JPS6127998B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control device for a linear synchronous motor, and more particularly to a control device for a linear synchronous motor suitable for use in vehicle control of ultra-high-speed railways.

To propel a supersonic railway vehicle, as shown in Figure 1, a linear synchronous motor (hereinafter abbreviated as LSM), which has a superconducting magnet mounted on the vehicle 1 as a field 1a and an armature coil 2 installed on the track side, is used. It is powerful. To drive this LSM, it is sufficient to pass a current such as a sine wave through the armature coil in synchronization with the magnetic field, and to adjust the thrust, the current value is controlled.

FIG. 1 is a block diagram of a drive control system for such a linear synchronous motor. Vehicle 1
A position detection device 3 detects the relative position of the field 1a mounted on the train and the armature coil 2 installed on the track side. The position detection device 3 is, for example, a device that optically detects a detection target plate installed in each pole pitch unit of the armature coil 2, or a position detection device that utilizes a cross-guide wire arranged to cross each other in each pole pitch unit of the armature coil 2. A known position detection device is used, such as a detection device or a device that detects the induced voltage induced in the armature coil 2 by movement of the field 1a. A position signal 4 detected by such a position detection device 3
(usually replaced by a pulse train), the speed calculator 17 calculates the actual speed of the vehicle (for example, by measuring pulse intervals), compares it with the speed reference command Vr in the comparator 11, and reduces the speed deviation 12. Preferably, the speed control device 13 calculates the magnitude of the current to be applied to the armature coil. The magnitude of this current is usually limited to the maximum value on the positive side and negative side by a current limiter 14,
In other words, the acceleration and deceleration forces of the LSM are limited so as not to impair the ride comfort of the vehicle. on the other hand,
The current waveform pattern generator 19 creates a current waveform pattern 20 synchronized with the position signal 4, and is a so-called synchronous oscillator, and includes, for example, a phase comparator, a low-pass filter, a DC amplifier, and a VCO.
It is simple and common to configure it with a PLL (phase lock loop) circuit consisting of a voltage controlled oscillator (voltage controlled oscillator). A current waveform pattern 20 (usually a sine wave pattern) synchronized with this position signal 4 is multiplied by the previous current peak value pattern 15 using a multiplier 16 to create a current pattern 5 to be passed through the armature coil 2.
This current pattern 5 is a current pattern (usually a sine wave) that is synchronized with the position signal 4 and has a magnitude corresponding to the thrust required for driving the vehicle. The current control device 7 controls a power conversion device 8, such as a thyristor type cycloconverter, to reduce the deviation when the armature coil current 10 detected by the current detector 9 and the current pattern 5 are compared by the comparator 6,
The current following the current pattern 5 is passed through the armature coil 2.
energize. Due to the electromagnetic action of this armature coil current and the field on the vehicle, the vehicle obtains thrust and runs.
An overview of these controls can be found in ``Proceedings of the 16th Domestic Symposium on Cybernetics Utilization in Railways''.
It is described on pages 477-480.

Drive control of a linear synchronous motor has conventionally been performed as described above using a system configuration as shown in FIG. What should ultimately be controlled here is the speed of the vehicle, and in order to quickly reach the target speed or reduce the speed deviation from the target speed,
It is necessary to operate the LSM with an appropriate thrust, that is, an appropriate current value. In the conventional example shown in FIG. 1, the speed reference command and the speed calculation result are compared and the current value is adjusted to reduce this deviation, so there are some insufficiencies in the following points. First, there is a drawback that the speed of the vehicle is greatly influenced by the accuracy of the speed calculator. In other words, if the speed calculation accuracy is, for example, ±2%, an error of ±10 km/h will occur when the vehicle is traveling at a maximum speed of 500 km/h. In addition, in order to speed up the speed control response and reduce speed deviation, it is necessary to increase the gain of the speed control device 13, but in this case, if there are calculation variations in the speed calculator, the current value will fluctuate and the vehicle Thrust pulsations occur and the ride quality worsens. If the gain of the speed control device is lowered to reduce the influence of this variation, the responsiveness of the speed control will be poor and the speed deviation will increase. As described above, the conventional method of setting a current pattern based on the speed deviation is insufficient in speed control of a vehicle driven by an LSM in terms of followability and speed control accuracy.

An object of the present invention is to provide a control device for a linear synchronous motor with high speed control accuracy.

The present invention calculates a phase difference between a position signal with a frequency uniquely equal to the speed of a linear synchronous motor (LSM) and a frequency pattern corresponding to the speed pattern of the vehicle, and adjusts the LSM to a linear synchronous motor (LSM) according to this phase difference.
The LSM is controlled by adjusting the magnitude of the current pattern applied to the armature coil.

A detailed explanation will be given below based on specific examples.

FIG. 2 is a block diagram of an LSM drive control system showing one embodiment of the present invention, and FIGS. 3 and 4 are operational waveform diagrams for explaining its operation. Symbols in the figure that are the same as those in Figure 1 mean the same content.

In FIG. 2, a frequency pattern generator 21 outputs a frequency pattern 22 corresponding to the speed pattern of the vehicle. Note that the speed v of the vehicle and the frequency f of the LSM have the following relationship, with the pole pitch of the LSM being _LP , so it is sufficient to focus on the frequency.

v=2fl _P ...(1) The phase difference detector 23 detects the phase difference between the frequency pattern 22 and the position signal 4, and according to this phase difference 24, the phase difference compensator 25 detects whether the position signal matches the frequency pattern. On the other hand, if the phase is delayed, the current peak value 26 is increased to accelerate, and if the phase is ahead, the current peak value is decreased to decelerate, or the current peak value is adjusted to perform regenerative braking with a negative peak value. conduct. That is, as seen in the operating waveform of FIG.
If the phase is delayed (the actual speed is slow with respect to the speed pattern), the phase difference detector 23 outputs an output 24 with respect to the phase difference 24A. Although FIG. 3 shows the phase difference 24A for one phase for the purpose of explaining the principle, in reality, the phase differences for three phases are obtained and averaged for use. Further, in FIG. 3, the change in phase difference is depicted abruptly for convenience of drawing, but since the actual change in phase difference is gradual, the output 24 of the phase difference detector 23 can be assumed to be smooth as shown in the figure. The phase difference compensator 25 outputs a current peak value 26 according to the phase difference 24. The maximum value of this current is limited by the current limiter 14, resulting in a current peak value pattern 15.
In FIG. 3, when the phase difference 24 is large, the current peak value pattern 15 is the limiter value _IPP , and the LSM is accelerated with the maximum thrust in order to reduce this delay phase difference. Then, when the phase difference becomes sufficiently small, the current peak value becomes _IPL , and the vehicle is driven with torque balanced with a thrust force corresponding to running resistance at that speed.

FIG. 4 shows a case where the phase of the position signal 4 is ahead of the frequency pattern 22 (actual speed is faster than the speed pattern) compared to the case of FIG. 3.
At this time, the current peak value pattern becomes negative. Therefore, the phase of the armature coil current with respect to the induced voltage of the LSM is opposite to that in the case of FIG. 3, and the LSM is in brake operation. The current peak value pattern 15 when the leading phase difference is large is the negative maximum value _-IPB .
The LSM operates the brakes, and when the phase difference becomes smaller, the vehicle is driven with thrust equivalent to the running resistance at that speed.

As described above, the phase difference compensator 25 receives the phase difference 24 as input and outputs the current peak value 26, but the input/output transfer characteristic may be normal proportional, proportional integral, lead/lag compensation, or the like. Further, the limit value of the current limiter 14 is set so as not to impair the riding comfort of the vehicle, but the limit value on the brake side becomes small due to running resistance.

As described above, in the present invention, the phase difference between the position signal of the frequency uniquely equal to the speed of the linear synchronous motor (LSM) and the frequency pattern corresponding to the speed pattern of the vehicle is determined, and the LSM is adjusted according to this phase difference. Since the LSM is controlled by adjusting the magnitude of the current pattern applied to the armature coil, speed control accuracy is high and speed pattern (frequency pattern) followability is good. That is, when the phase difference between the position signal and the frequency pattern becomes small, the vehicle speed that uniquely corresponds to the frequency and the speed pattern are the same, and speed control accuracy is dramatically improved compared to the conventional method. In other words, even if there is a minute frequency difference that causes an error in terms of speed calculation accuracy, the phase difference will eventually increase.As a result of detecting this and adjusting the thrust, speed control accuracy can be improved by an order of magnitude. sell. Furthermore, when the speed pattern changes, the phase difference between the frequency pattern and the position signal increases, so the control device of the present invention adjusts the magnitude of the current pattern, that is, the thrust of the LSM, based on this phase difference. Now, the speed pattern (frequency pattern) is determined from the control device that adjusts the thrust by finding the speed deviation as shown in Figure 1.
This has the advantage of faster follow-up.

FIG. 5 is a block diagram of a control system illustrating a more practical embodiment of the invention. In the figure, the same symbols as in FIG. 2 have the same contents, so the explanation will be omitted. In the embodiment shown in FIG. 5, in addition to creating a frequency pattern 22 with a frequency pattern generator 21 and giving it to the phase difference detector 23, a current peak value reference calculator 61 calculates the required thrust expected for the current running. The corresponding current peak value 27 is transferred to the previous phase difference compensator 25.
This is different from FIG. 2 in that an adder 28 adds this to the output 26 of , and this is passed through a current limiter 14 to form a current peak value pattern. The features will be explained below, focusing on this point.

The frequency pattern generator 21 uses a speed reference V _R
When set, a speed pattern with respect to time is created so that the acceleration/deceleration and jerk of the speed pattern 59 are within the limit values, so as not to impair the ride comfort of the vehicle. That is, comparator 5
The deviation between the speed reference _VR determined in step 1 and the speed pattern 59 is converted by the acceleration/deceleration limiter 52 into an acceleration/deceleration command 53 within the limit value. Further, if necessary, the jerk is limited by a jerk limiter 55, and this is integrated by an integrator 56 to obtain an acceleration pattern 57. Acceleration/deceleration command 53 with comparative construction 54
The reason why a feedback loop is formed by comparing the acceleration pattern 57 and the acceleration pattern 57 is to create an acceleration pattern 57 that follows the acceleration/deceleration command 53 with a jerk less than the limiter value. When this acceleration pattern 57 is integrated by an integrator 58, a velocity pattern 59 is obtained. This speed pattern is created so that its acceleration/deceleration and jerk are within the limit values. If the oscillator 60 is driven with this speed pattern 59, the frequency pattern 22 will be obtained.

In the embodiment shown in FIG. 5, the magnitude of the LSM current is adjusted based on the phase difference between the position signal and the frequency pattern in which acceleration/deceleration and jerk are within the limit values as described above, so tracking of the frequency pattern is good. Additionally, the ride comfort of the vehicle is improved.

On the other hand, in FIG. 5, the current peak value reference calculator 61 is
Based on the acceleration pattern 57 (acceleration α _P ), speed pattern 59 (velocity V _P ), etc., calculate the required thrust (F _P ) expected for the current running, and generate a current wave according to this. High standard (I
_P ) is created, and this is added in advance to the output 26 of the phase difference compensator 25 to determine the size of the current pattern. That is, the expected required thrust F _P is as follows, where M is the mass of the vehicle and F _D (v _P ) is the running resistance when the vehicle is traveling at a speed v _P .

F _P = Mα _P + F _D (v _P ) ...(2) Since the thrust force F _LSM of the LSM is proportional to the current peak value, F _LSM = K _P ... (3). From equations (2) and (3), the required current peak value expected for the current running is calculated. Therefore, this current peak value (or some percentage of this value) 27 is added to the current peak value 26 of the phase difference compensator 25 by an adder 28, and this is used as a current peak value pattern. In this way, the phase difference compensator only needs to compensate for the difference between the predicted current peak value corresponding to the thrust force and the current peak value corresponding to the actually required thrust force. Therefore, the dynamic range of the phase difference compensator may be small, which has the advantage of making control easier. That is,
The current peak value predicted in advance is given by a feedback, and the difference from the actually required value is compensated for by a feedback group including the phase difference detector 23.

In the embodiment described above, the phase difference between the frequency pattern 22 and the position detection signal 4 was determined, but as shown in the embodiment of FIG. 6, the phase difference between the output of the current waveform pattern generator 19 and the frequency pattern 22 is determined. Doing so has the following advantages: The same reference numerals in FIG. 6 as in FIG. 2 mean the same contents. 6th
In the illustrated embodiment, the output 20 of the current waveform pattern generator 19 is shaped via a waveform shaper 19A, and the phase difference between this signal 20A and the frequency pattern 22 is determined. In this case, as mentioned above, the current waveform pattern generator 20 is usually configured with a PLL (phase lock loop) circuit, so noise may be introduced into the position detection signal, or disturbances such as partial signal loss may occur. Even when exposed to heat, the current waveform pattern is hardly disturbed. Therefore, there is no possibility that the phase difference detector detects an abnormal phase difference, which causes thrust fluctuation of the LSM and impairs the ride comfort of the vehicle.

As described above, according to the present invention, the phase difference between the position signal of the frequency uniquely equal to the speed of the linear synchronous motor (LSM) and the frequency pattern corresponding to the speed pattern of the vehicle is determined, and the phase difference is determined according to this phase difference. Since the magnitude of the current pattern applied to the armature coil of the LSM is adjusted, it is possible to control a linear synchronous motor with high speed control accuracy and good followability to the speed pattern (frequency pattern).

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a drive control system for a general linear synchronous motor, Fig. 2 is a block diagram of a control system showing an embodiment of the present invention, and Figs. 3 and 4 are basic diagrams of a drive control system of the present invention. 5 and 6 are block diagrams of a control system showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Vehicle, 2... Armature coil, 8... Power conversion device, 7... Current control device, 5... Current pattern, 16... Multiplier, 15... Current peak value pattern, 20... Current Waveform pattern, 3...Position detection device, 19...Current waveform pattern generator, 21
... Frequency (velocity) pattern generator, 23 ... Phase difference detector, 25 ... Phase difference compensator, 22 ...
Frequency pattern, 61...Current peak value reference calculator.

Claims (1)

[Scope of Claims] 1. A control device for a linear synchronous motor comprising a field and an armature coil, comprising: position detection means for detecting the relative position of the magnetic field and the armature coil;
a phase difference detection means for determining the phase difference between the reference frequency pattern of the linear synchronous motor and the output of the position detection means; and a current for creating a waveform pattern of the current to be applied to the armature coil in synchronization with the output of the position detection means. A waveform pattern generation means; a means for adjusting the size of the waveform pattern according to the output of the phase difference detection means to create a current pattern of the armature coil, and generating an armature coil current based on the current pattern. A control device for a linear synchronous motor. 2. The control device for a linear synchronous motor according to claim 1, wherein the current pattern creating means is configured to limit positive and negative sides of the current pattern to preset maximum values. 3. The control device for a linear synchronous motor according to claim 1, wherein the phase difference detection means is configured to obtain a phase difference between the reference frequency pattern and the waveform pattern.