JPS5899288A - Controlling method for synchronous motor - Google Patents

Abstract

PURPOSE:To control the speed of the synchronous motor readily and to perform fine, resposive control by providing a pulse encoder, a reversible counting means, a computing means, and a converting means, and generating the phase of an induced electromotive voltage. CONSTITUTION:The pulse encoder 2 outputs both a position pulse train and rotary pulses. An up down counter 4 presets the position of the rotor of the synchronous motor 1 by the position pulse train and performs the reversible counting by therotary pulse. A processor 8 computes three phase current command values IU, IV, and IW from the value of costheta and the value of sintheta which are obtained based on the counted value of the counter 4. A DA converter 9 converts said three phase current command values IU, IV, and IW into analog values. In this way, since the phase of the induced electromotive voltage is generated, the synchronous motor 1 can be controlled by the similar way as a DC motor, the speed control can be made more readily, the torque generation control is made easy, and the fine, responsive control can be performed.

Description

[Detailed description of the invention] The present invention is a Hiro synchronous motor, especially a rotating field type synchronous motor 1iK.
Concerning a suitable synchronous motor control method, which allows speed control to be simple and fine-grained, a rotating field type synchronous motor uses the armature as a stator and the field pole as a rotor* fixed pre-winding (electrical pre-winding l1)
) A rotating magnetic field is generated by applying K three-phase alternating current, and the field pole is pulled by the rotating magnetic field, causing the field a pole to rotate at the same speed as the rotating magnetic field.

The speed control of such a synchronous motor is more complicated than that of a DC motor, and the configuration of the control circuit is also complicated. Synchronous Tortoise 5T enables torque generation control equivalent to that of an electric motor, allowing for fine-grained control with immediate response.
It is an object of the present invention to provide an r-as control system.Furthermore, it is an object of the present invention to provide an intermediate electric motor IIJJ control system that can achieve torque generation control similar to that of the riItIL motor of the present invention with a simple configuration. for other purposes.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the principle of torque generation in a shunt-wound DC machine. As shown in Fig. 1(a), the shunt-wound DC machine consists of an armature in which an armature winding λW is wound around an Amart air AM, and this armature is installed in a pair of fields. . This torque generation mechanism is as shown in Figure (b) of jI11, where the main magnetic flux φ of the field i11 pole FM generated by the stator is
W's armature current is switched so that the generated torque T is directed in the direction of rotation, and the generated torque T is expressed by the following equation.
In a shunt DC machine, if the main magnetic flux φ is constant, the generated torque T
is compared to armature electrician a, and the control of torque and speed is extremely good! On the other hand, as shown in the configuration wAK in Figure 2, a rotating field type synchronous motor has a field pole M1 rotor and a Kameko@@SW stator, and the main field pole RM is The armature current t-1 current of the armature winding SW is used to switch so that the torque generated per magnetic flux is directed in the direction of the rotational force. Generated torque and IE of rotating field type synchronous motor
The machine current relationship is that the main magnetic flux φ in equation (1) above is the field a.
The amperage current La can be made to correspond to the main magnetic flux vector φ$ of the one-pole kLM and the current vector Im of the electric machine prewinding @SW, and therefore, the generated torque T of the synchronous motor is expressed by the following equation OT = to/−φa −Is, ttmr
(21 Here, r is the phase difference between the armature current Is and the induced electromotive force EO, referring to the equivalent circuit diagram of the synchronous motor in Figure 5.
resistance, Xi is 9 synchronous reactance taking into account armature reaction and armature leakage. Therefore, if the induced electromotive force EO and armature leakage fils are made in phase, in other words, the main magnetic flux φS The torque T given by the dynamic type becomes T = 'φ-Is (3), which is exactly equivalent to the torque generation of a DC motor, and is frugally equivalent to the torque generation of a synchronous motor. Therefore, in the present invention, the position of the field pole (which is also the phase of the main magnetic flux, which is 90 degrees out of phase with the induced electromotive force Eo) is detected, and the field pole is adjusted to correspond to the position. The basic concept is to generate a current command with a phase, apply this ttIL command to the armature winding of the 13th stage electric motor, and drive and control it in the same way as a - period electric WAt DC motor.And 1. The present invention. The structure for detecting the position of the field pole is simple, and the position detection signal can be handled in the same manner as the phase signal used to control the speed of the rotor.

FIG. 4 is a diagram showing an embodiment of the synchronous motor control method of the present invention.

In the figure, 1 is a rotating field type synchronous motor, and 2 is a pulse encoder that is inserted into the shaft of the synchronous motor 1 to generate various position signals.About this pulse encoder 2 , 5 @ and 6 block diagram, 7
This will be explained in detail using the circuit diagram and No. 8 @Operation explanation rIAt. ) The pulse encoder 2 has a code &23 provided on a rotating shaft 20 directly connected to the shaft of the synchronous motor 1, and includes a light emitting element 22 such as a light emitting diode for obtaining a position signal ta of a code plate 25, and a photo i° diode. A light-receiving element 21 such as the one shown in FIG.

Further, the 0 code plate 23 on which the output circuit 24 is provided has, as shown in FIG. 6, a phase A→track 3, a phase B→track b1, a z phase track C, and a code track d that fits from the 4 tracks are formed on concentric circles. .

In the human phase and B phase tracks a and b, a pattern is formed such that a nine-turn pulse train with a phase shift of 1c/2 is generated when the code plate rotates.In the two-axis track C, the synchronous motor 1 rotates once. A turn is formed in such a way that one pulse is generated every time the pulse is turned. on the other hand,
The code track d consists of 4 tracks, and the notches of each track are formed so that a different 4-bit position code is generated corresponding to each rotation angle of the code plate, and a gray code is used as the position code. . and the seventh
As shown at @, the light receiving element 21 is composed of seven elements 21- to 210 corresponding to each track of the code plate 25.
1a is physiognomy 12728% element-21b or B phase hook b
.

The element 21c corresponds to the Z-phase track C, and the four elements 21d correspond to the code track d. As shown in the output circuit diagram of FIG. 7, the elements 21g to 21c are connected to amplifiers 24a to 24cK, respectively, while the four elements 21d are connected to a parallel-to-serial converter znct (hereinafter referred to as a p8 converter). The P8 converter 24d is connected to the pulse generator 24a, and uses four elements 21d to coat the 4-bit position of the reading hole code plate 2S with pulses 11 and 2.
For example, the above-mentioned 4-bit position code is set, and an up/down counter that counts down the output pulses of the pulse generator 24e and an up/down counter that counts down the output pulses of the pulse generator 24e are used. When the value of the down counter becomes zero and 9 o'clock, it can be considered that W# is formed by the passage t of the output pulse of the gate-on-gate pulse generator 24e and the gate circuit that blocks it. This P8 converter 2
4d outputs the number of pulse trains corresponding to the position code to the output terminal tA', and also outputs the pulse train B' to the output terminal up to a phase difference of π/2 from this pulse train, and further outputs the pulse train B' to the output terminal during the generation time of the pulse train. On the other hand, the switching circuits 24g and 24bK, which are composed of a pair of AND gate circuits and an OR gate circuit, are inverted by this control signal circuit and the inverter 24f, and the statement control signal 2 is input. Perform switching operation.

The switching circuit 24g receives the human phase rotation pulse from the amplifier 24m and the position pulse train from the A' output terminal of the P8 converter 24d, and outputs the position pulse train when the control signal 2 is on, and outputs the position pulse train when the control signal 2 is off. Occasionally, a human phase synchronized pulse train is generated. Similarly, the switching circuit 24h has an amplifier 2.
When the B-phase rotation pulse from 4b and the position pulse train from the B' output end of the P8 converter 24d are input manually, and control NI No. 2 is on, the position pulse train is output, and the control signal 2
When is off, a B-phase rotation pulse train is generated. Valley switching circuit 24g, 24 has line drivers 24i, 24j
K is connected, and its output is given to the outside. Also, element 21c
The two-phase pulse output from the amplifier 24C, ? The clear signal CL is output to the outside of the P8 converter 24k via the intriver 24k. Referring to the operation explanatory diagram in FIG.
is man-powered. At this time, the synchronous motor 1 is not rotating,
The P8 converter 24d uses the clear signal CL as a tri-power to read the 4-bit code signals of the four elements 21d, that is, the position of the field pole, and changes the phase of the pulse train A' of the number corresponding to the code and the pulse train A' by π/2. Generates a shifted pulse train B' and generates a control signal 2 at
ll, and each pulse train A' is output from each switching circuit 24'g, 24+.

B' is output, and J! line driver 24i, 24j
The generation period of this control Iia signal 2 is the field pole position detection period DT, and the falling edge of the control signal 8 switches the switching circuits 24g, 24h to the amplifiers 24m, 24bll, During the servo control period 8R of the synchronous motor 1, the line drivers 24i and 24j output rotation pulses for each phase and B phase according to the rotation of the synchronous motor 1.
, From 24j onwards, during the position detection period L)T, a 1-position pulse is output, and during the following servo control period, during >B, the fly, human phase, and B-phase rotation pulses are output.・Such an output The circuit 24 is based on recent +a density integrated circuit technology.
With miniaturization, ε can be mounted on the 8-pulse encoder 2 itself.

Returning to FIG. 4, reference numeral 5 is a rotational direction determination circuit, and the output pulses of the pulse encoder 2's line and r-iha 24i, 24j are input, and the synchronous motor 10 detects the rotational direction and rotates in the forward direction. When it is, pulse encoder 2 is set to 4.
A positive pulse train PPt- is output at the same speed or four times the pulse speed generated from the pulse encoder 2, and when the rotation is negative, a negative pulse NPI at the same speed or four times the pulse speed generated from the pulse encoder 2 is output at iI4. 4 is an up/down counter, which counts up the positive pulse PPt from the rotation direction determination l1g1 path 5, and counts down to the negative pulse NP1. 5 is an interface circuit for exchanging commands and data with the outside; 5 directive VCMI)
is input to the 6#i bus line, an up/down counter 4, an interface circuit 5, a memory 7 to be described later,
Processor 8. It is a method for connecting iJA transformations and exchanging commands and data. 7 is a memory, and the processor 8 (2) # contains a phase conversion table for direct conversion and a speed conversion table for converting the difference in the count basket of the up/down counter 4 into the rotational speed WIL@ of the synchronous motor 1. Remember ◇ 8 is a processor as a calculation means, 1 consists of a microprocessor, for example,
The following processing is executed based on the block diagram in the memory 7.

(1) reads the contents of the up/down counter 4 at predetermined intervals, and reads the corresponding si from the phase conversion table in the memory 7.
n # basket, search possible θ value association.

(2) Find the difference between the content read from the up/down counter 4 at each predetermined period and the content read last time, and search the speed conversion table in the memory 7 for the actual speed T8At from the difference.

(3) Calculate the speed command (dIVcMiJ and the vibration from the actual speed ftsu Ti1iA to the 11th gear turtle - 15 as follows) received through the interface circuit 5t. )
-TSA) However, Σ(VCMD-TSA) -Σ(VCMD-'l'SA)
+ (VCML) - TSA) K, , is a constant O The current commands 1, a, Ilb f can be obtained as follows.

II a=I s *5jua II b=I 5-(2)-(5) The two-phase '#L flow command 11a obtained in steps (5) and (4).

I, b as below 5-phase current commands Iu, Iv, Iw K! Convert O Iu=11m i get=-UII-a-Fuilb 2 9 is a digital-to-analog converter (hereinafter referred to as DA converter)
Then, calculate the current command II of the 5-phase
Iu, Iv, Iwt7 analog voltage 1u, lv,
What are the 10 things that can be converted to Iw? This is an arithmetic circuit that calculates the difference between the h-older currents Iu, Iv, and Iw and the sliding current of an actual animal, and has the configuration shown in FIG. ylJ, each phase silver command current Iu, Iv,
Arithmetic circuits 10a, 10b, 10c that calculate the difference between Iw and actual phase currents Iau, Iav, and Iaw, and an arithmetic circuit that adds tfay and law detected by the current transformer and outputs the U-phase sliding current fiIau. 10d, and current boosters 10C110f and 10g, which are provided in each phase and amplify the current difference between the phases. 11 is a pulse width modulation circuit, 12 is an inverter controlled by the output signal of the pulse width conversion circuit, and an externally provided five-phase alternating current and a rectifier circuit (diode group) that rectifies the five-phase alternating current into direct current. and a capacitor), a DC voltage is applied. The pulse width modulation circuit 12 includes a sawtooth wave generation circuit MST8G generated in the sawtooth signal 8T81 as shown in FIG.
Comparators COMU, COMv, C0Mw.

Not Gate NOT, ~NOT,, Driver DV, ~D
V.

The inverter 12 has six power transistors Q.
+=Q· and ~Dst for the diode. Pulse-
ta41iaN1s11's comparator etJMu, (,
:L)My.

COMW compares the amplitudes of the sawtooth wave signal STS and three-phase father current signals iu, iv, and IW, respectively, and outputs iu, iv,
When iw is larger than the basket of b'rs, it outputs ``1,'', and when it is smaller, it outputs ``0#''.Now, focusing on iu, the comparator COMU outputs a pulse width change as shown in Fig. 11. g and a nine current command 1uC is output. That is, 1
u.

Three-phase current commands iuc, ivc, and iwc whose pulse widths are varied by 14-g according to the amplitudes of tv and tw are output. Next.

Not game) NOT, ~NOT, , driver circuits LIV, ~DV・are these electric current components uc, ivc
, iwcl into drive signals 8Q+ to 8Q-, and each power transistor Q+-Q@ that constitutes the inverter 12
◎Tao, 12' is the above-mentioned l[fL
#11 circuit for lit $4 Explain the operation of the circuit shown in the figure. When the power is turned on, the clear signal 2 is generated in the pulse encoder 2 as described in the song, and the factory circuit Position pulse trains A/ and B/ indicating the position am are output, and the one rotation direction discrimination circuit 3 receives the position pulse train A'.

From B' to this position pulse train A', H', the four consecutive axillary positive pulse trains PPz-output 0. In this case, the synchronous motor 1
is stationary without rotating, but the pulse encoder 2 generates the next position pulse train B with a phase shift of π/2 with respect to the position pulse train A'.
/l, so the rotation direction determining circuit 5 considers it to be a positive rotation and outputs a positive pulse train PPf. This positive pulse train PPFi is counted by the up town counter 4. As a result, the initial rotational position of the field S* of the synchronous electric motor Wk1 at rest is preset in the counter 4.The contents of the 0 counter 4 are periodically read by the processor 8 via the bus 1I4t, and the processor 8 Determine the fiber # cage and steel # values, and then set the commanded speed cage VCMLI.
The interface circuit 5, the bus network 6 receives the armature current amplitude Is (calculates it, and further calculates the two-phase turtle a control cage 1
1m and 11b are obtained, and from this, the 5-phase current command value Iu is obtained.

lma, Iw t'' is calculated and sent to l) A converter 9 via bus 6, and three-phase analog voltages 1u, Iv, Iw
Set i output. From then on, when the synchronous motor 1 rotates, the rotation direction discrimination circuit 5 generates a positive pulse PP or a negative pulse N P k 4m4 or similar depending on the rotation direction, and the up/down counter 4 counts this positive pulse PP1. The counter 4 counts up or counts down the negative pulse NPft, and updates St in the counter 4. Along with this, processor 8
takes the contents tm of the counter 4 every predetermined period and writes the corresponding w
While determining the e value and C08a value, the rotation speed value 'l'sA is determined from the difference between them, and the amplitude Isf is calculated from the first order speed VCMD, and the two-phase current command values 11a and l1 are calculated.
bf: Calculate 5-phase current command values Iu, Iv, I
wt-calculated and sent to the DA converter via bus line 6t;
By making the five-phase analog voltages Iu, Iv, and 1wi output such that they are 0 or more, the phase component t-4 of the induced electromotive voltage Eo can be obtained from the contents of the counter 4. After that, S The sliding electric currents Iu, iv, and Iw are determined by the actual phase currents Iau, lay, and Ia in the arithmetic circuit 10.
The difference is taken from w, and then the three-phase AC signal ju, iv which is the difference of seven.

tW is increased by Im and applied to the comparators COMU, COMV, COMW of the pulse control circuit 11. Each comparator COMU, COMV, COMW u Sawtooth wave signal s'rs and three-phase AC signal +u, iv,
It softens the amplitude of iw, pulse width modulates the nine three-phase current commands iuc, ivc, iwc (output) NOT, ~NOT, and driver D V t -D.
These inverter drive signals 8Qr-8Q, which output inverter drive signals 8Qt to 8Qs via V*t'', are input to the bases of each power transistor Q+-Q- constituting the inverter 12iH, and these power transistors Qs-Qs t on/off control, and three-phase silver flL is supplied to the synchronous motor 1. Thereafter, similar control is performed, and the synchronous motor 1 finally rotates at the commanded speed.

As described above, the present invention provides a pulse encoder that outputs both one-position pulse train and rotational pulse sounds.

The position of the rotor is preset according to the position pulse train, and a reversible counting means is provided to reversibly count the number of stitches according to the rotation pulse, thereby generating the phase of the induced electromotive force. can be controlled as desired,
When speed control becomes easier, torque generation control also becomes easier, and in addition to being able to perform finely responsive control, a single pulse encoder enables A&! Since the position pulse for the initial cage adjustment of the rotational position of the first trochanter and the rotation pulse during rotation can be obtained, individual pulse generation parts can be shared, making it possible to reduce the size and simplification of 11g. Matching adjustment is also easy ◎Also, the pulse encoder output me position pulse and rotation pulse are shared.

The number of output lines and line drivers is reduced, and manufacturing can be facilitated. Furthermore, since the position pulses are generated in the same format as the rotation pulses, the reversible counting means can handle them as the same signal without being aware of them. O1#1 The present invention has been described with reference to examples, but various modifications may be made within the spirit of the present invention, and these are not excluded from the scope of the present invention.

[Brief explanation of drawings]

#E1@l explains the torque generation principle of a shunt DC machine lol
L light diagram, 2nd diagram, explanatory diagram of rotating field type synchronous motor, 5th
The figure is an equivalent circuit diagram of a synchronous motor, and Figure 4 is a block diagram of an embodiment of the present invention. Figure 5 is the encoder configuration diagram of Figure 4,
6 is a block diagram of the arrangement shown in FIG. 5, FIG. 7 is an output circuit diagram of the encoder shown in FIG. 5, FIG. 8 is an explanatory diagram of the operation of the circuit shown in FIG. FIG. 10 is a circuit diagram of the pulse width modulation circuit and inverter of FIG. 4, and FIG. 11 is an explanatory diagram of the operation of the pulse width modulation circuit. 1...Synchronous motor, 2...Pulse encoder, 5.
...Rotation direction discrimination circuit, 4...Up/down counter, 5...Interface circuit, 6...Bus line, 7
...Memory, 8.. Processor, 9.. DA converter, 10.. Arithmetic circuit, 11.. Pulse width modulation circuit, 12.. Inverter. Patent Applicant Fujitsu Fanuc Co., Ltd. Agent Benken Tsuji Sangai 2 people 7th word Hayabusa 2nd Figure 3 6 S 7th WJ 2 9th g

Claims (1)

[Claims] The phase of the induced electromotive force of the synchronous motor is detected, a current command in phase with the skeleton phase is generated, and the electric machine pre-charge fI1. In a synchronous motor control system that controls the rotor in a fluid manner, a pulse encoder detects the position of the rotor of the synchronous motor and outputs a position pulse train -5, and also outputs a rotation pulse train when the synchronous motor rotates; A numerical value corresponding to the position of the rotor is preset by two rows, and the rotation pulse is calculated based on the counts of a reversible stitch count means that reversibly counts the rotation pulse in a positive or negative direction depending on the rotation direction, and a cough reversible count means. -q am #, su
a calculation means for calculating a three-phase current command ILt from #;
DA that converts the current command value of the calculation means into an analog voltage
A synchronous motor control method in which a converter is provided, and the pulse encoder switches and outputs the skeleton position pulse train and the phase pulse.