JPH0720391B2 - Controller for three-phase brushless motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for driving a three-phase brushless motor (hereinafter abbreviated as a motor) having a permanent magnet rotor by energizing a half cycle of 120 °. Is.

[Prior art]

Conventionally, a control device for driving a motor of this type is roughly divided into a means for detecting a position of a rotor of the motor in the motor, and the motor obtained by appropriately processing a signal obtained by the means. It has been proposed to drive the motor and to drive the motor by utilizing an induced voltage generated in a stator winding of the motor and appropriately processing a signal including the induced voltage.

In the former, generally three Hall elements are mounted in the motor at 120 ° or 60 ° pitch to detect the magnetic pole of the rotor of the motor, and the control device detects the original position sent by the Hall element. It is configured to process the signal.

An example of the control device is shown as a block diagram in FIG.

1d is a position detection circuit, 3d is a decoding circuit, 4 is a three-phase inverter circuit, and 5f is a motor equipped with a Hall element for position detection.

In this figure, the original position detection signal Iu sent by the Hall element
_The signals ₃ , ₃ , Iv ₃ , and Iw ₃ are input to the position detection circuit, and are normally converted to the logicalized position detection signals Ju ₃ , Jv ₃ , and Jw ₃ , respectively.

The position detection signals Ju ₃ , Jv ₃ , Jw ₃ are input to the decoding circuit 3d, and the decoding circuit 3d is input to the position detection signals Ju ₃ , Jv ₃ , Jw.
_In response to ₃ , drive signals U, V, W, X, Y and Z for driving the energization control elements of the three-phase inverter circuit 4 are transmitted.

The three-phase inverter circuit 4 receives the drive signal and supplies power to the motor 5f.

As shown in FIG. 26, the three-phase inverter circuit 4 has six energization control elements 4a to 4f connected to a three-phase bridge, and the output end of the three-phase inverter circuit 4 is a stator of each phase of the motor 5f. Connected with the winding.

With the control device as shown in FIG. 23, the position of the rotor of the motor can be detected even when the rotor is stopped,
As a result, a closed loop for control via the Hall element is possible regardless of the state of the motor.

Therefore, it is possible to drive the motor 5f even when the rotor of the motor 5f is stopped. In the latter control device utilizing the induced voltage generated in the stator winding of the motor, the induced voltage generated in the stator winding of the non-energized motor is used, and an example of the control device is shown in FIG. 24, Another example is shown in FIG. 25 as a block diagram.

In FIG. 24, 19a is an oscillating circuit, 20a is a pseudo position detection signal generating circuit, 21a is a selecting circuit, 3e is a decoding circuit, 4 is a three-phase inverter circuit, 1e is a position detecting circuit, 22a is a switching discrimination circuit, and 5g is It is a motor.

In this figure, the induced voltage signals Iu ₄ , Iv ₄ , Iw ₄ generated by the rotation of the rotor of the motor are processed by the position detection circuit 1e and generally converted into logic signals.

On the other hand, the oscillation signal Js ₁ of the oscillation circuit 19a is input to the pseudo position detection signal generation circuit 20a, and the pseudo position detection signal generation circuit 20a
Generates from the oscillation signal Js ₁ pseudo position detection signals Ju ₄ ′, Jv ₄ ′, Jw ₄ ′ having the same phase relationship as the position detection signal sent by the position detection circuit 1e.

The selection circuit 21a receives the pseudo position detection signals Ju ₄ ′, Jv ₄ ′, Jw ₄ ′ and the position detection signals Ju ₄ , Jv ₄ , Jw ₄ as input, and the switching discrimination circuit 2
Either one of the signals is selected according to the switching signal Jc _{1 of} 2a and sent to the decoding circuit 3e as selection signals Ju ₅ , Jv ₅ , Jw ₅ .

Decryption circuit 3e sends drive signals U for driving the selection signal Ju _5, Jv _5, receives the Jw ₅ three-phase inverter circuit 4, V, W, X, Y, each signal Z.

The three-phase inverter circuit supplies power to the motor 5g according to the drive signal.

In a control device such as this example, when the rotor of the motor 5g is in a stopped state, the induced voltage generated in the stator winding of the motor 5g cannot be obtained, so It cannot be driven in a closed loop via voltage.

Therefore, at startup, the pseudo position detection signals Ju ₄ ′, Jv
₄ ′, Jw ₄ ′ are selected by the selection circuit 21a, the motor 5g is synchronously driven as a result by the pseudo position detection signal, and the induced voltage generated in the stator winding of the motor 5g by the synchronous drive is detected by the position detection circuit 1e. Is sufficient for transmitting the position detection signal of, and the switching determination circuit 22a determines that the phase difference between the corresponding signals of the pseudo position detection signal and the position detection signal has disappeared or becomes very small. , The selection circuit 21a according to the switching signal Jc ₁ sent from the switching determination circuit 22a.
When the position detection signals Ju ₄ , Jv ₄ , Jw ₄ are selected in, the motor 5g thereafter becomes a closed loop drive driven by the position detection signal. FIG. 25 shows an example of a control device in which the selection circuit for switching the synchronous drive and the closed loop drive is moved after the decoding circuit. 19b is an oscillation circuit, 20b is a pseudo drive signal generation circuit, 21b is a selection circuit, and 22b is a switching discrimination. A circuit, 1f is a position detection circuit, 3f is a decoding circuit, 4 is a three-phase inverter circuit, and 5g is a motor.

In the figure, the oscillation signal Js ₂ of the oscillation circuit 19b is received to generate the pseudo drive signals U2, V2, W2, X2, Y2, Z2, and the pseudo drive signal is selected through the selection circuit 21b at the time of startup. The motor 5g is synchronously driven by the position detection signal Ju ₆ sent by the position detection circuit 1f due to the induced voltage generated in the stator winding of the motor 5g as in the example of the control device shown in FIG. 24. , Jv ₆ , Jw ₆ is sufficient for the decoding circuit 3f to output the driving signal, and the phase difference between the pseudo driving signal and the corresponding signal of the driving signal output by the decoding circuit 3f is eliminated or very small. The switching discriminating circuit 22b judges that it has become small, and the switching circuit Jc ₂ sent from the switching discriminating circuit 22b causes the pseudo-driving signals U2, V2, ..., Z2 in the selection circuit 21b.
To the selection of drive signals U1, U2, ..., Z1.

After that, the closed loop drive is performed via the induced voltage generated in the stator winding of the motor 5g.

[Problems to be solved by the invention]

In the conventional control device as described above, in which the motor rotor position detecting means is mounted in the motor,
No special circuit is required to start the motor, but the number of wires between the motor and the control device is generally the stator winding of the motor when three Hall elements are mounted. 11 for the total of 3 wires to the Hall element, 2 wires to supply power to the Hall element, and 2 wires for each of the signal wires from the Hall element.
I need a book.

This is due to the complexity of the work and structure for providing the position detecting means in the motor, the reliability resulting from the manufacturing due to this, and the decrease in the reliability associated with the mounting of various parts, and the increase in the manufacturing cost of the motor. Was causing problems. Also, when using a semiconductor component such as a Hall element for the position detecting means,
There is a problem in heat resistance and chemical resistance, and the usable range of such a motor is narrow.

Next, in the control device that uses the induced voltage generated in the stator winding of the motor, the above-mentioned problem does not occur because it is not necessary to provide the position detecting means on the motor side. As described in the operation of the control device in FIG. 25, at the time of start-up, the induced voltage generated in the stator winding of the motor cannot be obtained, so closed-loop drive by the induced voltage is impossible. Therefore, synchronous driving must be performed by the signal generated by the oscillation circuit inside the control device up to the rotation speed of the motor at which the level of the induced voltage that enables closed-loop driving is obtained.

This means that in addition to the circuit originally required to drive the motor, it is a special circuit for starting that is used only for a short period of time, such as an oscillation circuit, a pseudo position detection signal generation circuit or a pseudo drive signal generation circuit, and a selection circuit. Since the switching determination circuit and the like are required, the control device is complicated and the reliability of the control device is impaired accordingly.

Further, in such a control device, it is necessary to pay attention to the shift from the synchronous drive to the closed loop drive, and between the two signals, which are the pseudo signal and the signal for the closed loop drive, which are input to the selection circuit. If there is a phase difference, the energization timing of the energization control element of the three-phase inverter circuit is disturbed at the time of switching the two signals, resulting in stalling of the motor to be driven or a rapid change in torque, which deteriorates the life of the motor or the motor. In the worst case, an overcurrent will flow through the conduction control element of the three-phase inverter circuit, and the function of the control device will be deteriorated and destroyed.

The present invention has been made in view of the above, and in the case where the position detecting means is provided in the motor, the number of wires between the motor and the control device is reduced, and the induced voltage generated in the stator winding of the motor is reduced. In order to detect the position of the rotor of the motor by utilizing, the above circuits used only at the time of starting the motor are unnecessary, and further smooth starting is possible. is there.

[Means for solving problems]

According to the present invention, between a position detection circuit that sends a position detection signal and a decoding circuit that drives a three-phase inverter circuit in response to the position detection signal, in series with the system of the position detection signal, when there is no signal, By inserting a starter circuit configured to perform self-oscillation and, when a signal is input, to output a signal synchronized in phase with the input signal, various problems of the conventional control device are summarized. It is a solution.

A block diagram of a control device according to the present invention is shown in FIG.

1 is a position detecting circuit, 2 is a starting circuit, 3 is a decoding circuit, and 4 is a three-phase inverter circuit.

Reference numeral 5 is a drive target motor.

First, when the present control device is performing the closed loop drive, the original position detection signal I obtained from the motor 5 is input to the position detection circuit 1 and appropriately processed by the position detection circuit 1 to perform the position detection signal. Sent as M.

The position detection signal M becomes a synchronized position detection signal F via the starting circuit 2 and is input to the decoding circuit 3. Decoding circuit 3
Is a three-phase inverter circuit 4 in response to the input signal.
A drive signal G is sent to drive the motor, and as a result, the three-phase inverter circuit 4 supplies power to the motor 5 according to the drive signal G.

If the starting circuit 2 outputs a signal of a level required by the decoding circuit 3 at the same phase timing as in the case where the position detection signal as shown in the example of the conventional control device is directly input to the decoding circuit. That is, that is, the starting circuit 2 sends the signal to the decoding circuit 3 with no phase difference or with a sufficiently small phase difference with respect to the input position detection signal M. If it is a circuit having an amplifying function, a buffer function or a comparator function, the starting circuit 2 simply has a function of passing or level conversion with respect to the position detection signal M, and a closed loop drive via the motor 5 of the present control device. Does not interfere.

On the other hand, if the position detection signal M is not obtained when the control device starts the motor 5, the starting circuit 2 self-oscillates and outputs the oscillation signal E as shown in the block diagram of FIG. The oscillation signal E supplies power to the motor 5 through the decoding circuit 3 and the three-phase inverter circuit 4, and as a result, the motor 5 is synchronously driven by the oscillation signal E.

When the position detection signal M is obtained as a result of the synchronous drive, the position detection signal M is input to the starting circuit 2.

If the starting circuit 2 gives priority to the operation of sending the oscillation signal E by self-oscillation to the synchronized position detection signal F by the input position detection signal M, the position detection signal M is Immediately after the input, the present control device shifts to the closed loop drive via the motor 5.

In order for the present invention to be realized as a control device for driving a motor, the starting circuit 2 in the block diagrams shown in FIG. 1 and FIG. As described above, each of them must have a different function depending on the driving state during rotation.

That is, it must function as an oscillation circuit when the motor is started and as a signal transmission circuit that outputs a signal in synchronization with the position detection signal that is input when the motor rotates.

This is shown in FIG.

FIG. 3A shows a state at the time of starting, and the starting circuit 2 outputs an oscillation signal E having a frequency f ₀ by self-oscillation.

FIG. 3 (b) shows a state at the time of steady driving, in which the starting circuit 2
Outputs a synchronized position detection signal F which also has a frequency fs synchronized with the input position detection signal M of frequency fs and has no phase difference.

Here, the oscillation frequency of the starting circuit 2 in FIG.
The size of f ₀ will be described.

If the original position detection signal I from the motor 5 shown in FIG. 1 is a signal including an induced voltage generated in the stator winding of the motor 5, the induced voltage of the original position detection signal due to the rotation of the motor will be described. It is clear that the level of becomes like the graph shown in FIG. That is, assuming that the motor 5 is synchronously driven by the oscillation circuit E of the starting circuit 2, the horizontal axis represents the frequency f ₀ of the oscillation signal E, and the vertical axis represents the level of the induced voltage included in the original position detection signal I. It is obvious that the graph shown in FIG. 4 is obtained when the size of ve is taken.

In general, a motor of this type driven by a control device to which the present invention is applied, when an attempt is made to perform synchronous drive by giving an oscillation signal of a high frequency from the beginning relative to the height of the voltage to be fed, the rotor of the motor is rotated. The power supply to the stator windings of the motor is switched one after another before the motor completes the rotational movement, and the motor cannot reach the rotational speed by synchronous drive, or the phenomenon such as reciprocating motion or reverse rotation occurs. Is well known, on the contrary, when trying to drive synchronously with the low-frequency oscillation signal f ₀ corresponding to the voltage to be fed, the movement of the rotor of the motor is more Is relatively quicker than the switching of, and as a result, rotation is performed in synchronization with the oscillation signal. Now, with the power supply voltage of the three-phase inverter circuit fixed, the upper limit of the frequency of the oscillation signal at this time when the motor can be synchronized is set to f _0N, and the position detection circuit 1 sends the position detection signal M by the original position detection signal I. Assuming that the minimum level ve of the induced voltage included in the sufficient original position detection signal I is V1 and the oscillation signal frequency for synchronous drive for generating the induced voltage of the level V1 is _f0M , FIG. frequency f ₀ of the oscillator signal E for performing driving by closed loop by starting the motor 5 in may be set within a range satisfying _{f 0M ≦ f 0 ≦ f 0N} ...... ( first formula) the condition. Therefore, it is obvious that the motor 5 can be started by the oscillation signal E having a single frequency if the oscillation signal E has a frequency satisfying the first expression.

Further, normally, when the power supply voltage of the three-phase inverter circuit 4 is gradually increased, the frequency upper limit f _0N of the oscillation signal that can be synchronously driven is also gradually increased, and the _settable frequency range _represented by the first expression is obtained. Is expanded. As described above, if the starting circuit 2 has the function and the oscillation signal frequency as described above, it is possible to smoothly drive the motor including starting.

〔Example〕

Next, a means for the starter circuit 2 to simultaneously satisfy the two functions of sending the oscillation signal by self-oscillation and sending the synchronized position detection signal by the input position detection signal will be described.

FIG. 5A is a block diagram showing an example of a main part of the internal configuration of the starting circuit 2.

Reference numeral 8 is an adding unit, 6 is an amplifying unit, and 7 is a negative feedback unit. Now, assuming that the gain of the amplifier unit 6 is μ, the gain of the feedback unit 7 is β, and the gain of the entire circuit is A. At this time, when a Nyquist diagram that draws a locus of μ × β called loop gain as a frequency angular velocity ω on a complex plane is created, as shown in FIG. 5B, (−1,0 It is a well-known fact that the oscillation condition is satisfied if the locus of the loop gain is drawn so as to include the point (). That is, when the phase rotation of the output E1 with respect to the input in the cutoff region of the low frequency and the high frequency of the amplification section 6 is rotated by 180 electrical angle, | μ × β |> 1 ... Become.

Therefore, the circuit shown in FIG. 5 (a) is the starting circuit 2 that satisfies the above conditions, or the circuit configuration includes a circuit that processes and outputs the signal of the circuit without a phase difference. With the starting circuit 2 which is provided, synchronous drive for starting the motor 5 shown in FIG. 2 can be performed. Thus, when the oscillation signal E1 of FIG. 5 (a) has a frequency f ₀ that satisfies the first expression, the motor 5 is synchronously driven by the oscillation signal E1 via the signal transmission path of FIG.

The motor 5 is driven synchronously, and as a result, the frequency of the position detection signal M obtained should be at least equal to the frequency f _{0 of the} oscillation signal E1.

If the motor 5 of the three-phase inverter circuit 4 in FIG.
If the power supply voltage to the motor 5 is greater than the minimum amount that can be synchronized with the frequency f ₀ of the oscillation signal E1 of the motor 5, the motor 5 generates a torque that exceeds the minimum torque that can be synchronized, and supplies power to the stator winding of the motor. The movement of the rotor of the motor with respect to the moving speed of the field generated by the above is from the time when the above-mentioned movement of the field is performed until the completion of the movement of the rotor of the motor to the place corresponding to the state of the field. Therefore, the position detection signal obtained by this operation is always in advance of the oscillation signal output from the starter circuit and exceeds the frequency f ₀ .

If the position detection signal M having such a condition is input as the input signal amount M1 in FIG. 5, assuming that the negative feedback amount at the time of oscillation is m1, M1 >> m1 ... (Equation 4) As a result of the fact that the negative feedback amount m1 is almost ignored and the frequency of the input position detection signal M exceeds the frequency of the oscillation signal due to self-oscillation of the circuit of FIG. The circuit of (1) shifts from the oscillation condition to a circuit having a function as an amplifier circuit which is slightly negatively fed back to the input position detection signal M.

Therefore, as soon as the position detection signal M is input to the circuit of FIG. 6, it becomes an amplifier circuit for the position detection signal M, so that the synchronous drive of FIG. 2 smoothly shifts to the closed loop drive of FIG.

From the above, it can be seen that the starting circuit required for the control device of the present invention can be easily constructed.

In the above description, the control device using the original position detection signal I utilizing the induced voltage generated in the stator winding of the motor has been mainly described, but the original position detection signal I is obtained from the stopped state. However, in the control device, the position detection signal M in the above description is applied from the stopped state, and the signal is immediately synchronized with the position detection signal M without passing through the process in which the starter circuit sends the oscillation signal E. The motor is driven in the state of sending out.

Therefore, it is easy to understand.

Next, FIG. 6 shows an example in which the block diagram of FIG. 5 is more developed.

FIG. 6 shows an operational amplifier 9 as a comparator for comparing the levels of input signals, and a negative feedback section for negatively feeding back the output of the operational amplifier 9 to the inverting input of the operational amplifier 9.
11 and a positive feedback unit 10 that performs positive feedback to the non-inverting input. The inverting input terminal is connected via the resistor R _N , the non-inverting input terminal is connected via the resistor R _P, and the Low v _C
Biased at If the negative feedback unit 11 is a resistor and negatively feeds back a feedback amount having no phase difference with respect to the output, and the positive feedback unit 10 is capacitive and the positive feedback amount v _P is gradually attenuated, the operational amplifier 9 If the initial positive feedback amount v _P due to the change of the output v ₀ of
Oscillation occurs as shown in FIG.

On the contrary, assuming that the positive feedback unit 10 is a resistor and positively feeds back the feedback amount v _P having no phase difference with respect to the output, and the negative feedback unit 11 is inductive and the negative feedback amount vn is gradually increased, the operational amplifier 9
If the maximum negative feedback amount due to the change in the output v ₀ of the above is larger than the positive feedback amount v _P , oscillation occurs as shown in FIG. 7 (b).

That is, in either case, one input terminal changes the threshold level as a comparator of the operational amplifier 9 with no phase difference from the output, and the other input terminal changes the level with time, This is a stable and reliable oscillation.

The embodiment specifically showing FIG. 6 is shown in FIG. 8, and the one that oscillates with the waveform of FIG. 7 (a) is the one embodiment of FIG. 8 (a) and the waveform of FIG. 7 (b). The one that oscillates is the one shown in FIG. 8 (b).

Here, in order for FIG. 6 to operate as an amplifier circuit, it suffices to input the signal to be amplified to the operational amplifier 9, and input it to the inverting input terminal for amplification by inverting, and input it to the non-inverting input terminal for amplification in phase. To do.

In FIGS. 8A and 8B, since the operational amplifier 9 is biased at a voltage of v _C via a resistor for oscillation, the input signal v _S to be amplified is AC by the capacitor C1 and the resistor R1. The component is taken out and level-converted into a signal that oscillates with reference to a voltage of v _C.

Further, the resistor R1 serves both as a bias for the non-inverting input terminal of the operational amplifier 9 for oscillation and for a level shift of the input signal v _S to be amplified.

In the circuit constructed in this way, the input signal to be amplified
If the amplitude level of v _S is sufficiently larger than the positive feedback amount v _P and the negative feedback amount vn generated during oscillation, that is, in FIGS. 8 (a) and 8 (b), R1 + R2 << R3. ) R4 << R2 (Equation 6) R1 + R6 << R7 (Equation 7) R8 << R9 (Equation 8) and the output v ₀ obtained when the frequency of the input signal v _S is obtained by oscillation If the frequency is larger than the frequency of, the circuits of both embodiments perform an amplifying operation on the AC component of the input signal v _S to be amplified.

Up to this point, the conditions and examples to be possessed for a single starting circuit have been described. However, the starting circuit 2 in FIGS. 1 and 2 receives the plurality of position detection signals M, A case where it is necessary to output the same number of oscillation signals E as the detection signals will be described.

For example, a three-phase motor of this type normally drives three closed loops based on three position detection signals. However, in such a control device, in order to perform smooth startup at startup, It is necessary to send out a low-frequency oscillation signal having a phase relationship corresponding to the position detection signal.

In this case, it can be achieved by providing a starter circuit for each position detection signal, using each starter circuit as a multistage negative feedback amplifier circuit in series with respect to the oscillation signal, and regarding the amplification from the first stage to the last stage as one amplifier circuit.

FIG. 9 is a block diagram showing one example thereof.

It is well known that the position detection signal is usually a signal having a phase difference of 120 ° in electrical angle between adjacent signals. Therefore, the adjacent oscillating signals of the respective starting circuits are also transmitted to the respective starting circuits. It must have the same phase relationship and the same phase difference as the input position detection signal.

In FIG. 9, for example, the input position detection signals are Mu ₁ and Mv.
_{If the} phase has a phase difference of 120 ° in terms of electrical angle in the order of ₁ and Mw ₁ , the oscillation signal must also have a delayed phase difference of 120 ° in phase in the order of Eu ₁ , Ev ₁ and Ew _1. I won't.

Here, paying attention to the oscillation signal Ew ₁ located at the end of the phase sequence, the oscillation signal Ew ₁ is an inversion of the signal delayed by 60 ° in phase from the oscillation signal Eu ₁ located first.

Therefore, when this matter is used, the negative feedback having the lead phase is individually applied to the outputs of the amplifiers 6a, 6b, 6c.
a, 7b, 7c, respectively, and each of the oscillation signals Eu ₁ , Ev ₁ , Ew ₁ which are the outputs of the respective sub-units are sequentially phased in the intended phase by the subsequent amplification unit and coupling unit 12a, 12b, 12c. By combining them, it is possible to obtain oscillation signals with a phase difference of 120 °. For example, if each amplifier has an inverting input terminal and a non-inverting input terminal like an operational amplifier, the input from the negative feedback section and the coupling section is connected to the inverting input terminal, and the position detection is an external input. By inputting the signals Mu ₁ , Mv ₁ , and Mw ₁ to the non-inverting input terminals via capacitor coupling, as described in the above single start-up circuit, the position detection signals Mu ₁ , Mv ₁ , and Mw ₁ are input. Negative feedback amount mu ₁ , mv ₁ , mw ₁
If the coupling amount of the joint or mc ₁ , mc ₂ , mc _{3 is} sufficiently large,
The position detection signals Mu ₁ , Mv ₁ , and Mw ₁ serve as amplifier circuits, respectively, and satisfy all the conditions of the target starting circuit.

FIG. 10 and FIG. 11 are block diagrams showing a circuit for generating an oscillation signal for starting a motor having a similar phase difference in response to a plurality of position detection signals as described above. ,
In the case of FIG. 9, each starting circuit oscillates in a closed loop state via the coupling portion, but in this case, it is an open loop.

That is, in FIG. 10, only the starter circuit inserted in one specific position detection signal system causes self-oscillation, and the starter circuits are combined to sequentially perform a phase shift of 120 ° with reference to the oscillation signal of the starter circuit. Therefore, the circuit inserted in the other two position detection signals becomes a synchronous oscillation circuit which synchronizes with the oscillation signal of the immediately preceding phase and outputs the oscillation signal with a 120 ° phase delay.

Similarly in FIG. 11, only the starter circuit input to one specific position detection signal system causes self-oscillation, and the remaining 2 signals are based on the oscillation signal of the starter circuit that causes the self-oscillation.
Of these, the circuit inserted into the system of the position detection signal that requires the next phase is 120 °, and the circuit inserted into the system of the position detection signal that requires the next phase is delayed by 240 °, It is connected to the starting circuit so that the same waveform as the oscillation signal of the starting circuit that self-oscillates is output.

Therefore, as described above, one is a start-up circuit having a self-oscillation function, and the other two are output in synchronization with the oscillation signal of the start-up circuit, with the oscillation signal being delayed by 120 ° and 240 ° phases. It becomes a synchronous oscillation circuit.

In each of the circuits shown in FIGS. 10 and 11, as in the case of FIG. 9, the amplitude level of the input position detection signal becomes sufficiently larger than the signal amplitude level of the feedback section or the coupling section. If so set, with respect to the input position detection signal, each circuit inserted in series with the system of the position detection signal operates as an amplifier circuit.

Although the starter circuit has been described above in the case of three position detection signals, it is easily analogized that a starter circuit that achieves the same purpose can be configured by using the same method even when the number of position detection signals is larger. You can

It is assumed that all the starting circuits in the following description satisfy the conditions as the starting circuit described so far.

Now, the operation of the control device when the starting circuit is applied to the control device of the motor that requires a plurality of position detection signals as described above will be described.

FIG. 12 shows an example of a control device utilizing an induced voltage generated in a stator winding of a motor, and FIG. 13 shows a timing chart of waveforms of respective parts according to FIG. 12, which will be described below. .

Unless otherwise specified, the starting circuit described here is
It means an individual starting circuit inserted in series in each position detection signal system or an entire starting circuit including the synchronous oscillation circuit shown in FIGS. 10 and 11.

In FIG. 12, 1a is a position detecting circuit, 2a is a starting circuit, and 3a.
Is a decoding circuit, 4 is a three-phase inverter circuit, and 5a is a motor.

At the time of start-up, the start-up circuit 2a self-oscillates and outputs the oscillation signals Eu ₄ , Ev ₄ , and Ew ₄ which are out of phase with each other by 120 °.

Oscillation signal Eu _4, Ev _4, Ew ₄ are taken drive signal U for driving the by the three-phase inverter circuit 4 decodes at decode circuit 3a, V, W, X, Y, and Z, the motor 5a is synchronized as a result Driven.

A motor 5 including an induced voltage generated by the synchronous drive
The voltage of the stator winding is input to the position detection circuit 1a as the original position detection signals Iu ₁ , Iv ₁ and Iw ₁ . In the position detection circuit 1a, the original position detection signal is integrated by a method such as integrating the shift signal u ', which has an amplitude delayed by 90 ° in phase.
Get v ', w'. The position detection signals Mu ₄ and Mv are obtained by converting each of the shift signals into a rectangular wave as a comparator at the center of the amplitude.
_{When 4} and Mw ₄ are obtained and input to the starter circuit 2a, the starter circuit 2a immediately operates as an amplifier circuit, so that the same waveform with almost the same phase as the position detection signal is synchronized with the position detection signals Fu ₁ and Fv.
₁ and Fw ₁ are sent to the decoding circuit 3a.

After that, the control device continues to drive the motor 5a by the original position detection signal.

In the case of this figure, if the gain of the amplifier to which each position detection signal in the starting circuit 2a is input is sufficiently large and the amplitude level of the shift signal is the amplitude of various levels excluding the output accompanying the self-oscillation of the starting circuit. , If the shift signal u ′,
By inputting v ′ and w ′ by capacitor coupling as shown in FIG. 8, a rectangular wave similar to the case where the shift signal is compared at the center of the amplitude can be transmitted as the synchronized position detection signal.

This is because the conventional control device obtains a rectangular wave position detection signal to be input to the decoding circuit, for example, by replacing the comparator circuit with a starting circuit having a sufficient gain according to the present invention. It is possible to omit the circuit for obtaining the above-mentioned pseudo signal and the circuits for selecting the signal only for starting.

Note that Eu ₄ , Ev ₄ , and Ew ₄ are oscillation signals due to self-oscillation of the startup circuit 2a, Z, X, Y, V, W, and U are drive signals transmitted by the decoding circuit 3a, and u,
For v and w, the voltage supplied by the three-phase inverter circuit 4 is weighted by the induced voltage generated in the motor 5a. motor
The voltage of the stator winding of each phase based on the neutral point of the stator winding of 5a, u ′, v ′, w ′ is the 90 ° position by integrating the signals of u, v, w above. Amplitude waveform of delayed signal, Mu ₄ , Mv ₄ ,
Mw ₄ is a rectangular wave position detection signal obtained by comparing the respective signals of u ′, v ′ and w ′ at the center of amplitude.

The synchronized position detection signal transmitted through the start-up circuit 2a has the same phase and the same waveform as the above position detection signal, so the waveforms of the position detection signals Mu ₄ , Mv ₄ , and Mw ₄ are used instead. As is clear from the timing chart in this figure, the oscillation signal and the synchronization position detection signal of the startup circuit for synchronous drive are sent from the same startup circuit, so the oscillation signal and the synchronization position detection signal are straightforward. By switching, the motor may not be started at all by any means for switching.

Conventionally, in the position detection of this type of three-phase motor, position detection is performed for each phase, three position detection signals are obtained, and the motor is finally driven again by the three position detection signals. There is.

By inserting a starter circuit in series with the position detection signal system of such a control device, the motor to be driven can be operated from start-up to steady drive without adding an additional circuit for start-up. This is as described above, and this alone is a sufficient advantage compared to the conventional control device, but the design requires that an oscillation signal having the same phase relationship as the position detection signal input by the starting circuit is required. It is a cause that requires consideration regarding the setting of the constant.

Therefore, if there is only one signal input to the startup circuit,
Since only one oscillation signal is required for the start-up circuit, therefore, between the circuits that send out each oscillation signal in the start-up circuit for obtaining the oscillation signal having the same phase relationship with the three position detection signals as described above. There is no need to consider the coupling between the two, and there is no need to worry about the shift in the phase difference between the oscillating signals, and as a result, the oscillating signal that satisfies the conditions sufficient to start the above-mentioned motor in the minimum unit is sent out. It is hoped that the above configuration will facilitate design, simplify the circuit configuration, and facilitate manufacturing.

FIG. 14 is a block diagram showing a method of starting and steadily driving a motor by a single oscillation signal in a control device having three position detection signals.

It is assumed that the control device uses the induced voltage generated in the stator winding of the motor.

In FIG. 14, 1b is a position detecting circuit, 1b1 is an initial position detecting circuit, 1b2 is an encoder circuit, 2b is a starting circuit, 3b is a decoding circuit, 4 is a three-phase inverter circuit, and 5b is a motor.

The initial position detection circuit 1b1 sends three logicalized initial position detection signals Ju ₂ , Jv ₂ , Jw ₂ , and the encoder circuit 1b2 outputs the three initial position detection signals as one code signal J.
Convert to 2.

Therefore, the position detecting unit 1b has three original position detection signals Iu ₂ ,
Upon receiving Iv ₂ and Iw ₂ , one code signal J2 is transmitted.

Unlike the decoding circuits described above, the decoding circuit 3b is a decoding circuit that includes a decoder circuit that operates in the opposite manner to the encoder circuit 1b2, or converts the input signal directly into the required drive signal. It is a decoding circuit. Although it is easy to understand that the decoding circuit including the above decoder circuit can be realized by providing the decoder circuit in the preceding stage of the decoding circuit used in the conventional control device or the like described above, the explanation is omitted, but it is input. The decoding circuit for converting the code signal from the encoder circuit into the drive signal which is input through the starting circuit and directly requested will be described later.

Now, by the oscillation signal E2 sent from the starting circuit 2b, the driving signals U, V, and
If W, X, Y, Z are transmitted, the drive signals U, V, W, X, Y, Z
Thus, the three-phase inverter circuit 4 appropriately supplies power to the motor 5b.

Therefore, the motor 5b is synchronously driven by the oscillation signal E2 sent from the starting circuit 2b to start.

An induced voltage is generated in the motor 5b by the synchronous drive.

The voltage of each stator winding of the inclusive motor 5b to the induced voltage obtained as an original position detection signal _{Iu 2, Iv 2, Iw 2} , as in the case of Figure 12, the logic by the process of integration and comparator The converted initial position detection signals Ju ₂ , Jv ₂ , Jw ₂ are generated.

The initial position detection signals Ju ₂ , Jv ₂ and Jw ₂ are three-phase signals which are 120 ° out of phase with each other, and the initial position detection signals Ju ₂ , Jv ₂ and Jw ₂ are coded by the encoder circuit 1b2 as one code. Sent out as signal J2,
The code signal J2 is input to the starting circuit 2b.

The start-up circuit 2b operates as an amplifier circuit for the input code signal J2 and is input to the decoding circuit 5b as a synchronized code signal F.

Therefore, up to this point, the control device shown in FIG.
Will be driven in a closed loop.

This state is shown in FIG. 16 by the waveforms and timing charts of the signals of the respective parts in FIG.

E2 in FIG. 16 is an oscillation signal of the starting circuit 2b, U, V, W, Z, X, Y are drive signals sent by the decoding circuit 3b according to the oscillation signal E, u, v,
w is the stator winding voltage of each phase of the motor 5b and the drive signals U, V, W, X,
The superposed voltage of the voltage supplied from the three-phase inverter circuit 4 by Y and Z and the induced voltage generated in the stator winding is viewed with reference to the neutral point of the stator winding.

u ′, v ′, w ′ is the original position detection signal I obtained by converting the above u, v, w signals.
u ₂ , Iv ₂ , Iw ₂ and the original position detection signals Iu ₂ , Iv ₂ , Iw
Shift signal Ju _{2 2} is the amplitude waveform of integrating the voltage, Jv _2, I
w ₂ is a logicalized initial position detection signal obtained by comparing the above u ', v', and w'in the center of the amplitude.

J2 'is the original code signal that is output when two of the three initial position detection signals are at the logic high level, and J2 is the code that is the inverse of J2' after the original code signal J2 'has started to be sent. It is a signal.

Therefore, conversely, if the signals output by the circuits and the position detection section shown in FIG. 14 have the timings shown in FIG. 16,
The control device shown in FIG. 14 is established.

Although the configuration of the decoding circuit 3b will be described later, anyway, the decoding circuit 3b inputs the duty ratio of 50% to FIG.
Input the single oscillation signal E2 of U, V, W,
If the X, Y, Z drive signals are output, the oscillation signal E2
In contrast, the drive signals U, V, W, X, Y, and Z have a frequency of 1/3 and the oscillation signal
1 cycle of E2 is set to logic high level, 2 cycles are set to logic low level, 120 ° in electrical angle of drive signal is set to logic high level, 2
It is a signal that sets 40 ° to a logical low level, each drive signal has the same waveform, and 180 °, which is a half cycle of the oscillation signal E2,
It is transmitted with a phase difference of 60 ° in terms of electrical angle of the drive signal.

The drive signals U, V, W, X, Y, Z drive the three-phase inverter circuit, and as a result, the motor 5b is synchronously driven by the oscillation signal E2.

The voltage of each stator winding of the motor 5b obtained by the synchronous drive has a 120 ° phase difference shown in FIG. 16 when viewed as a phase voltage with reference to the neutral point of the stator winding.
So-called three-phase voltage u, v, w.

By using the phase voltage as the original position detection signals Iu ₂ , Iv ₂ , Iw ₂ and processing such as integration, each original position detection signal can be made into shift signals u ′, v ′, w ′ with a 90 ° phase delay. .

By comparing the shift signal at the center of the amplitude, it is possible to obtain the logicalized initial position detection signals Ju ₂ , Jv ₂ and Jw ₂ which are delayed by 90 ° in phase with respect to the original position detection signal.

The initial position detection signal is a three-phase phase voltage having a phase difference of 120 °, and the original position detection signal is delayed by 90 ° with respect to each original position detection signal. The signal has a phase difference of 50% and a duty ratio of 50%.

Therefore, since the adjacent initial position detection signals should have an overlap of 60 ° at each of the rising and falling portions of the initial position detection signal, the logic HI of the initial position detection signal is high.
If the signal where the overlapping GH levels are the logical high level and the other parts are the logical low level, the logical high level and the logical low level are reciprocated three times for one cycle of the initial position detection signal, and the duty ratio Of the 180 ° logic high level of the initial position detection signal of 50%, 60 at both ends
Since the ∘ portion overlaps with the logic HIGH level of the initial position detection signal of the other phase, the central portion which does not overlap with the logic HIGH level of the initial position detection signal of any of the other phases is still 60 °. Minutes.

Therefore, the original code signal J2 'obtained as described above has a duty ratio of 50%, has a frequency three times as high as that of the initial position detection signal, and the logic HIGH of any initial position detection signal.
The rising edge of the level coincides with the rising edge of the logic HIGH level of the original code signal.

The original code signal J2 ′ obtained in this way is inverted, and after the original code signal J2 ′ starts to change, it is output from the position detection circuit 1b as the code signal J2, and in phase with the start circuit 2b. If the code signal J2 is input so as to be output as the synchronization code signal, that is, the synchronization code signal F2 that has the same phase as the oscillation signal sent by the starting circuit 2b until then.
To get As shown in FIG. 16, the synchronization code signal F2 has a frequency three times as high as that of the oscillation signal E2 with respect to the drive signal, and as described above, switching is performed without a phase difference from the oscillation signal E2. Therefore, it can be used as the input signal of the decoding circuit 3b.

At this point, the motor 5b is driven in the closed loop.

Here, an encoder circuit for converting the three initial position detection signals Ju ₂ , Iv ₂ , Jw ₂ into one code signal J2 will be described.

FIG. 15 shows an example of the encoding circuit, and 13a to 13d.
Is an AND circuit, 14 is a NOR circuit, 15 is a D flip, and 16a is an inverting circuit.

In the figure, AND circuits 13a to 13c logically AND two different initial position detection signals to obtain AND circuits 13a to 13c.
When the output of 13c is ORed by the OR circuit 14, the position detection signal J
It is possible to obtain the original code signal J2 ′ having a frequency three times as high as the frequency of the position detection signal, the rising of which coincides with the rising of any of the waveforms u ₂ , Jv ₂ , and Jw ₂ .

A signal obtained by inverting the original code signal J2 ′ is used as the original code signal J
The code signal is detected by the D flip-flop 15 which detects that 2'has started to change, and is passed through the AND circuit 13d.
If obtained as J2, the three position detection signals Ju ₂ , Jv ₂ , and Jw ₂ are encoded.

This state is the same as that shown in the signal waveforms and timing charts of Ju ₂ , Jv ₂ , Jw ₂ , J2 ′, and J2 in FIG.

As described above, if the code signal J2 sent from the position detection unit 1b by encoding is input to the decoding circuit 3b as the synchronized code signal F2 via the starting circuit 2b, the decoding circuit 3b drives it to a frequency of 1/3. The signals U, V, W, X, Y, Z result, and as a result, the motor 5b can be driven.

In the above description, the code signal J2 is non-inverted by the starting circuit 2b to become the synchronized code signal F2, but conversely, if it is input to the starting circuit 2b so as to become inverted and become the synchronized code signal F2. If, for example, the input signal is not input to the non-inverting input terminal of the operational amplifier 9 as in (a) and (b) of FIG. 8 but is input to the inverting input terminal side by capacitor coupling, , The code signal J2 becomes the inverted sync signal F2.

Therefore, if there is a relationship in which the signal input by the starting circuit configured to output the signal inverted as described above and the oscillation signal have opposite phases, E2, J2 'in FIG. As is clear from the timing chart, in FIG. 15, by directly inputting the original code signal J2 'to the above-mentioned start-up circuit, a signal equivalent to the intended synchronization code signal F2 can be obtained, so that D The flip-flop 15, the inverting circuit 16a, and the AND circuit 13d can be omitted.

Now, the relationship between the starting circuit 2b and the decoding circuit 3b shown in FIG. 14, that is, the frequency of the oscillation signal E2 transmitted by the starting circuit 2b
Driving signals U, V, W, X, Y, Z from the decoding circuit 3b at a frequency of 1/3 are
If the relationship is such that the signals are sent out as shown in FIG. 16, the configuration of the control device shown in FIG. 17 in which the neutral point voltage of the motor is used as the original position detection signal can be achieved.

Description will be given below with reference to the block diagram of FIG. 17 and FIG. 18 showing the waveforms and timings of the signals of the respective parts of FIG.

In FIG. 17, IC is a position detection circuit, 2C is a start circuit, and 3C.
Is a decoding circuit, 4 is a three-phase inverter circuit, and 5C is a motor.

When starting motor 5C, start circuit 2C causes oscillation circuit.
E3 is sent out.

Assuming that the decoding circuit 3C sends the drive signals U, V, W, Z, X, and Y at the frequency of 1/3 of the frequency of the oscillation signal E3 at the timing shown in FIG. 18, the motor 5C is The drive signal U,
Power is supplied through the three-phase inverter circuit 4 driven by V, W, Z, X, and Y to be synchronously driven.

By being driven synchronously, the power supply voltage V of the three-phase inverter circuit 4 is changed from the neutral point of the stator winding of the motor 5C.
An original position detection signal I3 is obtained, in which the induced voltage of the stator windings during non-energization of each phase is superimposed in the state of being biased with half the voltage of _B (see Fig. 26). In the position detection circuit 1C, the original position detection signal I3 is made into a shift signal I3 ′ whose phase is delayed by 90 ° by means such as integration, and the shift signal I3 ′ is compared at the center of the amplitude and logicalized position. The detection signal J3 is input to the starting circuit 2C as the output of the position detection circuit 1C. When the position detection signal J3 is input, the starting circuit 2C operates as an amplification function and outputs the synchronized position detection signal F3.

The synchronized position detection signal F3 is input to the decoding circuit 3C in place of the oscillation signal E3, and the motor 5C shifts to driving by a closed loop.

The reason why this control device is established is as follows.

Since the decoding circuit 3C sends a drive signal at a frequency of 1/3 of the frequency of the oscillation signal E3 sent by the starting circuit 2C, the synchronized position detection signal F3 during steady drive is the required drive signal. Must have three times the frequency of.

In general, when a three-phase motor of this type is driven by 120 ° energization, the frequency of the amplitude of the voltage at the neutral point of the stator winding of the motor will be It is known to all that the voltage swings at a frequency three times as high as the power supply frequency to the stator winding of each phase.

Therefore, the waveforms of the phase voltages u, v, w are shown in FIG. 18 in which the voltage fed with the induced and induced voltages appearing in the stator winding of each phase is superimposed on the basis of the neutral point of the stator winding. Therefore, only the induced voltage part of V remains as the voltage amplitude of the neutral point of the stator winding of the motor 5C.

As is clear from FIG. 18, the amplitude is synchronized with any of the phase voltages u, v, w and has a frequency three times the frequency of the phase voltage.

Therefore, by extracting the amplitude of the neutral point voltage and adjusting the timing of the oscillation signal and the phase due to the self-oscillation of the starting circuit, that is, in the position detection circuit, the amplitude of the neutral point voltage is determined.
The control device is established by taking measures such as delaying the 90 ° phase.

In the above description, the position detection signal J3 is a signal that is logicalized by comparing the shift signal I3 ′ at the center of the amplitude, but as explained in the start circuit of FIG. 12, the amplitude level of the shift signal I3 ′ is , The shift signal I3 ′ is directly input to the starting circuit 2c if the amplitude of various levels excluding the output accompanying the self-oscillation of the starting circuit is sufficiently large and the gain when operating as an amplifying function of the starting circuit is sufficiently large. You can

Further, when the shift signal I3 'is advanced by 90 ° with respect to the original position detection signal I3 and is shifted as much as possible to have a phase, the shift signal or the shift signal is logicalized as in the case of FIG. The present control device can be configured by using the position detection signal as the synchronized position detection signal inverted by the starting circuit.

As described above, in the control device of FIG. 17, the original position detection signal is obtained from the neutral point of the stator winding of the motor 5c, but as shown in FIG. 19, the resistance Ru having the same resistance value, It is generally known that a voltage amplitude similar to the neutral point of the stator winding can be obtained by combining the voltage supplied to each stator winding of the motor 5d and the induced voltage generated by Rv and Rw. ing.

Therefore, by using the voltage obtained by the resistance combination as the original position detection signal, it is possible to configure a control device exactly the same as that shown in FIG.

Further, as described above that the position detection signal J3 is three times as high as the frequency of each phase voltage of the motor 5c according to the explanation of FIG. 17, the decoding circuit inputs the signal shown in FIG. Oscillation signal E3, or by sending the drive signal U, V, W, Z; X, Y from the signal of the synchronized position detection signal F3 obtained via the start circuit by the position detection signal J3, that is, the motor It has been clarified that a three-phase motor of this type can be driven by one position detection signal having a frequency three times as high as the phase voltage frequency.

This means that when the means for detecting the position of the rotor of the motor is provided in the motor, the position of the rotor of the motor is detected during one cycle of the frequency of the voltage supplied to the stator winding of the motor. Conventionally, if the signal for detecting 3 has three amplitudes at equal intervals, the position detecting means of the rotor of the motor is 3
What was obtained by sending the three signals to the control device side is aggregated into only one signal.

For example, in the case of a motor equipped with a Hall element, the rotor magnetic poles detected by the Hall element are provided with position detecting magnetic poles three times the number of magnetic poles at equal intervals in the rotation direction, or are rotated together with the rotor. Similarly, magnets each having three times as many magnetic poles as the magnetic poles of the rotor are provided at equal intervals in the rotation direction, and one Hall element is attached to the non-movable portion so as to face the magnets. As a result, it is possible to easily obtain a signal that is completely equivalent to the original position detection signal having a frequency three times the phase voltage frequency of the motor.

The original position detection signal having a frequency three times the phase voltage frequency of the motor thus obtained is shown in the explanation of FIG. 17 and FIG. 18 by selecting the position detection position in the motor. It is obtained as a signal in phase with the shift signal I3 '.

Therefore, as shown in FIG. 20, the rotation of the rotor of the motor 5e causes the phase voltage frequency of 3 to be supplied to the motor 5e.
By using the original position detection signal I5 sent from the original position detection unit G which can obtain a signal of double frequency, the motor 5e can be driven by the configuration of the control device which is exactly the same as that of FIG.

Now, the decoding circuit of the control device shown in FIGS. 14 and 20 is a drive signal U, V, with respect to the input oscillation signal E2 and synchronization position detection signal F2 as shown in FIG. It must be a circuit that sends out W, Z, X, Y.

In FIG. 14, three position detection signals are encoded to be converted into one code signal.
The signal input to the decoding circuit as a result is the same as the code signal of FIG. 14, although there is a difference in the original position detection signal.

Therefore, in any of the control devices, a decode circuit that performs an operation reverse to that of the encoding shown in FIG. 14 is used to obtain a decode signal equivalent to three position detection signals, and FIG. Although the decoding circuit required for the control device of FIGS. 14 to 20 can be realized by inputting the decode signal to the decoding circuit shown in FIG. 25 and the control device example of the present invention shown in FIG. A more simple and extremely effective method is shown in FIG. 21 as an example of the decoding circuit and will be described.

In FIGS. 21A and 21B, 18a to 18d are shift registers, 16b and 16c are inverting circuits, and 17a and 17b are NOR circuits.

In the case of FIG. 21 (a), a shift register 18a for inputting a signal F4 having a duty ratio of 50% corresponding to a synchronization code signal as a clock pulse and an inverted signal ▲ ▼ obtained by inverting the signal F4 by an inverting circuit 16b. A shift register 18b that receives a clock pulse as an input is a main component.

The shift register 18a performs a NOR operation on the output signal U of the first shift terminal Q11 and the output signal V of the second shift terminal Q12 of the shift register 18a so that the shift register 18a operates to divide the signal F4 into 1/3. Data d1 to which the output of 17a should be shifted by itself
The first shift register circuit S1 is input to the data input terminal D1 as described above, and the shift register 18b is the second shift register circuit S2 that obtains the data to be shifted from the first shift terminal Q11 of the shift register 18a. Now, both shift registers 18a and 18b perform a shift operation at the rising edge of the input signal, and the data shift order is the data input terminal → the first shift terminal → the second shift terminal → the third shift terminal disappears or a shift other than the above. It shall be performed in the order of terminals.

When the signal F4 is input after the circuit configured as described above is reset, the signal F4 is generated by the shift register 18a and the NOR circuit.
A signal that is divided into 1/3 by the shift count operation performed by 17a and has one cycle of the signal F4 as a logical HIGH level and two cycles as a logical LOW level is output from the respective shift terminals Q11, Q12, Q13. Output as output signals U, V, W.

Since the output signals U, V, W have one cycle for three cycles of the signal F4, if expressed by the electrical angle of the output signal itself, the signals are sequentially sent for one cycle of the signal F4, that is, with a phase difference of 120 °. Will be done.

This fact is something everyone knows.

Now, the shift register 18b outputs an inverted signal of the signal F4 ▲
Since the shift operation is performed by ▼, the electrical angle of the signal F4 is 180 °, and the electrical angle of the output signal of the shift register 18a is 60 °.
The shift operation is performed when the phase is delayed by a degree.

Further, since the shift register 18b obtains one of the output signals of the shift register 18a as the data to be shifted, the resulting overall output signal has the same waveform as the overall output signal of the shift register 18a. Then, the signal is delayed by 60 °.

This state is shown as a timing chart in FIG.

As is clear from FIG. 22 (a), the signals output from the shift terminals of the shift registers 18a and 18b.
U, V, W, Z, X, Y are the drive signals U, V, W, Z, X, Y in FIGS. 16 and 18.
Is the same as

Therefore, as a result of the present invention so far, only one signal is inputted to the starting circuit, but the control device uses the circuit of FIG. 21 (a) as a decoding circuit.
It is not necessary to perform the decoding as described above to restore the three signals, and the motor can be started and constantly driven by directly inputting the synchronization code signal and the oscillation signal.

In FIG. 21 (b), a signal F4 having a duty ratio of 50% corresponding to the input synchronization code signal is directly input to the shift register 18d as a clock pulse, and the signal F4 is input to the inverting circuit 1
The inverted signal ▲ ▼ inverted by 6c is the shift register 18
The first shift register circuit, which is input to c as a clock pulse, performs a shift count operation in which the shift register 18c divides the inverted signal ▲ ▼ into 1/3 together with the NOR circuit 17b as shown in FIG. 21 (a). The shift register 18d that constitutes S1 is a second shift register circuit that performs a shift operation by using one of the output signals of the shift register 18c as data to be shifted.

Also in this case, both shift registers 18c and 18d are shown in FIG. 21 (a).
Similar to the above, assuming that the shift operation is performed at the rising edge of the input signal and the operation is performed in the data shift order, when the signal F4 is input to the circuit configured in this way, the shift register 18c outputs the inverted signal ▲ The output signal obtained by dividing ▼ into 1/3 is sent by the electrical angle of the output signal divided by 180 ° by the electrical angle of the input signal F4 after the input of the signal F4.
It is output after the phase is delayed by 0 °.

This is because the inversion signal ▲ ▼ divided in 1/3 is the inversion of the signal F4 with a duty ratio of 50%, so the shift register 18c performs the shift count operation at the falling edge of the signal F4. Because it is the same. Next, the shift register 18d performs a shift operation at the rising edge of the signal F4, and the shift register 18c outputs an inverted signal ▲ at the falling edge of the signal F4.
Since the shift count operation is performed by ▼, the operation of each shift register is
Is started prior to the shift register 18c.

However, since the first shift register 18d does not output the frequency-divided output at the time of the shift operation, the shift register 18c remains at the logic low level.

Therefore, even if the shift register 18d performs the shift operation,
The output of the shift register 18d does not change.

From this, the shift register 18d sends the changed signal because the signal F4 is output from the time when the shift terminal of the shift register 18c, which has obtained the data to be shifted by the shift register 18d, starts sending the frequency-divided output signal. 180 electrical angle
This is because the phase is delayed by 60 ° due to the electrical angle of the divided output signal.

From the above, the shift register is the same as in Fig. 21 (b).
18c directly outputs an output signal obtained by dividing the inverted signal ▲ ▼ into 1/3, but as a result, the signal F4 is divided into 1/3.
The output signal from the signal F4 for one cycle is a logical high level, and two cycles are a logical low level. The output signal from each shift terminal is one cycle of the signal F4. That is, the signals whose phases are delayed by 120 ° in terms of the electrical angle of the output signal divided by 1/3 are output in the shift terminal shift order.

Since the shift register 8d uses one of the output signals of the shift register 8c as data, it outputs an output signal having the same waveform and a phase delay of 60 ° in electrical angle of the output signal.

This situation is shown as a timing chart in FIG.

As is apparent from this figure, the output signals U, V, W, Z, X and Y output from both shift registers 18c and 18d are all the same as in the case of FIG. 22 (a).

Therefore, if the signal F4 is input as the synchronization code signal and the oscillation signal, the motor can be started and steadily driven by using the output signals of both shift registers as drive signals.

However, as can be seen by comparing the timing charts of (a) and (b) of FIG.
The output signal of FIG. 22 (a) and the output signal of FIG. 22 (b) have a phase difference of 180 ° in the electrical angle of the signal F4. This means that when the decoding circuit according to this method is used, the operation of the decoding circuit as a whole can be positive or negative with respect to the signal F4 simply by exchanging the signal F4 input to both shift registers and the inverted signal ▲ ▼. It means that it can be done in logic.

As described above, in FIGS. 21 (a) and 21 (b), the description has been made under the condition that the operation of the shift register is performed at the rising edge of the input clock pulse. However, the signal F4 and the inverted signal ▲ ▼ are input. It is possible to operate both shift registers at the falling edge of the clock pulse because it can be operated with positive logic or negative logic with respect to the input signal F4, by exchanging the shift register in the decoding circuit. Even if you use, it can be used as a decoding circuit.

If one shift register in the decoding circuit shifts at the rising edge of the input clock pulse, the other shift register shifts at the falling edge of the input clock pulse. It can be easily understood that the inverting circuits 16b and 16c for inverting F4 in FIGS. 21A and 21B can be omitted.

Hereinafter, the shift register of the first shift register circuit S1 will be referred to as a shift register on the shift count operation side, and the shift register of the second shift register circuit S2 will be referred to as a shift register on the shift operation side.

22 (a) and 22 (b) are output signals output from the first shift terminal of the shift register on the shift count operation side for dividing the signal into 1/3 by using the input signal as a clock pulse. The shift register on the shift operation side was operated as the data to be shifted, but the data to be shifted on the shift register on the shift operation side can be obtained from another shift terminal on the shift register on the shift count operation side. Good.

This is because the output signals of the shift terminals, which are output by the shift count operation that divides the frequency by 1/3 of the shift register that uses the input signal as a clock pulse, have the same phase difference only with a phase difference of 120 °. Therefore, no matter which output signal of the shift terminal is selected, the output signal of the shift register on the shift count operation side has a phase delay of 120 ° or 240 °, based on the case of FIG. This is because the output is only started.

That is, if the data to be shifted is obtained from the second shift terminal, it is 120 °, and if it is obtained from the third shift terminal, it is 240 °.
Output starts after a delay.

Therefore, according to the shift terminal selected as the data to be shifted, the output signal of the shift register on the shift operation side is replaced with the energization control element in the three-phase inverter circuit driven as the output signal of the decoding circuit. However, the function as the decoding circuit is not damaged.

Further, in FIG. 21, in comparison with the three-phase inverter circuit shown in FIG. 26, the shift register on the shift count operation side shows that the energization control elements 4a to 4c on the upper arm side of the three-phase inverter circuit 4 are arranged.
The shift register on the shift operation side, which outputs an output signal for driving each of the shift count side and shifts one of the signals output by the shift register on the shift count side, is the energization control elements 4d-4f on the lower arm side of the three-phase inverter circuit 4. The output signals are sent to drive each of the output signals U, V, W, Z,
As can be seen from the waveform timings of X and Y, if the output signal of the shift register on the shift count side and the output signal of the shift register on the shift side are compared with each other. The output signal of the shift register on the shift operation side has a phase delay of 60 ° with respect to the output signal of the shift register on the shift count operation side.

That is, the output signal Z is output for the output signal U, the output signal X is output for the output signal V, and the output signal Y is output for the output signal W.
It has a phase delay of 60 °.

However, if the output signals of the shift registers are individually compared with each other, the phase relationship is, for example, with reference to FIG. 22, an output signal V for the output signal Z, an output signal W for the output signal X, and an output signal W for the output signal X. The output signals of U have a phase delay of 60 ° with respect to Y.

However, with respect to the output signal U with respect to the output signal Y, the output signal U has a phase lead of 300 °, which is equivalent to a delay of 60 ° for a signal delayed by one period.

From the above, the output signal of the shift register on the shift count operation side is used as the drive signal for the lower arm side of the three-phase invertor circuit 4, and the output signal of the shift register on the shift operation side is used for the upper arm side of the three-phase inverter circuit. It can also be a drive signal.

As described above, the degree of freedom in design when the circuit shown in FIG. 21 is used as a decoding circuit, that is, selection of negative logic correspondence / positive logic correspondence for the input signal F4, rising operation for the clock pulse of the shift register, rising Freedom in design due to selection in various places such as selection of down operation, selection of output signal destination to three-phase inverter circuit of each shift register, selection of data to be shifted in shift register on shift operation side You get a degree.

As described above, the use as the decoding circuit shown in FIG. 21 is achieved by using the signal F4 as a simple clock pulse for the signal F4 input as the synchronization code signal or the oscillation signal in the present invention. Since the drive signal necessary for driving the inverter circuit is output in a format such as ring count, the output signal with respect to the input signal F4 does not necessarily have to be strictly matched.

Further, the drive signal necessary for the three-phase inverter circuit has the same waveform when the energization control element of the three-phase inverter circuit is driven at 120 ° energization, with the 1/6 cycle of the drive signal as the minimum unit. Since the signal F4 has a duty ratio of 50% and has a frequency three times as high as that of the drive signal as an output signal as the bottom condition, The circuit shown in FIG. 21 can be used as a decoding circuit according to the present invention.

Therefore, in the present invention, a code signal obtained by encoding three position detection signals into one, a code signal obtained from the amplitude of the neutral point voltage of the stator winding of the motor, and magnetized to three times the number of poles of the motor. Since the code signal and the like obtained by the detecting means provided for detecting the rotor side magnetic pole satisfy all of the above-mentioned bottom conditions, the circuit of FIG. 21 can be adopted as a decoding circuit.

In the description of the decoding circuit, the description has been given with the timing after resetting both shift registers, but without resetting, if the signal F4 is input for three cycles or more,
Output signals can be obtained from both shift registers at the timings shown in FIG. The reason is that even if the shift terminals of both shift registers are output signals whose levels are randomly set at the initial power-up, etc., if the signals are sequentially shifted by the input of the signal F4, the output signals after the third shift terminal are This is because it disappears or is shifted to an unnecessary shift terminal and does not affect subsequent output signals.

Therefore, while the signal F4 is input for three cycles or more, for example, the power supply voltage of the three-phase inverter circuit is not applied, or the output signal from the decoding circuit is not applied to the three-phase inverter circuit. If so, the initial reset in the decoding circuit can be unnecessary.

〔The invention's effect〕

As described above, according to the present invention, by inserting the starting circuit in series between the position detecting signal system between the position detecting circuit and the decoding circuit, the oscillation circuit and the pseudo signal for only starting the motor of the related art have been conventionally used. It is possible to eliminate various circuits such as a generation circuit, a selection circuit for selecting a pseudo signal and a signal required for closed loop drive, and a determination circuit for determining the selection.

Further, since the present invention can be applied to a control device in which a motor is provided with a position detecting means and a control device utilizing an induced voltage generated in a stator winding of a motor, most of conventional control devices can be applied. Can be applied to.

The above-mentioned start-up circuit can have a function of converting the input signal into a logical signal necessary for the decoding circuit by giving a sufficient gain to the input signal,
With this function, it is also possible to configure a starting circuit by using a comparator for logicalizing a conventional position detection signal.

Therefore, the above-mentioned various circuits used only for starting the motor can be removed by adding a few parts to the position detection circuit in the closed loop drive in the conventional control device.

Alternatively, the starter circuit may be an amplifier for the minute position detection signal input to the oscillator and a comparator may be provided in the latter stage to provide a logicalized position detection signal. This is
The same can be applied to a device which previously obtains an original position detection signal having a frequency three times the phase voltage frequency of the motor.

Further, by using an encoder circuit for converting three position detection signals as shown in FIG. 15 into one signal and a decoding circuit as shown in FIG. A starter circuit that sends out multiple oscillation signals as shown in Fig. 11 can be used to start the motor with a starter circuit that has only a single oscillation signal, or to drive the motor steadily. It is possible to solve the troublesomeness in designing and further simplify the control device.

Further, by not performing the operation of encoding the three position detection signals into one as described above, but by making the original position detection signal a frequency three times the phase voltage frequency of the motor, that is, the stator of the motor. An original position detection signal is obtained from the neutral point voltage of the winding or a virtual neutral point, and a position detecting means is provided to detect magnetized magnetic poles three times the number of poles of the rotor in the rotor in a cycle. By obtaining the above, the position detection signal system can be made one and the starting circuit can be configured by a circuit for sending a single oscillation signal.

The decoding circuit according to the present invention can send a driving signal for a three-phase inverter circuit energized at 120 ° almost directly to one input signal, so that it has a simple structure and an input signal. Since it is simply used as the clock pulse of the shift register, the drive signal holds the state except the rising and falling edges of the clock pulse.
Also, since one of the shift registers used in the decoding circuit uses the output signal of the other shift register as the data to be shifted, it is uniquely determined by the relationship of the output signals of the two shift registers. It is possible to prevent a short circuit between the upper and lower arms of the driven three-phase inverter circuit, which is a fatal condition for the control device.

As described above, according to the present invention, in the case where the motor is provided with the position detecting means using the Hall element or the like, the rotors in the motor are equidistantly arranged at positions three times the number of magnetic poles necessary for the motor to rotate. By only providing magnetic poles for detection, one that conventionally required three original position detection signals is now one, and the wiring between the motor and the control device can be significantly reduced.

Further, in the case of utilizing the induced voltage generated in the stator winding of the motor, various circuits conventionally used only for starting can be eliminated.

Therefore, the control device can be simplified, and the reliability of the control device can be improved and at the same time the cost can be reduced.

[Brief description of drawings]

1 and 2 are block diagrams for explaining the main points of the present invention. FIG. 3 is a block diagram showing an operation function of a starting circuit according to the present invention. FIG. 4 is a relationship between an induced voltage generated in a stator winding of a motor to which the present invention is applied and an oscillation signal frequency for synchronous drive. The graph showing. FIG. 5 (a) is a block diagram for explaining the self-oscillation operation of the starting circuit used in the present invention. FIG. 5B is a Nyquist diagram when the conditions for self-oscillation are satisfied. FIG. 6 is a block diagram of FIG. 5 (a) constructed using an operational amplifier. 7 (a) and 7 (b) are timing charts showing waveforms of various parts when FIG. 6 is operated under predetermined conditions. FIGS. 8 (a) and 8 (b) are an example in which FIGS. 6 and 7 are embodied, and FIG. 8 (a) and FIG. 7 show an operation which corresponds to FIG. 7 (a). FIG. 8 (b) shows the operation corresponding to (b). FIG. 9 is a block diagram showing an example of a starting circuit corresponding to a plurality of position detection signals. FIG. 10 is a block diagram showing another example of a starting circuit having the same function as in FIG. FIG. 11 is a block diagram showing still another example of a starting circuit having the same function as in FIG. FIG. 12 is a block diagram showing the configuration of the control device when one of the starting circuits shown in FIGS. 9 to 11 is applied. FIG. 13 is a timing chart of various signals according to FIG. FIG. 14 is a block diagram showing the configuration of a control device in which a plurality of position detection signals are encoded into one signal and the starting circuit is configured to send out a single oscillation signal. FIG. 15 is an example of the encoder circuit according to FIG. FIG. 16 is a timing chart diagram of various signals according to FIG. FIG. 17 is a block diagram showing a configuration of a control device according to the present invention when a signal required for position detection is obtained from a neutral point of a motor. FIG. 18 is a timing chart of various signals according to FIG. FIG. 19 is a diagram showing an example of a case where a virtual neutral point is obtained as a destination from which a signal for position detection in FIG. 17 is obtained. FIG. 20 is a diagram showing an example of a case where the position detecting means provided in the motor is obtained as a destination for obtaining a signal for position detection in FIG. 21A and 21B are circuit diagrams showing an example of a decoding circuit applicable to the decoding circuit in FIGS. 14 and 17. FIGS. 22 (a) and 22 (b) are timing charts of various signals according to FIGS. 21 (a) and 21 (b), and FIG.
FIG. 22 (a) and FIG. 22 (b) correspond to FIG. 21 (b). FIG. 23 is a block diagram showing the configuration of a conventional control device for a motor having position detecting means in the motor. FIG. 24 is a block diagram showing an example of the configuration of a conventional control device when the induced voltage generated in the stator winding of the motor is used. FIG. 25 is a block diagram showing the configuration of another conventional control device that uses an induced voltage similar to that shown in FIG. FIG. 26 is a block diagram showing the configuration of a three-phase inverter circuit for supplying power to a motor by the control device of the present invention and the conventional control device. The same symbols indicate the same or similar functions. 1 and 1a to 1f ... position detection circuit 1b1 ... initial position detection circuit 1b2 ... encoder circuit 2 and 2a to 2c ... start circuit 3 and 3a to 3e ... decoding circuit 4 ... three-phase inverter circuit 5 and 5a 〜5g …… Motor 6 and 6a ～ 6c …… Amplifier 7 and 7a ～ 7c …… Feedback unit 9 …… Operational amplifier 8,8a ～ 8c …… Adding unit 10 …… Positive feedback unit 11 …… Negative feedback unit 12a 〜12d …… Coupling part 13a ～ 13d …… AND circuit 14 …… OR circuit 15 …… D flip-flop 16a ～ 16c …… Inversion circuit 17a, 17b …… NOR circuit 18a ～ 18d …… Shift register 19a, 19b …… oscillation circuit 20a ...... pseudo position detection signal generation circuit 20b ...... pseudo drive signal generating circuit 21a, 21b ...... selecting circuit 22a, 22b ...... switching threshold filter circuit R _P, R _N, R1~R9 ...... resistance C _1, C ₂ ...... capacitor L ₁ ...... coil v _+, v _- input terminal potential of the ...... operational amplifier

Claims (9)

[Claims] 1. A stator winding of a three-phase brushless motor having a rotor of a permanent magnet is connected to each of the output ends of a three-phase inverter circuit composed of an energization control element connected to a three-phase bridge, and the rotor is provided. A position detecting circuit for detecting the position of the position detecting circuit and transmitting a position detecting signal, and a decoding circuit for receiving the position detecting signal and transmitting a signal for turning on / off the energization control element in a timely manner. An amplifier circuit or a buffer circuit configured to be capable of self-oscillation when there is no signal by a feedback loop having an attenuation characteristic or a saturation characteristic and a feedback loop having a pure resistance characteristic between the circuit and the decoding circuit, A three-phase brushless circuit in which a starting circuit is inserted so that the amplitude levels of various signals in the circuit are sufficiently small with respect to the amplitude level of the input signal. Motor controller. 2. The position detecting circuit for transmitting a plurality of the position detecting signals, wherein the same number of the starting circuits as the number of the position detecting signals are inserted in series with each position detecting signal system, 3. The control device for a three-phase brushless motor according to claim 1, wherein the self-oscillation phase relations of the starting circuits are coupled to each other so as to satisfy the phase relation between the systems of the position detection signals. . 3. The position detecting circuit for sending out a plurality of the position detecting signals, wherein the starting circuit is inserted in series with one system of the position detecting signals, and the other position detecting signal systems are provided with: 3. The three-phase system according to claim 1, wherein a synchronous oscillation circuit coupled to the starting circuit is inserted in series so as to transmit a synchronous oscillation signal satisfying the same phase relationship as the position detection signal. Controller for brushless motor. 4. The position detecting circuit for sending out a plurality of the position detecting signals, wherein the starting circuit is inserted in series with one system of the position detecting signals and is synchronized with another system of the position detecting signals. The oscillator circuit is inserted in series, and the synchronous oscillator circuit sequentially sends the synchronous oscillator signals starting from the self-oscillation of the startup circuit so as to have the same phase relationship as the position detection signal. The control device for a three-phase brushless motor according to claim 1, wherein the two are connected to each other. 5. The position detection circuit includes an initial position detection circuit for detecting a position corresponding to each phase of the three-phase brushless motor, and a plurality of initial position detection signals sent from the initial position detection circuit. The encoder circuit according to claim 1, wherein the encoder circuit is configured to transmit a code signal having a frequency three times the frequency of the initial position detection signal. Phase brushless motor controller. 6. The position detection circuit receives the voltage amplitude of a neutral point of a Y-connected stator winding of the three-phase brushless motor as an input. Controller for three-phase brushless motor. 7. The three-phase brushless motor according to claim 1, wherein the position detection circuit receives a voltage amplitude of a virtual neutral point of a stator winding of the three-phase brushless motor as an input. Control device. 8. A position provided by the position detecting circuit for detecting position detecting magnetic poles magnetized at equal intervals to three times the number of magnetic poles of the rotor mounted on the rotor of the three-phase brushless motor. The control device for a three-phase brushless motor according to claim 1, wherein a signal sent from the detection element is input. 9. The decoding circuit includes a first shift register circuit that performs a shift count operation for dividing an input signal into 1/3, and one of the shift count outputs of the first shift register circuit as shift data. , A second shift register circuit that performs a shift operation for shifting the shift data, and the second shift register circuit and the first shift register circuit are 180 ° out of phase with each other in electrical angle of the input signal. The control device for a three-phase brushless motor according to any one of claims 5 to 7, characterized in that it is configured to perform each operation at the point of time.