TWI227591B - Brushless DC motor control device, control method, control program and recording medium - Google Patents

Abstract

A brushless DC motor control device and a control method are provided. When the brushless DC motor is started up, a position holding current is provides so that the rotor of the brushless DC motor is in a stationary state within a predetermined time. After the position holding current is provided, the position holding current is made to form a circular current. By using the position holding current that flows through a circular current path, a start-up current is provided under a condition that the rotor is in the stationary state. Therefore, the power consumption is reduced and the start up of the brushless DC motor is actually executed.

Description

1227591 V. Description of the invention (1) Field of the invention The present invention relates to a brushless DC motor control device, a control method, a control program, and a recording medium. In particular, it relates to a brushless DC motor technology used in compressors such as air conditioners to reduce the starting current and increase the starting probability. The conventional brushless DC motor control device of the prior art is disclosed in Japanese Patent Application Laid-Open No. 9-3 2 7 1 9 4. The brushless DC motor control device disclosed in Japanese Patent Application Laid-Open No. 9-3 2 7 1 9 No. 4 does not use magnetic pole position detection elements such as Hall elements. Instead, it detects the position of the rotor and uses a non-brush DC motor. The induced voltage of the energized phase (non-energized armature (armature) winding) detects the position of the rotor, and according to the position detected in this way, the energization of the armature winding current of the brushless DC motor is switched. In addition, at the beginning of the start of the brushless DC motor, the induced voltage is not generated because the rotor is stopped, so it must be operated synchronously. More specifically, the conventional brushless DC motor control device described above uses an AC / DC conversion unit to convert an AC power source into a predetermined DC power source. The switching element of the inverter unit is used to switch the DC power source to The brushless DC motor knows the armature winding. When controlling this brushless DC motor, a position detection circuit is set. The position detection circuit compares the terminal voltage of the brushless DC motor with the reference voltage, and uses this comparison result as a position detection signal to output to the control circuit. (Microcomputer).

11170pi f.ptd Page 5 1227591 _ ^ a —- " ^ --- 5. Description of the invention (2) ^ _ This' control circuit is used to digitally process the input position detection signal to switch the brushless DC The drive signal (pWM signal) energized by the motor's electric coil winding current is output to the drive circuit of the brushless DC motor to drive the switching element of the inverter unit. When the above-mentioned conventional brushless DC motor is suitable for a rotary compressor, if the energization of the brushless DC motor is stopped for a short period of time after the rotary compressor is stopped, the brushless DC motor may be affected by the pressure in the rotary compressor. And the reverse rotation occurs, which causes the problem of rotor position deviation. Therefore, it is necessary to grasp the energized phase of the rotor when restarting. When the position holding current used to maintain the rotor's stopping position is supplied to the brushless DC motor, if the position holding current is stopped to reduce power consumption, the brushless DC motor will occur. 'Reverse rotation' creates the problem of rotor position shift. In addition, in order to prevent the rotor position from shifting, when the brushless DC motor is started, the position holding current is continuously supplied and the starting current is supplied. In the CMOS structure transistor connected in series to the inverter, both sides are turned on. Timing. In other words, a through current may flow to damage the transistor, or the protection circuit may operate to cause a failure to start. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a brushless DC motor control device, a control method, a control program, and a recording medium, which can reduce power consumption and reliably perform the startup of a brushless DC motor. To achieve the above and other objectives, the present invention provides a brushless DC (DC) motor control device. The brushless direct current (d C) motor control device includes a rotor position holding portion, a circulating current path forming portion, and a starter.

11170pif.ptd Page 6 1227591 V. Description of the invention (3) Dynamic current supply unit. The rotor position holding portion supplies a position holding current when the brushless DC motor is started to maintain the rotor of the brushless DC motor in a stopped state for a predetermined time. The circulating current path forming unit stops the supply of the position holding current, and then forms a circulating current path from the supplied position holding current. The starting current supply unit maintains the current from the position where the circulating current path flows, and supplies the starting current while the rotor is held in this stopped state. According to the above structure, the rotor position holding portion supplies a position holding current when the brushless DC motor is started to maintain the rotor of the brushless DC motor in a stopped state for a predetermined time. After the circulating current path forming section stops the supply of the position holding current, the circulating position path is formed by the supplied position holding current. Thereafter, the starting current supply unit maintains the current from the position through which the circulating current path flows, and supplies the starting current while the rotor is maintained in the stopped state. In this case, the aforementioned brushless DC motor is three-phase controlled. The rotor position holding portion may further include a first rotor holding portion and a second rotor holding portion. The first rotor holding portion should hold the rotor in a stopped state with the first phase, and supplies a first holding current as a position holding current. The second rotor holding portion should hold the rotor in a second phase different from the first phase in this stopped state, and supply a second holding current as a position holding current. In addition, the effective voltage during position hold can be set lower than the effective voltage at start. In addition, the effective voltage when the position is maintained is set by the duty cycle.

11170pif.ptd Page 7 1227591 V. Description of the invention (4) The present invention further proposes a brushless direct current (DC) motor control method, including: rotor position maintaining step: when starting the brushless DC motor, supplying a position maintaining current, In order to maintain the rotor of the brushless DC motor in a stopped state within a predetermined time; the circulating current path forming step: after the position holding current is stopped, the supplied position holding current is formed into a circulating current path; and the starting current supplying step: The current is maintained by the position flowing through the circulating current path, and the starting current is supplied while the rotor is kept in a stopped state. In this case, the rotor position retaining step may further include: a first rotor retaining step: the rotor should be retained in the stopped state with the first phase, and a first retaining current as a position retaining current is supplied; and a second rotor retaining step: When the second phase different from the first phase should keep the rotor in the stopped state, the second holding current should be held as the position holding current. In addition, the effective voltage during position hold can be set lower than the effective voltage at start. In addition, the effective voltage when the position is held is set by the duty cycle. The invention further provides a control program for controlling a brushless DC (DC) motor, which can be executed by a computer. The control program for controlling the brushless direct current (DC) motor includes: when the brushless direct current motor is started, the position holding current is supplied to maintain the rotor of the brushless direct current motor in a stopped state for a predetermined time; the current is maintained at the position After the supply is stopped, the position holding current is supplied to form a circulating current path; and the position holding current is passed through the circulating current path, and the rotor is maintained at the stopped position.

11170pi f.ptd Page 8 1227591 V. Description of the invention (5) In the stop state, the starting current is supplied. In this case, when the position holding current is supplied, the rotor should be held with the first phase in a stopped state, and the first holding current serving as the position holding current should be supplied; The rotor should be held in the stopped state, and the second holding current should be supplied as the position holding current. In addition, the effective voltage during position hold can be set lower than the effective voltage at start. Each of the above control programs can be recorded and stored in a computer-readable recording medium. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, the preferred embodiments are described below in detail with the accompanying drawings, which are described in detail as follows: Embodiments The following describes the present invention with reference to the drawings. The preferred embodiment. [1] First Embodiment FIG. 1 is a block diagram showing a schematic structure of a brushless DC motor control device of this embodiment. The brushless DC motor control system 100 can be divided into an AC power supply 1, an AC / DC conversion unit, an inverter unit 3, a brushless DC motor 4, a position control circuit 5, a control circuit 6, and a drive circuit 7. AC power supply 1 supplies AC power to the brushless DC motor control system 100 ° AC / DV conversion unit 2 uses the supplied AC power for AC / DC conversion

11170pif.ptd Page 9 1227591

V. Description of the invention (6) Replace and supply the inverter unit. The inverting unit 3 includes TY and TZ. Under the control of the control circuit 6 and the transistors TU, TV, TW, τχ, and the AC / DC conversion unit 2 provided by the deer circuit 7, the inverter unit 3 sources and supplies the brushless DC horse DC The power source is converted into a three-phase driving electric brushless DC motor 4 which is driven by a reverse source. The two-phase drive power supplied by the eye unit 4 is detected by the position detection circuit 5 = the brushless DC motor 4 is not shown: the supply status of the phase drive power, and detection; The rotor position is notified to the control circuit. The control circuit 6 stores the so-called micro-unit according to the ROM not shown in the figure and puts it in the RAM not shown in the figure. An unillustrated microprocessor program temporarily stores various data on the lines notified by the position detection circuit 5 to control the driving of the brushless motor ef, # τπ, and controls the power of the inverter unit 3 under the control of the control circuit 6. ON / ONF of TU, TV, TW, TX, TX, and TZ of the sun and sun. First, before describing the starting control in detail, the general operation of the brushless DC motor control system 100 and the brushless DC motor 4 during general driving will be described. The brushless DC motor control system 100 uses an ac / DC conversion unit 5 to convert the AC power provided by the AC power supply unit 1 into a predetermined DC power. The transistors TU, TV, TW, TX, TY, TZ of the inverter unit 3 are appropriately switched, and this DC power is supplied to the motor winding of the brushless DC motor 4.

1227591 V. Description of the invention (7) f This parallel 'position debt test circuit 5 compares the terminal voltage (induced voltage induced) of the brushless dc motor 4 with a reference level, and uses this result as a position detection signal, Output to control circuit 6. The control circuit 6 digitally processes the input position detection signal, and outputs a drive Λ signal (P W Μ signal) for switching the armature winding current of the brushless DC motor 4 to the drive circuit 7. Thereby, the brushless DC motor 4 is rotationally driven at a predetermined number of revolutions. Fig. 2 is a timing chart at the time of general driving. As shown in FIG. 2, the control circuit 6 turns on the transistor TY through the driving circuit 7 at time t1, and drives the transistor TW by PWM driving. Thereby, the DC power supplied from the A / C conversion unit 2 to the inverter unit 3 is pulse-width-modulated via the transistor tw (PWM: for example, the duty cycle ratio is 5 to 0, and flows to the equivalent of " In contrast, the coil of the brushless DC motor 4 is driven on one side, and the rotor is generally returned to the AC / DC conversion unit 2 via the transistor TY. Xue said that after the time t2 arrives at the stomach, the control circuit 6 sends the Ar / aan "H pass, driving the transistor TY with PM drive. By this, the DC power supplied from the i switching unit 2 to the inverting unit 3 flows through the electric two fTU 'to the brushless DC motor equivalent to the UV phase. The coil of 4 is controlled by the transistor ^ after being adjusted by the pulse width. Then it returns to Lei Yuedao. At time t3, the control circuit 6 turns on the% B through the driving circuit 7 and drives the transistor with PWM driving. TU. With this, you = the DC power supplied by the conversion unit 2 to the inverting unit 3 is wrong, or the coil is equivalent to the UW phase brushless DC motor 4, and the side is 11170pif.ptd. Explanation (8) The drive rotor is generally pulse-width modulated via a transistor TU Return to the AC / DC conversion unit 2. Then, after the time t4, the control circuit 6 turns on the transistor TV via the driving circuit 7, and drives the transistor TZ by PWM driving. Thus, the AC / DC conversion unit 2 is driven. The DC power supplied to the inverter unit 3 flows through the transistor TV to the coil of the brushless DC motor 4 corresponding to the VW phase, while driving the rotor generally through the transistor TZ socks pulse width modulation, and then returns to AC. / DC conversion unit 2 〇 Then, after time t 5, the control circuit 6 turns on the transistor TW via the driving circuit 7 and drives the transistor TX by PWM driving. This supplies the AC / DC conversion unit 2 to the inverter The DC power of unit 3 flows through the transistor TW to the coil of the brushless DC motor 4 corresponding to the UW phase. While driving the rotor, the pulse width is generally adjusted via the transistor TX, and then returns to the AC / DC conversion unit. 2. At this point, one cycle of the brushless DC motor is ended. Then, at time t7, the transistor TY is turned on again through the driving circuit 7 and the transistor TW is driven by PWM driving. Hereinafter, the brushless DC is repeatedly performed by the same process. Motor 4 Drive Next, the starting control of the brushless DC motor will be described. Fig. 3 is a timing chart during the start control of the first embodiment. In addition, Fig. 4 is a processing flowchart during the start control of the first embodiment. As shown in FIG. 3, the control circuit 6 turns on the transistor TY via the driving circuit 7 at time 11 1 and drives the transistor TW by PWM driving. As a result, the DC power supplied from the AC / DC conversion unit 2 to the inverter unit 3 , The pulse width modulation (PWM: Example

11170pif.ptd Page 12 1227591 V. Description of the invention (9) If the duty cycle ratio is 25 [%]) and flows to the coil of the brushless DC motor 4 corresponding to the v W phase, the rotor is generally driven by a transistor τγ returns to AC / DC conversion unit 2. Thereby, the rotor of the brushless DC motor 4 is fixed at a predetermined position (step S1). After the time 112, the control circuit 6 keeps the transistor TY on through the driving circuit 7, and turns off the transistor TW. As a result, the diode Dz is turned on, and a circulating current flows through the transistor τγ to the coil of the brushless DC motor 4 corresponding to the vw phase, and the rotor is held in a fixed position (step S2). The circulating current of the coil of the brushless DC motor 4 starts to become smaller due to the impedance component of the motor coil as shown in FIG. 5. When the circulating current flowing through the coils of the brushless DC motor 4 reaches the minimum current that can keep the rotor in a fixed position, the time before the time TL, the time before the time TL, the time before the time 11 M, the control circuit 6 passes the transistor through the driving circuit 7 τζ is turned on and the transistor TU is driven by P ^ ίΜ. As a result, the DC power supplied from the AC / DC conversion unit 2 to the inverter unit 3 is pulse-width modulated (PWM) via the transistor TU and flows to the coil of the brushless DC motor 4 corresponding to the phase phase. The one-side driving rotor generally returns to the AC / DC conversion 2 via a transistor τζ. (Step S3). After that, the rotor position is detected, and the brushless "motor 4 moves to one and drives. After time t 丨 3, it enters the same general driving operation as after time t3 in Figure 2 (step S4). In the above description, according to the first embodiment, the current required to maintain the position of the rotor is passed as a circulating current.

11170pif.ptd Page 13 1227591 V. Description of the invention (ίο) Start control is performed, so it will not cause the position of the rotor to shift and can start reliably. In addition, when the position of the rotor is fixed, since the through current does not flow through the transistor of the CMOS structure constituting the inverting unit 3, the problem that the transistor cannot be started because the transistor is damaged or the protective circuit of the transistor operates can be prevented. In this case, in the PWM control when the rotor position is fixed, the control is performed at a duty cycle ratio smaller than the duty cycle ratio of the PWM control at the time of starting, so the power consumption can be reduced. [2] Second embodiment In the first embodiment described above, the rotor position fixing process is performed only once. However, occasionally, in the positional relationship between the rotor and the stator, it may stop at a stable position in mechanics, and there may be a situation where the start control cannot be started (the energized phase that cannot be started). The second embodiment is an embodiment in which the brushless DC motor is started more reliably, and the rotor is fixed at a plurality of positions where the current is different from each other. Fig. 6 is a timing chart in the start-up control of the second embodiment. In addition, FIG. 7 is a flowchart of processing in the start control of the second embodiment. As shown in FIG. 6, the control circuit 6 turns on the transistor TY through the driving circuit 7 at time t 2 1 and drives the transistor TW by PWM driving. As a result, the DC power supplied from the AC / DC conversion unit 2 to the inverter unit 3 is pulse-width-modulated when the rotor position is fixed via the transistor TW (PWM: for example, the duty cycle ratio is 5 [%]), And it flows to the coil of the brushless DC motor 4 corresponding to the VW phase, while driving the rotor generally returns via the transistor TY

11170pif.ptd Page 14 1227591 V. Description of the invention (11) AC / DC conversion unit 2. Iksan ^ The rotor of the brushless DC motor 4 that you borrowed was fixed to be mechanically stable at the first booking, and the position of Λ and the stator is related to the position of the driver called 〇 starting (unrotatable) (step S 1 1 ).

% ii, VJLplu ^, the control circuit 6 sets the transistor TU unit 2 佴 U to the driving transistor TY via the driving circuit 7. Here, the DC power supply from AC / DC conversion = 5 / to the inverting unit 3 is passed through the transistor TU, L 丨 L to the phase § The benefit of the UV phase brush D Γmin, yl ΛΑ ^ ^ ^ … Den U U ^ The coil of the motor 4 drives the rotor two 一边 J transistor TY, is pulse width modulated (PWM, for example, the working week ratio is 5 [%]), and then returns to the AC / DC conversion unit 2 . Thereby, the rotor of the brushless DC motor is fixed at the second predetermined position (: ^ 12). That is, in the step S11, even if the rotor stops at a position where the positional relationship between the rotor and the stator is mechanically stable and cannot be started (cannot be turned), it can be fixed to the startable position. When the stomach reaches time t23, the control circuit 6 turns on the transistor 711 via the driving circuit 7 and turns off the transistor 1 ^. As a result, the diode DV becomes conductive, and the current flows to the brushless motor corresponding to the uw phase through the transistor Tϋ, and the rotor is held in a fixed position (step § 丨 3). ^ Afterwards _ ′ The circulating current flowing through the coil of the brushless DC motor 4 is as shown in Figure 5 ^, and it starts to decrease due to the impedance component of the motor coil. When the circulating current flowing through the coil of the brushless DC motor 4 reaches the minimum current Imin that can keep the rotor in a fixed position at time t24 before time TLIM, the control circuit 6 conducts the transistor τν through the drive circuit 7 and PWM drive transistor TZ. As a result, the DC power supplied from the AC / DC conversion unit 2 to the inverting unit 3 flows through the transistor TV to the equivalent

Page 15 1227591 V. Description of the invention (12) The coil of the brushless DC motor 4 of the VW phase, while driving the rotor and a furnace of fine crystal TZ, is pulse-width modulated (PWM), and returns to AC / DC vibration (Step S14). , Early Fan 2. After that, the rotor position is detected and driven like a brushless DC motor. After time t 2 4, it enters the same general driving operation as that of time 2 in FIG. 2 (step s5). As described above, according to the second embodiment, the rotor is maintained at a predetermined position, and the current required to maintain the rotor as a circulating current flows through it. Causes the position of the rotor to be shifted, and it is possible to say "externally" as in the first embodiment when the position of the rotor is fixed. This current does not flow through the transistor of the CMOS structure constituting the inverting unit 3, so as to prevent the problem that the transistor can be started because the transistor is damaged or 99-'of the transistor. Operation without 4 ί ί In the PWM control when the rotor position is fixed, the duty cycle of the PWM control at start-up is still smaller ′ Because the control is performed, the power consumption can be reduced. [3] The duty cycle ratio is [3] A modified example of the embodiment. The above description is based on the use of a brushless DC motor for the r i: sub ’, but it is not limited to this. Need to use: various machines from the electrical situation to 25, such as fan horse 4: R η μ reached from the description of the description, the control program is stored in the control circuit for processing. However, it is also possible to store the control program in a hard disk, a removable recording medium, an I c card, and other recording media, and then read it out.

1227591 V. Description of Invention (13), or you can also download the control program through the Internet. According to the present invention, the effect of reducing power consumption can be achieved, and the brushless DC motor can be surely started. In summary, although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Retouching, so the scope of protection of the present invention shall be determined by the scope of the attached patent application.

11170pif.ptd Page 17 1227591 Brief description of the diagram Brief description of the diagram The first diagram is a schematic block diagram of the brushless DC motor control device of the present embodiment, and the second diagram is a timing diagram of a general drive; the third diagram It is a timing chart at the time of starting control of the first embodiment; FIG. 4 is a processing flowchart at the time of starting control of the first embodiment; FIG. 5 is an explanatory diagram of a bad current, and FIG. 6 is an example of the second embodiment. A timing chart at the time of starting control; and FIG. 7 is a flowchart of processing at the time of starting control of the second embodiment. Description of figure numbers 2 AC / DC conversion unit 3 Inverter unit 5 Position detection unit 6 Control circuit

11170pi f.ptd Page 18

Claims (1)

No. 92107fi (^ 6. The scope of the patent application. 1. A brushless direct current (DC) motor control device, comprising:… holding portion 'at the start of a brushless DC motor, in a predetermined time, the brushless straight M motor The rotor is kept in a stopped state; 4 1 = the flow path forming part is in; the position holding current is stopped to supply J '; and then the position holding current supplied is formed into a circulating current path and supplied with a dynamic current supply part, and the current is held by the household. And flow at that position of the transition current path. ， 'Qτ stop the evil, supply power together 2 · If the patent control scope of the patent application No. 1 control device, 1 哕 辕,;' ”, brushed direct current (DC) motor ΐ 2: The sub-position holding part further includes · Holding the rotor, # to be a first holding current that should be maintained and maintained in the stopped state; a second rotor holding portion should be maintained in the stopped state, The first phase is different from one of the second phase and the second holding current ^^ is supplied as the position holding current 3 · As described in the patent application (DC) motor control device, item 2 or item 2 The brushless DC is set to be lower than the effective voltage when the effective position is maintained at start-up. 4. The control device is the brushless direct current (DC) motor described in item 3 of the patent application. /, ^ The effective voltage during the setting hold is based on the duty cycle 11170pifl.ptc Page 19_No. 92107608__August + Revision 6 'Application Patent Scope 5 · A brushless direct current (DC) motor control method, including: Rotor position maintaining step in a brushless DC When the motor is started, a position holding current is supplied to maintain a rotor of the brushless DC motor in a stopped state for a predetermined time; 时间 内 / a circulating current path forming step, after the position current is stopped at the position 'The position holding current supplied again forms a circulating current and': the starting current supplying step, from the current bit j flowing through the circulating current path, while the rotor is maintained in the stopped state, the motion control 6 is supplied. ^ ^ ^ The brushless DC pump motor described in item 5 of the patent scope "", the rotor position maintaining step further includes: maintaining ::; turn: ":: step" with a first phase in the It should flow in the stopped state; with 丨 仏 ', "Therefore, one of the holding currents at this position is the first holding electric phase at 1 T T holding step of the rotor •' to be different from the-phase-the--phase is V In the stop state, the second holding current should be guaranteed. , Q for A 仏 for the position holding electric (DC) motor control 'J: dry brushless DC as described in item or item 6 is set to be lower than the effective voltage at startup; the effective voltage when the position is maintained is set to 8 · As stated in the patent control method, the bit, 'right brushless direct current (DC) motor is set. The effective voltage is based on the duty cycle. 11170pifl.ptc Page 20 A control circuit of a computer-readable DC motor brushless DC motor-a brushless DC motor will be stopped for a predetermined time; the current is maintained at this position to stop the flow of a circulating current path. The circulating current path is supplied in the stopped state. As recorded in the 9th patent application, it is used to control the brushless current to control the current, so that the current is maintained at 10, including 4 n a. + To control the non-type, which can be executed by a computer, the control program used includes: 'starting to supply a position-maintaining electric δ 1 brushless DC motor rotor protection, and then supply the position protection; and " The current is maintained at this position, and the current is driven together at the rotor. The computer-readable recording medium described in the item controls the direct current (DC) motor control program. When the current is maintained at this position, a first phase should be applied below. Hold the rotor, supply the sacrifice sacrifice, supply, and the uncle maintain the first current for this position, and the two phases should be maintained in this stopped state. One of the second holding currents. The effective voltage when the computer is readable as described in item 10 is set to be low to hold the rotor in one of the phases different from the first phase, and the supply is maintained as the position 11 · For example, the recording medium in the scope of patent application No. 9 or above, in which the effective voltage at that time remains at the starting point. Page 21