Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Masaki Tagome

Yasuhiro Kondo

Shun Kazama

Makoto Kitabatake

Satoshi Tamaki

Naoyuki Kadoya

Hisanori Nagase

Makoto Gotou

Noriyoshi Nishiyama

Yasufumi Ikkai

Tomokuni Iijima

Takashi Haruguchi

Hideaki Mori

Kazushige Narazaki

Mineaki Isoda

Yoshiaki Igarashi

Maki Murakami

To aim to reduce ripple current flowing through a capacitor in a power converter apparatus including a converter, the capacitor and an inverter. A current sensoris connected between a capacitorand an inverter circuitfor detecting current Iinv flowing from the capacitorto the inverter circuit. A frequency detecting subunitperforms fast Fourier transform on a waveform of the current Iinv to detect a frequency of a frequency component having the largest amplitude. Also, the frequency detecting subunitdetects a zero-cross point of the frequency component having the largest amplitude. Then a carrier signal control subunitperforms control such that a frequency and a rise time of a PWM carrier signal for driving the converter circuitmatch the frequency and the zero-cross point that have been detected by the frequency detecting subunitand the phase detecting subunit

Electric power converting apparatus and induction heating apparatus

A power converter for effectively reducing switching noise is provided. The power converter comprises a capacitor; switching devices Qand Qconnected to the capacitorin parallel; and a controllerthat controls each switching device individually to perform switching operations. Each of the switching devices Qand Qforms a closed circuit together with the capacitor. The controllercontrols the switching devices Qand Qto perform switching operations of switching ON or OFF at different timings such that at least two closed circuits including the switching devices Qand Qmutually cancel ringing voltages occurring therein, each ringing voltage occurring due to the switching operations performed by a corresponding switching device and having a frequency defined by an inductance of a corresponding closed circuit and an output capacity of a switching device included in the corresponding closed circuit.

Power converting apparatus suppressing switching noise by controlling switching operation

A small-sized load drive system which, even with three three-phase inverters, significantly reduces noise regardless of control duty ratio. The load drive system includes three-phase inverters, and first, second, and third control units. The inverters are connected to loads, respectively. The first control unit generates sawtooth wave voltage and controls the inverter according to the sawtooth wave voltage. The second control unit generates inverse sawtooth wave voltage and controls the inverter according to the inverse sawtooth wave voltage. The third control unit generates triangular wave voltage which has ramps respectively equal to the sawtooth/inverse sawtooth wave voltage and either has a same phase or is out of phase by half a period relative to the sawtooth/inverse sawtooth wave voltage, and also controls the inverter according to the triangular wave voltage.

Load drive system, motor drive system, and vehicle control system

A synchronous electric motor includes rotor having a plurality of radially-oriented magnetic dipoles and a stator. Stator teeth group with a plurality of sets of stator teeth are arranged in the same position in terms of an electrical angle with another stator teeth group to provide rotational symmetry about an axis of the rotor. In each of the stator teeth groups a predetermined number of stator teeth are arranged at intervals different from intervals of the rotor magnetic dipoles. A main coil is wound about a predetermined number of stator teeth with a sub-coil further wound around one or more a teeth. Phase and magnitude of a resulting magnetic field is adjusted by the number of loops of the main coil and sub-coil. A given stator tooth can produce maximum torque despite any difference between an alignment of the stator tooth and an inter-polar interval of the stator.

Synchronous electric motor

A motor drive apparatus receiving power from a power source and driving a motor with independent polyphase systems of excitation coils, comprises: a control circuit and power converters each corresponding to one system, each including an inverter circuit, an interrupter circuit, and a temperature detector, the inverter circuits being connected in series to the power source and, while not short-circuited, supplying power to the excitation coil, wherein the control circuit detects an operating state of the motor, short-circuits the inverter circuits and interrupts the interrupter circuits for a subset of power converters defined according to the operating state, such that a source voltage is supplied to non-short-circuited inverter circuits, and, when a power converter exceeds a predetermined temperature, the control circuit short-circuits the inverter circuit and interrupts the interrupter circuit thereof, and, in another power converter not exceeding the predetermined temperature, operates the inverter circuit and connects the interrupter circuit.

Motor drive apparatus

Provided are semiconductor elementsA,B, andC that allow a current to flow that is at most a maximum current determined by the level of control signals VGA, VGB, and VGC and that depends on the difference between the voltage of a DC power supply BA and the charging voltage of a capacitor, a controllerthat outputs a control signal to each semiconductor element, and a temperature detection circuit that detects the temperature of each semiconductor element. Until a predetermined time elapses after the electric circuit is closed, the controlleradjusts the level of each control signal based on the temperature detected by the temperature detection circuit so that current through the electric circuit does not exceed a current limit, and after the predetermined time period elapses, the controlleradjusts the level of each control signal so that current through the electric circuit is allowed to exceed the current limit.

Power source switch device and power source system provided with same

The present invention provides a synchronous motor drive system designed to realize reduced vibration and noise along with high output. The system includes: inverters, andfor converting a direct current to a three-phase alternating current; a current application control unitthat controls operations of the three-phase inverters; and a synchronous motordriven by three-phase alternating currents supplied from the three-phase inverters. The current application control unitdetermines, for each three-phase inverter, a current phase angle and a current amount of a three-phase alternating current to output, and each inverter supplies a three-phase alternating current having the determined current phase angle and current amount to a different one of three-phase coil groupsto

Synchronous electric motor drive system

The present invention aims to provide a synchronous motor drive system that is capable of suppressing ripples in current while reducing switching loss. The system includes three-phase inverters-, a control circuitfor controlling the operations of the three-phase inverters and a synchronous motorincluding a plurality of three-phase coils. To control the operations of the three-phase inverters, the control circuitcauses the three-phase invertersandand the three-phase inverterto use different carrier frequencies to generate three-phase AC power, and each of the three-phase inverters supplies a different one of the three-phase coils with three-phase AC power.

Synchronous electric motor system

Provided is a synchronous motor including a rotor having magnetic poles distributed circumferentially along a rotation direction of the rotor at equal intervals, and a stator having stator teeth arranged circumferentially along the rotation direction of the rotor, each tooth wound with a stator coil by concentrated winding. Every M consecutive stator teeth belong to one of stator teeth groups arranged at equal intervals. The M consecutive stator teeth in each stator teeth group are arranged at intervals different from the intervals of the magnetic poles of the rotor. The stator coils wound around the M consecutive stator teeth are connected to separate terminals. A motor driver supplies currents of different phases to the stator coils via the respective terminals.

Synchronous motor drive system

In a power conversion circuit operating with high frequency, an off-voltage control circuitof a lower-arm gate drive circuitcontrols the output voltage of a gate drive power supplyto change the output voltage to a voltage lower than a predetermined off voltage during a time period from termination of turn-off operation of a lower armuntil start of turn-on operation of an upper arm, and thereafter return the output voltage to the predetermined off voltage immediately after termination of the turn-on operation of the upper arm. With this control, short-circuiting through the upper and lower arms occurring due to a high voltage change dv/dt can be avoided, and the life of a switching element constituting the power conversion circuit improves, increasing the reliability of the power conversion circuit.

Power conversion circuit having off-voltage control circuit

The present invention aims to provide a power converter with an arm including switching devices connected in parallel, realizing long lifespans of switching devices. An inverter includes an upper and a lower arm, and gate drive circuits each driving the corresponding arm according to a gate control signal Gup_s indicating ON/OFF periods. Each arm includes switching devices connected in parallel. Each gate drive circuit includes: a switching gate control circuitbringing a switching deviceinto conduction at the beginning of the ON period and bringing the same out of conduction within the ON period; and a conduction gate control circuitbringing switching devicesandwithin a period from when the switching deviceis brought into conduction until the same is brought out of conduction, wherein the switching devicehas a lower parasitic capacitance than the switching devicesand the

Power conversion device

A gate voltage detecting circuitdetects a gate voltage Vgs of a switching device, and when the gate voltage is less than a predetermined voltage that is set to be less than a threshold voltage of the switching device, outputs an H-level boost instruction signal. A voltage control circuit, when the boost instruction signal is at the L level, outputs a predetermined voltage Vof a control power supplyas it is, and when the boost instruction signal is at the H level, outputs a voltage Vobtained by boosting the predetermined voltage V. The drive signal output circuitamplifies a voltage of a PWM pulse output from a PWM pulse output circuitto a voltage output from the voltage control circuit. Therefore, a drive signal from the drive signal output circuitto the switching deviceinitially becomes the boosted voltage Vwhen the PWM pulse goes to the H level, and then becomes the predetermined voltage Vwhen the gate voltage Vgs of the switching deviceincreases to a predetermined voltage. Therefore, a switching loss of the switching device can be suppressed.

Switching device drive circuit

A camera moduleincludes a movable sectionthat includes a lens, a fixed sectionhaving a hollow space extending in the optical axis direction of the lens, and an elastic bodythat elastically supports the movable sectionand the fixed section, an imaging elementthat is fixed to the fixed sectionand has a light-receiving surface perpendicular to the optical axis of the lens, a plurality of magnets,,, andarranged along the fixed section, and a coil sectionprovided in the movable section. The elastic bodyincludes an upper springand a lower spring, which support the fixed sectionbetween adjacent ones of the magnets, andalong the arrangement direction of these magnets on a plane perpendicular to the optical axis of the lens. With this configuration, it is possible to provide a camera module with an automatic focusing control function, whose thickness can be reduced remarkably.

Camera module

A camera module including: a lens portion including at least one lens; an imaging element; a fixed portion; a first elastic body that is provided on a side opposite to the imaging element side with respect to the lens and couples the lens portion and the fixed portion; and a second elastic body that is provided on the imaging element side with respect to the lens and couples the lens portion and the fixed portion. The first elastic body and the second elastic body have the same shape. The first elastic body and the second elastic body are arranged so as to oppose each other while sharing a common central axis. The second elastic body is arranged so that so that the shape of the second elastic body is different from a shape of the first elastic body projected in the optical axis direction of the lens.

A brushless motor has first and second power transistors which form current paths to three-phase windings so as to rotate a rotor. A position detecting part produces a position signal in response to a rotation of the rotor. An activation operation block controls active operation of the first and second power transistors in response to the position signal. The activation operation block includes a starting operation part which comprises an initial phase setting part, phase changing part and a phase correcting part. The initial phase setting part sets an initial phase of drive signals to the three-phase windings in response to the level of the position signal at the timing of a start signal. The phase changing part changes sequentially the phase of the drive signals to the three-phase windings in the positive direction in response to time. The phase correcting part corrects the phase of the drive signals to the three-phase windings in response to the occurrence of the rising and falling edges of the position signal. Therefore, the brushless motor with reduced position sensor can stably start the rotation of the rotor by using one position signal of one position sensor.

Growing community of inventors

Osaka, Japan

Masaki Tagome