JP2755057B2 - DC brushless motor drive circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC brushless motor driving circuit.

[0002]

2. Description of the Related Art A DC power supply and an inverter circuit are conventionally used for driving a DC brushless motor composed of two-phase windings. FIG. 8 shows, for example,
FIG. 1 is a circuit diagram showing a drive circuit of a conventional DC brushless motor disclosed in Japanese Patent Application Publication No. 275/275. In the figure,
(5) is a DC power supply, (7) and (8) are armature windings of a brushless motor, and (1X) is a semiconductor switch group that outputs a winding current of the armature windings (7) and (8); (10) is a rotor of the brushless motor.

The conventional DC brushless motor drive circuit is constructed as described above, and the two semiconductors are arranged so that the currents flowing through the two-phase armature windings (7) and (8) have a phase difference of 90 ° from each other. By providing four arms composed of switching elements,
It is controlled independently so as not to be affected by other phases. The drive signal of the semiconductor switch group (1X) is, for example, a detection circuit (not shown) using a semiconductor element utilizing the Hall effect
Is generated when a magnetic pole of the rotor (10) is detected. Thus, the rotor (10) generates torque and rotates.

[0004]

The above-described conventional DC brushless motor drive circuit is composed of four arms having two semiconductor switching elements.
There is a problem that the number of arms is large, the circuit configuration is complicated, and the cost is high.

The present invention has been made to solve the above problems, and has as its object to provide a DC brushless motor drive circuit having a simple circuit configuration and capable of reducing costs.

[0006]

According to a first aspect of the present invention, there is provided a drive circuit for a DC brushless motor, wherein two arms each comprising two semiconductor switching elements of the same type connected in series are connected in parallel to each other. A circuit in which one of the two-phase armature windings of a DC brushless motor and the other of the two-phase armature windings are connected with a phase-advancing capacitor between the output terminals of the inverter circuit connected to the power supply. It is.

A DC brushless motor drive circuit according to a second aspect of the present invention is an output terminal of an inverter circuit in which one arm composed of two semiconductor switching elements connected in series is connected to a double voltage DC power supply circuit. A circuit in which one of the two-phase armature windings of a DC brushless motor and the other of the two-phase armature windings are connected to a phase-advancing capacitor between the neutral point of the DC voltage power supply circuit and It is.

[0008] The driving circuit of the brushless DC motor according to the third invention, an arm composed of two semiconductor switching elements connected in series is two parallel-connected, die
A circuit in which two-phase armature windings of a DC brushless motor are connected in series between the output terminals of an inverter circuit connected to a voltage doubler DC power supply circuit consisting of an The neutral point is connected to the common terminal of the two-phase armature winding .

[0009]

According to a first aspect of the present invention, between an output terminal of an inverter circuit connected to a DC power supply, and in a second aspect, an output terminal of an inverter circuit connected to a voltage doubler DC power supply circuit is connected to a voltage doubler. A circuit in which one of the armature windings is connected between the neutral points of the DC power supply circuit and the other is connected with a phase-advancing capacitor is connected to each other. Then only one arm is required.

Further, in the third invention, between the output terminals of the inverter circuit connected to the double voltage DC power supply circuit,
Since the two-phase armature windings are connected in series and the neutral point of the power supply circuit is connected to the common terminal of the armature windings, the inverter circuit only needs to have two arms .

[0011]

[Embodiment 1] 1 to 3 show one embodiment of the first invention of the present invention. FIG. 1 is a circuit diagram, FIG. 2 is an operation explanatory diagram, FIG. 3 is a current waveform diagram of an armature winding, The same parts as those of the conventional device are denoted by the same reference numerals (the same applies to other embodiments).

In FIG. 1, (1) and (2) are upper stage transistors, and (3) and (4) are lower stage transistors. A semiconductor switch group comprising two arms for outputting a winding current of a brushless motor. And connected to a DC power supply (5) to form an inverter circuit (6). (7) and (8) are the armature windings of the brushless motor.Each terminal of the armature winding (8) is connected between the output terminals of the inverter (6), and the armature winding (7) is a phase advance capacitor. (9) are connected in series and connected between the output terminals of the inverter circuit (6). That is, the overall circuit configuration is the same as that of the AC capacitor drive motor using the inverter (6) as an AC power supply.

In the drive circuit for the DC brushless motor having the above configuration, the transistors (1) forming the two arms
As shown in FIG. 2, the transistors (3) and the transistors (2) and (4) operate so that two out of four transistors are always turned on, as shown in FIG. When the transistors (1), (2), (3), and (4) are sequentially turned on in the combination shown in FIG. 2, either positive or negative voltage is applied to the armature windings (7) and (8). S phase back electromotive force e of armature winding (7) to which voltage V and phase advance capacitor (9) are connected
_s and the M-phase back electromotive force e _{M of the} other armature winding (8) are as shown in FIG. Current i _M of the current i _s and the armature winding (8) of the armature winding (7) in FIG. 1 may difference in phase by phase advancing capacitor (9) as shown in FIG. That is, a rotating magnetic field is generated similarly to the AC capacitor motor.
This allows the armature winding of a two-phase DC brushless motor
(7) The current to (8) can be controlled and driven by the two arms, so that the circuit configuration is significantly simplified and the cost is reduced.

Embodiment 2 FIG. FIGS. 4 and 5 show an embodiment of the second invention of the present invention. FIG. 4 is a circuit diagram, and FIG.

In this DC brushless motor drive circuit, the transistors (2) and (4) of the first embodiment are replaced with DC power supplies (5) and (5A), respectively. A circuit (6) is configured, and the other configuration is the same as that of the first embodiment. Then, the transistors (1) and (3) are sequentially turned on at the timing shown in FIG.
By doing so, a rotating magnetic field is generated as in the case of the AC capacitor motor, as in the first embodiment. As a result, the current to the armature windings (7) and (8) of the two-phase brushless DC motor can be controlled and driven by two DC power supplies (5) and (5A) in series with one arm. As a result, the circuit configuration is significantly simplified, and the cost is reduced.

Embodiment 3 FIG. 6 and 7 are views showing an embodiment of the third invention of the present invention. FIG. 6 is a circuit diagram, and FIG. 7 is an operation explanatory diagram thereof. In the figure, (15) is a commercial AC power supply, (16) is a voltage doubler rectifier circuit connected to the AC power supply (15) and supplying DC power to the inverter circuit (6), and includes a diode (17) and a smoothing capacitor (18).
It consists of. The armature windings (7) and (8) of the DC brushless motor are connected in series to form an inverter circuit.
The common terminal of the armature windings (7) and (8) is connected to the neutral point of the DC power supply of the voltage doubler rectifier circuit (16). (19) (20) is, for example, a flux linkage detecting element that detects the position of the rotor (10) using the Hall effect, (21) is a signal from the linkage flux detecting element (19) (20), A drive signal generation circuit that determines the transistors (1) to (4) to be energized in the inverter circuit (6), V _a and V _b are armature windings, respectively.
(7) electromotive force generated in (8), is the current flowing I _a, are each I _b armature winding (7) (8).

In the drive circuit of the DC brushless motor having the above structure, the transistors (1) forming the two arms
The transistors (3) and the transistors (2) and (4) operate so that only one of the four transistors is turned on as shown in FIG. Since the common terminal of the armature windings (7) and (8) is connected to the neutral point of the bus power of the inverter circuit (6), when one of the transistors (1) to (4) is turned on, the armature winding Winding (7)
Either positive or negative voltage is applied to (8). Therefore, in order to apply a positive or negative voltage to the one-phase armature winding (7), only one of the two transistors (1) and (3) constituting the arm of the inverter circuit (6) is used. The currents Ia and Ib to the armature windings (7) and (8) of the two-phase DC brushless motor can be controlled by the two arms.
The circuit configuration is significantly simplified .

[0018]

As described above, according to the first aspect of the present invention, the output terminal of the inverter circuit connected to the DC power supply in which two arms each including two semiconductor switching elements connected in series are connected in parallel. According to the second invention, one of the two-phase armature windings of the DC brushless motor is provided between the output terminal of the inverter circuit also connected to the voltage doubler DC power supply circuit and the neutral point of the voltage doubler DC power supply circuit. Since a circuit in which a phase-advancing capacitor is connected to the other side of the armature winding is connected, the inverter circuit only needs to have two arms in the first invention and one arm in the second invention. There is an effect that the cost can be significantly reduced and the cost can be reduced.

Also, in the third invention, the two series-connected
A two-phase armature winding of a DC brushless motor is connected in series between two output terminals of an inverter circuit connected to a voltage doubler DC power supply circuit. together with the connection, da
Since the neutral point of the double voltage DC power supply circuit consisting of an ion bridge and a capacitor was connected to the common terminal of the two-phase armature winding, the inverter circuit only needed to have two arms.
This has the effect of significantly simplifying the circuit configuration and reducing costs.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of FIG. 1;

FIG. 3 is a current waveform diagram of the armature winding of FIG. 1;

FIG. 4 is a circuit diagram showing a second embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of FIG. 4;

FIG. 6 is a circuit diagram showing a third embodiment of the present invention.

FIG. 7 is an operation explanatory diagram of FIG. 6;

FIG. 8 is a drive circuit diagram of a conventional DC brushless motor.

[Explanation of symbols]

1, 2, 2A, 3, 4, 4A Semiconductor switching element (transistor) 5, 5A DC power supply 6 Inverter circuit 7, 8 Armature winding 9 Leading capacitor 10 Rotor 16 Double voltage DC power circuit (double voltage rectifier circuit) ) 21 drive signal generation circuits

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02P 6/00

Claims (3)

(57) [Claims] 1. An arm comprising two semiconductor switching elements of the same kind connected in series and connected in parallel, connected to a DC power supply, and detecting a magnetic pole position of a rotor of the DC brushless motor to detect the semiconductor switching element. An inverter circuit for selecting the energization of the DC brushless motor is provided between the output terminals of the inverter circuit, and one of the two-phase armature windings of the DC brushless motor is connected to the other of the two-phase armature windings by a phase-advancing capacitor. A DC brushless motor drive circuit consisting of the circuits connected to each other. 2. An inverter circuit in which one arm composed of two semiconductor switching elements connected in series is connected to a doubled voltage DC power supply circuit, and an output terminal of the inverter circuit and the doubled voltage DC power supply circuit. Driving of a DC brushless motor in which one of two-phase armature windings of a DC brushless motor is connected between neutral points and a circuit in which a phase advance capacitor is connected to the other of the two-phase armature windings is respectively connected. circuit. 3. A diode bridge connected to an AC power supply.
A double voltage DC power supply circuit comprising
An inverter circuit is provided in which two arms composed of two semiconductor switching elements connected in series are connected in parallel and connected to a voltage doubler DC power supply circuit. A two-phase DC brushless motor is provided between output terminals of the inverter circuit. A circuit for driving a DC brushless motor, comprising connecting a circuit in which the armature windings are connected in series and connecting a neutral point of the voltage doubled DC power supply circuit and a common terminal of the two-phase armature winding .