JP6537716B2 - Motor drive device, motor and air conditioner - Google Patents

Description

  The present invention relates to an electric motor provided with a substrate on which circuit components are mounted, an electric motor drive device for driving the electric motor, and an air conditioner provided with the electric motor.

  As a motor for driving a fan mounted on an indoor unit or an outdoor unit of an air conditioner, Patent Document 1 below describes pulse width modulation (Pulse Width Modulation: hereinafter referred to as “Hall IC, inverter IC, and switching element of inverter IC A configuration is disclosed that includes a drive circuit board on which a microcomputer, which is control means for performing "PWM", is mounted. A sine wave signal is required to PWM control the switching element of the inverter IC. When the control of the motor is realized by a microcomputer, in the conventional air conditioner, the value of the sine wave signal is read as table data and stored in a dedicated memory (Read Only Memory: hereinafter referred to as “ROM”).

JP, 2014-230363, A

  As described above, in the prior art, when the control of the motor is realized by a microcomputer, it is necessary to store the value of the sine wave signal in the ROM as table data. In this case, a large amount of ROM capacity is required, resulting in an increase in cost and size. The same table data is also required when the control of the motor is realized by a dedicated IC (hereinafter referred to as "control IC"), and the same type of problem occurs.

  The present invention has been made in view of the above, and it is possible to reduce the size of a table that holds signal values necessary for generating a PWM signal, and to suppress an increase in cost and an increase in size. The purpose is to obtain an air conditioner.

  In order to solve the problems described above and achieve the object, a motor drive device according to the present invention includes a drive element for applying a drive voltage to the motor and a control element for generating a PWM signal for controlling the drive element. The control element generates a PWM signal using a waveform using a linear function and a quadratic function.

  According to the present invention, it is possible to reduce the size of a table holding signal values necessary for generating a PWM signal, and it is possible to suppress an increase in cost and an increase in size.

Sectional view of a motor according to an embodiment An external view showing an air conditioner equipped with a motor according to an embodiment Plan view of the circuit component disposed on the drive circuit board of the embodiment as viewed from the non-load side Plan view of the circuit component disposed on the drive circuit board of the embodiment as viewed from the load side A partial cross-sectional view of a portion of the drive circuit board of the embodiment on which the power IC is mounted Block diagram showing an electrical connection relationship of drive circuit components of the embodiment A circuit diagram showing an internal configuration of a power IC according to an embodiment Block diagram showing the internal configuration of the control IC in the embodiment A block diagram showing an internal configuration of the pseudo sine wave generation unit shown in FIG. 8 A diagram for explaining the shape of the pseudo sine wave waveform Graph showing change of harmonic content rate when using pseudo sine wave FIG. 9 is a block diagram showing an internal configuration of a quadratic function value calculation unit shown in FIG. 9 Diagram illustrating the generation method when generating a quadratic function value using counter output Side surface sectional view showing another example of the motor according to the embodiment A plan view of the circuit component disposed on the drive circuit board shown in FIG. 14 as viewed from the non-load side A plan view of the circuit components disposed on the drive circuit board shown in FIG. 14 when viewed from the load side The figure which shows an example in case the drive circuit component which drives an electric motor is not incorporated in an electric motor.

  Hereinafter, a motor drive device, a motor and an air conditioner according to an embodiment of the present invention will be described in detail based on the drawings. The present invention is not limited by the following embodiments.

Embodiment.
FIG. 1 is a cross-sectional view of a motor according to the present embodiment. FIG. 2 is an external view showing an air conditioner equipped with the motor according to the present embodiment.

  The air conditioner 300 shown in FIG. 2 includes an indoor unit 300a and an outdoor unit 300b connected to the indoor unit 300a. An indoor unit fan (not shown) is mounted on the indoor unit 300a, and an outdoor unit fan 310 is mounted on the outdoor unit 300b. The electric motor 100 shown in FIG. 1 is used as a drive source of these fans. Although FIG. 2 exemplifies an air conditioner as an application example of the motor according to the present embodiment, the invention is not limited to the air conditioner, and various electric motors such as a blower, a ventilation fan, a machine tool, etc. It can be applied to equipment.

  Next, the configuration of motor 100 according to the present embodiment will be described. As shown in FIG. 1, the motor 100 is configured to have a mold stator 1, a rotor assembly 18 and a bracket 25 as main components. As the motor 100, a brushless DC motor driven by an inverter is exemplified.

  A shaft 10 serving as a rotation shaft of the motor 100 penetrates through a central portion of the rotor assembly portion 18. The load of the motor 100 is mounted on the shaft 10 of the motor 100. In the case of the air conditioner shown in FIG. 2, a fan for the indoor unit or a fan 310 for the outdoor unit is mounted as a load.

  The mold stator 1 is formed in a cylindrical shape centering on the shaft 10, and is composed of a stator assembly 3 and a mold resin portion 2 filled with a mold resin.

  The stator assembly 3 is a component of the motor 100, in which the stator 5, the drive circuit board 4 and the connector 6 are integrally formed. A Hall IC 21 which is a surface mounting component, a power IC 22 and a control IC 23 are mounted on the drive circuit board 4. Hereinafter, the circuit components mounted on the drive circuit board 4 will be appropriately referred to as "drive circuit components". The drive circuit board 4 is sealed integrally with the stator 5 with a mold resin. Thereby, the heat dissipation of the power IC 22 mounted on the drive circuit board 4 is improved, and the maximum output of the power IC 22 is improved. Moreover, the loss of the electric motor 100 is reduced by the heat dissipation of the power IC 22 being improved. However, since the drive circuit board 4 and the like have a weak structure, low-pressure molding is preferable, and unsaturated polyester is used as a mold resin used for the mold resin portion 2 for integrally molding the drive circuit board 4 and the stator 5. Thermosetting resins such as resins are preferred. The details of the drive circuit component will be described later.

  The mold resin portion 2 constitutes the outer shell of the motor 100 and constitutes the housing 19 on the side surface of the substrate of the mold stator 1. The housing 19 surrounds and supports the outer ring of the load side bearing 16.

  An opening provided on the mold resin portion 2 on the side opposite to the side (hereinafter referred to as “load side”) on which a load such as a fan is mounted (right hand side in FIG. 1, hereinafter referred to as “anti-load side”) A mortar-shaped recess 26 is provided, which is formed to be able to accommodate the rotor assembly 18 from the portion 29 into the mold stator 1. The opening 29 is a portion where the bracket 25 is provided in FIG. The bracket 25 is manufactured, for example, by pressing a conductive metal.

  The stator 5 is composed of a winding 7, a stator core 8 and an insulator 9. The stator core 8 is formed by punching, caulking, and welding electromagnetic steel plates having a thickness of about 0.1 to 0.7 mm. It is laminated and manufactured by adhesion etc. The band-like stator core 8 includes a plurality of teeth (not shown), and the insulators 9 are applied to the teeth. The insulator 9 is molded integrally with or separately from the stator core 8 using, for example, a thermoplastic resin such as polybutylene terephthalate (hereinafter referred to as "PBT"). The concentrated winding 7 is wound around the teeth to which the insulator 9 is applied. When the plurality of concentrated windings 7 are connected, for example, a three-phase single Y-connection winding is formed. However, it may be a distributed winding.

  The rotor assembly portion 18 is a component of the motor 100 in which the rotor 15, the load side bearing 16 and the non-load side bearing 17 are combined.

  The rotor 15 is disposed so as to face the stator iron core 8 and provided on the shaft 10, an annular rotor insulating portion 12 provided on the outer peripheral portion of the shaft 10, and the outer periphery of the rotor insulating portion 12 The rotor magnet 13 is a permanent magnet, and the position detection magnet 11 is provided between the rotor magnet 13 and the drive circuit board 4 in the axial direction of the shaft 10.

  The rotor 15 is rotatable about the shaft 10, obtains rotational force by the rotating magnetic field from the stator core 8, transmits torque to the shaft 10, and directly or indirectly connects the load to the shaft 10. To drive.

  The rotor insulating portion 12 is provided to insulate the shaft 10 from the rotor magnet 13 and to insulate the shaft 10 from the stator core 8. The rotor magnet 13, the shaft 10 and the position detection magnet 11 are integrally formed by a rotor insulating portion 12 which is injected by a vertical molding machine. A thermoplastic resin is used for the rotor insulating portion 12. Examples of the thermoplastic resin include PBT and polyphenylene sulfide (hereinafter referred to as “PPS”), but those obtained by blending a glass filler with these PBT or PPS are also suitable. Rotor insulator 12 constitutes a dielectric layer.

  For the rotor magnet 13, a resin magnet, a rare earth magnet, or a ferrite sintered magnet formed by mixing a thermoplastic resin and a magnetic material is used. The rare earth magnet is exemplified by neodymium or samarium iron.

  In the axial direction of the shaft 10, the load side bearing 16 is attached to the load side (left side in FIG. 1) of the shaft 10, and the anti-load side bearing 17 is attached to the non-load side (right side in FIG. 1). The shaft 10 is rotatably supported by the load side bearing 16 and the non-load side bearing 17.

  The load-side bearing 16 is, for example, a ball bearing, and an inner ring 16a that rotates integrally with the shaft 10, an outer ring 16b fitted on the inner peripheral surface of the housing 19, and a plurality of rotations disposed between the inner and outer rings. It comprises a moving body 16c, a lubricating oil (not shown) for rolling the rolling elements 16c for lubrication, and a seal plate (not shown) for sealing the lubricating oil. The inner ring 16a, the outer ring 16b, the rolling elements 16c and the seal plate are generally made of a conductive metal such as iron. The seal plate is fixed to the outer ring 16b and rotates with the outer ring 16b. The seal plate is electrically connected to the outer ring 16b but not in contact with the inner ring 16a.

  The non-load side bearing 17 is also configured similarly to the load side bearing 16. The constituent elements of the non-load side bearing 17 are also the same as or equivalent to the constituent elements of the load side bearing 16, and the detailed description will be omitted.

  When the rotor assembly 18 is inserted into the recess 26 from the opening 29 of the molded stator 1, the load side bearing 16 attached to the shaft 10 is incorporated into the housing 19. Then, one end of the shaft 10 on the load side bearing 16 side penetrates the housing 19, and the above-described fan or the like is attached to the shaft 10. On the other hand, when the non-load side bearing 17 is attached to the other end of the shaft 10 and the bracket 25 is press-fit to the inner peripheral portion of the mold resin portion 2 and fitted so as to close the opening 29, The non-load side bearing 17 is incorporated inside.

  The drive circuit board 4 is formed with a through hole 8 a penetrating the shaft 10 and the load side bearing 16. The drive circuit board 4 in which the through holes 8 a are formed is held by the insulator 9. The drive circuit board 4 is disposed between the load side bearing 16 and the winding 7 in the axial direction of the shaft 10, and is disposed perpendicularly to the axial direction. Here, the term "perpendicular" does not have to be 90 degrees with respect to the axial direction of the shaft 10, and may be deviated from 90 degrees.

  Next, details of the drive circuit components mounted on the drive circuit board 4 will be described with reference to the drawings of FIGS. 3 to 7. FIG. 3 is a plan view of the circuit components disposed on the drive circuit board 4 shown in FIG. 1 when viewed from the non-load side. FIG. 4 is a circuit diagram of the circuit components disposed on the same drive circuit board 4 on the load side It is a top view at the time of visual recognition from. FIG. 5 is a partial cross-sectional view of a portion of the drive circuit board 4 on which the power IC 22 is mounted. FIG. 6 is a block diagram showing the electrical connection of drive circuit components. FIG. 7 is a circuit diagram showing an internal configuration of the power IC 22. As shown in FIG.

  As shown in FIG. 3, the Hall IC 21, the power IC 22, and the control IC 23 are mounted on the non-load side of the drive circuit board 4, that is, the stator 5 side. The Hall IC 21 is a magnetic pole position sensor for detecting the rotational position of the rotor 15, and is typically a Hall element. The control IC 23 is a control element that generates a PWM signal for PWM control of the power IC 22 based on the detection information of the Hall IC 21. The power IC 22 is a drive element for applying a drive voltage to the winding 7 of the stator 5, and is mounted on the drive circuit board 4 via the heat dissipation pattern 30 which is a first heat dissipation pattern as shown in FIG. . The power IC 22 shown in FIG. 3 is a surface mount type, and can be mounted together with the Hall IC 21 and the control IC 23 in a single-sided reflow process. Also, the power IC 22 and the control IC 23 can be integrally formed as a drive IC.

  On the load side of the drive circuit board 4, as shown in FIG. 4, a heat radiation pattern 32 which is a second heat radiation pattern for radiating heat generated by the power IC 22 is provided. As shown in FIG. 5, the power IC 22 and the heat radiation pattern 32 are injected with a heat radiation pattern 30 formed of a metal having a high thermal conductivity and a metal having a high thermal conductivity to facilitate transfer of the heat generated in the power IC 22. Are connected through the through holes 34. Copper, silver, etc. are illustrated as a metal with high heat conductivity. The positions of the connector 6, the Hall IC 21, the power IC 22 and the control IC 23 shown in FIGS. 3 to 5 are merely an example, and it goes without saying that other arrangements are also permitted.

  The Hall IC 21 mounted on the drive circuit board 4, the power IC 22, and the control IC 23 are connected as shown in FIG. 6 to drive the motor 100. More specifically, the magnetic pole position signal, which is a signal including the position information of the rotor 15 detected by the Hall IC 21, is input to the control IC 23. The control IC 23 is also provided with a rotational speed command (also referred to as a “rotational speed command”) for commanding the rotational speed of the rotor 15. The control IC 23 generates a PWM signal for controlling the power IC 22 based on the magnetic pole position signal from the Hall IC 21 and the rotation speed command from the outside, and applies the PWM signal to the power IC 22.

  The power IC 22 includes an inverter circuit 114 and an arm drive circuit 116 as shown in FIG. The inverter circuit 114 is configured by bridge connection of switching elements 114 a to 114 f of three pairs of upper and lower arms for driving the three-phase winding 7 (see FIG. 1) in the motor 100. Of switching elements 114a to 114f, switching elements 114a and 114d constitute upper and lower arms of U phase, switching elements 114b and 114e constitute upper and lower arms of V phase, and switching elements 114c and 114f represent upper and lower arms of W phase Configure.

  The connection point between the switching elements of the upper and lower arms is drawn out as an AC end and connected to the stator. On the other hand, the connection point between the upper arms and the connection point between the lower arms are drawn out as a DC end and connected to the rectifier circuit 112. The rectifier circuit 112 converts the AC voltage of the commercial power source 110 into a DC voltage and applies the DC voltage to the inverter circuit 114. Control IC 23 generates PWM signals for PWM driving of switching elements 114 a to 114 f of the upper and lower arms, and outputs the PWM signals to arm drive circuit 116. The arm drive circuit 116 is provided with an upper arm drive circuit 116a that drives the switching elements 114a to 114c of the upper arm, and a lower arm drive circuit 116b that drives the switching elements 114d to 114f of the lower arm. The upper arm drive circuit 116 a and the lower arm drive circuit 116 b drive the switching elements to be driven based on the PWM signal. By driving the switching elements 114a to 114f, the DC voltage from the rectifier circuit 112 is converted to an AC voltage of variable frequency. The converted AC voltage is applied to the winding 7 through the winding terminal 24 (see FIG. 1) that electrically connects the drive circuit board 4 and the winding 7, and the motor 100 is driven. The power IC 22 and the control IC 23 described above may be configured as a motor drive device for driving the motor 100.

  Next, the configuration, operation, and effects of main parts of motor 100 according to the present embodiment will be described with reference to the drawings in FIGS. 8 to 13. FIG. 8 is a block diagram showing the internal configuration of control IC 23 in the present embodiment, FIG. 9 is a block diagram showing the internal configuration of pseudo-sine wave generation unit 50 shown in FIG. FIGS. 11A and 11B are graphs showing changes in harmonic content when a pseudo sine wave is used, and FIG. 12 is a graph showing the quadratic function shown in FIG. FIG. 13 is a block diagram showing an internal configuration of the value calculation unit 54, and FIG. 13 is a diagram for explaining a generation method when generating a quadratic function value using a counter output.

  As shown in FIG. 8, the control IC 23 includes a pseudo sine wave generation unit 50 and a PWM signal generation unit 70. The pseudo sine wave generation unit 50 generates a pseudo sine wave to be described later and outputs the pseudo sine wave to the PWM signal generation unit 70. The magnetic pole position signal from the Hall IC 21 is input to the PWM signal generation unit 70. Further, inside the PWM signal generation unit 70, a carrier wave synchronized with the magnetic pole position signal is generated. The PWM signal generation unit 70 generates a PWM signal for PWM control of the switching elements 114 a to 114 f by comparing the pseudo sine wave and the carrier wave. The PWM signal generation method is known, and further detailed description is omitted here.

  As shown in FIG. 9, the pseudo-sine wave generation unit 50 includes a linear function value calculation unit 52, a quadratic function value calculation unit 54, and a function value selection unit 56. The linear function value calculation unit 52 generates an output value that increases or decreases in proportion to the elapsed time, that is, a linear function value, and outputs the generated output value to the function value selection unit 56. The quadratic function value calculation unit 54 generates an output value having a relationship of a quadratic function with respect to the elapsed time, that is, a quadratic function value, and outputs the generated value to the function value selection unit 56. The function value selection unit 56 receives the primary function value and the secondary function value, selects one of them, and outputs it to the outside.

  In FIG. 9, the output of the function value selection unit 56 is a pseudo sine wave value. That is, the pseudo sine wave value is an output value in which one of the primary function value generated by the primary function value calculation unit 52 and the secondary function value generated by the secondary function value calculation unit 54 is selected.

  As the linear function value calculation unit 52, a counter is exemplified. The counter can be realized by counting the number of clock pulses used in the calculation process and setting the counted value as an output value. The configuration of the quadratic function value calculator 54 will be described later.

  In FIG. 10, the appearance of the waveform generated by the pseudo sine wave generation unit 50 is shown. In FIG. 10, the waveform indicated by the thick solid line is the waveform of the quadratic function generated by the quadratic function value calculating unit 54, and the waveform indicated by the thick broken line is the waveform of the linear function generated by the linear function value calculating unit 52.

That is, the waveform shown in FIG. 10 has the first feature shown below.
(A) A pseudo sine wave is generated with a constant angle before and after zero crossing as a linear function and the others as a quadratic function.

  According to the first feature, since the pseudo sine wave can be generated by a simple function of a linear function and a quadratic function, a PWM signal can be generated using a waveform using the linear function and the quadratic function. As a result, the circuit scale of the control IC can be reduced, and an effect of suppressing an increase in cost and an increase in size can be obtained. Further, when a microcomputer is used instead of the control IC, the ROM capacity can be reduced, so that the same effect as the control IC can be obtained.

The waveform shown in FIG. 10 has the second feature shown below.
(B) The slope of the linear function is "1" or "-1", that is, the absolute value of the slope of the linear function is "1".
(C) Of the switching points when the linear function and the quadratic function are switched, the derivative of the quadratic function in the C and F parts is "1", and the derivative of the quadratic function in the D and E parts Is "-1". That is, the absolute value of the derivative of the quadratic function at the switching point when the linear function and the quadratic function are switched becomes "1" equal to the absolute value of the slope of the linear function.
(D) The absolute value of the peak of the quadratic function (hereinafter referred to as "peak value") is "1".

  When a waveform having a peak value other than “1” is required as the pseudo sine wave, the value of the normalized waveform shown in FIG. 10 may be multiplied by a scale factor to obtain a desired peak value. For example, when a waveform having a peak value of "3" is required, the entire output value of the waveform shown in FIG. 10 may be tripled.

  According to the second feature, since the pseudo sine wave can be generated by a simple function of a linear function and a quadratic function, a PWM signal can be generated using a waveform using the linear function and the quadratic function. As a result, the circuit scale of the control IC can be reduced, and an effect of suppressing an increase in cost and an increase in size can be obtained. Further, when a microcomputer is used instead of the control IC, the ROM capacity can be reduced, so that the same effect as the control IC can be obtained.

The waveform shown in FIG. 10 has the third feature shown below.
(E) The angle when switching from a linear function to a quadratic function and a quadratic function to a linear function (hereinafter referred to as "switching angle") is arbitrary using any real number α greater than 0 ° and smaller than 90 ° It is set as follows.
(I) When the value of the pseudo sine wave is positive: Switching angle from linear function to quadratic function: α
・ Switching angle from quadratic function to linear function: 180 ° -α
(Ii) When the value of the pseudo sine wave is negative: Switching angle from linear function to quadratic function: 180 ° + α
・ Switching angle from quadratic function to linear function: 360 ° -α

  That is, when α is any real number greater than 0 ° and less than 90 °, the waveform of the pseudo-sine wave is a linear function to a quadratic function when α and 180 ° + α are in the range of 0 ° to 360 °. Switching to a linear function from a quadratic function at 180 ° -α and 360 ° -α.

  According to the third feature, in FIG. 10, the waveform is point-symmetrical with respect to a point having an angle of 180 °, and is symmetrical with respect to a straight line passing through the angles 90 ° and 180 ° and parallel to the vertical axis. Because of the waveform, as shown in FIG. 11 described later, it is possible to generate a pseudo-sine wave having a small harmonic content.

  FIG. 11 shows the change in the harmonic content with the switching angle α as a parameter. In FIG. 11, the solid line represents total harmonic distortion (hereinafter referred to as "THD"), and the one-dot chain line represents the third harmonic distortion (hereinafter referred to as "third distortion"). The two-dot chain line represents the distortion factor of the fifth harmonic (hereinafter referred to as "fifth-order distortion factor"). The broken line represents the largest distortion, that is, the third distortion and the fifth distortion represent the larger distortion. The THD, the third-order distortion factor, and the fifth-order distortion factor are index values that represent the degree of distortion of the signal. THD is the ratio of the entire harmonic component to the fundamental wave component, the third-order distortion factor is the ratio of the third-order harmonic component to the fundamental wave component, and the fifth-order distortion factor is the fifth-order harmonic component It is a ratio to the fundamental wave component.

  When the motor 100 is a three-phase motor, it is a preferred embodiment to set α within the range of 25.5 ° to 34 ° in the waveforms having the first to third features.

  When α is set in the range of 25.5 ° to 34 °, the third-order distortion factor is less than 1%, as shown in FIG. In particular, in the case of a three-phase motor, it is known that the third noise is likely to occur. For this reason, in the case of a three-phase motor, if α is set to 25.5 ° to 34 °, driving is performed with a pseudo-sine wave having a small third harmonic, and an effect of reducing noise can be obtained.

  In the waveforms having the first to third features, it is also a preferable embodiment to set α within the range of 27 ° to 31.5 °.

  When α is set in the range of 27 ° to 31.5 °, THD is less than 1%, as shown in FIG. For this reason, if the motor is driven using a pseudo sine wave in which α is set in the range of 27 ° to 31.5 °, noise other than the third harmonic is reduced in addition to the above-described effects of the three-phase motor. In addition, the effect of improving the operating efficiency is obtained.

  Also, in the case where the motor is a motor having a (N × 5) pole magnet (N is a natural number) in the rotor (hereinafter referred to as “5N pole motor”), α is set in the range of 13 ° to 22.5 ° Is a preferred embodiment.

  When α is set in the range of 13 ° to 22.5 °, the fifth-order distortion factor is less than 0.36%, as shown in FIG. In particular, in the case of the 5N pole motor, it is known that the fifth order noise is likely to occur. For this reason, in the case of a 5N pole motor, if α is set to 13 ° to 22.5 °, driving is performed with a pseudo sine wave having few fifth harmonics, and an effect of reducing noise can be obtained.

  The quadratic function value calculation unit 54 can be realized by the counter 54a, the adder 54b, and the delay unit 54c as shown in FIG. The counter 54a counts the number of clock pulses and outputs it to the adder 54b. The first output value, which is the output value of the adder 54b, is delayed by the delay unit 54c and then returned to the adder 54b. The second output value delayed by the delay unit 54c is sequentially added to the output value of the counter 54a, that is, the first output value in the adder 54b, and is again input to the delay unit 54c. At this time, as shown in the lower part of FIG. 13, when the value of the pseudo sine wave is in the positive range, the counter output value which is the output value of the counter 54 a counts down, and the value of the pseudo sine wave is negative. In the range of, the counter output value outputs a value that is counted up. As a result, it is possible to generate a waveform shown in the upper part of FIG. 13 in which the zero crossing point of the counter output value is the peak value of the pseudo sine wave.

  According to the configuration shown in FIG. 12, since no multiplier is used, calculation time can be shortened. Therefore, when the control of the motor is realized by the control IC, an effect that the circuit scale of the control IC can be reduced can be obtained. When the control of the motor is realized by a microcomputer, the calculation time can be shortened, so that an expensive microcomputer can be eliminated. In the case of control of a motor, it is sufficient to use a sine wave value of successive angles. For example, if the angular resolution is 1 °, 360 ° in the order of 1 ° pseudo sine wave value, 2 ° pseudo sine wave value, 3 ° pseudo sine wave value, ..., 360 ° pseudo sine wave value Generate pseudo-sine wave values up to As described above, the method of generating a pseudo-sine wave value according to the present embodiment is useful for a motor provided with a substrate on which circuit components are mounted, and in particular, a blower motor for an outdoor unit and an indoor unit of an air conditioner. And it is suitable to use for a compressor motor in an outdoor unit of an air conditioner.

  The configuration shown in the above embodiment shows an example of the content of the present invention, and can be combined with another known technique, and a configuration without departing from the scope of the present invention It is also possible to omit or change part of.

  For example, FIG. 14 is a side cross-sectional view showing another example of the motor according to the present embodiment, and FIG. 15 is a circuit component disposed on the drive circuit board 4 shown in FIG. FIG. 16 is a plan view of the case, and FIG. 16 is a plan view of a circuit component disposed on the drive circuit board 4 shown in FIG. 14 as viewed from the load side. Although in FIG. 1 the power IC 22 which is a surface mount component is mounted on the non-load side, as shown in FIGS. 14 and 16, the power IC 27 which is a lead type component is mounted on the load side. It goes without saying that a motor having such a configuration is also included in the scope of the present invention. In the case of a lead type power IC, only the power IC disposed on the load side can be mounted in a single-sided flow process.

  FIG. 17 is a diagram showing an example where the drive circuit component for driving the motor 100 is not incorporated in the motor 100, and the drive circuit component is mounted on the indoor unit board 320 in the indoor unit 300a shown in FIG. Is shown. A power IC 22 and a control IC 23 are mounted on the indoor unit substrate 320. The magnetic pole position signal from the Hall IC 21 is input to the control IC 23. The control IC 23 generates a PWM signal for controlling the power IC 22 based on the magnetic pole position signal from the Hall IC 21 and the rotation speed command from the outside, and applies the PWM signal to the power IC 22. The subsequent operation is as described above, and the detailed description is omitted here.

  Further, although the control with the magnetic pole position sensor including the Hall IC has been described in the present embodiment, it is needless to say that the present invention can be applied to so-called sensorless control without the magnetic pole position sensor such as the Hall IC.

  DESCRIPTION OF SYMBOLS 1 mold stator, 2 mold resin part, 3 stator assembly part, 4 drive circuit board, 5 stator, 6 connector, 7 windings, 8 stator iron core, 8a through hole, 9 insulator, 10 shaft, 11 position detection Magnets, 12 rotor insulation parts, 13 rotor magnets, 15 rotors, 16 load side bearings, 16a inner ring, 16b outer ring, 16c rolling elements, 17 non-load side bearings, 18 rotor assembly parts, 19 housings, 21 holes IC (magnetic pole position sensor), 22 power IC (drive element: surface mount component), 23 control IC (control element), 24 winding terminal, 25 bracket, 26 recess, 27 power IC (drive element: lead type component), 29 opening, 30 heat radiation pattern (first heat radiation pattern), 32 heat radiation pattern (second heat radiation pattern), 34 through holes Reference Signs List 50 pseudo sine wave generation unit, 52 linear function value calculation unit, 54 quadratic function value calculation unit, 54a counter, 54b adder, 54c delay unit, 56 function value selection unit, 70 PWM signal generation unit, 100 motor, 110 commercial Power supply, 112 rectification circuit, 114 inverter circuit, 114a to 114f switching element, 116 arm drive circuit, 116a upper arm drive circuit, 116b lower arm drive circuit, 300 air conditioner, 300a indoor unit, 300b outdoor unit, 310 fan, 320 Indoor unit board.

Claims (10)

A motor drive device for driving a motor, comprising:
A drive element for applying a drive voltage to the motor;
A control element that generates a PWM signal for controlling the drive element;
Equipped with
The motor drive device wherein the PWM signal is generated using a waveform using a linear function and a quadratic function. In previous KIHA form,
The absolute value of the slope of the linear function is 1,
The absolute value of the derivative of the quadratic function at the switching point when the linear function and the quadratic function switch is 1,
The motor drive device according to claim 1, wherein an absolute value of a peak of the quadratic function is one.   3. The motor drive device according to claim 2, wherein when the peak uses a waveform other than 1, a multiplier for multiplying the entire waveform to a desired peak value is multiplied. Let α be any real number greater than 0 ° and less than 90 °
Before KIHA type, switching from the primary function when the alpha and 180 ° + alpha to the quadratic function, according to claim 1, from the quadratic function at 180 °-.alpha. and 360 °-.alpha. switched to the linear function The motor drive device according to any one of to 3. The motor is a three-phase motor,
The motor drive device according to claim 4, wherein the α is set in a range of 25.5 ° to 34 °.   The motor drive device according to claim 4, wherein the α is set in a range of 27 ° to 31.5 °. When N is a natural number, the motor is a 5N pole motor,
The motor drive device according to claim 4, wherein the α is set in a range of 13 ° to 22.5 °.   The value of the quadratic function is generated by sequentially adding a first output value which is an output value of a counter and a second output value obtained by delaying the output value of the counter. The motor drive device according to any one of the above.   A motor comprising the motor drive device according to any one of claims 1 to 8.   An air conditioner equipped with the motor according to claim 9.

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