JP2000023315A - Control equipment for linear motor electric rolling stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce changes in thrust which is caused by change of an air gap by using vector control and to restrain overcurrent when a part where a reaction plate is not present is passed. SOLUTION: This control equipment is provided with a linear induction motor 2 which is driven a PWM inverter 1, has a primary winding on the vehicle side of an electric rolling stock and is provided with a reaction plate as a secondary conductor on the ground side, a current command generator 3 for operating an exciting current command and a torque current command which are applied to the motor 2, and a coordinate converter 10 for detecting an exciting current component from a primary current of the motor 2. In the control equipment, a current command corrector 7 is installed which operates a correction value, on the basis of a quantity that the output of a subtracter 4 for calculating the deviation between an exciting current command value, and an exciting current detection value is limited to a specified range by a limiter 6. By using the correction value, a torque current command is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor electric vehicle in which a primary linear induction motor on a vehicle supported by iron wheels is driven by vector control using a power converter that outputs a variable voltage and a variable frequency alternating current. It relates to a control device.

[0002]

2. Description of the Related Art In a linear motor electric vehicle having a primary winding of a linear induction motor on the upper side of a vehicle and a reaction plate laid on the ground side as a secondary side, a space between the primary winding and a secondary reaction plate is provided. The air gap length fluctuates during the running of the electric vehicle, so that the thrust also fluctuates. A technique for compensating for this thrust fluctuation is described in JP-A-7-147706. The technique disclosed in this publication detects a power factor of a linear induction motor, and controls a primary frequency to compensate for a thrust fluctuation.

[0003]

In a linear motor electric vehicle, there are places where a reaction plate cannot be provided, such as a turnout section or a garage. The technology disclosed in the above publication controls the primary frequency by detecting the power factor of the linear induction motor. However, when the primary side of the linear induction motor passes through the portion without the reaction plate, the power factor drops extremely. However, there is a problem that the amount of thrust compensation increases and an excessive current flows. Further, the technology disclosed in the above publication performs V / f constant control, and the accuracy of torque control is not sufficient.
There was a problem that.

[0004] It is an object of the present invention to reduce the variation in thrust caused by the variation of the air gap by using vector control, and to reduce the variation in thrust caused by the variation of the air gap. An object of the present invention is to provide a vehicle control device.

[0005]

An object of the present invention is to provide a method for controlling a torque current based on an exciting current command value of a linear induction motor and a deviation of an exciting current component detected from a primary current within a predetermined range by a limiter. The problem is solved by providing a means for correcting the command value. Further, by providing a means for correcting the torque current command value based on the amount of limiting the deviation between the current effective value command of the linear induction motor and the current effective value detection value of the primary current within a predetermined range by a limiter,
Will be resolved. A means for correcting a torque current command value based on an exciting current command value of the linear induction motor and a deviation of the exciting current component detected from the primary current within a predetermined range by a limiter; This problem can be solved by providing a means for correcting the slip frequency command value and the voltage command value of the linear induction motor based on this. Further, this problem can be solved by providing a means for correcting the torque current command value based on an amount in which the deviation between the acceleration command value and the detected acceleration value of the electric vehicle is limited to a predetermined range by a limiter. Here, means for detecting a torque current from the primary current of the linear induction motor and means for correcting the torque current command based on a deviation between the torque current command and the detected torque current value are provided.
Here, when the excitation current command changes, the command value correction amount is set to zero or the absolute value of the correction amount is reduced.

If the air gap length between the primary side and the secondary reaction plate of the linear induction motor becomes larger than a normal value, the magnetic flux generated from the primary side and coupled to the secondary side decreases. Become. At this time, considering the equivalent circuit of the linear induction motor, the exciting inductance is reduced. As a result, the impedance of the excitation circuit decreases, the excitation current increases, and the generated thrust decreases. Conversely, as the air gap length decreases, the exciting current decreases and the generated thrust increases. Therefore, when the air gap length changes, a deviation occurs between the excitation current command value and the excitation current detection value. If the air gap length is increased, the generated thrust is reduced. Therefore, by correcting the torque current command value to be increased according to the deviation, the fluctuation of the thrust can be reduced. Further, when the primary side of the linear induction motor moves from the reaction plate to a place where there is no reaction plate, the excitation inductance of the equivalent circuit is significantly reduced in terms of the equivalent circuit of the linear induction motor. At this time, the impedance on the secondary side decreases, and a large exciting current component flows. At this time, the deviation between the excitation current detection value and the excitation current command value becomes even larger than when the air gap length is simply increased. Therefore, if the torque current command value is increased in accordance with the deviation, an excessive current will flow. Therefore, when the deviation between the excitation current detection value and the excitation current command value becomes larger than a predetermined value,
By limiting the current to a predetermined value or less, an increase in current can be suppressed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a control device for a linear motor electric vehicle according to a first embodiment of the present invention. In FIG. 1, a DC supplied from a DC power supply 11 is smoothed by a filter capacitor 12 and applied to a pulse width modulation (PWM) inverter 1 as a power converter. The PWM inverter 1 converts a DC voltage serving as a power supply into a three-phase variable voltage and a variable frequency AC, and supplies a voltage to a primary winding of the linear induction motor 2. The electric vehicle runs by the interaction between the primary winding and a reaction plate (not shown) provided on the ground side facing the primary winding.

The control device includes a current command generator 3, a subtractor 4, a voltage command calculator 5, a limiter 6, a current command corrector 7, a slip frequency calculator 8, coordinate converters 9, 10, PW
M signal calculator 13, current detector 14, speed detector 16,
It comprises an adder 17 and a subtractor 18. Current command generator 3
Generates an exciting current command value Id * and a torque current command value Iq *. The voltage command calculator 5 calculates the linear induction motor 2 based on the excitation current command value Id *, the torque current command value Iq *, and a primary frequency command value ω1 * described later, according to (Equation 1).
, And Vd * and Vq *, which are the commands of the two voltage components of the rotating magnetic field coordinate system supplied to.

(Equation 1) r1: primary resistance of the linear induction motor, l1: the same primary leakage inductance, lm: the same excitation inductance, l2: the same secondary leakage inductance. , And outputs the slip frequency command value ωs * from the torque current command value Iq *.

(Equation 2) r2: Secondary resistance of the linear induction motor The subtracter 4 outputs to the limiter 6 a deviation ΔId between the excitation current command value Id * and the excitation current detection value Id output from the coordinate converter 10 described later. The limiter 6 limits the deviation of the exciting current to fall within a predetermined range. Limiter 6
Is input to the current command corrector 7, and the current command corrector 7 outputs a correction amount ΔIq of the torque command value. This correction amount is input to the subtractor 18 and corrects the torque current command value of the current command generator 3. On the other hand, the electric vehicle speed ωr output from the speed detector 16 attached to the wheel 15 is added by the adder 17 to the slip frequency command value ωs * output from the slip frequency calculator 8, and the primary frequency command value ω1 *
Generate The primary frequency command value ω1 * is given to the voltage command calculator 5 and the coordinate converters 9 and 10. The coordinate converter 9 receives the voltage commands Vd * and Vq * and receives the three-phase voltage command V of the stationary coordinate system based on the primary frequency command value ω1 *.
u, Vv, and Vw. The coordinate converter 10 is a PWM
A current detector 14u for detecting the output current of the inverter 1,
Motor currents iu, i detected by 14v, 14w
v and iw are input and converted into an exciting current component Id and a torque current component Iq of the rotating magnetic field coordinate system based on the primary frequency command value ω1 *. In the PWM signal calculator 13, the ON / OFF pulse S is obtained from the outputs Vu, Vv, Vw of the coordinate converter 9.
u, Sv and Sw are generated and given to the PWM inverter 1.

FIG. 2 shows an equivalent circuit for one phase of a linear induction motor. In FIG. 2, r1 is a primary resistance, and l1 is 1
Next leakage inductance, lm is excitation inductance, l
2 indicates a secondary leakage inductance, r2 indicates a secondary resistance, and s indicates slip of the linear induction motor. 1 of linear induction motor
If the air gap length between the secondary side and the secondary reaction plate becomes larger than a normal value, the magnetic flux coupled to the secondary side among the magnetic fluxes generated from the primary side will decrease.
At this time, considering the equivalent circuit of the linear induction motor, the exciting inductance lm decreases. In addition, the secondary leakage inductance l2 and the secondary resistance r2 change, but the effect is smaller than lm. As a result, the impedance of the excitation circuit decreases, and the excitation current increases. Further, the thrust F of the linear induction motor is represented by (Equation 3).

(Equation 3) τ: pole pitch of the linear induction motor It can be seen that the thrust F also decreases because the exciting inductance lm decreases as the air gap length increases. vice versa,
As the air gap length decreases, the exciting current decreases and the generated thrust increases.

In the present embodiment, if the air gap length is increased, the exciting current value Id becomes larger than the exciting current command value Id *, and a negative deviation ΔId is generated in the subtractor 4. The correction amount ΔIq of the torque current command is calculated by the
Correct so that q * increases. This compensates for a decrease in the thrust F due to a decrease in the excitation inductance lm.
Here, as the configuration of the voltage command corrector 7, a first-order lag element is used. In this case, the correction amount ΔIq of the torque current command
Is calculated by (Equation 4). Note that a coefficient unit that multiplies a predetermined coefficient may be used.

(Equation 4) K: constant, T: time constant, p: lab operator On the other hand, when the air gap length returns to the original value, the exciting current of the linear induction motor changes in a decreasing direction, so the exciting current value Id and the exciting current command The deviation from the value Id * disappears,
When the state returns to the original state and the air gap further decreases, the operation is reversed.

Next, when the primary side of the linear induction motor moves from the reaction plate to a place where there is no reaction plate, the magnetic flux generated in the primary winding does not link to the secondary side. Thus, it appears that the excitation inductance lm is reduced. In the circuit of the secondary leakage inductance l2 and the secondary resistor r2, the absence of the secondary conductor also increases r2 and can be regarded as an open circuit. As a result, when there is no reaction plate, the impedance of the equivalent circuit decreases, and a large current flows when the applied voltage is the same. At this time, the deviation between the excitation current detection value and the excitation current command value is further larger than when the air gap length is simply changed. Therefore, if the torque current command value is increased according to the deviation by the operation of the current command corrector 7 as it is. , A larger current will flow. Therefore, in the present embodiment, the deviation of the exciting current of the output of the subtracter 4 is limited by the limiter 6, so that the torque command value is prevented from increasing more than a certain degree, and the increase in the current is suppressed. The limit value of the limiter 6 is set, for example, in the case of normal air gap fluctuation, to output the deviation as it is, and to exceed the limit value when the reaction plate disappears and the deviation becomes significantly large. The limiter 6 also has a function of preventing a current flowing through the PWM inverter 1 and the linear induction motor 2 from exceeding a predetermined maximum value. With the configuration described above, it is possible to realize a control device for a linear induction motor in which a change in thrust is small even when the air gap fluctuates and an excessive current does not flow even when traveling in a place without a reaction plate. it can.

FIG. 3 shows a second embodiment of the present invention.
The difference from the first embodiment shown in FIG.
Thus, the effective value of the three-phase currents iu, iv, iw is obtained, and the current command generator 3 outputs the current effective value command Im *. Here, there is a relationship (Equation 5) between Im *, the excitation current command value Id *, and the torque current command Iq *.

(Equation 5) Also, the subtractor 4 receives the excitation current command value Id * and the excitation current detection value Id in FIG. 1, but in the present embodiment, the current effective value command value Im * and the current effective value detection The current command corrector 7 calculates the correction amount ΔIq of the torque command value, inputs the correction value ΔIq to the subtractor 18, and inputs the current command generator The torque current command value of No. 3 is corrected.
In the present embodiment, the sensitivity of the command value correction amount is slightly reduced by using a current effective value that is easily detected instead of the excitation current, but is substantially the same as the embodiment of FIG. 1 without using the excitation current detection value. Similar operations and effects can be obtained.
Further, since the current flowing when the reaction plate has disappeared is almost an exciting current, there is almost no difference even if it is detected by the current effective value.

FIG. 4 shows a third embodiment of the present invention.
The difference from the first embodiment in FIG. 1 is that the voltage command values Vd *, Vq * and the slip frequency command value ωs are corrected by the excitation inductance lm ′ corrected by the constant corrector 20 based on the deviation from the subtractor 4. It is a point to do. FIG. 5 shows a configuration example of the constant corrector 20. The output of the first-order lag element 51 with respect to the deviation of the excitation current is regarded as the correction of the excitation inductance lm, and the adder 52 adds the output of the constant generator 53 that gives the standard value of the excitation inductance lm, thereby obtaining the corrected excitation inductance lm 'Is output. This lm ′ is given to the voltage command calculator 5 and the slip frequency calculator 8. The voltage command calculator 5 calculates a voltage command using lm ′ instead of lm in (Equation 1). Similarly, in the slip frequency calculator 8, instead of lm in (Equation 2), l
Calculation is performed using m ′. When the reaction plate runs out, no thrust is produced even when a current is supplied, so it is desirable to reduce the voltage as much as possible. Therefore, with the above configuration, the voltage command is reduced by setting the excitation inductance correction value lm 'to a value smaller than the normal value, and the current when the vehicle travels without a reaction plate can be further suppressed.

FIG. 6 shows a fourth embodiment of the present invention.
The difference from the first embodiment of FIG.
The difference Δa is obtained from the acceleration command a * of 1 and the acceleration value a of the acceleration detector 22 and is output to the limiter 6. In the embodiment described so far, the thrust is compensated based on the deviation between the command value of the exciting current or the effective value current and the detected value, but the same is true of the command value of the electric vehicle acceleration and the detected value. This may be performed based on the deviation. As a method of detecting the acceleration, there are a method of differentiating the wheel speed, a method of using a sensor for directly detecting the acceleration, and the like. FIG.
The acceleration command a * output from the acceleration command generator 21 and the acceleration detection value a output from the acceleration detector 22
Is obtained by a subtractor 4 and output to a current command corrector 7 via a limiter 6. In the present embodiment, if the air gap length is increased, the thrust decreases, and the output a of the acceleration detector 22 decreases. As a result, a negative deviation Δa is generated in the subtractor 4, and based on the negative deviation Δa, the current command corrector 7 corrects the torque current command correction amount ΔIq
*, The torque current command value I
Correct so that q increases. When the primary side of the linear induction motor moves from a position above the reaction plate to a position where there is no reaction plate, no more thrust is generated, so a larger negative deviation Δa is generated in the subtractor 4. At this time, even if the torque current command value Iq is corrected,
Since no thrust is generated, an increase in current is suppressed by limiting the torque current command value Iq by the limiter 6 so as not to increase to a certain degree or more.

FIG. 7 shows a fifth embodiment of the present invention.
The difference from the first embodiment shown in FIG.
The point is that a torque current command value Iq ** obtained by correcting q * with the torque current detection value Iq by the current controller 23 is used. In the present embodiment, the voltage command values Vd * and Vq * and the slip frequency command value ω are calculated using the corrected torque current command value Iq **.
Calculate s. As an example of the configuration of the current controller 23, the deviation between the torque current command value Iq * and the detected torque current value Iq is corrected by proportional-integral control as shown in (Equation 6).

(Equation 6) K2: Constant, T2: Time constant, p: Labrass operator This embodiment is the same as the operation and effect of the first embodiment. By this correction, the primary resistance other than the exciting inductance lm of the linear induction motor is changed. It is possible to reduce the change in thrust with respect to the change in r1, the secondary resistance r2, and the like. This embodiment can be applied to the first to fourth embodiments.

Here, in the vector control, since it is usually necessary to control the excitation current to be constant, the excitation current is reduced when the PWM inverter is started, and the excitation current is reduced according to the speed. When the current command is changed, vector control cannot be performed, and an error occurs between the command value and the detected value.
May malfunction. In this case, the command value correction amount may be set to 0 or the correction amount may be reduced. Specifically, when the exciting current command changes, the gain of the current command corrector 7 or the constant corrector 20 may be set to 0 or smaller than usual.

[0017]

As described above, according to the present invention,
By using the vector control, when the air gap length between the primary winding of the linear induction motor and the secondary reaction plate fluctuates during running of the electric vehicle, the fluctuation of the thrust due to the fluctuation of the air gap is reduced. be able to. Further, even when the primary side of the linear induction motor passes from a position above the reaction plate to a position where there is no reaction plate, the current can be suppressed so that an excessive current does not flow.

[Brief description of the drawings]

FIG. 1 is a control apparatus of a linear motor electric vehicle according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an equivalent circuit of a linear induction motor.

FIG. 3 shows a second embodiment of the present invention.

FIG. 4 shows a third embodiment of the present invention.

FIG. 5 is a configuration example of a constant corrector;

FIG. 6 shows a fourth embodiment of the present invention.

FIG. 7 is a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... PWM inverter, 2 ... Linear induction motor, 3 ... Current command generator, 4 ... Subtractor, 5 ... Voltage command calculator, 6 ...
Limiter, 7: current command corrector, 8: slip frequency calculator, 9, 10: coordinate converter, 11: DC power supply, 12: filter capacitor, 13: PWM signal calculator, 14: current detector, 15: wheel , 16: speed detector, 17: adder, 18: subtractor, 19: effective current calculator, 20: constant corrector, 21: acceleration command generator, 22: acceleration detector, 23: current controller

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tsutomu Ozawa 1070 Ma, Hitachinaka-shi, Ibaraki Pref.Hitachi, Ltd., Mito Plant (72) Inventor Toshihiko Sekizawa 1070 Ma, Hitachinaka-shi, Ibaraki, Hitachi, Ltd. Inside Mito Plant (72) Inventor Masahiro Ando 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo F-term (reference) 5H113 AA05 AA06 AA07 BB01 BB07 CC03 CC07 CD03 CD13 DD01 EE01 GG08 GG12 GG30 HH08 HH09 HH13 HH14 H18 JJ01 5H540 AA02 BA02 BB06 BB08 BB10 EE08 EE10 EE14 EE15 EE19 FB01 FC02 FC10 FC10 GG02

Claims (6)

[Claims] 1. A power converter for outputting a variable voltage and a variable frequency AC, a primary winding on an upper side of an electric vehicle driven by the power converter, and a reaction plate as a secondary conductor on the ground side. Control of a linear motor electric vehicle comprising: a linear induction motor provided with a motor; means for calculating an exciting current command and a torque current command given to the linear induction motor; and means for detecting an exciting current component from a primary current of the linear induction motor. In the apparatus, there is provided a means for correcting the torque current command value based on an amount obtained by limiting a deviation between the excitation current command value and the excitation current detection value to a predetermined range by a limiter. Control device. 2. A power converter for outputting a variable voltage, variable frequency alternating current, a primary winding on the upper side of an electric vehicle driven by the power converter, and a reaction plate as a secondary conductor on the ground side. A linear motor having a linear induction motor provided with: a means for calculating an excitation current command, a torque current command, and a current effective value command given to the linear induction motor; and a means for detecting an effective value of a primary current of the linear induction motor In the control device for an electric vehicle, there is provided means for correcting the torque current command value based on an amount obtained by limiting a deviation between the current effective value command and the current effective value detection value to a predetermined range by a limiter. Control device for linear motor electric vehicle. 3. A power converter for outputting a variable voltage, variable frequency alternating current, a primary winding on an upper side of an electric vehicle driven by the power converter, and a reaction plate as a secondary conductor on the ground side. , A means for calculating an exciting current command and a torque current command given to the linear induction motor, means for detecting an exciting current component from a primary current of the linear induction motor, A control apparatus for a linear motor electric vehicle, comprising: means for calculating a slip frequency command value from a current command; and means for calculating a voltage command value from a primary frequency command value including the excitation current command, the torque current command, and the slip frequency command value. In the method, the torque current command value is supplemented based on an amount obtained by limiting a deviation between the excitation current command value and the excitation current detection value to a predetermined range by a limiter. A controller for correcting the slip frequency command value and the voltage command value based on the deviation. 4. A power converter that outputs a variable voltage and a variable frequency AC, a primary winding on the upper side of the electric vehicle driven by the power converter, and a reaction plate as a secondary conductor on the ground side. A linear induction motor provided with a means for calculating an excitation current command, a torque current command and an acceleration command given to the linear induction motor, and a control device for a linear motor electric vehicle including means for detecting acceleration of the electric vehicle. A control device for a linear motor electric vehicle, comprising: means for correcting the torque current command value based on an amount in which a deviation between an acceleration command value and an acceleration detection value is limited within a predetermined range by a limiter. 5. The linear induction motor according to claim 1, further comprising: a torque current detection unit configured to detect a torque current from a primary current of the linear induction motor; A control device for a linear motor electric vehicle, comprising means for correcting a torque current command. 6. In any one of claims 1 to 3 or 5, when the exciting current command changes,
A control device for a linear motor electric vehicle, wherein a command value correction amount is set to zero or an absolute value of the correction amount is reduced.