Sanden Corporation

Sanden Holdings Corporation

Tatsuki Kashihara

Hiroshi Yoshida

Yushi Araki

Koji Kobayashi

Takahiro Saigusa

Kouji Kobayashi

Provided is an active filter device capable of effectively reducing common mode noise and differential mode noise and optimizing filter characteristics. The active filter device includes an inverting amplifier circuitthat inverts and amplifies a common mode voltage and a differential amplifier circuitthat differentially amplifies a differential mode voltage, and an output voltage of the inverting amplifier circuitis applied as a common mode compensation voltage to Y capacitors, an output of the differential amplifier circuitobtained by amplifying a voltage of a positive-side power supply lineis applied as a differential mode compensation voltage to a negative-side X capacitor, and an output of the differential amplifier circuitobtained by amplifying a voltage of a negative-side power supply lineis applied as a differential mode compensation voltage to a positive-side X capacitor

Active filter device and electric compressor comprising same

The invention provides an inverter device which effectively cancels the generation of common mode noise associated with dead-time effects and misjudgement of the polarity of a phase current at switching in the case where a fluctuation in a neutral point potential of a motor is suppressed by canceling a change in a phase voltage with another change in the phase voltage. A phase voltage command operation unitof a control device includes a phase current prediction partwhich predicts a phase current at a switching timing of each phase, and a correction control partwhich corrects a switching operation so as to cancel a change in the phase voltage applied to the motor with another change in the phase voltage, based on the phase current of each phase at the switching timing predicted by the phase current prediction part

Inverter device

There is provided a motor control device which enables torque ripple suppressing control high in followability by executing direct voltage control. A motor control device includes a voltage command calculation unitwhich calculates a d-axis voltage command value Vand a q-axis voltage command value Vfrom a d-axis current command value i* and a q-axis current command value i* of a motor, a feed forward command value calculation unitwhich calculates a qi-axis voltage feed forward command value V* for generating a q-axis current ripple on the basis of spatial harmonic parameters and the frequency characteristics of a motor winding, and a subtraction unitwhich subtracts the q-axis voltage feed forward command value V* calculated by the feed forward command value calculation unitfrom the q-axis voltage command value Vcalculated by the voltage command calculation unit

Motor control device

An inverter device is provided which is capable of effectively eliminating or suppressing common mode noise in consideration of the influence of a dead time by using the function of a PWM signal generating unit. A control deviceincludes a phase voltage command calculating unitwhich calculates three-phase modulation voltage command values for generating voltages to be applied to respective phases of a motor, and a PWM signal generating unitwhich, based on the three-phase modulation voltage command values and a single carrier signal, generates a PWM signal to PWM-control an inverter circuit. The PWM signal generating unitcorrects the three-phase modulation voltage command values output by the phase voltage command calculating unitto thereby cancel a change in the phase voltage applied to the motorby a change in another phase voltage.

There is provided a power conversion device capable of eliminating a disadvantage of a sharp temperature rise in a switching element by using a discontinuous modulation method. The power conversion device includes a phase voltage command operation unitwhich calculates a sinusoidal modulation voltage command value to be applied to a motor, an inter-line modulation operation unitwhich, based on the sinusoidal modulation voltage command value, calculates a discontinuous modulation voltage command value for allowing an ON/OFF state of a switching element of one phase of a three-phase inverter circuitto be fixed, and modulating ON/OFF states of switching elements of other two phases, and a PWM signal generation unit. The inter-line modulation operation unit sets a switching density of the switching element of at least one phase to a value different from that of the other phase.

Power conversion device

There is provided a power conversion device capable of effectively reducing a surge voltage generated by a parasitic inductance of a circuit. The power conversion deviceis configured to operate a motordriving a compression mechanismof an electric compressorby means of a three-phase inverter circuithaving a plurality of switching elementsA toF. The power conversion device calculates a surge voltage value of each phase from a parasitic inductance of the circuit and phase currents iu, iv, and iw of the motorto derive a phase in which the surge voltage value becomes maximum, and suppresses the switching of the switching elementsA-F of the phase having the maximum surge voltage value by a discontinuous modulation method.

A motor control device according to the present invention includes: a boost converter circuitthat boosts a direct-current voltage; an inverterthat generates a drive pulse for a motorfrom the direct-current voltage of the boost converter circuit; and a control sectionthat presets a set value Id_hold obtained by multiplying a set value Id_max by an intermediate current threshold coefficient &#x3b1;, controls a pulse width of the drive pulse of the inverterbased on a speed deviation, controls a d-axis current in the motorbased on the speed deviation so that the pulse width of the drive pulse of the inverterdoes not exceed a threshold value, and controls the direct-current voltage of the boost converter circuitbased on the speed deviation so that the d-axis current in the motordoes not exceed the set value Id_hold.

Growing community of inventors

Isesaki, Japan

Tatsuki Kashihara