JP3019858B1 - Motor drive unit, control conversion unit, and air conditioner - Google Patents

Abstract

A motor drive device, a control conversion device, and an air conditioner can be easily manufactured by using an induction motor control means and have high efficiency by using a DC brushless motor. A control converter having a motor command rotation speed detecting means, a magnetic pole position detecting means, and a DC brushless motor control means converts an induction motor control signal of the induction motor control means into a DC brushless motor control signal. The conversion is performed to control the inverter bridge circuit 56 of the DC brushless motor 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor drive, a control converter, and an air conditioner, and more particularly to a motor drive, a control converter, and an air conditioner for controlling the speed of a motor using an inverter bridge circuit. It is suitable for.

[0002]

2. Description of the Related Art In a motor drive control device for controlling the speed of a motor using an inverter bridge circuit, the control method of the inverter bridge circuit differs between a DC brushless motor and an induction motor. The main difference is that the DC brushless motor needs to detect the magnetic pole position of the rotor by the magnetic pole position detecting means and controls using the magnetic pole position detection signal, whereas the induction motor does not need to. That is, different drive signals are required because the conduction patterns of the respective phases of the inverter bridge circuit are different.

[0003] DC brushless motor driving devices include:
For example, as described in JP-B-59-36519, the relative position between the magnet rotor and the armature winding is detected based on the speed electromotive force induced in the armature winding, and the magnetic pole position is detected. Is detected, and rotational speed control is performed using the magnetic pole position detection signal. Specifically, the three-phase speed electromotive force generated in the armature winding is converted into three triangular waveform signals having a phase relationship of approximately 90 degrees with respect to the speed electromotive force through the primary filters, respectively. A semiconductor that forms a triangular wave signal into a star-connected resistor, inputs a neutral point voltage of the star connection and the triangular wave signal to a comparator, and forms an inverter using a pulse signal obtained as an output of the comparator. By controlling the switches, the DC brushless motor is rotated. As shown in this example, a DC brushless motor driving device requires a rotor magnetic pole position detection circuit. The energization pattern of each phase of the inverter bridge circuit in this example is a 120-degree energization method in which two phases out of all three phases are energized.

On the other hand, as an induction motor driving device, for example, as described in Japanese Patent Application Laid-Open No. Sho 61-10968, a so-called V / F constant control for keeping a ratio between an inverter output voltage and a motor rotation frequency constant. Therefore, there is no need to use magnetic pole position detecting means unlike the DC brushless motor driving device. The energization pattern of each phase of the inverter in this example is a 180-degree energization method in which all three phases are always energized. This is because the efficiency is highest when a sine wave voltage is applied to the motor, and the reason is that 180-degree energization is performed to generate the sine wave voltage.

[0005]

The conventional induction motor driving apparatus has a problem that the efficiency of the induction motor is lower than that of the DC brushless motor. For this reason, there is a need to change from manufacturing a conventional induction motor driving device to manufacturing a DC brushless motor driving device. In this case, as described above, since the control method is different between the induction motor driving device and the DC brushless motor driving device, it is necessary to newly design and manufacture the DC brushless motor driving device. If the control means for controlling the bridge circuit also controls devices other than the motor, it is necessary to newly design and manufacture the entire control system, which makes the production of the control system extremely troublesome and costly. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motor drive device, a control converter, and an air conditioner which can be easily manufactured by using an induction motor control means and have high efficiency by using a DC brushless motor.

[0007]

A first feature of the present invention to achieve the above object is that a motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor, and an induction motor control signal. A motor driving device comprising an induction motor control means for outputting and controlling a device other than the motor, wherein the motor is a DC brushless motor, and a control conversion device is provided between the inverter bridge circuit and the induction motor control means. The control conversion device has a motor command rotation speed detection means, a magnetic pole position detection means, and a DC brushless motor control means,
The motor command rotation speed detection means converts an induction motor control signal of the induction motor control means into a motor command rotation speed signal and outputs the signal to the DC brushless motor control means, and the magnetic pole position detection means comprises a DC brushless motor. And outputs a magnetic pole position detection signal to the DC brushless motor control means.The DC brushless motor control means outputs a DC brushless motor control signal based on the motor command rotation speed signal and the magnetic pole position detection signal. The output is output to the inverter bridge circuit.

Preferably, the control conversion means has a structure in which the motor command rotation speed detection means, the magnetic pole position detection means, and the DC brushless motor control means are integrated and mounted on an independent wiring board in a highly integrated manner. is there.

A second feature of the present invention is that a motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor, and a PW signal as an induction motor control signal.
In addition to outputting an M signal, a motor driving device including an induction motor control unit that controls devices other than the motor, wherein the motor is a DC brushless motor, and the motor is connected between the inverter bridge circuit and the induction motor control unit. With the control converter interposed, the control converter has a motor command rotation speed detection unit, a magnetic pole position detection unit, and a DC brushless motor control unit, and the motor command rotation speed detection unit includes a control unit for the induction motor control unit. An integration circuit that integrates a PWM signal as an induction motor control signal to extract a plurality of rotation speed fundamental waves, and compares the plurality of rotation speed fundamental waves to convert them into a motor command rotation speed signal, thereby controlling the DC brushless motor control means. And a magnetic pole position detecting means for detecting the magnetic pole position of the DC brushless motor and detecting the magnetic pole position of the DC brushless motor. A magnetic pole position detection signal is output to a series motor control unit, and the DC brushless motor control unit is configured to output a DC brushless motor control signal to the inverter bridge circuit based on the motor command rotation speed signal and the magnetic pole position detection signal. It is to have done.

[0010] Preferably, the PWM signal as the induction motor control signal is a rectangular wave signal obtained by comparing a carrier wave and a rotation speed fundamental wave, and the integrating circuit is formed of two circuits by a resistor and a capacitor. I did it.

A third feature of the present invention is that a motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor, a three-phase PWM signal as an induction motor control signal, In a motor drive device having an induction motor control means that also controls the device, the motor is a DC brushless motor,
A control converter is interposed between the inverter bridge circuit and the induction motor controller, and the control converter has a motor command rotation speed detector, a magnetic pole position detector, and a DC brushless motor controller, A motor command rotation speed detecting means for integrating a single one of the induction motor control signals of the induction motor control means with different time constants to extract a plurality of rotation speed fundamental waves; A comparator for comparing the wave to a motor command rotation speed signal and outputting the signal to the DC brushless motor control means, wherein the magnetic pole position detecting means detects a magnetic pole position of the DC brushless motor and A magnetic pole position detection signal is output to the brushless motor control means, and the DC brushless motor control means outputs the motor command rotation speed signal and the magnetic pole position detection signal. In that the DC brushless motor control signal was configured to output to the inverter bridge circuit based.

[0012] Preferably, the motor command rotation speed detecting means has a configuration in which a photocoupler is interposed on the input side of the integration circuit.

Preferably, the DC brushless motor control means is configured to detect abnormality of the DC brushless motor or the inverter bridge circuit and output an abnormality signal to the induction motor control means.

A fourth feature of the present invention is that the motor command speed detecting means, the magnetic pole position detecting means and the DC brushless motor control means are provided, and the motor command speed detecting means is a PWM for controlling an induction motor. A signal is converted into a motor command rotation speed signal and output to the DC brushless motor control means.The magnetic pole position detecting means detects a magnetic pole position of the DC brushless motor and outputs a magnetic pole position detection signal to the DC brushless motor control means. The DC brushless motor control means is configured to output a PWM signal for controlling the DC brushless motor based on the motor command rotation speed signal and the magnetic pole position detection signal.

A fifth feature of the present invention is that a refrigeration cycle in which a compressor for refrigerant compression, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected in a ring by a pipe, the indoor heat exchanger and the indoor heat exchanger. A fan that ventilates the heat exchanger, and a motor drive device for driving the compressor, the motor drive device includes a motor having a stator and a rotor, and an inverter bridge circuit that controls the speed of the motor. An air conditioner that outputs a PWM signal for controlling an induction motor and includes an induction motor control unit that also controls a device or a fan that configures a refrigeration cycle excluding the compressor. The motor is a DC brushless motor, a control converter is interposed between the inverter bridge circuit and the induction motor controller, and the control converter is Has a motor command rotational speed detecting means and the magnetic pole position detecting means and the DC brushless motor control means,
The motor command rotation speed detection means converts an induction motor control signal of the induction motor control means into a motor command rotation speed signal and outputs the signal to the DC brushless motor control means, and the magnetic pole position detection means comprises a DC brushless motor. And outputs a magnetic pole position detection signal to the DC brushless motor control means.The DC brushless motor control means outputs a DC brushless motor control signal based on the motor command rotation speed signal and the magnetic pole position detection signal. The output is output to the inverter bridge circuit.

Preferably, the brushless motor control means detects an abnormal stop of the DC brushless motor and outputs an abnormal stop signal to the induction motor control means.
The induction motor control means is configured to control equipment of the refrigeration cycle based on an abnormal stop signal.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a motor drive device, a control converter, and an air conditioner according to the present invention will be described with reference to the drawings. In the drawings of the respective embodiments, the same reference numerals indicate the same or corresponding components, and duplicate description will be omitted.

FIG. 1 is a circuit diagram of a motor driving device showing one embodiment of the present invention. 1 is a DC brushless motor control means comprising a microcomputer or the like, to which magnetic pole position detection signals A, B, C and a motor command rotation speed signal N are inputted,
PWM (Pulse Width Modulation) signals U +, U-,
V +, V-, W +, W- and an abnormal stop signal F are output. Reference numeral 2 denotes a smoothing capacitor of the inverter bridge circuit 56 for smoothing the DC voltage Vd. Reference numeral 3 denotes a rotor of the DC brushless motor 23,
-A together with the DC brushless motor 23. This DC brushless motor 23 is used as a driving device of a compressor in a refrigeration cycle of an air conditioner. 4-
a and b are detection resistors for detecting the DC voltage Vd, and output the divided voltage Vd / 2 to the comparators 8-a, b, and c. 5-a, b, c, d, e, f are freewheeling diodes, 6
Reference numerals a, b, c, d, e, and f denote semiconductor switching elements with control electrodes, which are connected in anti-parallel and are connected in a three-phase bridge to form elements of the inverter bridge circuit 56. Reference numerals 7-a, b, and c denote stator windings of the DC brushless motor, which are three-phase star-connected.

8-a, b, c are comparators, 9-a, b, c
Is a pull-up resistor, and 10-a, b, c, d, e, and f are motor terminal voltage detecting resistors, which are magnetic pole position detecting means 1.
8. Motor terminal voltage detection resistors 10-a, b,
As for c, d, e, and f, two pairs form a stator winding 7-.
a, b, c, and outputs the divided voltage to comparators 8-a,
Output to b and c. The comparators 8-a, b, and c compare the divided voltages of the DC voltage detection resistors 4-a and b with the divided voltages of the motor terminal voltage detection resistors 10-a, b, c, d, e, and f. The result is output to the DC brushless motor control means 1 as magnetic pole position detection signals A, B, and C.

11 is a pull-up resistor, 12 is a comparator, 1
3-a and b are resistors of the integrating circuit, 14-a and b are capacitors of the integrating circuit, 15-a and b are resistors of the integrating circuit, 16-
Reference numerals a and b denote photocouplers, which constitute a motor command rotation speed detecting means 17. This integrating circuit includes a resistor 13-
a, an integrating circuit composed of a capacitor 14-a and a resistor 16-a, a resistor 13-b, a capacitor 14-b and a resistor 1
6-b, and outputs its output signal to the comparator 12. The comparator 12 outputs the comparison result to the DC brushless motor control means 1 as a motor command rotation speed signal N.

Reference numerals 19-a and 19-b denote current limiting resistors on the primary side of the photocoupler, which are connected to the primary sides of the photocouplers 16-a and 16-b. Reference numeral 20 denotes an induction motor control means such as a microcomputer, which receives control signals and the like from an operation switch 61, an indoor temperature sensor 62, and an outdoor temperature sensor 63, which configure the air conditioner device, and configures the air conditioner device. Dehumidifying throttle device 105, four-way valve 151, electric expansion valve 1
53, outdoor fan motor 158, indoor fan motor 15
9 and PWM signals U + ', U-', V for controlling the induction motor.
+ ', V-', W + ', W-' are output. The abnormal stop signal F is input from the DC brushless motor control means 1 to the induction motor control means 20.

Reference numeral 21 denotes a control conversion device from an induction motor to a DC brushless motor, which is a DC brushless motor control means 1 such as a microcomputer, a motor command rotation number detecting means 17, and a magnetic pole position detecting means 18 of the DC brushless motor.
Are integrated and mounted on an independent printed wiring board with high integration.

Vd is the inverter bridge circuit 56
, Vu is the U-phase terminal voltage of the DC brushless motor 23, Vv is the V-phase terminal voltage, Vw is the W-phase terminal voltage, V
c is a control power supply voltage, GND is a circuit ground, and N is an abnormal state signal such as an abnormal stop signal.

Next, a specific operation of the motor driving device will be described.

The DC brushless motor control means 1 to the semiconductor switching element 6 of the inverter bridge circuit 56
a, b, c, d, e, and f as PWM drive signals U
+, U−, V +, V−, W +, W− are output, and the inverter bridge circuit 56 is driven. As a result, the speed of the DC brushless motor 23 is controlled to a predetermined rotation speed. In this state, the terminal voltage of the DC brushless motor 23 is detected by the motor terminal voltage detection resistors 10-a, b, c, d, e, and f of the magnetic pole position detection circuit 18, and the divided voltage is compared with the comparator 8- Input to one of a, b, and c. The DC voltage Vd is detected by the DC voltage detection resistors 4-a, b, and the divided voltage Vd / 2 is compared with the comparators 8-a, b, c.
Is input to the other side. Comparators 8-a, b, and c compare the two divided voltage values, and position detection signals A, B, and C are output to DC brushless motor control means 1. The rotor 3 is connected to the motor terminal of the non-energized phase of the DC brushless motor
The induced voltage generated by the rotation of appears,
1/2 of the motor terminal voltage of this non-energized phase and the DC voltage Vd
By comparing the values, the magnetic pole position detection signals A, B, and C of the rotor 23 are obtained. The DC brushless motor control means 1 refers to these position detection signals A, B, and C, and
The speed of the DC brushless motor is controlled by switching the energized phase at an appropriate timing.

On the other hand, a command speed signal N is input to the DC brushless motor control means 1 as the command speed of the DC brushless motor 23. The command speed signal N is generated by the motor command speed detecting means 17. Resistance 13
-A, b, capacitors 14-a, b, resistors 15-a, b
, The PWM signals U + ', U-', V + ', V-', W + ', W-', U- ', U-', V- ', which are output from the induction motor control means 20, for controlling the induction motor.
Any two of W- 'are input. In this embodiment, the PWM signals U + 'and V +' are configured to be input. Although the PWM signals U + 'and V +' for controlling the induction motor output from the induction motor control means 20 are rectangular waves, they are converted into sine waves according to the rotation cycle of the induction motor by the integration circuit. As a result, a square wave command rotation speed signal N is created. Details of the method of creating the command rotation speed signal N of the rectangular wave will be described later with reference to FIG. The charging time constant of the integrating circuit is set by a combination of the resistor 13-a and the capacitor 14-a and a combination of the resistor 13-b and the capacitor 14-b. Further, the discharge time constant is the resistance 1
5-a and a capacitor 15-a, and a combination of a resistor 15-b and a capacitor 14-b. At this time,
If the charge time constant and the discharge time constant are set differently, the amplitude of the sine wave increases, which is convenient for the comparator 12 to compare the two sine waves. The photocouplers 16-a and 16-b are provided for electrical insulation between the induction motor control means 20 and the DC brushless motor control means 1. If it is not necessary, it may be omitted. Similarly, the resistors 19-a and 19b can be omitted.

According to the motor driving device of the present invention,
The present invention can be easily developed from a motor drive device using an induction motor to a motor drive device using a DC brushless motor. This point will be specifically described with reference to FIGS.

FIG. 2 is a circuit diagram of a conventional induction motor driving device having a general inverter bridge circuit. 22
Is an induction motor whose speed is controlled by an inverter bridge circuit 56. The inverter bridge circuit 56 includes semiconductor switching elements 6-a, b, c, d, e, and
f and the reflux diodes 5-a, b, c, d, e, and f are connected in anti-parallel to form a three-phase bridge connection. The driving signals are PWM signals U + ', U-', V + ', V-',
W + 'and W-' are input. The inverter bridge circuit 56 has the smoothing capacitor 2 but does not have a DC voltage detecting resistor.

FIG. 3 is a circuit diagram of a DC brushless motor driving apparatus according to the present invention, in which the conventional induction motor driving apparatus shown in FIG. 2 is developed. Numeral 24 indicates the position detection signals A, B and C of each phase collectively. In FIGS. 2 and 3, portions related to input and output other than the PWM signal of the induction motor control means 20 are omitted. As is apparent from a comparison between FIG. 2 and FIG. 3, the DC brushless motor driving device of FIG. 3 includes two components of the DC voltage detection resistors 4-a and b and the control converter 21 in the induction motor driving device of FIG. It is added. The DC voltage detection resistors 4-a and 4-b are connected to appropriate places where the DC voltage of the inverter bridge circuit 56 for controlling the induction motor 22 can be detected. In addition, the control conversion device 21
Is connected between the conventional induction motor control means 20 for controlling the induction motor 22 and the inverter bridge circuit 56 for controlling the induction motor 22. By providing the control conversion device 21 as an integrated circuit and providing it as an independent control board, a user of the conventional induction motor driving device can change the DC brushless motor 23 and its control system from the induction motor 22 more easily. be able to.

Next, the process of creating a PWM command signal from the induction motor control means to creating a motor command rotation speed signal N to the DC brushless motor control means will be described with reference to FIG.

FIGS. 4A and 4B are signal waveform diagrams of the motor driving device according to the present invention. FIG. 4A is a waveform diagram for explaining generation of a PWM signal by the induction motor control means, and FIG. FIG. 4C is a waveform diagram illustrating the generation of a motor command rotation speed signal of the motor command rotation speed detection means. FIG. 25 is a carrier for generating a PWM signal of the induction motor control means 20;
6, 27, 28 are the fundamental frequency of the rotation of the induction motor, 29 is a PWM signal for controlling the induction motor, 30 is the commanded rotation number signal of the induction motor, 34 is the center of the amplitude of the fundamental frequency 26 of the rotation of the induction motor. , 35 are rotation frequency fundamental waves 26, 27, 2
8 is the center of amplitude.

PWM signal 2 for controlling the induction motor
9 is obtained by comparing the carrier wave 25 for generating a PWM signal for induction motor control with the fundamental frequency 26 of the rotation speed of the induction motor in the induction motor control means 20. In other words, the result of this comparison is the PWM signal 29. When the carrier 25 is larger than the fundamental frequency 26, the output is OFF, and when the carrier 25 is smaller than the fundamental frequency 26, the output is ON. Therefore, in the PWM signal 29, the on-duty of the PWM signal 29 periodically fluctuates in synchronization with the fundamental frequency of the rotation of the motor. When the PWM signal 29 is input to the CR integration circuit of the motor command rotation speed detecting means 17, a rotation speed fundamental wave 26 from which the carrier wave 25 has been removed can be extracted. The PWM signal 29 is output from the induction motor control means 20 for three phases of U, V and W.
It has a phase difference of degrees. When the rotational frequency fundamental wave of each phase is extracted by the CR integrator, the rotational frequency fundamental waves 26, 27, 2
It looks like 8. These rotation frequency fundamental waves 26, 27, 2
8, two are selected in this embodiment.
By selecting and comparing 6, 27, a rectangular wave signal 30 synchronized with the rotation cycle of the motor is obtained. The DC brushless motor control means 1 uses the rectangular wave signal 30 as a motor command rotation speed signal N, and controls the speed of the DC brushless motor 23 with reference to the motor command rotation speed signal N.

Next, an air conditioner of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a refrigeration cycle configuration of an air conditioner showing one embodiment of the present invention. 101 is a multi-stage bending indoor heat exchanger, 105 is a dehumidifying expansion device, 126 is an indoor auxiliary heat exchanger, 150 is a compressor for compressing a refrigerant whose capacity is variable by controlling the number of revolutions, etc., and 151 is a four-way valve for switching the operation state , 152 are an outdoor heat exchanger and 153 is an electric expansion valve capable of being fully opened without a throttling action, and these are connected in a ring by connecting pipes to constitute a refrigeration cycle.
The compressor 150 is driven by the DC brushless motor 23. An outdoor fan motor 158 drives the outdoor fan. Dehumidifying throttle device 105, four-way valve 151,
The electric expansion valve 153 and the outdoor fan 158 are devices other than the DC brushless motor 23, which are controlled by control signals of the induction motor control means 20, as shown in FIG.

In the refrigeration cycle configuration, when the dehumidifying operation is performed, the operation switch 61 is set to the dehumidifying state and input to the induction motor control means 20, and the output signal of the induction motor control means 20 controls the four-way valve 151. The compressor 150, the four-way valve 151, the outdoor heat exchanger 152, and the electric expansion valve 153 are switched as shown by a dashed line by switching and appropriately restricting the dehumidifying expansion device 105 and fully opening the electric expansion valve 153. , Indoor auxiliary heat exchanger 126, upper front part and rear part of indoor heat exchanger 101, dehumidifying throttle device 1
05, the lower front portion 102 of the indoor heat exchanger 101, the four-way valve 151, and the compressor 150 are circulated in this order, and the outdoor heat exchanger 152 is connected to the upstream condenser, the indoor auxiliary heat exchanger 126, and the indoor heat exchanger 101. The operation is performed such that the upper front part and the rear part become the downstream condenser, and the lower front part of the indoor heat exchanger 101 becomes the evaporator. When the indoor air is flown by the indoor fan as shown by the arrow, the indoor air is cooled and dehumidified in the lower front heat exchanger portion acting as an evaporator, and at the same time, the indoor air becomes a condenser or a heater on the downstream side. The auxiliary heat exchanger 126 and the indoor heat exchanger 101 are heated at the upper front portion and the rear portion, and the air is mixed and blown into the room. In this case, by controlling the capacity of the compressor 150 and the indoor fan and the outdoor fan 158 by the induction motor control means 20, it is possible to change the dehumidification amount and the blown air temperature in a wide range.

When the cooling operation is to be performed, the operation switch 61 is set to the cooling mode and is input to the induction motor control means 20, the dehumidifying throttle device 105 is opened, the electric expansion valve 153 is appropriately throttled, and the refrigerant is drawn by a solid line. By circulating as indicated by the arrows, the indoor heat is cooled using the outdoor heat exchanger 152 as a condenser, the indoor auxiliary heat exchanger 126 and the multi-stage bending indoor heat exchanger 101 as an evaporator.

When the heating operation is to be performed, the operation switch 61 is set to heating and input to the induction motor control means 20, the four-way valve 151 is switched, the dehumidifying throttle device 105 is opened, and the electric expansion valve 153 is appropriately throttled. By circulating the refrigerant as indicated by the dashed arrows, the indoor heating is performed by using the multi-stage bending indoor heat exchanger 101 as a condenser, the indoor auxiliary heat exchanger 126 as a supercooler, and the outdoor heat exchanger 152 as an evaporator. Do.

In the air conditioner, when the induction motor 22 is used as a motor for driving the compressor, the induction motor 22 has a slip in operation, so that the command rotation speed differs from the actual rotation speed. Is set to obtain a predetermined cooling and heating dehumidifying capacity. On the other hand, since the DC brushless motor 23 has no slip, when replacing the drive motor of the compressor from the induction motor 22 with the DC brushless motor 23, the motors before and after the replacement are replaced so that the cooling and heating and dehumidifying capacity of the air conditioner becomes the same. It is necessary to control the actual rotation speeds of the motors to match. Therefore, the induction motor 22
When the command rotation speed of the DC brushless motor 23 is calculated from the command rotation speed 30 of the DC brushless motor 23, the DC brushless motor control means 1 integrates a predetermined proportionality constant with the command rotation speed 30 of the induction motor to obtain an appropriate DC brushless motor. Motor 2
A command rotation speed of 3 is obtained.

In a conventional air conditioner, an inverter control for controlling the speed of a compressor driving motor and a compressor for driving a compressor such as a dehumidifying throttle device, a four-way valve, an electric expansion valve, an indoor fan, an outdoor fan, and the like are provided. It is general that the same microcomputer controls the devices specific to the air conditioner other than the motor. For this reason, in the motor drive device of the present invention shown in FIG. 1 applied to an air conditioner, the induction motor control means 20 controls an air conditioner-specific device other than the compressor drive motor. On the other hand, the DC brushless motor control means 1 serving as an additional circuit mainly controls the DC brushless motor for driving the compressor. Thus, the induction motor control means 2
0 indicates that it is necessary to grasp the operation state of the compressor 150 in order to control the devices specific to the air conditioner.
Since the DC brushless motor control means 1 controls 50, the operation state cannot be directly grasped. Therefore, when the DC brushless motor stops abnormally, for example, the DC brushless motor control means 1 transmits an abnormal stop signal F to the induction motor control means 20 to inform the operating state of the compressor. Thereby, the induction motor control means 20 can take appropriate measures.

Next, a second embodiment of the motor drive device of the present invention will be described with reference to FIG. FIG. 6 is a circuit diagram of a portion for generating a motor command rotation speed signal showing a second embodiment of the motor drive device of the present invention. This embodiment is for obtaining a motor command rotation speed signal from one rotation speed fundamental wave. In this embodiment, P of the induction motor control means 20
The WM signal V + 'is input to each CR integration circuit of the motor command rotation speed detecting means 17. At this time, each integration circuit, that is, the resistor 13-a and the capacitor 14-
a CR integrating circuit, a resistor 13-b and a capacitor 1
The time constant of the CR integration circuit according to 4-b is set differently. In the CR integrator, the larger the time constant is, the larger the amplitude of the sine wave obtained by the integration is.
As shown in (c), two sine wave signals 31 and 32 having different amplitudes are obtained. By comparing these with the comparator 12, a rectangular wave signal 33 synchronized with the rotation cycle of the motor is obtained. This rectangular wave signal 33 is used as a command rotation speed signal N of the DC brushless motor 23. In this embodiment, since the motor command rotation speed signal is obtained from one rotation speed fundamental wave, it can be manufactured more easily.

Next, a third embodiment of the motor drive device of the present invention will be described with reference to FIG. FIG. 7 is a circuit diagram of a portion for generating a motor command rotation speed signal showing a third embodiment of the motor drive device of the present invention. In this embodiment, when it is not necessary to electrically insulate the induction motor control means 20 and the inverter bridge circuit 56, the resistor 15- in FIG.
a, b, the photocouplers 16-a, b and the resistor 19-a are deleted, and the PWM signal V + 'of the induction motor control means 20 is removed.
Is directly input to the resistors 13-a and 13b of the respective CR integrating circuits of the motor command rotation speed detecting means 17.
This integrating circuit, that is, the resistor 13-a and the capacitor 14
The CR integration circuit based on -a and the CR integration circuit based on the resistor 13-b and the capacitor 14-b are set to have different time constants as in FIG. 6, and operate in the same manner as in FIG. Things.

In the present invention, since a DC brushless motor is used, the efficiency can be made higher than when an induction motor is used. A control converter is interposed between the induction motor control means and the inverter bridge circuit. The control converter has motor command rotation speed detecting means, magnetic pole position detecting means, and DC brushless motor control means. The rotation speed detecting means converts the induction motor control signal of the induction motor control means for controlling devices other than the DC brushless motor into a motor command rotation speed signal,
The magnetic pole position detection means detects the magnetic pole position of the DC brushless motor and outputs a magnetic pole position detection signal, and the DC brushless motor control means converts the DC brushless motor control signal based on the motor command rotation speed signal and the magnetic pole position detection signal into an inverter bridge. Output to the circuit, so that the DC brushless motor can be controlled based on the induction motor control signal of the induction motor control means. The control content of the motor control means can be simplified.

Further, the motor command rotation speed detecting means, the magnetic pole position detecting means, and the DC brushless motor controlling means of the control converting means are integrated and mounted on an independent printed wiring board with high integration. With the addition, it is possible to more easily cope with the control of the DC brushless motor.

An integration circuit for integrating the PWM signal as an induction motor control signal of the induction motor control means to extract a plurality of rotation speed fundamental waves;
And a comparator for comparing the plurality of rotation speed fundamental waves, converting them into a motor command rotation speed signal, and outputting the converted signal to the DC brushless motor control means, so that the motor command rotation speed signal can be obtained with a simple configuration. Can be

The motor command rotation speed detecting means includes an integration circuit for integrating one of the induction motor control signals of the induction motor control means with different time constants to extract a plurality of rotation speed fundamental waves. And a comparator for comparing the fundamental frequency of the motor speed to a motor command speed signal and outputting it to the DC brushless motor control means, so that the motor command speed signal can be obtained with a simpler configuration. Can be

Further, since the photocoupler is provided on the input side of the integration circuit of the motor command rotation speed detecting means, electrical insulation between the induction motor control means and the DC brushless motor control means can be achieved.

The brushless motor control means detects abnormal stop of the DC brushless motor, outputs an abnormal stop signal to the induction motor control means, and the induction motor control means controls the equipment of the refrigeration cycle based on the abnormal stop signal. Is controlled, so that the induction motor control means can appropriately cope with an abnormal state of the DC brushless motor driving the compressor.

[0047]

According to the present invention, a motor drive unit, a control converter, and an air conditioner which can be easily manufactured by using the induction motor control means and have high efficiency by using a DC brushless motor can be obtained. .

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a motor drive device showing one embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional induction motor driving device.

FIG. 3 is a circuit diagram of a DC brushless motor driving device according to the present invention.

FIG. 4 is a signal waveform diagram of the motor drive device of the present invention.

FIG. 5 is a diagram showing a refrigeration cycle configuration of the air conditioner showing one embodiment of the present invention.

FIG. 6 is a circuit diagram of a portion for generating a motor command rotation speed signal showing a second embodiment of the motor drive device of the present invention.

FIG. 7 is a circuit diagram of a portion for generating a motor command rotation speed signal showing a third embodiment of the motor drive device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... DC brushless motor control means, 2 ... Smoothing capacitor of inverter bridge circuit, 3 ... Rotor of DC brushless motor, 4-a, b ... DC voltage detection resistance, 5-a,
b, c, d, e, f ... reflux diode, 6-a, b,
c, d, e, f ... semiconductor switching elements, 7-a,
b, c: stator winding; 8-a, b, c: comparator, 9
-A, b, c ... pull-up resistors, 10-a, b, c,
d, e, f: motor terminal voltage detection resistance, 11: pull-up resistance, 12: comparator, 13-a, b: resistance of integrating circuit, 14-a, b: capacitor of integrating circuit, 15-a,
b: resistance of the integration circuit, 16-a, b: photocoupler, 1
7: Motor command rotational speed detecting means, 18: Magnetic pole position detecting means of DC brushless motor, 19: Current limiting resistor on primary side of photocoupler, 20: Induction motor control means such as microcomputer, 21 ... DC brushless from induction motor Control conversion device to motor, 22: induction motor, 23: DC brushless motor, 24: magnetic pole position detection signal for three phases, 25: carrier wave for generating PWM signal for induction motor control, 26, 27, 28 ... W-phase rotation frequency fundamental wave of induction motor, 29 ... PWM signal for controlling induction motor, 30 ... Induction motor command rotation speed signal, 31, 32 ...
Sine wave signal obtained by the integration circuit, 33: commanded rotation speed signal of the induction motor, 34: center of the rotation speed fundamental wave amplitude of the induction motor, 35: rotation speed fundamental wave amplitude of the induction motor and sine wave obtained by the integration circuit Center of signal amplitude, Vd: DC voltage between upper and lower arms of inverter bridge, Vc: Control power supply voltage, GND: Ground of circuit, U +, U-, V +,
V-, W +, W -... Semiconductor switching element drive signal,
A, B, C: magnetic pole position detection signals, Vu, Vv, Vw: motor terminal voltages, N: motor command speed signal, F: DC brushless motor abnormal stop signal.

──────────────────────────────────────────────────続 き Continued on the front page (72) Shigeru Kishi 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside the cooling division, Hitachi, Ltd. (56) References JP-A-6-58599 (JP, A) JP-A Heihei 6-165566 (JP, A) JP-A-6-225578 (JP, A) JP-A-63-209498 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02P 6/04 H02P 7/67-7/80

Claims (10)

(57) [Claims] A motor having a stator and a rotor; an inverter bridge circuit for controlling the speed of the motor;
A motor drive device that outputs an induction motor control signal and includes an induction motor control unit that controls devices other than the motor, wherein the motor is a DC brushless motor, and the inverter bridge circuit and the induction motor control unit are connected to each other. A control conversion device interposed therebetween, wherein the control conversion device has a motor command rotation speed detection unit, a magnetic pole position detection unit, and a DC brushless motor control unit; and the motor command rotation speed detection unit includes the induction motor control unit. Means for converting an induction motor control signal into a motor command rotation speed signal and outputting the signal to the DC brushless motor control means, wherein the magnetic pole position detecting means detects a magnetic pole position of the DC brushless motor and outputs the DC brushless motor control means. Output a magnetic pole position detection signal, the DC brushless motor control means,
A motor driving device for outputting a DC brushless motor control signal to the inverter bridge circuit based on the motor command rotation speed signal and the magnetic pole position detection signal. 2. The control conversion means according to claim 1, wherein the motor command rotation speed detection means, the magnetic pole position detection means and the DC brushless motor control means are integrated and mounted on an independent wiring board in a highly integrated manner. Item 2. The motor drive device according to Item 1. 3. A motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor,
A motor drive device comprising: an induction motor control means for outputting a PWM signal as an induction motor control signal and controlling devices other than the motor; wherein the motor is a DC brushless motor, the inverter bridge circuit and the induction motor control A control conversion device is interposed between the control conversion device and the control conversion device, the control conversion device includes a motor command rotation speed detection unit, a magnetic pole position detection unit, and a DC brushless motor control unit. An integration circuit that integrates a PWM signal as an induction motor control signal of an induction motor control unit to extract a plurality of rotation speed fundamental waves, and compares the plurality of rotation speed fundamental waves to convert them into a motor command rotation speed signal; A comparator for outputting to the DC brushless motor control means, wherein the magnetic pole position detection means Detecting a pole position and outputting a magnetic pole position detection signal to the DC brushless motor control means, wherein the DC brushless motor control means outputs a DC brushless motor control signal based on the motor command rotation speed signal and the magnetic pole position detection signal. A motor drive device for outputting to an inverter bridge circuit. 4. The PWM signal as the induction motor control signal is a rectangular wave signal obtained by comparing a carrier wave and a rotation speed fundamental wave, and the integration circuit is composed of two circuits including a resistor and a capacitor. 4. The motor drive device according to claim 3, wherein: 5. A motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor,
A motor drive device that outputs a three-phase PWM signal as an induction motor control signal and controls induction motors other than the motor; wherein the motor is a DC brushless motor; A control converter is interposed between the induction motor controller and the control converter. The control converter has motor command rotation speed detection means, magnetic pole position detection means, and DC brushless motor control means. An integration circuit that integrates one of the induction motor control signals of the induction motor control means with different time constants to extract a plurality of rotation speed fundamental waves; A comparator that converts the signal into a command rotation speed signal and outputs the command rotation signal to the DC brushless motor control means. A magnetic pole position of the brushless motor is detected, and a magnetic pole position detection signal is output to the DC brushless motor control means.The DC brushless motor control means receives a DC brushless motor control signal based on the motor command rotation speed signal and the magnetic pole position detection signal. Is output to the inverter bridge circuit. 6. The motor drive device according to claim 3, wherein said motor command rotation speed detecting means has a photocoupler interposed on an input side of said integration circuit. 7. The DC brushless motor control means according to claim 1, wherein the DC brushless motor control means detects an abnormality of the DC brushless motor or the inverter bridge circuit and outputs an abnormality signal to the induction motor control means. A motor drive device according to any of the above. 8. A motor command speed detecting means, a magnetic pole position detecting means and a DC brushless motor control means, wherein said motor command speed detecting means outputs a PWM signal for controlling an induction motor to a motor command speed signal. And outputs the DC brushless motor control means, and the magnetic pole position detecting means detects a magnetic pole position of the DC brushless motor, outputs a magnetic pole position detection signal to the DC brushless motor control means, and outputs A control converter, wherein the control means outputs a PWM signal for controlling a DC brushless motor based on the motor command rotation speed signal and the magnetic pole position detection signal. 9. A refrigeration cycle in which a compressor for refrigerant compression, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are annularly connected by piping, and a fan that ventilates the indoor heat exchanger and the indoor heat exchanger. And a motor driving device for driving the compressor, wherein the motor driving device has a motor having a stator and a rotor, an inverter bridge circuit for controlling the speed of the motor, and a motor for controlling the induction motor. P
In the air conditioner that outputs a WM signal and includes an induction motor control unit that controls the fan or a device that configures a refrigeration cycle other than the compressor, the motor for driving the compressor is a DC brushless motor, A control converter is interposed between the inverter bridge circuit and the induction motor controller, and the control converter has a motor command rotation speed detector, a magnetic pole position detector, and a DC brushless motor controller, The motor command rotation speed detection means converts the induction motor control signal of the induction motor control means into a motor command rotation speed signal and outputs the signal to the DC brushless motor control means, and the magnetic pole position detection means
Detecting the magnetic pole position of the DC brushless motor and outputting a magnetic pole position detection signal to the DC brushless motor control means, the DC brushless motor control means based on the motor command rotation speed signal and the magnetic pole position detection signal, An air conditioner that outputs a motor control signal to the inverter bridge circuit. 10. The brushless motor control means detects an abnormal stop of the DC brushless motor and outputs an abnormal stop signal to the induction motor control means, and the induction motor control means determines the abnormal stop based on the abnormal stop signal. The air conditioner according to claim 9, wherein the air conditioner controls a refrigeration cycle device.