JPS5837797B2 - Linear synchronous motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a control device for a polyphase synchronous motor powered by a polyphase power converter, and in particular to improvements in the relative position signals between the armature and the field, which are essential for the synchronous motor. This relates to the control of power conversion devices based on

Hereinafter, the present invention will be explained in detail, focusing on power supply control using a sirisk converter of a linear synchronous motor to which the present invention is most suitable.

Cyrisk conversion device, that is, as an AC conversion device, it is an inverter for DC-AC conversion where the input is direct current (DC) and the output is alternating current (AC), or an inverter for AC-AC conversion where the input is alternating current (AC) and the output is alternating current (AC). There are cycloconverters, etc., and since cycloconverters can directly convert alternating current (AC) to alternating current (AC) of a different frequency, they have a wide range of applications.

Until now, the load of an AC converter is energized by a synchronous motor, etc., and the frequency and voltage of the AC output are controlled by the AC converter.
Circuits that vary the current have been put into practical use.

Figure 1 shows AC converters c/c u , C/C v ,
This is a block diagram of control when a C/Cw is used and the load is energized, for example, a linear synchronous motor LSM. The secondary sides of the power transformers Tru, Trv, and Trw are connected to AC converters C/Cu, C/Cv, and C/Cw.

Output terminal U of AC converter C/Cu, C/Cv, C/Cw
p, vp, wp are connected to the armature windings U, V, W of the linear synchronous motor LSM, and the AC converter C/C u,
C/Cv t C/Cw's other output end UN,
vN, wN are the armature windings U, V of the linear synchronous motor LSM
, W to the neutral point 0.

F is a field winding of the linear synchronous motor LSM, which is energized by a separate field excitation device (not shown).

Ipu, Ipv, and Ipw are current command signals for each phase, and the signals from the position detector PD that detects the rotation angle of the rotor of the linear synchronous motor LSM are converted into rectangular waves or sine waves.
This is multiplied by a current signal corresponding to the LSM power and regenerative braking command.

Au, Av, Aw are current control devices for each phase, and output currents I of AC converters C/Cu, C/Cv, C/Cw for each phase.
This is a device that determines the point at which the forward and reverse currents of u, Iv, and Iw begin to flow, and also detects the output currents Iu, Iv, and Iw of each phase with current detectors CTu, CTv, and CTw, and uses these outputs as feedback signals for each phase. Current control devices Au, Av,
Aw to control the output currents Iu, Iv, and Iw of each phase.

1 is a line command that generates a command to drive the linear synchronous motor LSM by the AC converter C/Cu, C/Cv, C/Cw; 2 is the AC converter C/Cu, C/Cv, C/C
This is a regenerative braking command that generates a command to stop the linear synchronous motor LSM by w.

Next, the operation of the control block diagram in FIG. 1 will be explained.

When a command to drive the linear synchronous motor LSM is generated by the row command 1, current command signals Ipu, Ipv I Ip
From w, the driving torque of the linear synchronous motor LSM or the current value sufficient to overcome the running resistance of the floating vehicle when driving the floating vehicle with the linear synchronous motor LSM is given, so the AC converters C/Cu, C/Cv , C/Cw drives a linear synchronous motor LSM.

On the other hand, when a command to stop the linear synchronous motor LSM is generated from the regenerative braking command 2, current command signals Ipu, Ipv
, Ipw give the same current value as when the cursor command 1 is generated, so the AC converters C/Cu, C/
The linear synchronous motor LSM is regeneratively braked and stopped by Cv and C/Cw.

Fig. 2 is a block diagram of a current command signal generation circuit that generates current command signals Ipu2, IpvI, and Ipw for each phase using signals from the position detector PD. After converting to a sine wave, the current signal corresponding to the power running command 1 and rotary braking command 2 is multiplied, and the synchronized current waveform forming circuit 4 corrects the distortion of the current command signal during acceleration/deceleration, and the current of each phase is The command signals Ipu, Ipv, and Ipw are controlled.

It is conceivable to combine the three-phase signals using the position detection signal of one phase, but due to issues such as reliability and safety, the current command signal Ipu2 is combined using the position detection signal of each of the three phases.
Control is performed using Ipv and Ipw.

By the way, if the positive and negative time intervals of the U phase, for example, the positive and negative times of the position detector PD that detects the rotation angle of the rotor of the linear synchronous motor LSM are shifted by one phase, the output waveform of the current command signal Ipu becomes asymmetrical.

If this is given as an input signal to the current control device Au, the waveform of the output current Iu will also become asymmetrical, so the linear synchronous motor LS
There are drawbacks such as the driving torque of M fluctuating, causing the linear synchronous motor LSM to pulsate, or the power transformer Tru receiving direct current bias, which may cause the power transformer Tru to burn out.

An object of the present invention is to continue stable operation of a synchronous motor even when an abnormality occurs in any one of the multiphase relative position detection signals.

The feature of the present invention is to detect an abnormality in a multiphase relative position detection signal, and perform multiphase power conversion based on a second multiphase position detection signal created from a normal phase relative position detection signal. The goal is to control the equipment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 3A and 3B show one embodiment of the present invention, and are configuration diagrams of an abnormality detection circuit of a position detector and an input signal switching circuit of a current command signal generation circuit, respectively.

11 to 13 are OR circuits that receive two phases of the outputs of the circuit PDD for detecting the positive direction of the output signals U-W of the position detector PD; r11, C1 to rl3 j c3;
are resistors and capacitors for smoothing the respective outputs of OR circuits 11 to 13, 21 to 23 are smoothing circuits r1,
Operational amplifiers that invert the signs of the respective outputs of c1 to r13 and C3; 31 to 33 are smoothing circuits r11 t C1 to
Operational amplifiers r21 to F3tC3 and one output from each of the sign inversion operational amplifiers 21 to 23 as inputs;
r29 j r31-r33, r41-r46 and r
51 to r53 are resistors, and d1 to d3 are operational amplifiers 31 to 3.
Of each output of 3, a diode for negative direction cut,
41 to 43 are transistors, r61 to r63 are base current limiting resistors of each of the transistors 41 to 43, and 5
1 to 53 are, for example, auxiliary relays, d4 to d6 are switching surge absorption diodes for each of the auxiliary relays 51 to 53, DC is a direct current voltage, and 5 1-b1 to 53-b3 are normally closed diodes for each of the auxiliary relays 51 to 53. Contact, 51-a? 53
-a is each normally open contact of auxiliary relays 51 to 53, 5
is a three-phase generating circuit that outputs three phases even if the input is one phase; the other symbols are shown by the same symbols as the circuit in FIG. 2, and the explanation thereof will be omitted.

Next, the operation of the circuits shown in FIGS. 3A and 3B will be described. First, the case where the output signals UW of the position detector PD are both normal will be described using the waveform diagram shown in FIG. 4A.

In this case, the output signal U-W of the position detector PD is as shown in FIG.
As shown in (a) to (c), since the positive and negative time intervals T1 and T2 are equal, the OR circuits 11 to 13 whose inputs are two phases of the outputs of the positive direction detection circuit of the output signals U-W of the position detector. The respective outputs are equal as shown by the solid lines 2 to 2 in FIG. 4A.

Therefore, the respective voltages of the smoothing circuits r11, c1 to r13, c3 that smooth the respective outputs of the OR circuits 11 to 13 are equal as shown by the broken lines 2 to 2 in FIG. 4A, and the smoothing circuit r1 , c1-r13, c3 and the output voltages of the operational amplifiers 21-23 for sign inversion are equal, so the input voltages of the operational amplifiers 31-33 become zero, and the operational amplifiers 31-33 output I don't give out.

Therefore, since each of the transistors 41 to 43 is non-conductive, each of the auxiliary relays 51 to 53 does not operate, and the normally closed contacts 51- of each of the auxiliary relays 51 to 53 do not operate.
When b1 to 53-b3 continue to close, the output signal U of the position detector
-W to create current command signals Ipu, Ipv, and Ipw.

That is, when the output signals U-W of the position detector PD are both normal, the current command signals Ipu, Ipv2 Ipw are controlled by the output signals U-W of the position detector PD.

Next, of the output signal U-W of the position detector PD, for example, the waveform shown in FIG. This will be explained using figures.

In this case, since the output signal U-W of the position detector PD becomes as shown in A to C of FIG. 4B, the output signal U of the position detector PD becomes as shown by the solid line , W, the period during which the OR circuit 13 outputs an output becomes T3-t1, and the output signal U of the position detector,
A period T3 during which each of the OR circuits 11 and 12, which receives the positive direction of V, ■, and W, outputs an output.
Shorter than? It becomes.

For this reason, as shown by the broken lines 2 to 2 in FIG. gives output.

On the other hand, since the outputs of the smoothing circuits rll t cl and rl2 j C2 are equal as shown by broken lines in 2 and E in FIG. 4B, the operational amplifier 31 does not output an output, and
As shown by the broken line in , the outputs of the smoothing circuits r, 2, c2 are higher than the outputs of the smoothing circuits r13, c3, so the operational amplifier 33 tries to output a voltage in the negative direction, but it is blocked by the negative direction cutting diode d3. Since it is cut, the operational amplifier 33
also produces no output.

That is, if a failure occurs in which the time width in the positive direction of the U phase of the output signal U-W of the position detector is shorter than the time width in the negative direction, only the operational amplifier 32 outputs an output signal. The auxiliary relay 52 makes the transistor 42 conductive.
operates and the normally closed contacts 52-b1 to 52 of the auxiliary relay 52
In order to open each of -b3 and close the normally open contact 52-a of the auxiliary relay 52, the position detector output signal U~
W is cut off and a current command signal Ipu) Ipv) Ipw is created by the output of the three-phase generating circuit 5.

In addition, if a failure occurs in which the time width in the positive direction of the U phase of the output signal U-W of the position detector is longer than the time width in the negative direction, the voltages of the smoothing circuits r13 and c3 Since the voltage becomes higher than the voltage of each of r1, , c1 and r1, c2, only the operational amplifier 33 outputs an output and makes the transistor 43 conductive, thereby opening each of the normally closed contacts 53-b1 to 53-b3 of the auxiliary relay 53. At the same time, the normally open contact 53-a of the auxiliary relay 53 closes, so the output signal U-W of the position detector is cut off and the three-phase generating circuit 5
The current command signal Ipu2 (Ipv) Ipw is determined by the output of
is created.

As described above, according to the embodiments shown in FIGS. 3A and 3B, if the positive direction time width T1 and the negative direction time width T2 of any one phase of the output signals U-W of the position detector are different, Which phase is in an abnormal state is detected by the circuit for detecting the abnormal state of the output signal U-W of the position detector shown in Fig. 3A, and this output generates the current command signal shown in Fig. 3B. The input signal of the circuit is immediately switched from the output signal U-W of the position detector to the output signal of the three-phase analogue circuit 5, and the current command signal I is
A linear synchronous motor LSM operates so that the output waveforms of pu, Ipv, and Ipw are not asymmetrical.
can be operated stably, and the power transformer Tru2
Since Trv2Trw is not subjected to direct current biased magnetism, it is safe.

In the circuit of FIG. 3A, the time width T1 in the positive direction and the time width T1 in the negative direction of any one phase of the output signal U-W of the position detector PD.
2 is small, a smoothing circuit rll j cl~ smoothes the respective outputs of the OR circuits 11 to 13.
Since the voltage difference between rl3 j and C3 is small, there is a possibility that the above-mentioned abnormality cannot be detected.

However, in such cases, by using a digital circuit, it is possible to detect even a slight difference in time width.
Needless to say, abnormalities can be detected.

The above describes the detection method when the time width in the positive and negative directions of any one phase of the output signals U-W of the position detector differs when the operation of a linear synchronous motor is controlled by a cycloconvert as the main circuit configuration. Although the circuit has been described, a circuit system that uses the signal of the position detector as the reference value of the current depth signal or the reference value of the speed command signal, for example, P
It goes without saying that the present invention can be applied to WM, Cyrisk MG, commutatorless motors, and the like.

According to the present invention, in a circuit system that generates a reference value of a current command signal of an AC converter that drives an AC motor using an output signal of a position detector, when the output signal of the position detector becomes abnormal, This abnormal state can be reliably detected at a low operating frequency and in a small range of abnormal states, and the input command of the current command signal generation circuit can be switched to provide a normal current command signal to the AC converter. This has the effect of stably controlling the operation of the AC motor.

[Brief explanation of the drawing]

Figure 1 is a control block diagram when driving and controlling a linear synchronous motor with an AC converter, and Figure 2 is a current that generates a current command signal for the current control device used in the AC converter using a signal from a position detector. Block diagram of command signal generation circuit, 3rd
Figures A and B are specific circuit configuration diagrams of an abnormal state detection circuit of a position detector and an input signal switching circuit of a current command signal generation circuit, respectively, showing an embodiment of the present invention. 3
FIG. 2 is an explanatory diagram of the operation of the circuit shown in FIG. 1... Power running command, 2... Regenerative braking command, 3... Function generation circuit, 4... Synchronized current waveform forming circuit, 5... ...Three-phase generation circuit, PD
...Position detector, PDD...Forward direction detection circuit, A u -Aw...Current control device, ■
pu～■pw・・・・・・Current command signal, C/Cu-C
/Cw... AC converter.

Claims (1)

[Claims] 1 A polyphase power converter, a polyphase synchronous motor supplied with power by this power converter, and a polyphase positioner that detects the relative position between the armature of this synchronous motor and the field and generates a multiphase position detection signal. Abnormality detection for detecting an abnormality in the multiphase position detection signal for each phase, comprising a detection means and a control means for controlling each phase of the power converter based on the multiphase position detection signal. means, and in response to the operation of the abnormality detection means, the control means is configured to control each phase of the power converter based on a second multi-phase position detection signal generated by the normal phase position detection signal. A control device for a synchronous motor, comprising means for switching to a synchronous motor.