JP2002101686A - Brushless motor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor device provided with a brushless motor of higher performance at a low cost and the drive device. SOLUTION: In the brushless motor device provided with a rotor 11 having permanent magnets 11a-d, a brushless motor part M provided with a stator 12 having a three-phase winding and a drive device part D, induction voltage generated between the phases of the three-phase winding by the rotation of the rotor 11 in the brushless motor 10 is constituted to be in the form of a sine wave different in a phase every 120 degrees. The drive device is provided with a function energizing voltage V1 flowing sine wave current larger than induction voltage V0 between the phases of the three-phase windings and different in the phase of 120 degrees on the windings of each phase U, V, W respectively by timing of 180 degrees by the on-off control of switching elements Y1-T6 of an inverter part 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor having a rotor having permanent magnets and a stator having three-phase windings, and a brushless motor device having a driving device for driving the brushless motor. It is.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing a configuration of a conventional brushless motor device. As shown, the brushless motor device includes a brushless motor unit M and a drive unit D. The brushless motor unit M includes a brushless motor 10. The brushless motor 10 has a permanent magnet 11
a, 11b, 11c, 11d
And a stator 12 having windings 12u, 12v, and 12w, and a stator core (not shown) arranged on the outer periphery of the rotor 11. The drive unit D includes an inverter unit 21,
Switching control unit 22, magnetic pole position signal processing unit 23, rotation speed control unit 24, current detection unit 25, and converter unit 26
Is provided.

The timing of energizing each of the windings 12u, 12v, 12w is determined by a magnetic pole position sensor 13 comprising a Hall element or the like for detecting the magnetic pole position of the rotor 11 at a predetermined position.
2A, the magnetic pole position signal waveforms Hu, Hv, and Hw of the rotor 11 as shown in FIG. 2A are detected, and the rotor pole signal signals Hu, Hv, and Hw are used as shown in FIG. A switching output signal having a conduction timing of 120 degrees with respect to the induced voltage generated by the eleven permanent magnets 11a, 11b, 11c, and 11d is formed, thereby driving the switching elements T1 to T6 of the inverter unit 21 in FIG. . That is, a 120-degree energization method with two simultaneously energized phases was used.

For detecting the magnetic pole position of the rotor 11 in the above-described energizing method, the magnetic pole position sensor 13 composed of a Hall element or the like is used as described above, or an induced voltage generated during rotation of the rotor 11 is applied. A switching drive signal having an energization timing as shown in FIG. 2 (b) is formed by detecting from a winding having no phase and performing signal processing to drive the switching elements T1 to T6 of the inverter unit 21 on and off.

FIGS. 2C and 2D show a winding terminal voltage waveform and a winding current waveform during operation of the brushless motor 10, respectively. As is apparent from the figure, there is a problem that the winding current waveform during energization is not a sine wave but an M-shaped waveform, resulting in a low power factor. 2 (c) and FIG.
(D) shows the terminal voltage waveform and the winding current waveform of the U-phase winding 12u. The terminal voltage waveform and the winding current waveform of the V-phase and W-phase windings 12v and 12w are also about 120 degrees. The shape of the waveform is the same except for the phase difference. The brushless motor device having the above configuration has the following problems.

In order to detect the magnetic pole position of the rotor 11,
Since the magnetic pole position sensor 13 needs to be provided, the cost of the magnetic pole position sensor 13 itself is required.
It was necessary to restrict the installation environment of No. 3.

[0007] The type in which an induced voltage is detected without providing a magnetic pole position sensor to determine the energization timing and driven is as follows.
A complicated circuit for processing a signal for determining a phase to be energized was required. These have a problem that the cost and the driving circuit are complicated and cause a failure.

In the 120-degree rectangular wave energization system, as described above, the energization current has an M-shaped waveform as shown in FIG. 2D, and more iron loss occurs due to high frequency components, and the power factor is poor. Since a large amount of current needs to flow, copper loss increases, and there is a limit to further improving the efficiency.

[0009] The generated torque includes a ripple. This ripple has been a problem in obtaining high-precision motor characteristics in rotation control and position control applications.

The permanent magnets 11a, 11b of the rotor 11,
The magnetic field directions of 11c and 11d are arranged equally, whereas the number of simultaneously energized phases of the stator poles at the time of 120 degree energization is
Therefore, in a three-phase winding, there is also a disadvantage that, when energized, the magnetic pole generation position is not at the same distribution pole, so that the demagnetizing action is strong and the permanent magnet of the rotor is easily demagnetized. It also includes torque ripple.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a brushless motor which is inexpensive and has a higher performance and a brushless motor device having a driving device therefor.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a brushless motor having a rotor having permanent magnets and a stator having three-phase windings, and each winding of the brushless motor. A brushless motor device comprising a driving device including a switching element for energizing a wire and a control unit for controlling on / off of the switching element, wherein the brushless motor is an induction motor generated between each phase of a three-phase winding by rotation of a rotor. The voltage is configured to be a sine wave having a different phase by 120 degrees, and the driving device is larger than the induced voltage V0 between the phases when the rotor rotates at the operating frequency f0 between the phases of the three-phase winding. In addition, a voltage V1 in which sinusoidal currents having phases different from each other by 120 degrees are applied to the windings of each phase at a timing of 180 degrees is turned on and off of the switching element. Characterized by including the ability to more energized.

As described above, the driving device is configured such that the induced voltage V0 between the phases when the rotor rotates at the operation frequency f0 between the phases of the three-phase windings is larger than the induced voltage V0 between the phases and the windings of the respective phases have a phase difference of 120 degrees. Is applied by the on / off control of the switching element by applying a voltage V1 at which a sinusoidal current different from that at 180 ° is applied, and the state becomes an additional excitation state, and the generated torque is larger than the normally obtained torque. In addition, since a sinusoidal current is applied to the windings of each phase, unlike the conventional 120-degree rectangular wave energization method, the high-frequency component is small, iron loss is small, and the power factor is improved. The efficiency is improved because the loss is reduced. Further, since there is no need to provide a magnetic pole position sensor for detecting the magnetic pole position of the rotor, there is no need to consider the installation environment of the magnetic pole position sensor.

According to a second aspect of the present invention, in the brushless motor device according to the first aspect, the brushless motor has 2n rotor magnetic poles and 3n or 6n rotor poles (n = 1, 2, 2).
(3,...) Are provided with stator pole teeth having salient pole concentrated windings.

As described above, since the stator magnetic pole teeth having 2n rotor magnetic poles and 3n or 6n salient-pole concentrated windings are provided, the induced voltage generated between the phases of the three-phase winding is 120 degrees. Each phase becomes a sine wave having a different phase, and additional exciting torque can be generated by the saliency and the additional exciting action.

The third aspect of the present invention is the first or second aspect.
In the brushless motor device described in the above, the driving device,
The brushless motor is characterized in that it has a function of gradually increasing the drive voltage and the drive frequency after a DC current is passed through the winding for a predetermined time when the brushless motor is started.

As described above, when the brushless motor is started, a direct current is supplied to the windings for a predetermined time, whereby the magnetic pole alignment of the rotor of the brushless motor is surely completed, and thereafter the drive voltage and the frequency are gradually increased (soft start). ), The rotation of the rotor with respect to the drive frequency is not synchronized, that is, the motor is accelerated without so-called step-out, and the rated operation can be started.

The invention described in claim 4 is the first or second invention.
In the brushless motor device according to the third aspect, the driving device includes current detection means for detecting a current flowing in a winding of the brushless motor, and a step out of synchronization between the driving frequency and the rotation of the rotor during the driving of the brushless motor. Occurs, and when the energizing current becomes larger than the energizing current in the normal operation, a function of lowering the drive frequency or stopping energization is provided.

When the energizing current becomes larger than the energizing current in the normal operation as described above, the drive frequency is lowered to avoid out-of-step or to stop the energization, so that the brushless motor is out of step. Can be protected from

The invention described in claim 5 is the first or second invention.
Or the brushless motor device according to 3, wherein the driving device includes means for monitoring a current flowing in each phase and a phase of the voltage by a voltage applied between the phases of the brushless motor, and a phase difference between the current and the voltage is provided. It is characterized in that it has a function of controlling the phase by increasing or decreasing the applied voltage so as to approach a preset target value.

Since the brushless motor has the characteristic that the phase of the applied current fluctuates according to the increase or decrease of the applied voltage, the current applied to each phase of the brushless motor and the phase of the voltage are changed as described above. Monitor,
By increasing or decreasing the applied voltage so that the phase difference between the current and the voltage approaches a preset target value, it becomes possible to operate with a phase difference between the current and the voltage close to the target value.

According to a sixth aspect of the present invention, in the brushless motor device according to the fifth aspect, the driving device does not approach the target phase difference even if the applied voltage is repeatedly increased and decreased by the phase control, Is larger than a predetermined set value, step-out is determined, and the drive frequency is lowered or the energization is stopped.

As described above, if the applied voltage does not approach the target phase difference even if the applied voltage is repeatedly increased and decreased by the phase control, and if the current value is larger than the predetermined set value, it is determined that the step-out occurs and the drive frequency is decreased. Or by stopping the energization,
The step-out state of the brushless motor can be reliably detected, and the step-out state can be avoided or stopped.

[0024] The invention according to claim 7 provides the invention according to claims 1 to 6.
In the brushless motor device according to any one of the above, the driving device, when the output current exceeds a predetermined value in driving the brushless motor, the driving frequency such that the product of the output current and the driving frequency is constant Is provided with a function of controlling

As described above, when the output current exceeds a predetermined value, the driving frequency is controlled so that the product of the output current and the driving frequency becomes constant. It is possible to protect the motor by limiting the load applied to the brushless motor without using complicated means such as power detection.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing a configuration of a main part of the brushless motor according to the present invention, and FIG. 4 is a diagram showing a connection state of windings thereof. The stator 12 has magnetic pole portions U ₁ , U ₂ , V ₁ , V ₂ , W ₁ , and 6 of a 6-slot stator core 14.
W ₂ winding 12u ₁ by the salient pole concentrated winding in, 12u _2, 12
v ₁ , 12v ₂ , 12w ₁ , and 12w ₂ are wound. A U-phase winding by connecting the windings 12u ₂ wound on the winding 12u ₁ and the magnetic pole U2 wound poles U1 in series, wound on winding 12v ₁ and the magnetic pole V2 wound poles V1 and V-phase windings and a winding 12v ₂ connected in series, the magnetic poles W1
Wound windings 12w ₁ and wound around the magnetic pole W2 winding 12
w ₂ are connected in series to form a W-phase winding. And U
The phase winding, the V phase winding, and the W phase winding are connected in a star connection.

A rotor 11 having permanent magnets 11a, 11b, 11c and 11d provided on the outer periphery at the center of the stator core 14
Place. Here, an isotropic bonded magnet ring (magnet formed into a ring shape in which magnetic particles are solidified with resin) is used.
The poles are magnetized. As a result, the U-phase winding (winding 1) caused by the rotation of the rotor 11 due to the isotropic magnetic characteristics.
2u ₁ and 12u ₂ ), V-phase winding (windings 12v ₁ and 12
v ₂ ), the induced voltage waveform generated in the W-phase winding (windings 12w ₁ and 12w ₂ ) is sinusoidal.

The rotor 11 is not limited to the above-described structure, and a fan-shaped permanent magnet segment may be attached, skewed,
The induced voltage generated in the winding when the rotor rotates can be made to have a sine wave shape by a configuration such as an embedded type inside the rotor or a device on the stator winding side. It should be noted that the brushless motor is not limited to the above configuration, but has 2n rotor poles and 3n or 6n rotors (where n = 1, 2, 3, 3).
..) Having a stator magnetic pole tooth having a salient pole concentrated winding.

Further, the salient pole concentrated winding can minimize the coil end size and reduce the amount of windings to be used as apparent from FIG. 4, so that Joule heat, which is generated when current flows, so-called copper loss. In addition to the effect of reducing the power consumption, it is possible to save labor in the operation of attaching the windings to the stator core at the time of manufacturing, and to obtain a low-cost brushless motor.

FIG. 5 is a diagram showing the main configuration of the brushless motor device according to the present invention. As shown in the figure, the driving device section D includes an inverter section 21, a converter section 26, a current detection section 27, a voltage detection section 28, a frequency / voltage control section 29, and an output section 30. The inverter unit 21 includes six semiconductor switching elements T1 to T6. The generated voltages have a phase of 120 degrees between the U phase and the V phase, between the V phase and the W phase, and between the W phase and the U phase. The conduction current is 180
The sinusoidal current is supplied at the right timing.

Here, a magnetic pole position sensor 13 and a magnetic pole position signal processing unit 23 and a rotational speed control unit 24 for forming an inverter switching drive signal as shown in FIG.
Without providing a current detection unit 27 and a voltage detection unit 28 for detecting the current and voltage of each phase, and using the output thereof, a frequency / voltage control unit 29 via a switching control unit 22 to control each semiconductor switching element of the inverter unit. The brushless motor 10 is rotationally driven by controlling on / off of T1 to T6. FIG. 6A is a waveform of an applied voltage of the brushless motor 10 output from the driving device, FIG. 6B is a diagram showing currents Iu, Iv, Iw of the respective phases, and FIG. FIG. 3 is a diagram illustrating a positional relationship between a winding magnetic pole and a rotor 11.

FIGS. 6 (b) to 6 (c)
Corresponding to Sinusoidal currents Iu and I shown in FIG.
With respect to v and Iw, the rotor 11 continuously rotates as shown in FIG.

The salient pole concentrated winding has the following characteristics. As the load increases during rotation in the state shown in FIG. 6, a gap is gradually formed between the rotor magnetic pole of the brushless motor 10 and the magnetic pole formed on the stator magnetic pole teeth. Here, in the case of the present embodiment, the rotor 11
By applying a voltage V1 that is higher than the induced voltage V0 generated in the winding due to the rotation of, additional excitation occurs, and the generated torque is larger than the normally obtained magnet torque. Although a ring magnet is used for the rotor 11 here, the salient polarity and the additional exciting action reduce the additional exciting torque due to the salient polarity and the additional exciting action because the stator is shaped so that the magnetic pole teeth have salient polarity by salient pole concentrated winding. This is because it has occurred.

FIG. 7 is a diagram showing the states of the magnet torque, the additional excitation torque, and the total torque. In the figure, the vertical axis shows the torque value, and the horizontal axis shows the current phase. As shown
An additional excitation torque B is generated with respect to the magnet torque A, whereby a total torque C is obtained. Superposition of reluctance torque on the saliency of the rotor has been conventionally known,
Here is the application.

The salient polarity of the magnetic pole teeth in the salient pole concentrated winding according to the present invention is, as shown in the shape of the stator core 14 in FIG. 6C, the slot opening smaller than the size G0 of the magnetic gap between the stator core 14 and the rotor 11. The size G1 of the portion is increased.

Next, the actual driving operation will be described.
When the rotor 11 of the brushless motor having the configuration shown in FIG. 3 is rotated by external power, the induced electromotive force causes the winding 12u ₁ ,
It occurs at 12u ₂ , 12v ₁ , 12v ₂ , 12w ₁ , 12w ₂ . FIG. 8 shows measured data of the relationship between the rotation speed and the generated voltage (referred to as V / f rate). The data shown in FIG. 8 indicates that an induced voltage V0 is obtained when the rotor 11 rotates at the rated frequency f0. From the obtained data, a voltage V1 slightly larger than the induced voltage V0 is determined as the applied voltage. In this embodiment, the voltage V0 at the rated point
(The ratio of the voltage V1 to the voltage V0 is referred to as an applied voltage constant).

At the time of starting, if the drive voltage and frequency are gradually increased (soft start) at this V / f rate, the rotation of the rotor with respect to the drive frequency is out of synchronization. it can. At this time, the magnetic pole formed on the stator winding and the rotor magnetic pole are synchronized by the soft start, and the motor can be operated without step-out. However, in order to perform more reliable synchronization at the start, the soft start is performed in the present embodiment. Before starting, a one-way DC current is applied to the motor winding for a predetermined time. Thereby, the rotor 11 of the brushless motor
Is reliably completed, and the motor is reliably accelerated in the subsequent soft start.

At this time, the applied voltage V1 is changed to the induced voltage V0.
The number of times (hereinafter referred to as the applied voltage constant) may be determined in consideration of the balance between the desired torque and the obtained power factor.

If the applied voltage constant is always constant with respect to the load factor of the motor as shown in FIG. 8, the operation with a necessary balance can be performed. As shown in FIG. 9, the load in the present embodiment has a characteristic that the torque rises at a rotation speed of 2500 min ^-1 . Therefore, if a voltage whose applied voltage constant at the rotation speed is increased to 1.4 times in advance is applied, It can be driven without step-out for the increased torque.

The drive unit D shown in FIG. 5 has the following features. As shown in FIG. 5, means for constantly monitoring the phase of the voltage and current supplied to the brushless motor 10 and controlling the phase based on signals obtained from the current detection unit 27 and the voltage detection unit 28, that is, frequency / voltage control Part 2
9 are provided. This is because the phase difference with the energizing current varies depending on the increase or decrease of the voltage applied to the brushless motor 10. According to this, the phase difference is a preset phase, and in this embodiment, the phase difference is 90% (phase difference). None is 100
%).

Further, the brushless motor 10
If an unexpected increase in the load occurs during the operation, the applied phase and / or frequency may be increased or decreased repeatedly for a predetermined period of time several times to approach the preset target phase difference. If not, and if the current exceeds the predetermined allowable current value, this state is determined to be out of step, and the drive of the brushless motor 10 is stopped. In this embodiment, the rated current is 2
Since an overcurrent value of 50% is detected, twice the rated current is set as the reference value.

When the step-out is confirmed, the operation of the brushless motor 10 is stopped. Thereafter, the same start is automatically or manually performed to restart the operation. In this embodiment, the step-out described above is determined again even if the restart is performed in this way, and the operation is automatically repeated three times. If the engine still does not start, the automatic restart is stopped and the output is stopped. An alarm is output from the unit 30.

In the present invention, the following functions can be provided. As shown in FIG. 10, when the brushless motor 10 exceeds a predetermined current value for some reason during operation, the frequency is detected, and the driving frequency is reduced so that the product with the current value is constant. . As a result, a constant output characteristic region where the output becomes substantially constant can be provided, and the load applied to the brushless motor 10 can be limited to protect the motor. This eliminates the need for complicated means such as power detection.

[0044]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first and second aspects of the present invention, when the rotor is rotated between the phases of the three-phase winding at the operating frequency f0, the induced voltage V0 between the phases is larger than that of the three-phase winding. 180 sinusoidal currents, each with a 120 degree phase difference
By applying the voltage V1 flowing at the timing of
Unlike the conventional 120-degree rectangular wave energization method, the high-frequency component is small, the occurrence of iron loss is small, and the power factor is improved, so that the copper loss is reduced and the efficiency is improved. Further, since there is no need to provide a magnetic pole position sensor for detecting the magnetic pole position of the rotor, it is not necessary to consider the installation environment of the magnetic pole position sensor at a lower cost.

According to the third aspect of the present invention, a direct current is applied to the windings for a predetermined time when the brushless motor is started, so that the magnetic pole alignment of the rotor of the brushless motor is surely completed, and thereafter the drive voltage is gradually increased. By increasing the frequency (soft start), the rotation of the rotor with respect to the drive frequency is out of synchronization, so that acceleration can be performed without so-called step-out, and the rated operation can be started.

According to the fourth aspect of the present invention, when the energizing current becomes larger than the energizing current in the normal operation, the drive frequency is lowered to avoid step-out or to stop energizing. In addition, the step-out operation of the brushless motor can be avoided.

According to the fifth aspect of the present invention, since the brushless motor has a characteristic that the phase of the brushless motor varies with the applied current due to the increase and decrease of the applied voltage, the current flows through each phase by the voltage applied between the phases of the brushless motor. By monitoring the phase of the current and the voltage and increasing or decreasing the applied voltage so that the phase difference between the current and the voltage approaches a preset target value, it is possible to operate with a phase difference between the current and the voltage close to the target value. It becomes possible.

According to the present invention, when the applied voltage is repeatedly increased and decreased by the phase control, it does not approach the target phase difference, and when the current value is larger than the predetermined set value,
By determining that the step-out has occurred and lowering the drive frequency or stopping the energization, it is possible to reliably detect that the brushless motor has entered a step-out state, and to avoid or stop the step-out state.

According to the present invention, when the output current exceeds a predetermined value, the driving frequency is controlled so that the product of the output current and the driving frequency becomes constant, so that the output is substantially reduced. It can have a constant output characteristic area that is constant,
It is possible to protect the motor by limiting the load applied to the brushless motor without using complicated means such as detecting power.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a conventional brushless motor device.

FIGS. 2 (a), (b), (c), and (d) show a magnetic pole position signal waveform, a switching output signal waveform, a winding terminal voltage waveform, and a winding current waveform of a conventional brushless motor device, respectively. FIG.

FIG. 3 is a diagram showing a main part configuration of a brushless motor according to the present invention.

FIG. 4 is a diagram showing a connection state of windings of the brushless motor according to the present invention.

FIG. 5 is a diagram showing a configuration example of a brushless motor device according to the present invention.

6 (a), 6 (b) and 6 (c) are diagrams respectively showing an applied voltage waveform, an energizing current waveform, and a positional relationship between a stator winding magnetic pole and a rotor of the brushless motor according to the present invention.

FIG. 7 shows the magnet torque of the brushless motor according to the present invention,
It is a figure showing the state of additional excitation torque and total torque.

FIG. 8 is a diagram showing a relationship between a rotor speed and an induced voltage of the brushless motor according to the present invention.

FIG. 9 is a diagram showing the relationship between the rotor speed and the induced voltage of the brushless motor according to the present invention.

FIG. 10 is a diagram showing current-frequency characteristics (constant output characteristics) of the brushless motor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Brushless motor 11 Rotor 12 Stator 13 Magnetic pole position sensor 14 Stator core 21 Inverter part 22 Switching control part 23 Magnetic pole position signal processing part 24 Speed control part 25 Current detecting part 26 Converter part 27 Current detecting part 28 Voltage detecting part 29 Frequency / voltage Control unit 30 Output unit

Continuing on the front page (72) Inventor Kozo Matake 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Densan Co., Ltd. (72) Inventor Nobuto Miyashita 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Ebara Electric Co., Ltd. In-house (72) Inventor Takanori Inada 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Densan Co., Ltd. F-term (reference) 5H560 BB04 BB07 BB12 DA13 DC12 DC13 EB01 EC01 HA01 HA09 RR04 SS07 UA02 XA02 XA12

Claims (7)

[Claims] 1. A brushless motor comprising a rotor having a permanent magnet and a stator having a three-phase winding, a switching element for energizing each winding of the brushless motor, and a control means for controlling on / off of the switching element. A brushless motor device including a driving device, wherein the brushless motor is configured such that an induced voltage generated between each phase of the three-phase winding by rotation of the rotor has a sinusoidal waveform having a phase difference of 120 degrees. Operating frequency f0 between each phase of the driving device and the three-phase winding.
The voltage V1 that is larger than the induced voltage V0 between the phases when the rotor rotates and the sinusoidal currents having phases different from each other by 120 degrees are applied to the windings of the phases at the timing of 180 degrees is turned on / off of the switching element. A brushless motor device having a function of energizing by control. 2. The brushless motor device according to claim 1, wherein the brushless motor includes 2n rotor magnetic poles and 3n or 6n (n = 1, 2, 3,...) Salient-pole concentrated windings. A brushless motor device comprising a stator magnetic pole tooth having the same. 3. The brushless motor device according to claim 1, wherein the drive device supplies a direct current to the winding for a predetermined time when the brushless motor is started, and then gradually reduces the drive voltage and the drive frequency. A brushless motor having a function of raising. 4. The brushless motor device according to claim 1, wherein the driving device includes a current detection unit that detects a current flowing through a winding of the brushless motor, and the driving device is configured to drive the brushless motor while driving the brushless motor. A function for lowering the drive frequency or stopping the energization when the energization current becomes larger than the energization current during normal operation when a loss of synchronism occurs between the drive frequency and the rotation synchronization of the rotor. A brushless motor device. 5. The brushless motor device according to claim 1, wherein the driving device monitors a current flowing in each phase and a phase of the voltage by a voltage applied between the phases of the brushless motor. And a function of controlling the phase by increasing or decreasing the applied voltage so that the phase difference between the current and the voltage approaches a preset target value. 6. The brushless motor device according to claim 5, wherein the driving device does not approach a target phase difference even if the applied voltage is repeatedly increased and decreased by the phase control, and the current value is a predetermined value. A brushless motor device characterized in that if it is larger than a set value, it is determined that a step-out occurs, and the drive frequency is lowered or the energization is stopped. 7. The brushless motor device according to claim 1, wherein the driving device drives the brushless motor when the output current exceeds a predetermined value. A brushless motor device having a function of controlling the driving frequency so that the product of the frequencies is constant.