JPS6057315B2 - Drive control device for linear synchronous motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control device for a self-limiting linear synchronous motor (hereinafter abbreviated as LSM) that energizes a propulsion coil based on the detection result of the relative position of the field and the propulsion coil. It is.

One of the drive systems for high-speed land transportation is LSM, in which a superconducting magnet is mounted on a running body as a field and a propulsion coil is installed on the track.

A self-limiting LSM that is excited based on the detection result of the relative position between the field and the propulsion coil is energized in synchronization with the relative position detection signal, so there is no risk of step-out. There is a question as to whether it should be released.

Conventionally, in this type of LSM, a sweep signal is created in synchronization with a position detection signal, and a pattern of an arbitrary shape is extracted from a preset waveform generator using the sweep signal.

Here, the sweep signal is created from the speed detection signal of the running object, but it is difficult to accurately detect the speed over the entire speed range from startup to high speed, and the accuracy is particularly poor in the early startup and low speed ranges. .

In this way, when the speed detection signal differs from the actual speed, a correct sweep signal cannot be obtained and a pattern with an expected shape cannot be obtained.

For example, when the speed detection signal is smaller than the actual speed, the first
In the opposite case, the waveform is deformed during the sweep as shown in Figure b, and in the opposite case, the sweep is too fast as shown in Figure 1 c, resulting in a waveform that is far from the expected shape pattern as shown in Figure 1 a. Not only will the waveform become distorted, but the phase of the fundamental wave component of the waveform will also shift.

Therefore, if current is applied based on the pattern of this shape, there is a drawback that not only the thrust pulsation increases but also the average thrust decreases. In addition, the speed detection device is extremely complex in order to perform accurate speed detection over the entire speed range.
It also had the disadvantage of being expensive. Furthermore, when the running body is driven in a rectangular wave pattern when starting up, the output current instantly switches between positive and negative directions, which causes noise, causes the running body to sway from side to side, and prevents smooth running.

An object of the present invention is to be able to obtain a pattern with a shape with little pattern phase shift in the entire speed range from startup to high speed with a relatively simple device, and to gently switch the output current direction between positive and negative when starting the traveling body. The object of the present invention is to provide a drive control device for a linear synchronous motor that can perform the following steps. In order to achieve such an object, the present invention uses a rectangular wave created by a relative position detection signal between a field and a propulsion coil as a reference signal during startup and in a low speed range, and generates a pattern in a shape equivalent to a trapezoidal wave. In the medium and high speed range, a characteristic feature is that arbitrary-shaped patterns created based on the sweep signal obtained from the speed detection signal are used as the current patterns of the propulsion coils.

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

FIG. 2 is a diagram showing an embodiment for one phase of the drive control device for a linear synchronous motor according to the present invention, in which 1 is a speed pattern generation circuit, 2 is a speed detector, 3 is a position detector, and 4 is a comparison vessel,
5 is a thrust regulator, 6 is a multiplier, 7 is a waveform generator, 8 is a waveform conversion generator, 9 is a trapezoidal wave generator, 10 is a pattern shape switcher, 11 is a comparator, 12 is a gate control device, 13 is a current transformer, 14 is a thyristor type cycloconverter, 15
16 is a power supply, 16 is a feeder, 17 is a switch, 18 is a propulsion coil, 19 is a field, and 20 is a vehicle.

A superconducting magnet is mounted on the vehicle 20 as a field 19, and a propulsion coil 18 is installed on the track side. This propulsion coil 18 is excited by the thyristor type cycloconverter 14 via the feeder 16 and the switch 17.

The gate of the thyristor of converter 14 is controlled by gate control device 12 .

The output current of the converter 14 is detected by the current transformer 13,
This output and the current pattern are compared by a comparator 11 to perform constant current control.

The current pattern to be passed through the propulsion coil 18 must be synchronized with the relative position of the field 19 and the propulsion coil 18, have an appropriately shaped waveform, and have a size necessary for speed control. It is created as follows.

A comparator 4 compares the output of the speed pattern generation circuit 1 and the output of the speed detector 2, and a thrust force adjuster 5 determines a current pattern corresponding to the thrust value according to the deviation signal of the comparator 4.

The thrust regulator 5 is desirably of a saturated type in order to limit significant acceleration and deceleration so as not to impair the riding comfort of the vehicle. On the other hand, a reference waveform synchronized with the relative positions of the field 19 and the propulsion coil 18 is created as follows.

FIG. 3 shows an example of a specific configuration of the position detector 3. Three-phase position detectors 3U, 3V, and 3W are provided on the vehicle 20, and a detector 3D is installed on the track at each pole pitch. There is.

For example, a photosensitive semiconductor is used as this position detector,
A shield plate is used as the detection object.

The U-phase detector 3U is placed in the middle of the field poles, and
The phase and W phase detectors 3V and 3W are each arranged to be shifted from the detector 3U by 213 ball pitches.

On the other hand, the width of the detection body 3D is a ball pitch, and the detection body 3D is arranged centered on the propulsion coil 18U. Therefore,
For example, the detector 3U obtains a signal having the same phase as the induced voltage as the vehicle 20 moves forward.

In FIG. 4, a signal D opposite to the position detection signal D1 signal D is shown.
'' and the differential signal R are shown.

In FIG. 2, a waveform pattern of an arbitrary shape is created by a waveform generator 7 by inputting the speed signal of the speed detector 2 and the detection signal D of the position detector 3, while the detection signals D and D'' of the position detector 3 are input. The waveform conversion generator 8 which inputs the speed signal of the speed detector 3 creates a rectangular wave that is shorter by a certain time width than the waveform of the detection signals D and D'' of the position detector, and uses this waveform as the input. A trapezoidal wave generator 9 creates a waveform pattern having a shape similar to a trapezoidal wave. Then, the pattern shape switching device 10 switches the waveform pattern to a shape close to a trapezoidal wave at startup and at low speeds, and to an arbitrary shape waveform pattern at medium and high speeds, and the output becomes the waveform of the current pattern.

This waveform pattern and the output current value of the thrust regulator 5.

are multiplied by a multiplier 6 to create a current pattern.
That is, at low speeds including the initial stage of startup, the current is supplied with a current pattern having a shape close to a trapezoidal wave without using a speed signal with poor detection accuracy, thereby eliminating the drawbacks of the conventional motor. FIG. 5 shows the adverse effects on the converter 14 when any of the detection signals D and D'' of the waveform conversion generator 8, trapezoidal wave generator 9, and position detector 3 shown in FIG. 2 disappear for some reason. This figure shows an example of a specific configuration mainly consisting of a circuit that protects the device.

In FIG. 5, the position detector 3 generates detection signals D and D'' as shown in FIG. The output and fixed voltage E1 are subtracted by a subtracter 81 to set the respective outputs of the comparators 80 and 85 to be inversely proportional to the output of the speed detector 2, while the integrator circuits 82 and 87 are set to be inversely proportional to the output of the speed detector 2. Set the integration time to change in proportion to each output.

With this setting, the detection signals D, D of the position detector 3
An integrated waveform synchronized with `` is obtained, but if a failure occurs in which the time width of either one of the detection signals D, D'' of the position detector 3 suddenly becomes shorter, the output of the speed detector 2 will change. Since the outputs of the comparators 80 and 85 do not change, the output of the integrating circuit on the side whose time width is shorter among the detection signals D and D'' of the position detector 3 does not become zero.

However, the power to the comparator whose time width is shorter among the detection signals D and D'' of the position detector 3 disappears, so the output of the integrating circuit becomes zero at this point.The output of the speed detector 2 and the fixed voltage E2 are subtracted by the subtracter 86 and applied to the input of the arithmetic unit 90, and the output of the arithmetic unit 90 is set to be inversely proportional to the output of the speed detector 2.

The respective outputs of the integrating circuits 82 and 87 and the output of the arithmetic unit 90 are subtracted by the subtracters 83 and 88, and this output is sent to the amplifier 84.
, 87 to obtain a rectangular wave shorter than the detection signals D, D'' by a certain time width.The respective outputs of the amplifiers 84 and 89 are amplified by delay circuits 91 and 9 consisting of a resistor r and a capacitor C.
2 to obtain a waveform with a shape close to a trapezoidal wave. Delay circuit 9
The respective outputs of 1 and 92 are given to a calculator 95 to create an AC waveform having a shape close to a trapezoidal wave, and this is used as a current pattern at startup.

FIG. 6 shows the operating waveforms of the circuit shown in FIG. 5 when the detection signals D and D'' of the position detector 3 are normal.

1 and 2 are the waveforms of the detection signals D and D'' of the position detector 3, 3,
4 is the output waveform of the integrating circuits 82 and 87, the broken line is the output waveform of the arithmetic unit 90 that generates a voltage inversely proportional to the output of the speed detector 2, 5 and 6 are the output waveforms of the amplifiers 84 and 89, 7 and 8
are the output waveforms of the delay circuits 91 and 92, and 9 is the output waveform of the arithmetic unit 95.

The reason why the outputs of the amplifiers 84 and 89 are made to change in inverse proportion to the output of the speed detector 2, that is, in proportion to the output of the arithmetic unit 90, is because the time constants of the delay circuits 91 and 92 are constant. This is to ensure that the outputs of the delay circuits 91 and 92 fall within the time width of the detection signals D and D'' of the device 3.

The switching of the anti-parallel connected thyristor converters constituting the converter 14 is carried out using a signal based on the detection signals D, D'' of the position detector 3. Also, if the outputs of the delay circuits 91 and 92 are extended, the anti-parallel connected thyristor converters will cause an overcurrent to flow in the portion where the switching of the current pattern is delayed, causing problems such as noise, so this is prevented. It's for a reason. Next, a case where a failure occurs in which D out of the detection signals D and D'' of the position detector 3 disappears midway will be explained using the waveform diagram shown in FIG.

First, a circuit that performs this detection and protects the detection signals D and D'' of the position detector 3 in the event that a failure occurs where D disappears midway due to some reason is the detection signal D of the position detector 3. , D″ analog switches 93, 94
Therefore, this operation will be explained.

The analog switches 93 and 94 are turned on while the detection signals D and D'' of the position detector 3 are output.
Since the analog switch 93 is turned off when the detection signal D disappears at time t1, the input on one side of the arithmetic unit 95 becomes zero, and the input signal on one side of the arithmetic unit 95 becomes zero, as shown by the solid line in 7. It becomes a waveform.

On the other hand, even if the detection signal D becomes zero at time t1, the output of the integrating circuit 84 does not immediately become zero, but when the power to the comparator 80 is turned off, the output of the comparator 80 becomes zero, so at that point Since the output of the integrating circuit 84 becomes zero, the output of the delay circuit 91 starts to decrease from this point on as shown by the broken line 7 in FIG.

However, since the analog switch 93 is turned off when the detection signal D disappears, the input on one side of the arithmetic unit 95 becomes as shown by the solid line at 7 in FIG. 7, so the current pattern extends beyond the detection signal D. It is safe because there is no problem.

The above has described detection and protection in the event that a failure occurs in which one or both of the detection signals D, D'' of the position detector 3 disappears midway due to some reason. It goes without saying that even if the delay circuits 91 and 92 are normal, detection and protection are performed in the same way when the outputs of the delay circuits 91 and 92 extend beyond the detection signals D and D''.

Next, we will explain the operation of the circuit that defines the stop position of the traveling body so that the creation of the current pattern waveform at the time of starting the traveling body starts from the detection signal D of 3U of the position detectors 3U to 3W (see Fig. 3). do.

It is composed of an OR circuit 30 which inputs the detection signals D and D'' of the position detector 3, and an analog switch 96, and the analog switch 96 is turned off when the traveling body is in operation and when the traveling body is about to stop. It is turned on when a command is given (for example, a command generated when the speed signal of the speed detector 2 falls below a specified value), and when the analog switch 96 is turned on, the gate control device 12 is turned on. is operated to operate one of the anti-parallel connected thyristor converters constituting the converter 14.

When one of the thyristor converters connected in antiparallel is operated, direct current flows through the propulsion coil 18, and the traveling body stops at that point, so the stopping position of the traveling body can always be adjusted.

That is, when the position of the propulsion coil 18 changes when the traveling body is started, which of the position detectors 3U to 3W or the detection signals D and D'' is used to generate the current pattern waveform changes. Since a problem arises in which the shape of the current pattern waveform is uncertain, this circuit configuration is intended to eliminate this problem and stabilize the shape of the current pattern when starting the traveling body.As explained in detail above. As shown in FIG. 5, according to the present invention, the position of the propulsion coil at the time of starting the traveling body is always the same, so the shape of the current pattern at the time of starting the traveling body is stable, so smooth running is possible. In addition, the current pattern when starting the running body is similar to a trapezoidal waveform, so there is no noise or side-to-side shaking of the running body, allowing for smooth running, and the detection signal of the position detector disappears midway. This eliminates the phenomenon in which the current pattern extends longer than the detection signal when switching the thyristor converters connected in anti-parallel that make up the converter, so no overcurrent flows, resulting in stable switching. There is.

FIG. 8 shows an example of a specific configuration of the waveform generator 7 and pattern shape switch 10 shown in FIG. In FIG. 8, a trapezoidal wave generating circuit 800 is the same as that shown in FIG. 5, so its explanation will be omitted.
The operation of 0 will be explained.

First, to explain the operation of the waveform generator 7, the position detector 3
Since the detection signals D and D'' are generated as shown in FIG. 4, the ball is synchronized with the relative position of the field 19 and the propulsion coil 18 as shown in FIG. A pulse signal R for each pitch is obtained.

On the other hand, since the distance can be obtained by integrating the velocity, the position between ball pitches can be calculated by synchronizing with the pulse signal R using the sweep signal generator 72 consisting of an integrator and integrating and resetting the velocity from the velocity detector 2. be done.

The output of this generator 72 sweeps a function generator 73 in which an arbitrary waveform, for example, a sine wave, for a position corresponding to one ball pitch is set in advance, and this output and a signal whose polarity is inverted by an arithmetic unit 74 are Synchronized with the detection signals D and D'' of the position detector 3, the signals are alternately applied to the adder 77 by analog switches 75 and 76, and an AC waveform synchronized with the movement of the vehicle 20 is obtained.On the other hand, an AC waveform similar to a trapezoidal wave is obtained. The shape pattern is generated by the trapezoidal wave generation circuit 80 using the detection signals D and D'' of the position detector 3.
0 is created.

Next, the trapezoidal wave pattern and arbitrary shape pattern from the trapezoidal wave generation circuit 800 and the waveform generator 7 are switched by the switch 10 depending on the speed range. However, if the switch is made only based on the speed comparison result, the switch may occur in the middle of outputting the waveform pattern, resulting in uneven waveform patterns.
8 and a memory circuit 103, the switching is performed in synchronization with the ball pitch interval pulse signal R.

FIG. 9 shows the waveforms of each part of the switching device 10, the detection signals D, D'' of the waveform generator 7, and the waveforms of the pulse signal R.If the speed is below the set value, the speed comparator 100 Since the output is zero, the output of the AND circuit 102 is also zero, so the memory circuit 103 does not output an output, and the analog switch 106 is closed, so the arithmetic unit 107 uses the output of the trapezoidal wave generation circuit 800 as a waveform pattern. Output.

On the other hand, a differentiation circuit 1 that differentiates the detection signal D of the position detector 3
When the output of 01 is output, the AND circuit 109 outputs an output, the analog switch 110 is closed, and the memory circuit 103 is reset.

For example, when the speed exceeds the set value at time t1, the speed comparator 100 outputs an output as shown by the solid line 1 in FIG. The differentiating circuit 101 that differentiates the detection signal D of the detector 3 is the ninth
When the output shown in Figure 5 is output, the AND circuit 1
02 outputs an output as shown by a solid line at 6 in FIG. 9, so the memory circuit 103 outputs an output as shown at 7 in FIG. 9 with a solid line. Since the analog switch 105 is opened at the same time as the memory circuit 103 outputs an output, the output of the waveform generator 7 is output as a waveform pattern.

That is, when the speed exceeds the set value at a later point in time, the speed comparator 100 outputs an output, while the differentiating circuit 101 that differentiates the detection signal D of the position detector 3 outputs an output, and at the same time the AND circuit 102 outputs an output. Since the memory circuit 103 outputs an output, the output from the waveform generator 7 appears as a waveform pattern, and the current pattern changes from a shape close to a trapezoidal wave to a sine wave.

Next, a case will be described in which the speed exceeds the set value at, for example, T3. In this case, since the memory circuit 103 outputs an output at T4, the current pattern changes from a shape close to a trapezoidal wave to a sine wave.

Next, the operation when the speed goes from high to below the set value will be explained using the waveform diagram shown in FIG. For example, if the speed falls below the set value at a certain point in time and the output of the speed comparator 100 becomes zero, the output of the AND circuit 102 becomes zero.
The memory circuit 103 does not immediately become zero, but when the differentiating circuit 101 outputs an output and the analog switch 110 is turned on by the output of the AND circuit 109, the output of the memory circuit 103 is reset and becomes zero, and the waveform pattern changes to the waveform. Generator 7
to the output of the trapezoidal wave generating circuit 800, and the current pattern switches from a sine wave to a waveform having a shape close to a trapezoidal wave.

That is, if the speed becomes less than the set value at a later point in time, the waveform of the current pattern is switched at the time T2, so that the waveform pattern is smoothly switched.

Next, to explain the case where the speed becomes less than the set value at a later point in time, the output of the speed comparator 100 becomes zero at the time T3, and the output of the AND circuit 102 becomes zero, but the output of the memory circuit 103 becomes zero. The output does not immediately become zero, and the next differentiator circuit 1
At the time (T4) when the AND circuit 109 outputs an output based on the output from 01, the memory circuit 103 is reset via the analog switch 110, and at this point the output of the memory circuit 103 becomes zero, and the waveform pattern changes. The output of the waveform generator 7 is smoothly switched to the output of the trapezoidal wave generation circuit 800. The case where the detection signals of the position detector for one phase are used as the trapezoidal wave pattern has been described above, but if the detection signals of the position detector for three phases are used, a waveform pattern with a shape similar to a sine wave can be created. I can do it. As described above, according to the present invention, a waveform pattern with little phase shift of the fundamental wave component can be obtained in the entire speed range without using a complicated and expensive speed detection device, and the waveform pattern can be switched in response to speed changes. This has the advantage that thrust pulsation does not increase or average thrust does not decrease at low speeds.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of waveforms of signals generated by a conventional drive control device, FIG. 2 is an explanatory diagram showing the configuration of an embodiment for one phase of the drive control device for a linear synchronous motor according to the present invention, and FIG. The figure is an explanatory diagram of an example of the position detector in Fig. 2, Fig. 4 is an explanatory diagram of the waveform of the signal obtained in Fig. 3, and Fig. 5 is an example of a specific configuration of a part of Fig. 2. A block diagram, FIGS. 6 and 7 are waveform explanatory diagrams showing signals of each part in FIG. 5, and FIG. 8 is a block diagram of an example of a specific configuration of a part of FIG. 2 that is different from FIG. FIGS. 9 and 10 are waveform explanatory diagrams showing signals of each part in FIG. 8. 2... Speed detector, 3... Position detector, 7... Waveform generator, 8... Waveform conversion generator, 9... Trapezoidal wave generator, 10... Pattern shape switcher , 12... Gate control device, 14... Cycloconverter, 18...
- Propulsion coil, 19... Field, 30... OR circuit, 96... Analog switch.

Claims (1)

[Scope of Claims] 1. A linear synchronous motor equipped with a magnetic field on a running body and a propulsion coil installed on a track, generated by a signal from a position detector that detects the relative position of the field and the propulsion coil. The drive control device for the linear synchronous motor that energizes based on a current pattern includes: a circuit that generates a rectangular wave synchronized with the signal of the position detector; an integrating circuit that integrates the output of the rectangular wave generating circuit; A circuit that obtains a pulse having a shorter time width than the output of the rectangular wave generating circuit by comparing the output of the circuit with the output of the circuit that generates a voltage inversely proportional to the speed of the traveling object, and the output of this circuit. 1. A drive control device for a linear synchronous motor, comprising a circuit for creating the current pattern waveform by providing a delay circuit on the side thereof. 2 A linear synchronous motor with a magnetic field mounted on the running body and a propulsion coil installed on the track, energized based on a current pattern created by a signal from a position detector that detects the relative position of the field and the propulsion coil. In the drive control device for the linear synchronous motor, there is provided a circuit that generates a rectangular wave synchronized with the signal of the position detector, an integrator circuit that integrates the output of the rectangular wave generation circuit, and an output of the integrator circuit and the drive control device. A circuit that obtains a pulse with a shorter time width than the output of the rectangular wave generation circuit by comparing the output of a circuit that generates a voltage inversely proportional to the speed of the body, and a delay circuit on the output side of this circuit. a first means for creating the current pattern waveform by using the input means, and a second means for creating an arbitrary current pattern waveform synchronized with the signal from the position detector by inputting the output of the speed detector that detects the speed of the traveling object. and means for selecting a current pattern waveform from the first means and a current pattern waveform from the second means according to a speed range of the traveling body, and when the traveling body is started up and at low speed. Selecting the current pattern waveform from the first means when the speed is different, and selecting the current pattern waveform from the second means when the speed is other, and driving the linear synchronous motor according to the selected current pattern waveform. A drive control device for a linear synchronous motor featuring features.