JPH10295094A - Inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of an inverter device which drives a two-phase permanent magnet type DC motor and, furthermore, reduce its loss and improve its reliability. SOLUTION: The respective one side terminals 35a and 36a of stator coils 35 and 36 of a permanent magnet type DC motor 34 are connected to output terminals 31c and 31d of a switching circuit 31 respectively, and other side terminals 35b and 36b are connected to a common connection point 24e of two capacitors 27 and 28 of a voltage doubler rectifying circuit 24. When currents are applied to the respective stator coils 35 and 36 in the positive directions (directions of arrows A1 and B1), a voltage is supplied from the capacitor 27 of the voltage doubler rectifying circuit 24 through transistors 32a and 32c on the positive side of the switching circuit 31. When currents are applied to the respective stator coils 35 and 36 in negative directions (directions of arrows A2 and B2), a voltage is supplied from the capacitor 28 of the voltage doubler rectifying circuit 24 through transistors 32b and 32d on the negative side of the switching circuit 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inverter device for driving a two-phase permanent magnet type DC motor.

[0002]

FIG. 4 shows an electric circuit diagram of a conventional inverter device for driving a two-phase permanent magnet type DC motor. AC power supply buses 2 and 3 of AC power supply 1 are connected to AC input terminals 4a of rectifier circuit 4, respectively.
And 4b. The rectifier circuit 4 is formed by bridge-connecting four diodes 5a to 5d.
The DC output terminals 4c and 4d are connected to input terminals 8a and 8b of the switching circuit 8 via DC power buses 6 and 7, respectively. A smoothing capacitor 9 is connected between the DC power buses 6 and 7.

The switching circuit 8 has input terminals 8a and 8
b, eight NPN transistors 10 connected in a bridge so as to form two sets of switching units S1 and S2.
a to 10h, and flywheel diodes 11a to 11h connected between the collectors and emitters of the transistors 10a to 10h. The output terminal 8c of the switching circuit 8 is connected to the emitter of the transistor 10a and the collector of the transistor 10b, and the output terminal 8d is connected to the emitter of the transistor 10c and the collector of the transistor 10d. The output terminal 8e of the switching circuit 8 is connected to the emitter of the transistor 10e and the collector of the transistor 10f, and the output terminal 8f is connected to the emitter of the transistor 10g and the collector of the transistor 10h.

The terminals 13a and 13b of the stator coil 13 of the two-phase permanent magnet type DC motor 12 are connected to the output terminals 8c and 8d of the switching circuit 8, respectively.
And 14b are connected to output terminals 8e and 8f of the switching circuit 8, respectively.

The permanent magnet type DC motor 12 is provided with a position sensor 15 for detecting the rotational position of a rotor (not shown). When the position sensor 15 detects the rotational position of the rotor, the position sensor 15 rotates. A position detection signal corresponding to the position is sent to a microcomputer (hereinafter referred to as a microcomputer) 16
Output. The microcomputer 16 calculates the position detection signal given from the position sensor 15, determines the energization timing of each of the stator coils 13 and 14 based on the calculation result, and sets each of the transistors 10a to 10h.
An energization timing signal (base signal) is output to the base (gate) of the device.

Thus, according to the above configuration, the AC power supply 1
When the operating power is supplied from the microcomputer 16, an energization timing signal is output from the microcomputer 16 to the transistors 10 a to 10 h based on the position detection signal output from the position sensor 15, and the transistors 10 a to 10 h are turned on / off to control the stator coil 13. And 14 are energized, and the permanent magnet type DC motor 12 is driven.

However, in the above-described conventional device, the energization of the stator coil 13 is controlled by the transistor 10a.
-10d and the stator coil 1
4 is controlled by the transistors 10e to 10h, that is, the current of each phase is controlled by four transistors, respectively.
There is a problem that the number of transistors is required, and as a result, the cost is increased.

Generally, transistors 10a to 10a
Since 0h generates a residual voltage during the ON state, in the above-described configuration in which each of the stator coils 13 and 14 is energized through two transistors, the loss caused by the residual voltage increases and the amount of heat generated increases. Therefore, there is a problem that reliability is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inverter device capable of reducing costs and reducing losses and improving reliability. It is in.

[0010]

An inverter device according to the present invention drives a two-phase permanent magnet type DC motor, and is constituted by connecting two rectifying elements and two capacitors in a bridge, thereby obtaining an AC input. A voltage doubler rectifier circuit having terminals connected to an AC power supply, a switching circuit having four switching elements bridge-connected, and an input terminal connected to a DC output terminal of the voltage doubler rectifier circuit; Control means for supplying an energization timing signal to each of the switching elements, wherein one terminal of each of the two-phase stator coils of the permanent magnet type DC motor is connected to the output terminal of the switching circuit, and each of the other terminals of the stator coil Is characterized in that it is connected to a common connection point of two capacitors of the voltage doubler rectifier circuit (claim 1).

According to the inverter device having the above configuration, one terminal of each of the two-phase stator coils of the permanent magnet type DC motor is connected to the output terminal of the switching circuit, and the other terminal is connected to two capacitors of the voltage doubler rectifier circuit. When the energization timing signal is given in a predetermined order to the switching elements of the switching circuit from the control means, each stator coil is connected to the terminal of one of the two capacitors. Electric current is applied by the inter-voltage, and the permanent magnet DC motor is driven.

At this time, since the switching circuit is constructed by connecting four switching elements in a bridge, the cost can be reduced unlike the conventional one in which the switching circuit is composed of eight switching elements. .

[0013] Further, since current is supplied to each stator coil through one switching element, the loss caused by the residual voltage can be reduced unlike the conventional one through two transistors. At the same time, the calorific value can be reduced, and the reliability can be improved.

In the above-mentioned inverter device, a position sensor for detecting a rotational position of a rotor of the permanent magnet type DC motor is provided, and the control means generates an energization timing signal based on a position detection signal from the position sensor. You may comprise (claim 2).

According to the inverter device having the above configuration, the energization timing signal is generated based on the position detection signal from the position sensor, so that the energization control of the stator coil can be performed with high accuracy.

In the above-mentioned inverter device, the control means may be configured to generate an energization timing signal based on an induced voltage induced in a stator coil of the permanent magnet type DC motor.

According to the inverter device having the above-described configuration, the energization timing signal is generated based on the induced voltage induced in the stator coil, so that the position sensor is not required and the cost can be further reduced. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The AC power supply buses 22 and 23 of the AC power supply 21 are connected to AC input terminals 24a and 24b of a well-known voltage doubler rectifier circuit 24, respectively. The voltage doubler rectifier circuit 24 is configured by bridge-connecting two diodes 25 and 26 as rectifying elements and two capacitors 27 and 28. The DC output terminal 24 of the voltage doubler rectifier circuit 24
c and 24d are DC power supply buses 29 and 3 respectively.
0 is connected to input terminals 31a and 31b of the switching circuit 31.

The switching circuit 31 has an input terminal 31
four NPN transistors 32a to 32d as switching elements bridge-connected between a and 31b;
Flywheel diodes 33a to 33d connected between the collector and the emitter of each transistor 32a to 32d
It is composed of The output terminal 31c of the switching circuit 31 is connected to the emitter of the transistor 32a and the collector of the transistor 32b. The output terminal 31d is connected to the emitter of the transistor 32c and the transistor 32d.
Is connected to the collector.

In the two-phase permanent magnet type DC motor 34, the terminal 3 which is one terminal of the stator coils 35 and 36
5a and 36a respectively correspond to the switching circuit 3
The other terminals 35b and 36b are connected in common and also connected to a common connection point 24e of the two capacitors 27 and 28 in the voltage doubler rectifier circuit 24.

The permanent magnet type DC motor 34 is provided with a position sensor 37 such as a Hall element for detecting a rotational position of a rotor (not shown). Position sensor 37
Outputs a position detection signal corresponding to the rotational position of the rotor to a microcomputer (hereinafter referred to as a microcomputer) 38 as control means. The microcomputer 38 includes the position sensor 3
7 to calculate the rotational position of the rotor, determine the energization timing of each of the stator coils 35 and 36 based on the calculation result, and send the energization timing signal to the base of each of the transistors 32a to 32d. Output.

Next, the operation of the above configuration will be described with reference to a time chart shown in FIG. 2A to 2D respectively show the transistors 32a to 32d.
32d shows the energization timing signals Ga to Gd.

First, at time t1, the transistor 3
When the transistors 2b and 32c are turned on and the transistors 32a and 32d are turned off, the voltage between the terminals of the capacitor 27 of the voltage doubler rectifier circuit 24 is supplied to the stator coil 36 via the transistor 32c. The current is supplied in the positive direction 36 (the direction of arrow B1 in FIG. 1). The voltage between the terminals of the capacitor 28 is supplied to the stator coil 35 via the transistor 32b.
, So that the current flows in the negative direction of the stator coil 35 (the direction of the arrow A2 in FIG. 1).

Next, at time t2, the transistor 3
When 2b and 32d are turned on and transistors 32a and 32c are turned off, the voltage between the terminals of capacitor 28 is supplied to stator coil 35 via transistor 32b and to stator coil 36 via transistor 32d. Thus, power is supplied to the stator coil 35 in the negative direction (the direction of the arrow A2 in FIG. 1) and the stator coil 36 in the negative direction (the direction of the arrow B2 in FIG. 1).

Next, at time t3, the transistor 3
When the transistors 2a and 32d are turned on and the transistors 32b and 32c are turned off, the voltage between the terminals of the capacitor 27 of the voltage doubler rectifier circuit 24 is supplied to the stator coil 35 via the transistor 32a. The current flows in the positive direction 35 (the direction of the arrow A1 in FIG. 1). The terminal voltage of the capacitor 28 is supplied to the stator coil 36 via the transistor 32d.
, So that current is supplied to the stator coil 36 in the negative direction (the direction of the arrow B2 in FIG. 1).

At time t4, when transistors 32a and 32c are turned on and transistors 32b and 32d are turned off, the voltage between terminals of capacitor 27 is supplied to stator coil 35 via transistor 32a and at the same time. Is supplied to the stator coil 36 via the transistor 32c, so that electricity is supplied to the stator coil 35 in the forward direction (the direction of the arrow A1 in FIG. 1) and in the positive direction of the stator coil 36 (the direction of the arrow B1 in FIG. 1). become. Thereafter, the transistors 32a to 32
d is controlled to be turned on and off in the same order as the times t1 to t4 described above.
5 and 36 are commutated.

As described above, commutation is performed with a phase of 180 degrees in each phase, and the commutation timing is shifted by 90 degrees. Therefore, a rotational force is applied to the rotor in accordance with a change in the magnetic field accompanying the energization of the stator coils 35 and 36. As a result, the two-phase permanent magnet DC motor 34 is driven.

At this time, the transistors 32a-32
The microcomputer 38 calculates the position detection signal output from the position sensor 37 and supplies the transistors 32a to 32d with an energization timing signal G.
This is performed by outputting a to Gd.

As described above, according to the first embodiment, the one terminals 35a and 36a of the stator coils 35 and 36 of the permanent magnet type DC motor 34 are connected to the output terminals 31c and 31d of the switching circuit 31, respectively. The other terminals 35b and 36b are connected to the voltage doubler rectifier circuit 2
4 common connection point 24 of two capacitors 27 and 28
e, when the stator coils 35 and 36 are energized in the positive direction, the voltage is supplied from the capacitor 27 of the voltage doubler rectifier circuit 24 through the transistors 32a and 32c on the positive side of the switching circuit 31, and the voltage is supplied in the negative direction. When the power is supplied, a voltage is supplied from the capacitor 28 of the voltage doubler rectifier circuit 24 through the transistors 32b and 32d on the negative side of the switching circuit 31. Thereby, when the energization timing signals Ga to Gd are output from the microcomputer 38 to the switching circuit 31 in a predetermined order, the energization of the stator coils 35 and 36 is commutated, and the permanent magnet DC motor 34 is driven.

At this time, the switching circuit 31 is constructed by bridging the four transistors 32a to 32d, so that the cost is reduced unlike the conventional circuit in which the switching circuit is composed of eight switching elements. Will be able to do that.

The two-phase stator coils 35 and 3
6 is conducted through one transistor, unlike the conventional one through two transistors, the loss caused by the residual voltage can be reduced, and the heat generation can be reduced. And reliability can be improved.

In this case, the energization timing signals Ga to Gd are generated based on the position detection signal from the position sensor 37, so that the energization control to the stator coils 35 and 36 can be performed with high accuracy. Become.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The same portions as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, different portions will be described.

In the second embodiment, the position sensor 3
7 based on the position detection signal from
Unlike the first embodiment which is configured to generate a to Gd, a position detection signal is obtained by detecting an induced voltage induced in the stator coils 35 and 36 and electrically processing the detected voltage, thereby energizing the coil. Timing signals Ga to Gd are generated. Specifically, the induced voltage is obtained by comparing the voltage between the terminals of the stator coils 35 and 36 of each phase with the reference voltage, and the position detection signal is obtained at the point where the voltage between the terminals crosses the reference voltage. Is obtained by detecting

According to the second embodiment, the same operation and effect as those of the first embodiment can be obtained, and the position sensor 37 described in the first embodiment can be eliminated. , Cost can be reduced.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. As switching elements, transistors 32a to 32a to
Thyristor, GTO thyristor, MO instead of 32d
An SFET, IGBT, or the like may be used.

[0037]

As apparent from the above description, according to the inverter device of the first aspect, each terminal of the two-phase stator coil of the permanent magnet type DC motor is connected to the output terminal of the switching circuit. Since each other terminal is connected to the common connection point of the two capacitors of the voltage doubler rectifier circuit, when the energization timing signal is given to the switching elements of the switching circuit in a predetermined order, each stator coil is connected to one of the two capacitors. And the permanent magnet DC motor is driven.

At this time, since the switching circuit is constructed by connecting four switching elements in a bridge, the cost can be reduced unlike the conventional one in which the switching circuit is composed of eight switching elements. Become like

Further, since current is supplied to each stator coil through one switching element, unlike the conventional one in which two transistors are used, the loss caused by the residual voltage is reduced. And the amount of heat generated can be reduced, and reliability can be improved.

According to the inverter device of the second aspect,
Since the energization timing signal is generated based on the position detection signal from the position sensor, the energization control for the stator coil can be performed with high accuracy.

According to the inverter device of the third aspect,
Since the energization timing signal is generated based on the induced voltage induced in the stator coil, the position sensor can be dispensed with, and the cost can be further reduced.

[Brief description of the drawings]

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

FIG. 2 is a time chart

FIG. 3 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

In the drawing, 21 is an AC power supply, 24 is a voltage doubler rectifier circuit, 24
a and 24b are AC input terminals, 24c and 24d are DC output terminals, 25 and 26 are diodes (rectifier elements), 27 and 28 are capacitors, 31 is a switching circuit, 31a and 31b are input terminals, 31c and 31d are output terminals. , 32a to 32d are transistors (switching elements), 34 is a permanent magnet type DC motor, 35
And 36 are stator coils, 37 is a position sensor, 38
Is a microcomputer (control means).

Claims (3)

[Claims] 1. An inverter device for driving a two-phase permanent magnet type DC motor, comprising a bridge connection of two rectifying elements and two capacitors, and a voltage doubler having an AC input terminal connected to an AC power supply. It is composed of a rectifier circuit and a bridge connection of four switching elements.
A switching circuit having an input terminal connected to a DC output terminal of the voltage doubler rectifier circuit; and control means for providing an energization timing signal to each switching element of the switching circuit; and a two-phase stator of the permanent magnet type DC motor. Each one terminal of the coil is connected to an output terminal of the switching circuit,
An inverter device, wherein each other terminal of the stator coil is connected to a common connection point of two capacitors of the voltage doubler rectifier circuit. 2. A position sensor for detecting a rotational position of a rotor of a permanent magnet type DC motor, wherein the control means is configured to generate an energization timing signal based on a position detection signal from the position sensor. The inverter device according to claim 1, wherein 3. The inverter device according to claim 1, wherein the control means is configured to generate an energization timing signal based on an induced voltage induced in a stator coil of the permanent magnet type DC motor. .