Matsushita Electric Industrial Co., Ltd.

Kazuyuki Takada

Masahiro Yasohara

Yoshinori Isomura

Yoshihiro Fujisaki

Shinichi Emura

Toru Kishi

Yuji Tanaka

Yasushi Kato

Yoshihiro Ashizaki

Ryutaro Arakawa

Kouji Takada

Toshiki Tsubouchi

Yoshihiro Matsui

Pulse width modulation converter

A motor control apparatus supplies a current to the motor according to the control either by an average current controller or by an instantaneous current controller. The selection of the controller is done by a switching command signal selector, which selects the average current controller when the position deviation is within a specified range, and selects the instantaneous current controller when the position deviation is outside this specified range.

Motor control apparatus

A PWM inverter output circuit enabling circuit integration, having a fast response characteristic, and unaffected by dv/dt transients is provided. A predrive circuit 17 drives a power circuit 11 comprising first and second power elements P1 and P2 by controlling the gate and source potential of the power elements P1 and P2 based on a stored control state. The control state is detected from a logic signal output from an input signal processor 13, which converts a command signal instructing turning on and off the power elements P1 and P2 to predetermined logic signals. Operating power is drawn from a main dc power source V1, a control power source V2, and a power supply capacitor C1 that is charged using an output voltage from the control power source V2. The gates and sources of the power elements P1 and P2 are connected together.

PWM inverter with zero dead time and initial power supply capacitor

A protection apparatus used in a brushless motor is arranged by a brushless motor; a commutation signal detecting unit for detecting a position of a movable member of the brushless motor; a speed detecting unit for detecting a rotation speed of the movable member of the brushless motor, involving a rotation direction thereof, in response to the detection signal outputted from the commutation signal detecting unit; and a drive circuit for producing a commutation signal used to drive the movable member of the brushless motor in response to the detection signal outputted from the commutation signal detecting unit and for driving the brushless motor based upon the commutation signal. The protection apparatus is further constructed of an output voltage instructing unit for supplying to the drive circuit, an output voltage instruction signal for instructing an output voltage of the drive circuit, which constitutes a drive voltage when the brushless motor is driven; a voltage limit level setting unit for setting an upper limit value of the output voltage of the drive circuit; and a voltage limiter unit for limiting the output signal of the output voltage instructing unit based on the setting value of the voltage limit level setting unit to thereby limit an upper limit value of the output voltage of the drive circuit.

Protection apparatus for brushless motor

In a current command type PWM inverter apparatus including first to sixth main circuit switching power devices for supplying line currents to a three-phase motor, at a periodical state updating first timing, and at least one second timing when any one of first, second and third comparison signals between respective detected line currents and respective line current command signals change after the state updating first timing, a logic circuit generates and outputs first to sixth switching command signals to the main circuit switching power devices so as to minimize errors between respective line current command signals and respective detected line currents.

Current command type PWM inverter apparatus for driving and controlling

An output circuit for a PWM inverter is provided which has an N-type first power device and a P-type second power device. Gates of the first and second power devices are connected to each other. Also, emitters of the first and second power devices are connected to each other. An input electrode control circuit controls the voltage applied to the common gates with respect to the common emitters. The voltage may be a positive or negative value, or zero. The input electrode control circuit controls the conduction states of the two power devices based upon the states of input light emitting devices associated with a first and second photocoupler (current generator). When both of the photocouplers are not lit, no current is generated and the conduction states of the power devices are instantaneously interrupted.

Output circuit for PWM inverter with no floating state

To use a sinusoidal wave as a driving waveform, and reduce noise and vibration, in an inexpensive constitution, a driving apparatus for the brushless motor includes a first data latch 16 for holding the value of address Au at an output signal timing of a first edge detecting means 10, and issuing as address value Aus, and third frequency adjusting means 20, including it, for issuing the result of adding rotating frequency Fsen to the product of address error Aerr obtained by subtracting the address value Aus held by the first data latch 16 from the reference address value Aref, rotating frequency Fsen, and control gain Ka, to an address counter 9 as frequency command Fref.

Driving apparatus for a brushless motor and rotor position detecting

A low-cost, completely adjustment-free current-controlled PWM inverter substantially solving the conventional problems associated with the gain adjustment of a current error amplifier is provided. The current-controlled PWM inverter comprises a motor current detector, a main circuit power controller, a current comparator, a timing signal generator, and a switching control signal generator configured such that the switching control signal generator sets the switching control signal to switch the main circuit switching power elements on or off at the refresh timing and at the timing at which the current comparison result state changes.

Current controlled PWM inverter for driving a motor without gain

A driving apparatus of an induction motor applied for drive of a fan of an air conditioner has a voltage limiter unit for limiting an upper limit of an output voltage of an inverter circuit, a voltage slow-up unit for converting an output signal of an output voltage commanding unit into a signal which increases gradually when that output signal rises, a voltage slow-down unit for converting the output signal of the output voltage commanding unit into a signal which decreases gradually when that output signal falls, and a feed interruption processing unit for setting the output signal value of the output voltage commanding unit to 0 when interrupting feeding and delivering a feed interruption signal at the termination of the lapse of a predetermined time.

Apparatus for driving induction motor

Current command type PWM inverter apparatus with logic circuit for

A driver for an induction motor includes a voltage limiter which limits an upper limit value of an output voltage from an invertor circuit in accordance with an output frequency command, a lowest frequency limiter which limits a lower limit of an output frequency from the invertor circuit, a forward rotation limiter which outputs a first power supply interruption signal when the output frequency from the invertor circuit reaches the upper limit, a reverse rotation limiter which outputs a second power supply interruption signal when a reverse rotational speed of the motor reaches a reverse rotation limit level, and a low-speed overload detector which outputs a third power supply interruption signal when a state in which the second power supply interruption signal is not output continues in a low speed abnormality state.

Driver for an induction motor

An output circuit of a PWM inverter for PWM controlling a coil voltage of a motor includes an N channel power element, a P channel power element, a current control circuit having a current output terminal, and a second current control circuit having a current input terminal. A current flowing out from the current output terminal of the first current control circuit and a current flowing in from the current input terminal of the second current control circuit are subjected to particular control to thereby control the N channel power element and the P channel power element. The output circuit of the PWM inverter is configured inexpensively to control a voltage of a motor winding terminal with very small error and with low power consumption.

Output circuit of PWM inverter wherein floating time is reduced

An inexpensive output circuit of a PWM inverter for PWM controlling a coil voltage of a motor with small control error of voltage at a motor winding terminal and low power consumption includes an N channel power MOS-FET, a P channel power MOS-FET, a current control circuit 1 having a current output terminal, and a current control circuit 2 having a current input terminal. A current flowing out from the current output terminal of the current control circuit 1 and a current flowing in from the current input terminal of the current control circuit 2 are subjected to particular control to thereby control the N channel power MOS-FET and the P channel power MOS-FET.

Output circuit of PWM inverter

A clock signal is applied to an UP/DOWN counter, which counts up the clock signal from zero up to a predetermined value and then counts down from the predetermined value to zero, and thereby a triangular wave signal representing counted value is output therefrom; three threshold values which are different each other are selected between zero and the predetermined value in advance, and they are set in three digital comparators, respectively; in each digital comparator, the threshold value is compared with a level of the triangular wave signal, and when the threshold value is larger than the level of the triangular wave signal, a high level signal is output from each digital comparator, the high level signal is delayed by a predetermined delay time and three-phase PWM signal is generated.

Digital three-phase PWM signal

A dividing ratio is represented by a ratio (M/N) of two integers (M) and (N), and six data (N), (-N), (M), (M+N), (M-N) and (0) are generated, then one of the six data is selected on the basis of a condition that is predetermined by an input signal to be divided and a comparison result of the data (N), (-N) and data which is derived by addition or subtraction between the selected data from the six data and the previous calculation result of the addition or subtraction; and output or interception of an output signal is controlled on the basis the comparison result, and thereby the input signal is divided by the dividing ratio (M/N).

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Hirakata, Japan

Kazuyuki Takada