JPS5943916B2 - Control method of linear synchronous motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for controlling a linear synchronous motor used in an induced repulsion type magnetic levitation vehicle.

Guided-repulsion magnetic levitation vehicles are well known.

An example of this will be outlined with reference to FIGS. 1a to 1e. 1st
In Figure a, numerals 2 and 2' denote known superconducting magnets each having a conductor formed in a loop shape, and are arranged in two parallel rows at a predetermined interval apart from each other along the train traveling direction on the underside of the vehicle body. In this case, adjacent superconducting magnets usually have opposite polarities. On the other hand, conductors 3, 3 of the same shape and size made of ordinary conductive loop coils or conductive sheets are placed on the track.
' is placed at a position where electromagnetic induction is possible between the superconducting magnets 2 and 2' of the corresponding row.

Even with this configuration, as long as the vehicle is stopped, no electromagnetic action occurs between the superconducting magnet 2|2' on the vehicle and the conductors 3, 3' on the ground. The superconducting magnets 2, 2' are successively arranged at predetermined intervals along the vehicle traveling direction on the track by driving a vehicle drive mechanism using, for example, a linear motor to make the vehicle run. The superconducting magnets 2, 2' and the superconducting magnets in the same row in front of the vehicle in the direction of travel do not face the same conductors 3, 3' at the same time. As long as it is set as follows, a current is induced in the conductor 3|3'. However, the induced current of the lever increases with the running speed of the vehicle, becomes almost saturated at a certain running speed, for example, about 200 Ign/min, and remains at the same level as long as the vehicle is running at that speed or higher. In other words, the conductor 3|3' shown in FIG. 1a is linked with the magnetic flux φ as shown in FIG. The first drawn correspondingly
A voltage e for the floating earth shown in Figure c is induced, and a current 1 as shown in Figure 1D flows. As is well known, a current flowing through a first loop-shaped conductor causes a current induced in a second loop-shaped conductor opposing the first loop-shaped conductor to flow in a direction opposite to that of the first conductor. Therefore, superconducting magnet 2,
If the current 2' flows in the direction of arrow a as shown in FIG. 1e, the current induced in the conductor 3 by that current flows in the direction b. As a result, the floating blade F=BXi is obtained according to Fleming's left-hand rule. Here, B is the magnetic flux density created by superconducting magnets 2 and 2', i
is the current flowing through the conductors 3, 3'. That is, the vehicle is levitated by the repulsive force acting between the superconducting magnets 2 and 2' and the current induced in the conductors 3 and 3'. A ground-first linear synchronous motor system has been proposed as a propulsion system for such induction-repulsion magnetic floating vehicle propulsion.

Basically, this method generates a moving magnetic field by sequentially energizing ground conductors (hereinafter referred to as "earth coils") as the vehicle moves forward, and the moving magnetic field is applied to the superconducting magnets on the vehicle. By interlinking the magnetic fluxes, thrust to propel the vehicle is obtained according to Fleming's left-hand rule.

In the case of this system, it is necessary to match the traveling speed of the vehicle with the speed of the moving magnetic field generated by the ground coil, and to precisely control the phase of the moving magnetic field to generate the optimal propulsion force. It is essential for effective use.

Therefore, in the proposed linear synchronous motor system, the relative position of the traveling vehicle to the ground coil is detected by a detector installed on the vehicle or on the ground, and the frequency of the current in the ground coil is determined accordingly. A method is used to determine the phase. An example of this will be explained in detail with reference to FIGS. 2a to 2d. Figure 2 AVC 1
is a unit drive linear motor installed on the ground, as shown in Figure 2 d.
As shown in FIG. 2, propulsion ground coils 5 and 5' are continuously arranged on the track surface facing superconducting magnets 4 and 4' for vehicle propulsion which are attached to the lower side of the vehicle C, for example.

In the case where three-phase AC power is supplied to the propulsion ground coils 5, 5/ and the vehicle is propelled by the electromagnetic force generated between the coils 5, 5/ and the superconducting magnets 4, 41, the following is shown in Fig. 2B and c. In other words, the propulsion ground coils 51 to 532 are arranged continuously along the track 6 so as to be able to face the propulsion superelectromagnets 4 and 4' on the vehicle.
, 512 of the U phase, 52, 521, 522 of the phase,
Further, 53, 531, and 532 are each connected in series so that a W-phase current is applied thereto. It is assumed that vehicle C is propelled in the direction of arrow a as shown in FIG. 2c. Dgl and Dg2 are plates for detecting the relative position between the vehicle and the propulsion ground coil, which are made of a reflector, etc.
They are arranged so as to occupy an area corresponding to the first half of one phase period. DCl to DC3 are position detectors that detect the coil position by emitting light to the detection plates Dgl and Dg2 and receiving reflected light from the detection plates Dgl and Dg2VC, and are provided in the vehicle C. -DC3 is the same as the installation interval of the propulsion ground coil in the longitudinal direction. For convenience of explanation, immediately before the state shown in Figure 2c, the side of the U-phase coil facing the vehicle is set to the south pole, and the side facing the propulsion ground coil of the superconducting magnet on the vehicle soil is always set to the north pole. It is assumed that At such times, an electromagnetic force acts between the U-phase coil and the superconducting magnet on the vehicle to attract the vehicle in the direction of travel.

As the vehicle moves forward, the position detector DCl detects the U-phase coil 51 via the detection plate Dgl. When the U-phase coil 51 is converted to N-pole by the detection signal, a repulsive force acts between the superconducting magnets 4, 4' on the vehicle and the U-phase coil 51.
The phase coil 51 maintains the N pole during the half cycle period when DCl passes through the detection plate Dgl. When the position detector DC2 detects the rear end of the detection plate Dgl, the V-phase coil 5
2 is converted to N pole and repulsive force acts, DC2 becomes detection plate Dg
The north pole is maintained until it passes through l. Similarly, when the VCDC 3 detects the rear end of the detection plate Dgl, the W-phase coil is converted to the N-pole and maintains the N-pole until it passes the detection plate Dg. In this way, the vehicle is propelled while repeating attraction and repulsion. In this case, the relative position detection signals of the superconducting magnets 4, 4' on the vehicle and the ground coils 5, 5' are transmitted wirelessly from the transmitter on the vehicle to the ground via the antenna 16, as shown in FIG. 2a. A synchronized rectangular wave of 180 electrical degrees (hereinafter referred to as a "coil position signal") is transmitted to the receiving antenna 7 and input to the receiver 8 in accordance with the speed of the vehicle.

The pulse width prediction device 9 measures the time from the rise to the fall of the coil position signal, and based on the measurement result, when a new rise signal is input, predicts the rise signal of the signal. In the sine wave generator 10, a half period of the sine wave is arranged between the rising signal and the predicted falling signal (for example, between 0 degrees and 180 degrees in electrical angle).
Convert the coil position signal to a sine wave. On the other hand, the speed calculation device 13 calculates the actual speed of the vehicle based on the output of the receiver 8, and the actual speed is inputted together with the scheduled speed 8 to the comparison device 14, and the comparison device 14 calculates the deviation between both speeds. A current amplitude command commensurate with the current amplitude is input to the multiplier 11.

Thus, a sine wave current command created by multiplying the phase and the amplitude is input from the multiplier 11 to the power converter 12VC, and the power converter 12 converts the power supplied via the step-down transformer 15. The ground coil is energized via the feeder. However, Jumei measured the time from the rise to the fall of the coil position signal for each of the U, V, and W phases, and generated sine wave current commands separately.

Therefore, due to variations in the detection of the position detector, etc., variations occur in the phase of the coil position signal and the sine wave current command created from the coil position signal, making it difficult to accurately maintain a constant phase difference between each phase of the sine wave. It was. Therefore, based on these sine waves, the current in the ground coil supplied from the power converter 12 via the feeder becomes unbalanced, and a current flows through the feeder's neutral wire, thereby adversely affecting the levitation propulsion of the vehicle. In addition, there were defects such as the current causing induction in signal and communication equipment. The present invention was made in order to eliminate such defects, and by ensuring that the sum of the currents of each phase of the ground coil is always zero, the unbalance of the current flowing through the feeder and the current flowing through the feeder's neutral wire are eliminated. This is designed to prevent the generation of current.

The present invention will be explained according to the embodiment shown in FIG.

In FIG. 3, the same symbols as those shown in FIG. 2 indicate the same components.

In the present invention, the coil position detection signal is sent wirelessly from the transmitter on the vehicle to the receiver 8 on the ground via the antenna 16 based on the relative position of the superconducting magnet on the vehicle soil and the ground coil as shown in FIG. This is the same as the example shown in Figure 8, but the receiver 81
V.C. In this case, only the coil position signal of one of the three phases, for example, the U phase, is received.

The pulse width prediction device 91 predicts a falling signal from a rising signal of the U phase. The sine wave generator 101VC generates a sine wave from O degrees to 180 degrees for the U phase, -120 degrees to 60 degrees for the V phase, and -240 degrees to -60 degrees for the W phase by inputting the U phase predicted signal. A sine wave of each phase is created so that a half period of . Speed calculation device 1
3, calculate the actual speed of the vehicle, and calculate the actual speed and the planned speed Vs.
are compared by a comparison device 14, a current amplitude command commensurate with the deviation between both speeds is inputted to a multiplier 11, and a sine wave current command created by multiplying the phase and amplitude from the multiplier 11 is sent to the power conversion device. The input of 12 VC and the excitation of the ground coil by the power converter 12 are the same as in the example shown in FIG. FIG. 4 shows the sine wave generator 101 shown in FIG.
The part surrounded by the dotted line 102 is the part for explaining the structure of the present invention, and the other parts are the structures used for each phase since the beginning of the present invention. Pulse width prediction data B, which predicts the time width from the rise to the fall of the U phase, is input from the pulse width prediction device 91 to the comparator COM, while the count value A of the clock pulse CK is input to the comparator COM. It is human powered through.

The comparator COM detects when A=B or A>B and outputs it to the monostable multivibrator MM via the NOR circuit NOR. In this case, by appropriately selecting the pulse width of the clock pulse CK, the monostable multivibrator MM outputs an angle pulse such that, for example, one pulse represents one degree of the phase angle of the ground coil current. On the other hand, from the pulse width prediction device 91, rising and falling reference point signals predicted from the U-phase coil position detection signal are sent to an AND circuit AN via a flip-flop FF.
By inputting a DVC input, for example, a standing ground signal,
The angle pulse is outputted from the AND circuit AND and counted by the counter CT2. The rise and fall reference point signals are usually set to be more advanced than the coil position detection signal in order to correct the time delay of the signal. counter C
The count value of T2 is always inputted to the ROMs ROM1 to ROM3, and in the ROMs ROM1 to ROM3, the count value is converted into the instantaneous value of the sine wave of the coil current of each phase of U, V, and W. In this case, when the counter CT2 counts up to 180 degrees, the detector DT detects it and inverts the output of the flip-flop FF according to the detection signal, and the AND circuit A
ND is made non-conductive to prevent the angle pulse from being input to the counter CT2. Furthermore, a signal for determining whether the ground coil current is positive or negative is input from the pulse width prediction device 91 to the digital-to-analog converters D/A1 to D/A3. Above D/A
1 to D/A3, the instantaneous values of ROM1 to ROM3 are combined with the positive/negative discrimination signal and multiplied by a sine wave signal.
Enter 1. Therefore, the phase difference between ROM1 and ROM2 and between ROM2 and ROM3 is 120, respectively.
Sin corresponds to angles from 1 to 180 degrees, so that
l~Sinl8O゜, Sinl2l~Sin3OOS
, Sin24ll to Sin42O, the values of ROM1 to R can be stored by input from counter CT2.
The output data of OM3 represents the instantaneous value of the sine wave corresponding to the coil current of each phase of U, V, W, and by D/A converting this, as shown in Fig. 5, the U, V, W A sine wave signal corresponding to the coil current of each phase is obtained, and the phase difference between the sine wave signals can be maintained constant. According to the present invention, even if a phase variation of Δt occurs in the coil position signal corresponding to the U phase, the phase difference between each phase of the ground coil current can always be kept constant. That is, the ground coil current can be expressed as Iu+Iv+Iw=0, and the sum of the instantaneous values of the currents of each phase can always be zero.

Here, A is the amplitude value of the current. Thereby, it is possible to effectively prevent the generation of a neutral line current in the feeder and the induction of the current flowing in the feeder into the signal communication device. In addition, in the above embodiment, when the number of phases is n, m≦n
-1, the relative position of the traveling vehicle with respect to the m phases of the ground coil is detected, and the phase current to be passed through the ground coil is determined. The object of the present invention can be similarly achieved by making the sum of instantaneous values zero.

[Brief explanation of the drawings] Figures 1a to 1e are diagrams for explaining the operating principle of the guided repulsion magnetic levitation vehicle, and Figure 1a shows the superconducting magnet on the vehicle and the conductive coil on the ground. A perspective view showing the relationship between
is a diagram showing the magnetic flux induced in the conductive coil in Figure 1a, Figure 1c is a diagram showing the voltage generated by the magnetic flux in Figure 1b, and Figure 1d is a diagram showing the voltage generated by the magnetic flux in Figure 1c. A diagram showing the current generated by the voltage shown in FIG. -c is a block diagram for explaining the control system of the slave by a linear synchronous motor used in a magnetic levitation vehicle, FIG. 2d is a sectional view showing an example of the mechanism of a magnetic levitation drive vehicle, and FIG. FIG. 4 is a block diagram showing an example, FIG. 4 is a circuit diagram showing details of the sine wave generator shown in FIG. 3, and FIG. 5 is a waveform diagram showing relationships among various signals in the present invention. 4, 4'... Electromagnet or superconducting magnet, 5, 5'
...Ground coil, C...Vehicle, Dgl
, Dg2... Relative position detection plate between vehicle and ground coil, DC, ~DC3... Relative position detector between vehicle and ground coil, U... Ground 1 phase with coil, V, W...Other phases of ground coil.

Claims (1)

[Scope of Claims] 1 Ground coils are continuously arranged on the ground along the direction of vehicle travel, and an electromagnet or a superconducting magnet is installed on the vehicle at a position where electromagnetic induction is possible with the ground coil, and the ground coil of the traveling vehicle is connected to the ground coil. Detect the relative position and based on the detection signal,
A moving magnetic field is generated by energizing the ground coil from the power supply device via a feeder with multi-phase alternating current with a frequency and phase adapted to the speed and position of the traveling vehicle, and by mutual electromagnetic force with the electromagnet or superconducting magnet of the traveling vehicle. A method for controlling a linear synchronous motor, which comprises energizing a ground coil in a linear synchronous motor that propels a vehicle so that the sum of the instantaneous values of the currents of each phase thereof becomes zero. 2 Ground coils are continuously arranged on the ground along the direction of vehicle travel, and an electromagnet or superconducting magnet is installed on the vehicle at a position where electromagnetic induction can be achieved with the ground coil, and the relative position of the traveling vehicle with respect to the ground coil is detected. , based on the detection signal,
A moving magnetic field is generated by energizing the ground coil from the power supply device via a feeder with multi-phase alternating current with a frequency and phase adapted to the speed and position of the traveling vehicle, and by mutual electromagnetic force with the electromagnet or superconducting magnet of the traveling vehicle. In a linear synchronous motor that propels a vehicle, the relative position of the running vehicle to one phase with a ground coil is detected to determine the phase current to flow through the ground coil of that phase, and the other phases are always set at a constant phase from this phase current. 1. A method for controlling a linear synchronous motor, characterized in that currents having phases shifted by a certain amount are applied so that the sum of instantaneous values of currents of each phase becomes zero.