JPH07245983A - Sensorless brushless motor - Google Patents

Abstract

PURPOSE:To make it possible to restart the rotation of a permanent magnet rotor without completely stopping it from sensorless brushless operation. CONSTITUTION:The title sensorless brushless motor consists of a permanent magnet rotor 1, three-phase stator winding 2, a three-phase inverter 3, a commutation control circuit 4, a rotational position detecting circuit 5 and a microcomputer 6. The microcomputer 6 outputs a drive reference signal m1 at the start of the inverter. Thereafter it outputs a rotational speed corresponding signal e4 based on a rotational position signal e3, and further an inverter drive reference signal m2. When an operation signal e8 is input immediately after the input of a stop signal, the microcomputer outputs the inverter drive reference signal. The permanent magnet rotor 1 is started by initial excitation-synchronous motor operation-sensorless brushless operation. If the permanent magnet rotor is restarted immediately after the input of a stop signal, that is done by sensorless brushless operation-stop brushless operation-sensorless brushless operation. If the permanent magnet rotor is restarted a little while after the input of a stop signal, that is done after a restart prohibition time has passed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a permanent magnet rotor and a three-phase stator winding, the switching of the current of the three-phase stator winding is controlled by a three-phase inverter, and a synchronous motor operation is performed at the time of starting. And a sensorless brushless motor that performs electro-mechanical energy conversion equivalent to a DC motor by detecting an induced voltage corresponding to the rotational position of the permanent magnet rotor after starting,
Specifically, it is equipped with a permanent magnet rotor, a three-phase stator winding, a three-phase inverter, a rotational position detection circuit, a microcomputer and a commutation control circuit. Irrespective of the above, the synchronous motor operates by repeatedly outputting the drive reference signal when the inverter starts, and after the start, the microcomputer inputs a signal corresponding to the rotation position of the permanent magnet rotor from the rotation position detection circuit and the inverter drive reference The present invention relates to an improvement in a sensorless brushless motor that performs sensorless brushless operation by calculating and outputting a signal.

[0002]

2. Description of the Related Art In a conventional brushless motor, a permanent magnet rotor, a three-phase stator winding, and a DC power source are supplied to control an on / off state of a transistor group by a commutation control signal to output lines. A three-phase inverter that outputs an AC voltage to the three-phase stator winding to feed commutation to control commutation, and a commutation control circuit that controls the commutation of the three-phase inverter. A three-phase inverter is used to detect the rotation position of the rotor by detecting the voltage induced in the stator winding as the rotor rotates and switch the current of the stator winding according to the rotation position of the permanent magnet rotor. There is known a sensorless brushless motor which performs electromechanical energy conversion equivalent to that of a DC motor by controlling the phase of the output voltage of the three-phase inverter with the phase of the induced voltage of the three-phase stator winding. This sensorless brushless motor does not require a special sensor such as a magnetic sensitive element, has a simple structure, is excellent in environment resistance, controllability, wire saving, is inexpensive to manufacture, and can be used for fan drive or special environments. It can be used in a wide range of fields. However, the conventional sensorless brushless motor performs commutation (switching the current) of the three-phase stator winding as a method of detecting the voltage induced in the three-phase stator winding by the rotation of the permanent magnet rotor. At this time, in order to avoid mixing of commutation noise generated in the three-phase inverter, the sampling method is adopted aiming at the period during which the commutation noise generated periodically is reduced. For detection of, it is necessary to provide sufficient time from commutation to detection of induced voltage so that commutation noise is sufficiently attenuated, and it is not possible to use an inverter that conducts commutation many times during one cycle such as pulse width modulation. It was difficult. When performing pulse width modulation, there is also a method of attenuating commutation noise with an integrator having a sufficiently large time constant, but this method also causes a large time delay in the detection of induced voltage, which makes quick response control difficult. Becomes
It became unstable against external disturbances and could not be put to practical use.

Therefore, the applicant of the present application developed a sensorless brushless motor capable of solving the above-mentioned drawbacks and filed a patent application (Japanese Patent Laid-Open No. 62-189993). This sensorless brushless motor includes a permanent magnet rotor, a three-phase stator winding, a three-phase inverter, a commutation control circuit, a rotational position detection circuit (induced voltage detection circuit), and a microcomputer. The rotational position detection circuit inputs the potential of the neutral point of the three-phase resistance circuit connected in parallel with the three-phase stator winding and the potential of the neutral point of the three-phase stator winding to the differential amplifier. The three-phase stator winding is designed to output a required rectangular wave signal corresponding to only the triple harmonic of the fundamental wave contained in the induced voltage of each stator winding, and the microcomputer is An inverter drive reference signal composed of a pattern sequence of six kinds of two-phase excitation signals whose phases are sequentially changed by 60 degrees in a rotation direction is written in an internal ROM, and the inverter drive reference signal is read at the time of startup, Until the pattern repetition cycle becomes a predetermined short cycle, the pattern repetition cycle is gradually output to the commutation control circuit to perform synchronous motor drive, and after the start, the rotation position detection circuit outputs a rectangular wave signal. Enter The next pattern repetition period is calculated so that the time from the step update immediately before the input of the rectangular wave signal to the input of the signal becomes equal to the time from the input of the signal to the next step update. Then, the inverter drive reference signal in the next cycle is output to drive the sensorless brushless motor. Therefore, the sensorless brushless motor disclosed in JP-A-62-189993 can solve the drawbacks of the conventional sensorless brushless motor and can use the pulse width modulation type inverter, while the power transistor and the power transistor used before can be used. A reactor, a condenser, etc. are not needed, and the size and cost are reduced, and the time delay of the rotation position detection circuit can be suppressed to a small value.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to the sensorless brushless motor of No. 189993, the vibration may occur in the permanent magnet rotor when the permanent magnet rotor is positioned by initial excitation under the use condition in which the fluctuation of the load is large. When the synchronous motor operation is started, the rotating magnetic field and the permanent magnet rotor are out of synchronization due to the influence of the vibration of the permanent magnet rotor, the sensorless brushless operation cannot be switched, and the startup fails, or the vibration causes the permanent magnet rotor to move. It was found that the reverse rotation may occur, and the same unstable phenomenon as described above may occur even during the operation of the synchronous motor. For this reason, the initial excitation time must continue until the vibration of the permanent magnet rotor subsides, and the vibration of the permanent magnet rotor changes depending on the load. There was a problem that had to be long.

Further, the conventional sensorless brushless motor (including the sensorless brushless motor disclosed in Japanese Patent Laid-Open No. 62-189993) has a problem that when the permanent magnet rotor is restarted before being stopped after the stop signal is input, Since the permanent magnet rotor cannot be positioned even with excitation, the rotating magnetic field and the permanent magnet rotor will be out of synchronization even if the synchronous motor operation is started. The possibility of reverse rotation of the magnet rotor increases. Therefore, in the conventional sensorless brushless motor, a predetermined time after the stop signal is input, specifically 0.5 seconds is set as the restart prohibition time, and when the operation signal is input within the restart prohibition time. Restarts the motor in the order of initial excitation-synchronous motor operation-sensorless brushless operation after the restart prohibition time has elapsed. However, under use conditions in which the load inertia is larger than a predetermined value or the rotation speed of the permanent magnet rotor is higher than a predetermined value, the permanent magnet rotor may continue even after the restart prohibition time of 0.5 seconds. If the operation signal is input immediately after the stop signal is input because the rotation of the motor does not stop, as described above, the failure to switch from the synchronous motor operation to the sensorless brushless operation or the reverse rotation phenomenon of the permanent magnet rotor occurs. The possibility exists. In order to eliminate such a problem, the restart prohibition time is set to 6 seconds, which is extremely long, under the use condition that the load inertia is larger than the predetermined value or the rotation speed of the permanent magnet rotor is higher than the predetermined value. Had to do. However, if the restart prohibition time is set to be long, the problem that the restart cannot be performed until the restart prohibition time elapses even if the rotation of the permanent magnet rotor is actually stopped has occurred.

According to the present invention, when the operation is restarted immediately after inputting a stop signal, the sensorless brushless operation can be restarted without completely stopping the rotation of the permanent magnet rotor, and the restart prohibition time is set. It is possible to provide a sensorless brushless motor that can be restarted immediately when the operation is restarted after the stop brushless operation time has passed a short time after the stop signal was input and the stop signal was input. Has an aim.

[0007]

According to the present invention, as means for solving the above problems, a permanent magnet rotor 1 and three stator windings 21, 22, and 23 are Y-connected and are three-phase fixed. The transistor group U +, V +, W +, U-, V-, W is fed by the sub winding 2 and the DC power supply 7 and is subjected to a commutation control signal.
The output lines 31, 32, 33 are controlled by turning ON / OFF as required.
A three-phase inverter 3 that outputs an AC voltage to the three-phase stator winding 2 to control commutation, a commutation control circuit 4 that outputs a commutation control signal to the three-phase inverter 3, and the three-phase fixed A rotational position detection circuit 5 that detects the induced voltage of the child winding 2 and outputs a rotational position signal e ₃ according to the rotational position of the permanent magnet rotor 1, the rotational position detection circuit 5, and the commutation control circuit 4 And a microcomputer 6 interposed between the two, and the microcomputer 6 uses an inverter start-up drive reference signal for performing two-to-three-phase excitation or two-phase excitation at the time of start-up and two-phase excitation after start-up. A signal group to be used as an inverter drive reference signal for performing is written in the internal ROM 61, and when the operation signal e ₈ is input, the pattern repeating cycle is gradually accelerated until it becomes a predetermined short cycle, or all of the signal group. one All the parts of the signal group in accordance with each cycle by repeatedly outputting the part to the commutation control circuit 4 and inputting the rotational position signal e ₃ after the start to calculate the pattern repetition cycle. When the stop signal e ₈ is further input, the output of the inverter drive reference signal is stopped while the rotation position signal e ₃ is continuously input and the pattern repetition cycle is calculated every cycle as required. to continue, if, when the operation signal e ₈ is inputted until reduced rotation from the input stop signal e ₈ to the rotational position undetectable boundary point of the permanent magnet rotor 1, an inverter driven from that time reference signal is adapted to resume operation repeatedly outputted in accordance with the pattern repeating cycle, if also the permanent magnet rotor 1 from the input stop signal e ₈ rotational position undetectable When entering the run signal e ₈ after rotation reduction in Sakaiten, after elapse該再start prohibition time period from the rotational position undetectable border point to the permanent magnet rotor 1 stops rotating restart prohibition time The present invention provides a sensorless brushless motor characterized by being adapted to restart operation.

[0008]

The microcomputer 6 repeatedly outputs all or part of the signal group to the commutation control circuit 4 as the drive reference signal at the time of starting the inverter. The commutation control circuit 4 outputs a commutation control signal e ₆ corresponding to the drive reference signal at the time of starting the inverter to the three-phase inverter 3. The three-phase inverter 3 receives the commutation control signal e ₆ from the commutation control circuit 4, controls ON / OFF of the transistor groups U +, V +, W +, U−, V−, W− as required, and outputs the output line. An alternating voltage of two-three-phase excitation (or two-phase excitation) is output from 31, 32, and 33. An initial exciting current flows through the three-phase stator winding 2 to dampen the permanent magnet rotor 1, and then an exciting current flows to generate a rotating magnetic field. The permanent magnet rotor 1 is synchronized with the rotating magnetic field. Starts to rotate. In the above case, the drive reference signal at inverter startup is
Every time one pattern is output, the step angle is advanced by 30 degrees (60 degrees) to drive the permanent magnet rotor 1 by the synchronous motor. Then, the microcomputer 6 outputs all or a part of the signal group to the commutation control circuit 4 so as to gradually accelerate the pattern repetition period, thereby gradually accelerating the permanent magnet rotor 1 and permanently. The synchronous motor drive ends when the pattern rotor cycle is accelerated to a predetermined short cycle and output so that the magnet rotor 1 increases to a predetermined number of revolutions.

After the start-up, the microcomputer 6 receives the rotational position signal e ₃ from the rotational position detection circuit 5, calculates the pattern repetition period, and drives all or part of the signal group with an inverter in accordance with the period. The reference signal is repeatedly output to the commutation control circuit 4. Therefore, the commutation control circuit 4 outputs the commutation control signal e ₆ corresponding to the inverter drive reference signal m ₂ to the three-phase inverter 3, and at this time, the three-phase inverter 3 causes the electric power of the permanent magnet rotor 1 to change. An internal transistor group U +, V +, W +, U-, is input by inputting a _second signal group m ₂ of two-phase excitation that produces six times of commutation per one rotation of the angle.
Output lines 31, 32, 3 by controlling V- and W- on / off
An AC voltage for two-phase excitation is output from 3. Therefore, the induced current of the two-phase excitation is generated in the three-phase stator winding 2 by six times of commutation per one electrical angle, and the rotating magnetic field is generated. The sensorless brushless motor drive is performed by matching the phases of the output voltages of the three-phase inverters 3, and the electrical-mechanical energy conversion equivalent to that of the DC motor is performed. Thus, the permanent magnet rotor 1 rotates in synchronization with the rotating magnetic field. The permanent magnet rotor 1 is accelerated to a predetermined rotation speed.

When the stop signal e ₈ is input during operation, the microcomputer 6 thereafter reads all or a part of the signal group from the ROM 61 as the inverter drive reference signal to the commutation control circuit 4. Although the repetitive output is stopped, the rotation position signal e ₃ is continuously input from the rotation position detection circuit 5 to calculate the pattern repetition cycle every one cycle, and the signal group of the ROM 61 is continuously output from the ROM 61 corresponding to the pattern repetition cycle. All or part of the inverter drive reference signal is read, and the commutation control circuit 4
Is not output to. Therefore, the three-phase inverter 3 does not input the inverter drive reference signal and the commutation control signal e ₆ corresponding thereto from the commutation control circuit 4, so that the output lines 31,
The two-phase excitation AC voltage is no longer output from 32 and 33,
The rotating magnetic field of the three-phase stator winding 2 is demagnetized, and the rotation speed of the permanent magnet rotor 1 decreases. Then, when the operation signal e ₈ is input within the time from the input of the stop signal e ₈ until the rotation of the permanent magnet rotor 1 is reduced to the rotational position undetectable boundary point, the microcomputer 6 outputs the signal. Since then, even after the stop signal is input as described above, the output of all or part of the signal group read from the ROM 61 as the inverter drive reference signal to the commutation control circuit 4 is restarted, whereby the commutation control circuit 4 is restarted. Since the commutation control signal e ₆ is output so as not to step out, it is possible to immediately match the phase of the output voltage of the three-phase inverter 3 with the phase of the induced voltage of the three-phase stator winding 2, and drive the sensorless brushless motor again. Then, electric-mechanical energy conversion equivalent to that of the DC motor is performed.

Further, the microcomputer 6 stops the rotation of the permanent magnet rotor 1 after a lapse of time from the input of the stop signal e ₈ until the rotation of the permanent magnet rotor 1 is lowered to the rotational position undetectable boundary point. If the operation signal e ₈ is input before that, the step-out will occur even if the drive is restarted, so that the rotation of the permanent magnet rotor 1 drops to the boundary point where the rotation position cannot be detected, and then the permanent magnet rotor 1 moves. The time until the rotation is stopped is set as the restart prohibition time, and the operation is restarted after the restart prohibition time has elapsed.

[0012]

EXAMPLE A sensorless brushless motor of the present invention will be described below.
Embodiments will be described with reference to the drawings. 1 to 6
A first embodiment will be described. Sensorless brushless of this embodiment
As shown in the block circuit in FIG.
At normal rotation, the magnetic flux distribution in the gap with the stator is basic
Permanent magnet rotation with a shape containing harmonics of triple the wave
Child (rotor) 1 and three stator windings 21, 22, 23
Is a three-phase stator winding 2 that is Y-connected, and a DC power supply 7
Is connected so that power is supplied from
The wires 31, 32 and 33 are the three fixed wires of the three-phase stator winding 2.
In parallel with the non-neutral side terminals of the constant windings 21, 22, 23
Connected to the commutation control signal (pulse width modulation commutation control signal
No.) transistor groups U +, V +, W in the required arrangement
+, U-, V-, W- are on / off controlled to convert direct current to alternating current.
Converted to and output from output lines 31, 32, 33 and fixed in three phases
Three-phase inverter 3 for controlling commutation by supplying power to child winding 2
And the current limiter value control signal from the microcomputer 6.
Issue e₇And rotation speed corresponding signal e _FourAnd the first signal group m₁Also
Is the second signal group m₂Enter the required pulse width in the required order
The modulation is performed and the commutation control signal e is supplied to the three-phase inverter 3.₆To
A pulse width modulation type commutation control circuit 4 for outputting,
Of the induced voltage in the phase stator winding 2, three times the harmonics of the fundamental wave
Rotational position signal e required by detecting wave₃The micro computer
Data to the rotor 6 according to the rotational position of the permanent magnet rotor 1
And a rotational position detection circuit 5 for outputting

The rotational position detection circuit 5 includes three resistance wires 5
1, 52, 53 are Y-connected and each resistance wire 51, 52,
The non-neutral side terminal 53 includes a three-phase resistance circuit 5a connected to the corresponding non-neutral side terminals of the three stator windings 21, 22, and 23 of the three-phase stator winding 2. Then, the neutral point potential e ₃ of the three-phase resistance circuit 5a and the neutral point potential e _{1 of} the three-phase stator winding 2 are input to the differential amplifier 5b to input the three-phase stator winding 2 Of the fundamental wave contained in the induced voltage is detected from among the harmonics of 3 × n times the fundamental wave contained in the induced voltage, and the triple harmonic of the fundamental wave corresponding to the predetermined rotation position of the permanent magnet rotor 1 is detected. It is configured to output a required rotational position signal e ₃ corresponding to only waves. In the rotation position detection circuit 5,
It is possible to detect a triple harmonic of the fundamental wave corresponding to a predetermined rotary position of the permanent magnet rotor 1 and to output a required rotary position signal e ₃ corresponding to the triple harmonic of the fundamental wave. 62
In the specification of No. 1899993, the equivalent circuit of FIG. 2 is shown to explain it in detail as an electromagnetic theory and it is well known. Therefore, the theoretical proof is omitted in the present application.

The microcomputer 6 has twelve kinds of pattern strings corresponding to the output of the three-phase inverter 3 so that the three-phase excitation signal and the two-phase excitation signal are alternately output by advancing the phases by 30 degrees in sequence. A first signal group m ₁ and a second signal which is a pattern sequence of six types corresponding to the output of the three-phase inverter 3 so that the two-phase excitation signal is output by sequentially advancing the phase by 60 degrees. A group m ₂ , a startup pattern repetition period determination program p ₁ and a startup pattern repetition period determination program p ₂ are written in the internal ROM 61.

When the operation signal e ₈ is input, the microcomputer 6 reads the first signal group m ₁ as the drive reference signal for starting the inverter from the ROM 61 and controls the current limiter value to "high level". After the current limiter value control signal e ₇ is output and the initial excitation is performed, it is repeatedly output to the commutation control circuit 4 so that the pattern repetition cycle is gradually accelerated until it becomes a predetermined short cycle. At this time, the three-phase inverter 3 performs commutation so that the three-phase stator winding 2 alternates between two-phase excitation and three-phase excitation and the step angle of the rotating magnetic field advances by 30 degrees. When V- and W- are on and transistors V +, W +, and U- are off, respectively, in the three-phase excitation state, the V and W terminals of the motor have the same potential, and in this state, the permanent magnet rotor 1 When vibrating, an alternating current is generated in each of the stator windings 22 and 23 due to electromagnetic induction, and as shown in FIG. 1 (b), the vibration component of the current is (a DC component for rotating the permanent magnet rotor). However, since the phases of both phases are inverse to each other, a closed circuit is formed and flows into this to be converted into Joule heat, and the vibration energy is absorbed. As a result, the vibration of the permanent magnet rotor 1 is increased. Is small It made. In the two-phase excitation state, a closed circuit is not formed and vibration energy is not absorbed.

After the motor is started, the microcomputer 6 outputs a signal to switch the synchronous motor operation to the sensorless brushless operation. In order to switch from the synchronous motor operation to the sensorless brushless operation by the microcomputer 6, the microcomputer 6 inputs the rotational position signal e ₃ and, based on the signal, calculates the pattern repetition cycle as required for each cycle, and at each cycle. In addition, the commutation control circuit 4 reads the second signal group m ₂ from the ROM 61 as the inverter drive reference signal.
It is designed to repeatedly output to.

Then, even if the stop signal e ₈ is inputted by turning off the start switch of the motor, the microcomputer 6 continues to input the rotational position signal e ₃ as in the above sensorless brushless operation, and the signal is used as the signal. Based on this, the pattern repeating cycle is calculated for each cycle as required, and the inverter drive reference signal m ₂ is continued to be read from the ROM 61 in accordance with each cycle, and the inverter drive reference signal m ₂ is read. Is not output to the commutation control circuit 4. When the stop signal e ₈ is input, the microcomputer 6 outputs the current limiter value control signal e ₇ for controlling the current limiter value of the output current of the three-phase inverter 3 to “low level” from that time.

Then, the microcomputer 6 receives the stop signal e ₈ and then the rotational position detection circuit 5 detects the induced voltage of the three-phase stator winding 2 and rotates the permanent magnet rotor 1 accordingly. When the operating signal e ₈ is input within the time until the rotational position cannot be output to the rotational position undetectable boundary point of the permanent magnet rotor 1 which is the limit at which the rotational position signal e ₃ corresponding to the position cannot be output, The inverter drive reference signal m ₂ is repeatedly output from that time, and the current limiter value of the output current of the three-phase inverter 3 is changed from “low level” to “high level” after the required minute delay time has elapsed from that time. Current limiter value control signal e
It is designed to output ₇ . As a result, the sensorless brushless operation can be started without the synchronous motor operation.

Furthermore, the microcomputer 6 is
After inputting the stop signal e ₈ , the rotational position detection circuit 5 outputs a rotational position signal e ₃ according to the rotational position of the permanent magnet rotor 1 based on the detection of the induced voltage in the three-phase stator winding 2. When the operation signal e ₈ is input after the rotation position of the permanent magnet rotor 1 is reduced to the boundary point where the rotation position cannot be detected, the stable rotation position signal e ₃ can no longer be obtained. Since the signal m ₂ cannot be output so as to be synchronized with the rotation speed of the permanent magnet rotor 1 and step out occurs, it is necessary to check whether the rotation position detection impossible boundary point is reached by watching. When it is detected, the time constant circuit is activated at that time, and the time until the rotation of the rotor is stopped from the rotational position undetectable boundary point is defined as the restart prohibition time, and after the restart prohibition time has elapsed, the output of the inverter described above. Electric The current limiter value control signal for controlling the current limiter value of the flow to "high level" is output and the initial excitation is performed, so that the operation is restarted.

As described above, the microcomputer 6
Continues to rotate position signal e after inputting stop signal e _8.
3 is input and the pattern repetition cycle is calculated as required for each cycle, and the inverter drive reference signal is continuously read from the ROM 61 to the second signal group m ₂ according to each cycle. The signal m ₂ and the rotation speed corresponding signal e ₄ are not output to the commutation control circuit 4.

FIG. 2A shows ON / OFF of six transistors U +, V +, W +, U-, V-, W- of a three-phase inverter which operates based on the drive reference signal m ₁ at the time of starting the inverter. a function table showing, "1" is turned on, "0" indicates oFF, 2 ^{0-2 5} six transistors U +, V +, W + , U-, V-, and corresponds to the W-. FIG. 2B shows the drive reference signal m when the inverter is started.
Based on ₁ , the direction of the current vector when the three-phase inverter is driven by two- to three-phase excitation is shown. FIG. 3A shows six transistors U +, V +, W +, U-, V of a three-phase inverter that operates when the second signal group m ₂ is read and output from the ROM 61 as an inverter drive reference signal.
FIG. 3B is a function table showing ON / OFF of − and W−, and FIG.
The direction of the current vector when the three-phase inverter drives the two-phase excitation when the second signal group m ₂ is read and output from the OM 61 is shown. As shown in the function table of FIG. 2A, the first signal group m ₁ has the pattern 0-
Three-phase excitation signal so that the transistors U +, V +, W +, U-, V-, and W- are turned on and off in the order of 1--2-3-4-5-5-6-7-8-9-10-11. And the two-phase excitation signal are written in the ROM 61 as twelve types of pattern sequences that sequentially advance the phases by 30 degrees and output alternately. Similarly, the second signal group m ₂ is As shown in the function table of FIG.
━ 3 ━ 4 ━ 5 in order of transistors U +, V +, W +, U
The pattern of the two-phase excitation signal is written in the ROM 61 as six types of pattern sequences that are sequentially output by 60 degrees so that −, V−, and W− are turned on and off.
The start-up pattern repetition cycle determination program p ₁ has a predetermined order and timing for reading the inverter start-up drive reference signal m ₁ , and the start-up pattern repetition cycle determination program p ₂ reads the inverter drive reference signal m ₂ . The order and timing are fixed. Switching from the program p ₁ to the program p ₂ is performed by controlling the pattern repetition period at startup in the program p ₁ by a timer, and when the motor rotational speed at which the rotational position signal e ₃ can be detected sufficiently stably is reached, for example, 1800 r.p.m. p. m
Then, the program switching signal is transmitted to the program p ₂ . As shown in FIG. 2B, in the two-three-phase excitation, the current vector advances by 30 degrees in electrical angle and the step angle of the rotating magnetic field also advances by 30 degrees each time the pattern switches, and FIG. ), In the two-phase excitation, the current vector advances by 60 degrees in electrical angle and the step angle of the rotating magnetic field also advances by 60 degrees each time the pattern is switched.

At the time of start-up, the microcomputer 6 is actuated by the start-up pattern repetition cycle determining program p ₁ to act as the ROM start-up drive reference signal in the ROM 61.
To read and output the first signal group m ₁ . In this case, among the twelve types of pattern trains forming the first signal group m ₁ , as the initial excitation for damping, the commutation control circuit 4 is first read so as to be a three-phase excitation signal. To about 0.
It is output for 1 second, and then read so as to alternate with the two-phase excitation signal-three-phase excitation signal-two-phase excitation signal in the order of pattern arrangement, and repeatedly outputs to the commutation control circuit 4, and at the end of startup. Since the excitation after the start is two-phase excitation, is read so as to be a two-phase excitation signal, is output to the commutation control circuit 4, and is ended. A program p ₁ is written in the ROM 61 so that the first signal group m ₁ is read as a drive reference signal at the time of starting the inverter and is repeatedly output so as to gradually accelerate the pattern repetition period. This program p ₁ manages the basic clock with a timer to calculate the pattern repetition period, and the permanent magnet rotor 1 changes to a high rotation speed, for example, 1800 r. p. m
Then, the phase difference between the step switching timing and the induced voltage detection signal becomes, for example, 30 degrees, and is programmed so as to gradually accelerate the pattern repetition cycle until the pattern repetition cycle (predetermined short cycle) at this time is reached. There is. Then, the program p ₁ reads the post-startup pattern repetition period determination program p ₂ when detecting that the pattern repetition period has become a predetermined short period.

The microcomputer 6 after activation inputs the rotational position signal e ₃ repeating pattern from the rotating position signal e ₃ from the rotational position detecting circuit 5 acts startup after the pattern repetition period determination program p ₂ For each cycle, calculate the next pattern repetition cycle so that the time from the previous step update to the input of the signal is equal to the time from the input of the signal to the next step update At the same time, the second signal group m ₂ is read from the ROM 61 as an inverter drive reference signal, and the phase of the output voltage of the inverter 3 is adjusted to the phase of the induced voltage of the three-phase stator winding 2 so that the synchronous motor operation up to that point is achieved. As a switching adjustment for converting from drive to sensorless brushless motor drive (= DC motor drive), the output of the first reference signal is discontinuously required by the required angle. So as to output example, if 30 degrees to the commutation control circuit 4 to advance and the output of the inverter drive reference signal m ₂ is configured to repeatedly output in accordance with each cycle to the arithmetic. The output of the inverter drive reference signal m ₂ to the commutation control circuit 4 so as to advance the step switching timing discontinuously by the required angle is fixed when converting from synchronous motor drive to sensorless brushless motor drive after startup. This is because it is necessary to match the phase of the output voltage of the inverter 3 with the phase of the induced voltage of the child winding 2, and the phase of the induced voltage of the stator winding 2 is greater than the phase of the output voltage of the inverter 3 at the initial stage of startup. Is also started in a state where it has advanced 90 degrees, for example, 1800 r. p. At m, the phase difference decreases from 0 degrees to about 45 degrees depending on the magnitude of the load, and generally decreases to 30 degrees.
The phase difference can be eliminated by advancing the output of the first reference signal discontinuously by a required angle, for example, 30 degrees.

Further, the microcomputer 6 is activated by the action of the post-activation pattern repetition period determination program p _{2 and} , after activation, in parallel with the output of the inverter drive reference signal m ₂ , based on the rotational position signal e ₃ A rotation speed corresponding signal e ₄ corresponding to the rotation speed of the rotor 1 is output to the commutation control circuit 4.

The commutation control circuit 4 comprises a limiter circuit 41, a pulse width modulator (PWM) 42 and a comparator 43. The limiter circuit 41 inputs the current limiter value control signal e ₇ output from the microcomputer 6 at the time of startup to the internal limiter circuit 41, and also flows from the current detection resistor 3a of the three-phase inverter 3 to the transistor at the time of startup and after startup. The voltage signal e ₉ proportional to the current is input, and the ON / OFF signal is input from the pulse width modulation unit (PWM) 42.
The pulse width modulated on / off signal input from 2
When the current limiter value control signal e ₇ is 0, the commutation control signal e ₆ is output so that the current limiter value becomes “high level”, and when the current limiter value control signal e ₇ is 1, the current limiter value is “ The commutation control signal e ₆ is output so as to be “low level”, and when the voltage signal e ₉ is equal to or more than the limiter value, the commutation control signal e ₆ is output so that all the transistors of the three-phase inverter 3 are turned off. It is designed to be controlled. The pulse width modulator (PWM) 42 inputs the inverter start-up drive reference signal m ₁ output from the microcomputer 6 at the time of start-up, and inputs the inverter drive reference signal m ₂ after start-up. The comparator 43 receives the speed command e ₅ from the outside and also outputs the rotation speed corresponding signal e ₄ output from the microcomputer 6 after starting.
Is input to cancel the deviation between the rotation speed corresponding signal e ₄ and the speed command e ₅ , a sign (either positive or negative) that determines the increasing / decreasing direction of the pulse width modulation in the pulse width modulating unit 42 is input. It is adapted to output to the pulse width modulator 42.

4 to 6 show timing charts. The signals of (a) to (l) of FIGS. 4 to 6 will be described with reference to FIG. (A) is a basic clock of the microcomputer 6, (b) is a run / stop signal e ₈ input to the microcomputer 6, (c) is a current limiter output from the microcomputer 6 to the limiter circuit 41 of the commutation control circuit 4. The value control signals e ₇ and (d) are the first signal group m ₁ and the second signal group m ₂ output from the microcomputer 6 to the pulse width modulation section (PWM) 42 of the commutation control circuit 4, The rising and falling edges of the second signal group m ₂ become step switching timing signals that are the basis for generating the output voltage waveform of the three-phase inverter in the microcomputer. (E) is the differential amplifier 5b
The induced voltage detection signal before waveform shaping, which is the deviation between the induced voltages e ₁ and e ₂ input to the two input terminals of the differential amplifier 5b, is the harmonic wave three times the fundamental wave in the induced voltage. The rotational position signal e ₃ after detection and waveform shaping by ( ₃ ), (g), (h), (i) and (j) are three stator windings 21 and 21.
No. 2, 23 relating to one phase, (g)
Is an induced voltage generated in the one-phase stator winding when the motor is rotating while the transistor group of the three-phase inverter 3 is not on / off, and (h) and (i) are commutation control signals e.
Part of ₆ (Transistor U for one phase of three-phase inverter 3
A pair of commutation control signals e ₆ ), (j) for turning on / off + and U−, V + and V−, or W + and W− are pulse width modulated applied to the one-phase stator winding. In the inverter output voltages (h), (i), and (j), a large number of vertical dotted lines indicate that the waveform is pulse width modulated, and (k) is the current limiter value of the limiter circuit 41. ,
(Q) indicates the rotation speed of the permanent magnet rotor. In FIG. 4, the motor is initially excited to stop the rotation and vibration of the rotor, and then the first signal group m ₁ is repeatedly output so that the cycle becomes gradually faster. Phase excitation and three-phase excitation are alternately performed to perform a synchronous motor-like operation to increase the rotation speed of the rotor, and subsequently when the required rotation speed is reached, the second position is determined based on the timing of the rotation position signal e ₃ . The correlation of each signal in the operation process of performing the sensorless brushless operation by calculating and outputting the period of the signal group m ₂ and performing two-phase excitation that divides one rotation of the rotor into six equal parts is shown. FIG. 5 shows a sensorless brushless operation in which the initial excitation and the synchronous motor operation are omitted when the operation signal is input after the stop signal is input during operation in the sensorless brushless operation and before the rotation decreases to the rotational position undetectable boundary point. 3 shows the correlation of each signal in the operation process of transitioning again to. FIG. 6 shows that when the stop signal is input during operation in the sensorless brushless operation, and the operation signal is input after the rotation speed decreases to the rotation position undetectable boundary point, the initial excitation is performed after the restart prohibition time has elapsed and the synchronous motor operation is performed. The correlation of each signal in the operation process which transfers to performed sensorless brushless operation is shown. The phase of the induced voltage in the stator winding is advanced by about 90 ° with respect to the phase of the output voltage of the three-phase inverter at the initial stage of the synchronous motor operation during extremely low speed rotation, and the rotational speed increases. At the end of the operation, the state is advanced by about 30 °, and it becomes 0 ° when the pattern is switched and the sensorless brushless operation is performed.

The time charts of FIGS. 5 and 6 show that the brushless stop operation is the sensorless brushless operation in which the microcomputer 6 stops the three-phase inverter 3 after the stop signal e ₈ is input to the microcomputer 6 in FIG. It shows that the rotor position and speed detection from the triple harmonic of the fundamental wave of the motor-induced voltage that is being performed in 1. continues, and the rotation position cannot be detected reliably. At that point, the brushless stop operation ends. Since the triple harmonic becomes smaller as the rotation speed of the permanent magnet rotor 1 becomes slower, the rotation speed at the end of the stopped brushless operation, that is, the rotation position undetectable boundary point becomes
Set to the lowest speed that can reliably detect triple harmonics. According to the experiment, even if the rotational position undetectable boundary point is set to one-fourth of the rated rotational speed, the triple harmonic can be surely detected, and it has been confirmed that the microcomputer 6 operates normally. When the microcomputer 6 watches the rotational position signal e ₃ and reaches the rotational position undetectable boundary point, the microcomputer 6 operates the internal time constant circuit to prohibit the restart for a certain period of time. This time is the restart prohibition time. The current limiter value control signal e ₇ is a signal output from a predetermined output port of the microcomputer 6 to the limiter circuit 41 of the commutation control circuit 4, and the time charts of FIGS. 5 and 6 show the current limiter value control signal. e ₇ is 1 during the stop brushless operation, and is 1 for a short time after the operation signal is input during the stop brushless operation and the brushless sensorless operation is continued (This is restarted by delaying. Is stable), and is 0 during other operations. The time chart in FIG. 5 shows that when the operation signal e ₈ is input during the stop brushless operation, the microcomputer 6 outputs the inverter drive reference signal m ₂ corresponding to the rotational position signal e ₃ . Current limiter value is of a limiter circuit 41 of the commutation control circuit 4, the current limiter value control signal e ₇ is adapted to be set is switched to the low level and high level, the current limiter value control signal e ₇ When it is 0, the current limiter value is low, and the current limiter value control signal e
_{When 7} is 1, the current limiter value is set to a high level. In the time chart of FIG. 6, the restart prohibition time is 0.5 seconds.

Next, the operation of the sensorless brushless motor of the first embodiment of the present invention constructed as described above will be described.
When the driving signal e ₈ is input to the microcomputer 6,
The microcomputer 6 outputs the current limiter value control signal e ₇ to the limiter circuit 41 of the commutation control circuit 4 to set the current limiter value of the limiter circuit 41 to “high level” and is also stored in the ROM 61. The first signal group m ₁ is read and repeatedly output to the commutation control circuit 4.
The microcomputer 6 controls the timer based on the internal clock to calculate the pattern repetition period of the drive reference signal m ₁ at the time of starting the inverter so as to gradually increase the speed.
The microcomputer 6 initially reads as a three-phase excitation signal so as to output it to the commutation control circuit 4 as an initial excitation for damping, and then outputs the two-phase excitation signal-three-phase in the order of pattern arrangement. Excitation signal-Two-phase excitation signal is alternately read and output to the commutation control circuit 4. At the end of startup, the excitation after startup is two-phase excitation, so the two-phase excitation signal And outputs it to the commutation control circuit 4. The commutation control circuit 4 inputs the drive reference signal m ₁ at the time of starting the inverter to the pulse width modulation unit (PWM) 42 and pulse-width-modulates the ON / OFF signal to the limiter circuit 41.
Type and outputs a commutation control signal e ₆ in which the current limit value to "high level" of the limit full on. Therefore, the three-phase inverter 3 supplied with the direct current from the direct-current power supply 7 does not depend on the rotational position of the permanent magnet rotor 1 at the time of start-up, and the electrical angle of the permanent magnet rotor 1 is 12 times per rotation. The internal transistor group U + is inputted by inputting a three-phase excitation signal and a two-phase excitation signal which are alternately controlled so that the phase of which the pattern repetition period is controlled and the pulse width of which is modulated is changed by 30 degrees in order to generate commutation. , V +, W +,
Output lines 31, 3 by controlling U-, V-, W-on / off.
2, 33 outputs an AC voltage for two-phase to three-phase excitation. Therefore, an exciting current flows through the three-phase stator winding 2, and the induced voltages of the stator windings 21, 22, 23 become the output voltages of the output lines 31, 32, 33 of the corresponding three-phase inverter 3, respectively. On the other hand, a rotating magnetic field is generated with the phase advanced by about 90 °,
The permanent magnet rotor 1 rotates in synchronization with the rotating magnetic field. In this case, the drive reference signal at the time of starting the inverter m ₁ is a pattern sequence of twelve types in which the three-phase excitation signal and the two-phase excitation signal are alternately changed so that the phases are changed by 30 degrees in sequence. Each time the permanent magnet rotor 1 makes one-twelfth electrical angle rotation, the step angle is advanced by 30 degrees to drive the permanent magnet rotor 1 synchronously with the motor. Then, if vibration occurs in the permanent magnet rotor 1 when the motor is started, an oscillating current is generated in the stator winding of the three-phase stator winding 2 as shown in FIG. 1 (b). , When the three-phase stator winding 2 is excited in three phases, the induced currents flow in a closed circuit in a closed circuit and are consumed as Joule heat, and the vibration energy is absorbed. As a result, When the three-phase stator winding 2 is three-phase excited, the vibration of the permanent magnet rotor 1 can be greatly suppressed, the synchronous motor operating time can be shortened, and the reverse rotation phenomenon of the permanent magnet rotor 1 is less likely to occur. Even when the load fluctuates or the load inertia is large, stable starting characteristics can be obtained from the state where the rotation of the permanent magnet rotor 1 is completely stopped. Then, outputs the inverter startup drive reference signal m ₁ to the microcomputer 6 is gradually accelerated progressively periodic repeating pattern inverter startup drive reference signal m ₁ to commutation control circuit 4, thereby the permanent magnet The pattern repetition cycle is set to a predetermined short cycle (for example, converted to the rotation speed of the permanent magnet rotor 1 to 1800 rpm, so that the rotor 1 is gradually accelerated to increase the rotation speed of the permanent magnet rotor 1 to a predetermined rotation speed). At the time of accelerating to m) and outputting to the commutation control circuit 4, the above synchronous motor driving is completed, and thereafter, the vibration generated in the permanent magnet rotor 1 becomes extremely small. Note that, in conjunction with the acceleration of the permanent magnet rotor 1, the progress of the induced voltage of the three-phase stator winding 2 with respect to the output voltage of the inverter 3 gradually decreases from the initial 90 degrees to the final 30 degrees. , A harmonic of three times the induced voltage of the three-phase stator winding 2 and the rotational position signal e of the rotational position detection circuit 5
Similarly, the phase difference from ₃ is also reduced.

The microcomputer 6 switches the signal mode read from the ROM 61 from the inverter starting drive reference signal m ₁ to the inverter drive reference signal m ₂ when the pattern repeating cycle which has been watched at startup becomes a predetermined short cycle. The read signal is output to the pulse width modulation section (PWM) 42 of the commutation control circuit 4, and the rotation position signal e ₃ is input from the rotation position detection circuit 5 to calculate and repeat the pattern repetition cycle for each cycle. Speed corresponding signal e ₄
Is repeatedly output to the comparator 43 of the commutation control circuit 4. Then, the microcomputer 6 updates the inverter drive reference signal m ₂ stepwise so as to advance the step switching timing discontinuously by the required angle if necessary, and outputs it to the commutation control circuit 4 to output the three-phase stator winding. 2 stator winding 2
The phase of the output voltage of the inverter 3 is advanced and matched with the phase of the induced voltage of 1, 22, 23. Therefore, the commutation control circuit 4 inputs the code for determining the increase / decrease direction of the pulse width modulation from the comparator 43 to the pulse width modulation unit (PWM) 42, and based on the code, the pulse width modulation unit (PWM). The inverter drive reference signal m ₂ input to 42 is pulse-width modulated and input to the limiter circuit 41 to output the commutation control signal e ₆ whose current limiter value is set to the “high level” which is the limit, and if the voltage When the signal e ₉ exceeds the limiter value, the commutation control signal e ₆ is output so that all the transistors of the three-phase inverter 3 are turned off. For this reason, the three-phase inverter 3 inputs the commutation control signal e ₆ of two-phase excitation that generates commutation six times per one electrical angle rotation of the permanent magnet rotor 1 to input the internal transistor groups U +, V +, W +. , U
-, V-, W- are on / off controlled to output lines 31, 3
Since the two-phase excitation AC voltage is output from Nos. 2 and 33, the induced current of the two-phase excitation is generated in the three-phase stator winding 2 by six commutations per one electrical angle rotation, and the stator winding 21 , 22, 2
A rotating magnetic field is generated in a state in which the induced voltages of 3 correspond to the output voltages of the output lines 31, 32, and 33 of the three-phase inverter 3 corresponding to each other, and the permanent magnet rotor is synchronized with the rotating magnetic field. 1 rotates to drive a sensorless brushless motor, and electric-mechanical energy conversion equivalent to that of a DC motor is performed. Then, the commutation control circuit 4 compares the rotation speed corresponding signal e ₄ with the speed command e ₅ input from the outside and determines the increasing / decreasing direction of the pulse width modulation based on the sign of the comparison result. Since the commutation control signal e ₆ is output so as to gradually reduce the deviation between the signal e ₄ and the speed command e ₅ ,
In accordance with this, the permanent magnet rotor 1 is accelerated and rotated in synchronization with the rotating magnetic field so as to have a steady rotation speed.

Then, when the stop signal e ₈ is input during the operation, the microcomputer 6 thereafter reads the ROM 6
Although the inverter drive reference signal m ₂ is read from 1 and repeatedly output to the commutation control circuit 4 is stopped, the rotation position signal e ₃ is continuously input from the rotation position detection circuit 5 and the pattern repetition cycle is repeated every one cycle. Calculate to. Therefore, the three-phase inverter 3 does not input the commutation control signal e ₆ corresponding to the inverter drive reference signal m ₂ from the commutation control circuit 4, so that the AC voltage of the two-phase excitation is output from the output lines 31, 32 and 33. Output is stopped, the rotating magnetic field of the three-phase stator winding 2 is demagnetized, and the rotation speed of the permanent magnet rotor 1 decreases. Then, the microcomputer 6 causes the stop signal e
_{When the} operation signal e ₈ is input within the time from when ₈ is input until the rotation of the permanent magnet rotor 1 is reduced to the rotational position undetectable boundary point, the operation signal e ₈ continues from that time after the stop signal is input as described above. The commutation control is performed so that the inverter drive reference signal m ₂ is read from the ROM 61 and repeatedly output to the commutation control circuit 4 so as to correspond to the calculated pattern repetition period, and thereby the commutation control circuit 4 does not step out. Since the signal e ₆ is output, the phase of the output voltage of the three-phase inverter 3 can be immediately matched with the phase of the induced voltage of the three-phase stator winding 2, and the sensorless brushless motor drive is performed again to generate an electric current equivalent to that of the DC motor. -Mechanical energy conversion takes place.

Further, the microcomputer 6 stops the rotation of the permanent magnet rotor 1 after a lapse of time from the input of the stop signal e ₈ until the rotation of the permanent magnet rotor 1 is lowered to the rotational position undetectable boundary point. If the operating signal e ₈ is input before that, the step-out will occur even if the drive is restarted, so that the permanent magnet rotor 1 will not rotate until it reaches the rotational position undetectable boundary point. A slightly longer time including the time until the rotation is stopped is set as the restart prohibition time, and after the restart prohibition time has elapsed, the initial excitation is performed, so that the operation is restarted. In the initial excitation when the operation is restarted, the oscillating current is generated in the stator winding of the three-phase stator winding 2 as described above, and the induced current is generated when the three-phase stator winding 2 is three-phase excited. In addition, it flows in a closed circuit in a mutually inverted relationship and is consumed as Joule heat, and the vibration energy is absorbed, the vibration of the permanent magnet rotor 1 can be greatly suppressed, and the rotation of the permanent magnet rotor 1 is reduced. Stable starting characteristics can be obtained from the completely stopped state.

7 to 10 show a second embodiment of the present invention.
Show. The sensorless brushless motor of this embodiment is
The configuration of the micro computer 6 is different from that of the first embodiment.
It Therefore, the sensorless brushless motor of this embodiment
The explanation of only the parts different from the first embodiment
To do. As shown in FIG. 7, the microcomputer 6 is
The second signal group m shown in FIG.₂Written by
Is included, and at start-up, the pattern repeat cycle at start-up
Decision program p₁By the second signal group m₂I
Output to the commutation control circuit 4 as a drive reference signal when the inverter starts.
After starting, after starting
Pattern repetition cycle determination program p ₂By
Second signal group m₂Commutates as an inverter drive reference signal
It is output to the control circuit 4. Figure 8 (b)
, The second signal group m₂Is a three-phase inverter
The output of 3 is that the two-phase excitation signal advances in phase by 60 degrees
There are six types of pattern strings corresponding to be output. Ma
The micro computer 6 outputs the driving signal e₈If you enter
Second signal group m₂As the drive reference signal at inverter startup
The pattern is repeated after reading from the ROM 61 and initial excitation.
Gradually accelerate the return cycle until it becomes a predetermined short cycle
Output to the commutation control circuit 4 repeatedly for synchronous motor operation.
It is designed to be performed, and after starting, the sensor
Rotation position signal e when switching to brushless operation₃
To repeat the pattern repeat cycle as required.
Second signal group m calculated according to each cycle₂The inverter
Read from ROM 61 as drive reference signal and repeat
Output and stop signal e₈If is input, the inverter drive standard
Signal m₂Output is stopped while the rotation position signal e₃Pull
Continue to input and repeat pattern every cycle
To the stop signal e₈After typing
Rotational position of permanent magnet rotor 1 cannot be detected.
Until the driving signal e₈When you type
Kikara second signal group m₂Is the inverter drive reference signal
Read from ROM 61 according to the pattern repetition cycle.
And output it repeatedly to restart operation.
If the stop signal e₈After entering the permanent magnet
After lowering the rotation to the boundary point where the rotational position of the rotor 1 cannot be detected
Driving signal e₈When inputting, the rotational position cannot be detected
The time from the point until the permanent magnet rotor 1 stops rotating
As the restart prohibition time, after the restart prohibition time has elapsed, initial excitation is performed.
Since it is magnetized, it is designed to restart operation. This
As described above, in the second embodiment, the second signal group m₂Inver
Since the drive reference signal for starting the motor is used,
In contrast, no oscillating current is generated, so the initial excitation
Prolong the time to let it go. To suppress the permanent magnet rotor
The time required to achieve the initial excitation of
Then, it takes 0.1 seconds in the first embodiment, and in the second embodiment
It took 0.3 seconds. Then, the synchronization mode including the initial excitation is
In the first embodiment, the time required to complete the data operation is 0.3.
It took seconds, 2.5 seconds in the second example.

The present invention is not limited to the above two embodiments. For example, in the first embodiment, the microcomputer 6 advances the phase of the output voltage of the inverter 3 to match the phase of the induced voltage of the three-phase stator winding 2 at the time of switching from the startup to the startup, so that the step switching is performed. The inverter drive reference signal m ₂ is stepwise updated and output to the commutation control circuit 4 so as to advance the timing discontinuously by the required angle, but this is not necessary. The reason is that the stator windings 21, 2 are certainly
A rotating magnetic field is generated in a state in which the induced voltages of 2, 23 are advanced by about 90 ° with respect to the output voltages of the output lines 31, 32, 33 of the three-phase inverter 3 corresponding to each, but the rotational speed is increased. And the phase shift often approaches 0 °, it is not necessary to perform the phase adjustment, and when the phase adjustment is required, the phase shift is 20 ° to 30 ° even if the rotation speed is increased.
° It suffices to carry it out only under the conditions of use where there is a residual amount. Further, the present invention describes in the claims that "when a signal group is written in an internal ROM and an operation signal is input ... All or part of the signal group is repeated to the commutation control circuit. After output, after activation ... All or part of the signal group is output repeatedly. "
Although a, "the entire signal group" in the first embodiment is that the first signal group m ₁ and a second signal group m _2, therefore, if in the first embodiment type is "driving signal .... All of the signal groups are repeatedly output to the commutation control circuit, and after activation ... In the second embodiment, the second signal group m ₂ corresponds to “all of the signal groups”. Therefore, in the second embodiment, “when the operation signal is input ... Is repeatedly output, and after activation, the entire signal group is repeatedly output. "
In addition, the present invention relates to the ROM 6 of the microcomputer 6.
1 to keep in store only the first signal group m ₁ shown in FIG. 2, a second signal group m ₂ shown in FIG. 3 for every one of a first signal group m ₁ You may select, read, and output. In this case, the first signal group m ₁ corresponds to “all signal groups”, and therefore “when an operation signal is input ... All the signal groups are repeatedly output to the commutation control circuit, After the start-up, ... A part of the signal group is repeatedly output, which should be interpreted. Further, the present invention is based on the RO of the microcomputer 6.
In the first embodiment, the program written in M61 is
Although it is shown that the program p ₁ at the time of start-up and the program p ₂ after the start-up are separated, this is shown only to make the operation easy to understand. Further, the present invention does not use the pulse width modulation method as the three-phase inverter 3,
An amplitude modulation type is adopted, and along with this, a limiter circuit 41 of the commutation control circuit 4 and a pulse width modulation section (PWM) 4
Instead of 2, the current limiting circuit and the amplitude modulator (PAM) may be adopted. Further, the rotational position detection circuit 5 does not have a structure for detecting an induced voltage, and it is sufficient that the rotational position signal of the permanent magnet rotor 1 can be detected.
No. 591 electric motor control device and Japanese Patent Publication No. 58-25038
It may have a structure that employs the rotational position detection method shown in the rotor position detection circuit of the No.

[0034]

As described above, according to the sensorless brushless motor of the present invention, after the initial excitation, the drive reference signal at the time of starting the inverter is output to the commutation control circuit to start, and after the start, the rotation is started. Inputs a position signal and outputs an inverter drive reference signal according to the pattern repetition period. Even if a stop signal is input, the rotation position signal is input to calculate the pattern repetition period, and the rotation position of the permanent magnet rotor cannot be detected. When the operation signal is input before the rotation speed drops to the boundary point, the inverter drive reference signal is output from that time in synchronization with the pattern repetition cycle to restart the operation, and the rotation position cannot be detected. When the operation signal is input after the rotation speed has dropped to the boundary point, the operation is restarted from the initial excitation after the restart prohibition time has elapsed. , When trying to restart the operation immediately after inputting a stop signal (during stop brushless operation), restart prohibition time, initial excitation and synchronous motor operation are omitted, and the rotation of the permanent magnet rotor is completely stopped. It can be restarted without sensorless brushless operation. Further, in the present invention, the restart prohibition time can be shortened from about 6 seconds in the related art to 0.5 seconds by dividing into the stop brushless operation and the restart prohibition time in the present invention with respect to the conventional restart prohibition time. Even when the stop brushless operation time elapses shortly after the stop signal is input and the operation is restarted, the operation can be restarted after a maximum of 0.5 seconds has elapsed.

[Brief description of drawings]

FIG. 1A is a block circuit of a sensorless brushless motor according to a first embodiment of the present invention, and FIG. 1B is a diagram for explaining that a closed circuit of a vibration component voltage occurs during three-phase excitation at startup.

FIG. 2 is a function table showing an on / off pattern row in which six transistor groups of a three-phase inverter are activated based on a first signal group according to the first embodiment of the present invention. Yes, (b) is a diagram showing the direction of the current vector when the three-phase inverter is driven by two- to three-phase excitation based on the first signal group.

FIG. 3 is a function table showing an on / off pattern row in which six transistor groups of a three-phase inverter operate based on a second signal group according to the first embodiment of the present invention. Yes, (b) is a diagram showing the direction of the current vector when the three-phase inverter is driven in two-phase excitation based on the second signal group.

FIG. 4 is a timing chart showing initial excitation of the block circuit of the sensorless brushless motor according to the first embodiment of the present invention-synchronous motor operation-sensorless brushless operation.

FIG. 5 is a timing chart showing sensorless brushless operation of the block circuit of the sensorless brushless motor according to the first embodiment of the present invention-stop signal input-sensorless brushless operation.

FIG. 6 is a timing chart showing the sensorless brushless operation of the block circuit of the sensorless brushless motor according to the first embodiment of the present invention-stop-initial excitation-synchronous motor operation-sensorless brushless operation.

FIG. 7 is a block circuit of a sensorless brushless motor according to a second embodiment of the present invention,

FIG. 8 is a function table showing an on / off pattern row in which six transistor groups of a three-phase inverter operate based on a second signal group according to the second embodiment of the present invention. Yes, (b) is a diagram showing the direction of the current vector when the three-phase inverter is driven in two-phase excitation based on the second signal group.

FIG. 9 is a timing chart showing sensorless brushless operation of the block circuit of the sensorless brushless motor according to the second embodiment of the present invention-stop signal input-sensorless brushless operation.

FIG. 10 is a timing chart showing sensorless brushless operation of the block circuit of the sensorless brushless motor according to the second embodiment of the present invention-stop-initial excitation-synchronous motor operation-sensorless brushless operation.

[Explanation of symbols]

1 ... Permanent magnet rotor, 2 ... Three-phase stator winding, 3 ... Three-phase inverter, 31 ... Voltage output line, 32 ... Voltage output line, 33 ... Voltage output Lines, 4 ... Commutation control circuit, 41 ... Limiter circuit, 5 ... Rotation position detection circuit, 5a ... Three-phase resistance circuit, 5b ... Differential amplifier, 6 ... Microcomputer _{, 61 ··· ROM, m 1,} m 2 ··· signal group, 7 ... DC power source, e ₃ ... rotational position signal, e ₆ ... commutation control signal, e ₈ ... operation・ Stop signal,

Claims (1)

[Claims] 1. A permanent magnet rotor, a three-phase stator winding in which three stator windings are Y-connected, and a transistor group is turned on / off as required by a commutation control signal supplied from a DC power source. A three-phase inverter that controls and outputs an AC voltage to the output line to control the commutation of the three-phase stator winding; a commutation control circuit that outputs a commutation control signal to the three-phase inverter; A rotation position detection circuit that detects the induced voltage of the stator winding and outputs a rotation position signal according to the rotation position of the permanent magnet rotor, and is interposed between the rotation position detection circuit and the commutation control circuit. And a microcomputer, wherein the microcomputer is an inverter start-up drive reference signal for performing two-to-three-phase excitation or two-phase excitation at start-up, and an inverter drive reference signal for performing two-phase excitation after start-up. Signal group When the operation signal is input into the ROM, all or part of the signal group is repeatedly output to the commutation control circuit so as to gradually accelerate the pattern repetition cycle until it becomes a predetermined short cycle. The rotation position signal is input, the pattern repetition cycle is calculated for each cycle, and all or part of the signal group is repeatedly output according to each cycle. Further, when a stop signal is input, inverter drive is performed. While stopping the output of the reference signal, continue to input the rotational position signal and calculate the pattern repetition cycle for each cycle as required.
When the operation signal is input during the period from the input of the stop signal until the rotation position of the permanent magnet rotor cannot be detected at the boundary point where the rotation position cannot be detected, the inverter drive reference signal is repeatedly output in synchronization with the pattern repetition period from that time. If the operation signal is input after the rotation signal has decreased to the boundary point where the rotation position of the permanent magnet rotor cannot be detected after the stop signal is input, the rotation position cannot be detected. A sensorless brushless motor characterized in that a restart inhibition time is defined as a time from the boundary point until the rotation of the permanent magnet rotor is stopped, and the operation is restarted after the restart inhibition time has elapsed.