side potential or the positive side potential.

Abstract: A thrust generation mechanism includes magnetic pole teeth which are arranged so as to sandwich and hold permanent magnets disposed on movers, cores which serially connect the magnetic pole teeth which sandwich and hold the magnets, armature winding wires which are collectively wound around the cores, and the movers having the magnets arranged such that the different magnetic poles thereof alternately face the front side and the rear side. The magnetic pole teeth which are arranged so as to sandwich and hold the permanent magnets and the armature iron cores which have cores serially connecting the magnetic pole teeth which hold the magnets are arranged in the longitudinal direction of the movers, and armature iron cores have a common winding wire.

Abstract: A three-phase synchronous motor drive device includes: a three-phase inverter 3 that drives a motor 4 that is as a three-phase synchronous motor, and that includes switching elements for three phases; a controller 2 that functions as a control unit that selects four switched states from a plurality of switched states that represent on/off states of the switching elements for the three phases, and that sequentially controls the three-phase inverter in the four switched states; a neutral point potential amplifier 13 that functions as a neutral point potential detection unit that detects a neutral point potential Vn0 of stator windings (Lu, Lv, Lw) of the motor 4 in each of the four switched states. It is configured that a rotor position of the three-phase synchronous motor is estimated over a full range of an electrical angle cycle based on at least three of four neutral point potentials detected in the four switched states.

Abstract: In a system for driving an electric motor by an engine generator, there is a possibility that the effects of harmonics and DC voltage fluctuations of a power converter cause shaft oscillation to increase due to a phenomenon in which current pulsations caused by voltage disturbances at a d-axis and a q-axis are strengthened each other and thus oscillation and d-axis current are increased under the effect of interference between the d-axis and the q-axis.

Abstract: A drive system of a synchronous electrical motor includes a synchronous electrical motor; a power converter that is connected to the motor with a plurality of switching elements; a controller that outputs a voltage instruction to the power converter; a voltage detection unit for open phases upon application of respective positive and negative pulse voltages between respective two phases out of three-phase windings of the motor; an induced voltage difference for calculating an induced voltage difference that is a difference between an induced voltage detected by the voltage detection unit at each of the open phases upon application of the positive voltage pulse between the corresponding two phases and an induced voltage detected by the voltage detection unit at the open phase upon application of the negative voltage pulse between the two phases.

Abstract: In sequentially selecting and driving two phases of the three-phase stator windings of a synchronous motor, detect a speed electromotive voltage of a de-energized phase, relate the speed electromotive voltage to rotor position information beforehand, then count rotor position information backward based on the detected the speed electromotive voltage to estimate rotor position; and then detect rotation speed from the change rate of the rotor position information so as to achieve highly accurate position and speed control.

Abstract: The invention relates to a small size and lightweight linear motor having small thrust ripples, in which the magnetic attraction working between an armature and a mover is canceled out and therefore is small. A thrust generation mechanism includes a stator (3) and a mover (5). The mover (5) includes permanent magnets (4) installed in a row so that the magnetic poles at the front and backsides of the magnets are alternately reversed along the traveling direction. The stator (3) includes upper and lower pole teeth (6), (7) having a plurality of magnetic poles (2) and arranged so as to sandwich the permanent magnets (4) of the mover (5), cores for connecting the pole teeth, and a winding (1) wound around a set of a plurality of the cores. Thrust ripples are reduced by adjusting the magnetic pole pitch (Pc) of the magnetic poles (2).

Abstract: A synchronous electric motor drive system capable of driving at speeds near zero is provided. An energization mode determination unit switches six energization modes successively based on a terminal potential detected of the de-energized phase of a three-phase synchronous electric motor or on a stator winding wire connection point potential (neutral point potential) detected of the three-phase synchronous transmission unit. A voltage command correction unit corrects by a correction amount ?V an applied voltage command destined for the synchronous electric motor to supply the synchronous electric motor with a repeated waveform of a positive pulse, negative pulse, and zero voltage as a line voltage waveform of the energized phases in each of the six energization modes, the positive pulse voltage being polarized to cause the synchronous electric motor to generate a forward rotation torque, the negative pulse voltage causing the synchronous electric motor to generate a reverse rotation torque.

Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.

Abstract: The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.

Abstract: The present invention relates to a drive apparatus and drive method for switching an energization mode when a voltage of a non-energized phase of a brushless motor crosses a threshold. In threshold learning, first, the brushless motor is stopped at an initial position. The brushless motor is then rotated by performing phase energization based on the energization mode from the stopped state. The voltage of the non-energized phase at an angular position of switching the energization mode is detected from a maximum value or a minimum value of the voltage of the non-energized phase during the rotation, and the threshold is learned based on the detected voltage. Alternatively, the brushless motor is positioned at the angular position of switching the energization mode by maintaining one energization mode, and then the energization mode is switched to the next energization mode.

Abstract: The present relates to a sensorless driving apparatus and a sensorless driving method for a brushless motor. In a state that the brushless motor is driven by rectangular waves, when the driving apparatus detects that a rotation speed of the brushless motor becomes higher than a predetermined speed and thereafter it detects that an angle of a rotor of the brushless motor becomes a predetermined angle, the driving apparatus switches the drive from rectangular wave drive to sign wave drive. The driving apparatus sets as the predetermined angle an angle at which energizing mode is switched in the rectangular wave drive or an angle at which a motor torque is at a peak value in the rectangular wave drive.

Abstract: A position sensor-less driving method is provided that can drive rotation speed/torque control of a permanent magnet motor using an inverter with an ideal sinusoidal current with the minimum number of switching, and can drive at a speed as low as an extremely low speed region close to zero speed. A neutral point potential of a permanent magnet motor is detected in synchronization with PWM waveform of the inverter. A rotor position of the permanent magnet motor is estimated from change of the neutral point potential. When the neutral point potential is detected, timing of each phase of the PWM waveform is shifted to generate three or four types of switch states of which output voltage of the inverter is not zero vector, and neutral point potentials in at least two types of switch states among them are sampled, whereby rotor position of the three-phase synchronous motor is estimated.

Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.

Abstract: Provided is an AC motor in a three-phase unbalanced state such as a claw-teeth type AC motor (108), which is reduced in magnetic flux pulsations and torque pulsations. Among the current command values of individual phases to be intrinsically given to an inverter (106) for feeding three-phase alternating currents of variable voltages/frequencies to the electric motor, a current command of an intermediate phase (a V-phase) having a smaller magnetic resistance of a stator core than those of other phases is subjected to a reducing correction by a correction unit (102) on the basis of the correction amount calculated by a current correction amount calculating unit (103), and the unbalanced three-phase alternating currents are fed to the AC motor (108), so that magnetic flux pulsations of a secondary electric angle and torque pulsations of the same order are reduced.

Abstract: A drive system of a synchronous electrical motor includes a synchronous electrical motor; a power converter that is connected to the motor with a plurality of switching elements; a controller that outputs a voltage instruction to the power converter; a voltage detection unit for open phases upon application of respective positive and negative pulse voltages between respective two phases out of three-phase windings of the motor; an induced voltage difference for calculating an induced voltage difference that is a difference between an induced voltage detected by the voltage detection unit at each of the open phases upon application of the positive voltage pulse between the corresponding two phases and an induced voltage detected by the voltage detection unit at the open phase upon application of the negative voltage pulse between the two phases.

Abstract: When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time ?t since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.