JP2002281606A - Motor controller and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct appropriate speed sensorless vector control in consideration of differences between wheel diameters. SOLUTION: Current sensors 31, 32 measure currents flowing through three- phase induction motors 21, 22. An idling and skidding detection section 52 holds a difference in currents flowing through the induction motors 21, 22, and an absolute value of current which is always measured is corrected based on the current difference. The idling or skidding of any of drive shafts driven by the three-phase induction motors 21, 22, based on the correction result, is detected. Vector control computing device 40 vector-controls the three-phase induction motors 21, 22, based on the detection result of the idling and skidding detection part 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor control device for controlling an induction motor for driving an electric vehicle without using a speed sensor, and more particularly, to a diameter difference between wheels of the electric vehicle. And more precisely controlling an induction motor.

[0002]

2. Description of the Related Art Conventionally, a control system called a speed sensorless vector control for controlling an induction motor (motor) for driving an electric vehicle without using a speed sensor for detecting a rotation speed of a drive shaft of the induction motor. Has been proposed.
This control method detects slipping or sliding of wheels based on a drive current supplied to each induction motor. If slipping or sliding is detected, the slip current is reduced by reducing a torque current component or the like.・ It re-adheses the slid wheels to the track (rail).

[0003] In the speed sensorless vector control, since a speed sensor can be omitted, a large, high-output motor can be mounted.
In addition, since the wiring structure can be simplified, there are many effects such as improvement of maintainability. Therefore, early practical application of the speed sensorless vector control is desired.

[0004]

However, the conventionally known speed sensorless vector control in the case of supplying power to a plurality of induction motors by one inverter not only requires that the characteristics of the induction motors be the same but also that the electric vehicle It was assumed that the diameter of each wheel was kept equal. For this reason, when the technology is applied to an actual electric vehicle, there are problems for practical use such that the expected effect cannot be obtained and the expected control operation is not performed.

That is, in an actual electric vehicle, the wheels are worn by running, so that a small diameter difference occurs between the wheels. However, the prior art does not consider the diameter difference. As a result, inconveniences such as a delay in detection of wheel slippage due to a difference in wheel diameter due to wear have occurred.
In addition, the same inventors have reported a simulation result when the diameter difference between the wheels was 2 mm (“Influence of the wheel diameter difference in speed sensorless re-adhesion control of a plurality of induction motor driven trains”, The Institute of Electrical Engineers of Japan, Transportation Electric Railway Workshop,
TER-00-39, p31).

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor control device for feeding power to a plurality of motors and a method thereof, which can perform high-precision slip / slide detection by considering a wheel diameter difference in speed sensorless vector control. That is.

[0007]

In order to solve the above-mentioned problems, an electric motor control device according to the first aspect of the present invention provides an induction motor (for example, a three-phase induction motor 21 shown in FIG. 1) connected in parallel to a power supply line. , 22) are collectively controlled by power supply by vector control (for example,
1. A motor control device 1) shown in FIG. 1, wherein current measuring means (for example, the current sensor 3 shown in FIG. 1) measures a current flowing into at least two of the plurality of induction motors.
1, 32), holding means (for example, a holding unit 523 in FIG. 5) for holding a normal current value of the induction motor to be measured by the current measuring means, and a normal current value held by the holding means. While performing the correction, based on the relative value of the current measured by the current measuring means, the idling for detecting the occurrence of idling or sliding on any of the driving shafts driven by the plurality of induction motors. And a sliding detection means (for example, the addition / subtraction unit 524 and the comparator 525 in FIG. 5).

The normal current value referred to here is not particularly limited as long as it is a current value for the induction motor at the time of sticky running without slipping or sliding.
Difference (relative value) between currents flowing into each induction motor
Or the current value itself flowing into each of the induction motors may be used.

According to the first aspect of the present invention, the slip / skid detecting means performs the correction based on the normal current value held by the holding means, and performs the correction based on the relative value of the current measured by the current measuring means. Of the drive shafts driven by each of the induction motors, it detects the occurrence of slip or gliding on any of the drive shafts, but the normal current value is the diameter difference between the wheels driven by each induction motor. Because it is reflected, by performing correction based on the normal current value,
The effect on the idling detection due to the wheel diameter difference is canceled. As a result, the idling / sliding is detected in consideration of the wheel diameter difference. Furthermore, the normal current value reflects the steady-state characteristic difference between the induction motors, so even if a characteristic difference occurs between the motors, the influence on the idling detection due to the characteristic difference is canceled. Is done. As a result, it is possible to provide a motor control device capable of performing high-accuracy idling / sliding detection in consideration of the wheel diameter difference.

Further, the invention according to claim 1 is applied to claim 1
It may be realized as a method as in the invention described in 1. That is, an invention according to claim 11 is a motor control method for controlling a plurality of induction motors connected in parallel to a power supply line by power supply by vector control.
Of the plurality of induction motors, a current measurement step of measuring a current flowing into at least two induction motors, and for the induction motor to be measured, while performing correction based on a normal current value, Based on the relative value,
Of the drive shafts driven by each of the plurality of induction motors,
And a slipping / sliding detecting step of detecting occurrence of slipping or sliding in any of the drive shafts.

According to a second aspect of the present invention, in the motor control device according to the first aspect, the holding means holds, as the normal current value, a relative value of a current flowing into the induction motor to be measured. The slip / skid detecting means detects the occurrence of slip or skid based on whether or not the relative value of the current measured by the current measuring means has exceeded a predetermined threshold value. Or the predetermined threshold value is corrected by the normal current value.

According to the second aspect of the present invention, when the wheel slips or slides, the relative value of the current measured by the current measuring means fluctuates sharply. Based on whether or not the threshold value has been exceeded, occurrence of slip or gliding can be detected. However, this relative value includes the normal current value, that is, the relative value of the current flowing into the induction motor to be measured during the sticking running without slippage. However, the slip / skid detecting means corrects the relative value of the current measured by the current measuring means or a predetermined threshold value based on the normal current value when detecting the slip or the skid, so that the wheel diameter difference or each induction The difference in the characteristics of the motor is canceled, and slipping or sliding can be detected quickly. Therefore, the speed sensorless vector control can be performed more accurately.

Further, the invention according to claim 2 is applied to claim 1
It may be realized as a method as in the invention described in 2. That is, the invention according to claim 12 is the motor control method according to claim 11, further comprising a step of setting a relative value of a current flowing into the induction motor to be measured as the normal current value, wherein the idling slippage detection is performed. The step detects the occurrence of slip or gliding based on whether or not the relative value of the measured current has exceeded a predetermined threshold, but upon detection, the relative value of the measured current, or The predetermined threshold,
It is characterized in that it is a step of correcting with the normal current value.

According to a third aspect of the present invention, there is provided the first or second aspect.
In the motor control device described above, the holding unit updates the held normal current value based on the current measured by the current measuring unit.

According to the third aspect of the present invention, the holding means updates the normal current value to be held based on the current measured by the current measuring means. The correction can always be performed with the optimum normal current value. This makes it possible to more quickly and surely detect slip or gliding. Furthermore,
The wheel diameter difference and the characteristic difference of each induction motor are not always constant and change over time.However, since the held current value is updated, the sensitivity of idling detection is degraded due to the change. Can be avoided.

In a specific embodiment of the present invention, claim 4
As in the invention described in the above description, in the electric motor control device according to any one of claims 1 to 3, when the idling / skid detecting unit detects occurrence of idling or sliding, the unit performs a given readhesion control ( Re-adhesion control arithmetic unit 50).

According to a fifth aspect of the present invention, in the motor control device according to any one of the first to fourth aspects, the slip / skid detecting means holds a correction value at a predetermined power supply current value,
The correction is performed based on the held correction value and the change amount of the power supply current value (for example, calculation of Δβ by calculating (β / α) · Δα described in the embodiment of the invention).
It is characterized by:

According to the fifth aspect of the present invention, for example, the calculation of a correction value in a high speed range can be easily obtained. That is, in the high-speed range, the influence of the magnetic flux due to the wheel diameter difference is small, so that the power supply current value and the correction value are approximately proportional. Accordingly, the correction value at a certain power supply current value can be easily calculated by holding the correction value at a predetermined power supply current value and comparing / calculating the correction value with the current power supply current value.

According to a sixth aspect of the present invention, in the motor control device according to any one of the first to fourth aspects, the idling / skid detecting means is configured to guide the object to be measured based on the current measured by the current measuring means. A first means for obtaining a slip frequency of the electric motor; and a second means for obtaining a correction value based on the slip frequency, wherein the correction is performed based on the correction value obtained by the second means. It is characterized by performing.

According to the sixth aspect of the present invention, the slip frequency of the induction motor to be measured can be obtained, and the correction value can be obtained based on the difference or ratio of the slip frequency of each induction motor. That is, an appropriate correction value can be obtained based on the steady-state characteristics when a wheel diameter difference occurs.

According to a seventh aspect of the present invention, there is provided a motor control for integrally controlling a plurality of induction motors (for example, the three-phase induction motors 21 and 22 of FIG. 1) connected in parallel to a power supply line by power supply by vector control. A device (for example, the motor control device 1 of FIG. 1), which is a current measuring unit (for example, the current sensors 31 and 3 of FIG. 1) that measures a current flowing into at least two of the plurality of induction motors.
2) and based on the current measured by the current measuring means,
And estimating means for estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured (for example, a calculation by the expression (14) described in the embodiment of the invention).

According to the seventh aspect of the present invention, it is possible to estimate a wheel diameter difference or a diameter ratio. Therefore, it is possible to perform high-precision idling / sliding detection based on the estimated wheel diameter difference or the diameter ratio. Can be provided. A more specific detection of slipping / sliding is, for example, the invention described in claim 8.

That is, the invention described in claim 8 is based on claims 1 to
5. The motor control device according to any one of 4 to 4, further comprising: estimating means for estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured, based on the current measured by the current measuring means, The slippage detecting unit performs the correction based on the diameter difference or the diameter ratio between the wheels estimated by the estimating unit.

Further, as a specific configuration of the estimating means, for example, based on a difference between the currents measured by the current measuring means at a predetermined power supply current value as in the invention of claim 9, the distance between the wheels is determined. The diameter difference or the diameter ratio may be estimated, or, as in the invention according to claim 10, when the induction motor is in an excited state, based on a torque current difference with respect to the measurement target induction motor. By calculating the slip frequency of the induction motor, a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured may be estimated.

The invention according to claim 7 may be realized as a method as in the invention according to claim 13.
That is, an invention according to claim 13 is a motor control method for controlling a plurality of induction motors connected in parallel to a power supply line by power supply by vector control, wherein at least two of the plurality of induction motors are controlled. A motor measuring step of measuring a current flowing into two induction motors, and an estimating step of estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured based on the measured currents It is a control method.

[0026]

FIG. 1 is a block diagram showing a configuration of a motor control device according to an embodiment of the present invention. The motor control device 1 controls driving of a train, and includes an inverter (INV) 10, a three-phase induction motor 21,
22, current sensors 31, 32, vector control arithmetic unit 4
0, the re-adhesion control arithmetic unit 50, and the adder / subtractor 60 constitute the main part.

In FIG. 1, each control function is represented by a block diagram for convenience in describing the configuration of the present invention, but at least the vector control arithmetic unit 40, the re-adhesion control arithmetic unit 50,
The adder / subtractor 60 can be configured by software processing by a microcomputer.

The inverter 10 includes a pantgra (not shown)
DC power supplied from the overhead line via
And the voltage command value output from the vector control arithmetic unit 40
(V _u ^*, V_v ^*, V_w ^*) To generate three-phase AC power,
Three-phase induction of generated three-phase AC power through power supply line
Power is supplied to the electric motors 21 and 22.

The three-phase induction motors 21 and 22 are both connected in parallel to a power supply line, and include a rotor placed in a static magnetic field and three-phase coils u, v, and w mounted on the rotor. And are provided respectively. The three-phase coils u, v, w are connected to the inverter 1
When a three-phase AC voltage is applied by 0 and primary currents I _u , I _v , and I _w flow into the respective coils, a rotating magnetic field is generated. Then, the rotor rotates due to the interaction between the rotating magnetic field and the static magnetic field surrounding the rotor. As a result, the axle associated with the rotor rotates and the wheels rotate.

The current sensors 31 and 32 detect the primary current flowing into the three-phase induction motor 21 (IM_1) and the primary current flowing into the three-phase induction motor 22 (IM_2), respectively. Specifically, the current sensor 31 is a three-phase induction motor 2
1 of the primary currents flowing into the coil u
Primary current I _{u_1} and primary current I _{v_1} flowing into coil v
Is detected. Further, the current sensor 32 detects, among the primary currents flowing into the three-phase induction motor 22, the primary current I _{u_2} flowing into the coil u and the primary current I _{u_2} flowing into the coil v.
_{v_2} is detected.

The vector control computing unit 40 calculates a magnetic flux command value i _1d ^* (excitation current component of total current) and a torque command value i _1q ^* (torque current component of total current) output from a current command unit (not shown). detected current value by the sensor _{31,32 (I u_1, I v_1,} I u _2, I v_2), the corners of the rotor of the three-phase induction motor 21 of the rotor angular frequency _ω 2n_1, and 3-phase induction motor 22 based on the frequency omega _{2N_2,} voltage command value ^{_{(V u *, V v *}} , V w *) is calculated, and by outputting the calculated voltage command value to the inverter 10, two 3
The phase induction motors 21 and 22 are controlled collectively. In addition, the vector control calculator 40 includes three-phase induction motors 21 and 22.
The constant current control is performed so that the primary current flowing into the device always becomes constant.

The adder / subtractor 60 subtracts the torque current control command value output from the command unit 53 from the torque command value i _1q ^* (torque current component of the total current) output from a current command unit (not shown). The result is output to the vector control operation unit 40 at the subsequent stage.

The re-adhesion control arithmetic unit 50 includes a coordinate conversion unit 5
1. Consists of idling / sliding detection unit 52 and command unit 53
Is done. The coordinate conversion unit 51 uses the current sensors 31 and 32
Primary current I of the coil u detected_u(I_u_₁, I
_u__Two), Primary current I of coil v_v(I _{v_1}, I_{v_2}),
Excitation current component i_d(I_{d_1}, I_{d_2}) And torque current components
Minute i_q(I_{q_1}, I_{q_2}). In addition, I_u, I_v
From i_d, I_qFor example, the following equation is known as
ing.

(Equation 1) Here, θ represents the angle between the U-phase current and the magnetic flux.

The slip / slide detecting section 52 includes a coordinate converting section 51.
Current component i of the three-phase induction motor converted by
Based on the relative value of _q ( _{iq_1} , _{iq_2} ), idling or sliding in any of the drive shafts driven by each three-phase induction motor is detected.

Here, the principle by which the slip / skid detector 52 detects slip or slip of the wheels will be described with reference to FIGS. 2 to 4, the horizontal axis represents the d-axis component (excitation current component) of the primary current, the vertical axis represents the q-axis component (torque current component) of the primary current, and I _{1_1} is a three-phase induction motor. primary current vector that flows into 21, I _{1_2} primary current vector that flows to the three-phase induction motor 22, I ₁ is the total current vector, [Phi ₂ is 2 Tsugikusari交vector, the 2 Tsugikusari交The coordinates are set so that the vector Φ ₂ coincides with the d-axis.

FIG. 2 schematically shows the behavior of the current and voltage vectors when the difference in wheel diameter is zero and the train is running with stickiness. As shown in FIG. The amplitude and phase of the primary current vector I _{1_1} and the primary current vector I _{1_2} are equal.

Next, FIG. 3 is a diagram schematically showing the behavior of current and voltage vectors when the diameter difference between the wheels is zero and the wheels driven by the three-phase induction motor 22 (IM_2) idle or slide. It is. When the wheels driven by the three-phase induction motor 22 idle, the phase and amplitude of the primary current vector I _{1_2} change. However, the vector control arithmetic unit 4
0 controls the constant current so that the phase and the amplitude of the total current vector I ₁ , which is the sum of the primary current vector I _{1_1} and the primary current vector I _{1_2} , are always constant, so the primary current vector I _{1_1} Changes so as to cancel the change in the primary current vector I 1 _{_2} .

As a result, while the phase and amplitude of the total current vector I ₁ are kept constant, the primary current vector I _{1_1}
And a primary current vector I _{1_2} , a torque current difference indicated by a broken line viewed from both ends in the figure is generated. This torque current difference is a difference (relative value) between the q-axis component (i _{1q_1} ) of the primary current vector I _{1_1 and} the q-axis component (i _{1q_2} ) of the primary current vector I _{1_2} . Then, for example, the torque current difference is detected, and the idling or sliding of the wheel can be detected based on whether or not the torque current difference exceeds a certain threshold value. This is the principle of detecting slip or gliding in speed sensorless vector control.

However, in an actual train, a difference in diameter is generated due to wear of the wheels, etc., so that a slight, but slight, torque current difference always occurs irrespective of idling or sliding of the wheels. FIG. 4 is a diagram schematically illustrating the behavior of each vector when there is a wheel diameter difference during sticking traveling. In FIG. 4, it is assumed that the diameter of the wheel driven by the three-phase induction motor 22 is 6 mm larger than the diameter of the wheel driven by the three-phase induction motor 21. That is, this is the case where the shaft with the large wheel diameter (the three-phase induction motor 22 side) idles.

As described above, when there is a diameter difference between the wheels,
With the difference in the slip frequency of each three-phase induction motor, the primary current vector I _{1_1} and the primary current vector I _{1_2}
And the torque current difference (i
_{1q_1- i1q_2} ). Hereinafter, the torque current difference (i _{1q_1} −) between the primary current vector I _{1_1} and the primary current vector I _{1_2 in} a state where there is a wheel diameter difference during the sticking traveling.
i _{1q — 2} ) is particularly referred to as an adhesion current difference Δi _1q .

More specifically, as shown in FIG. 5, the idling / sliding detecting section 52 includes adding / subtracting sections 521 and 524 and a switch 52.
2, a hold unit 523, and a comparator 525. Each of these components can be constituted by hardware, but can also be constituted by software processing by a microcomputer.

The addition / subtraction unit 521 includes a torque current component i _{1q —} 1 of the primary current flowing into the three-phase induction motor 21 and a torque current component i of the primary current flowing into the three-phase induction motor 22.
The difference of _{1q_2} is always calculated.

The switch 522 is turned on (connected state) periodically or timely by a control means (not shown) when the train is running with low torque and sticky. At that time, the addition and subtraction unit 521 calculates i _{1q — 1} and i _{1q — 1.} The difference of _{1q_2} , that is, the adhesion-time current difference Δi _1q is output to the _subsequent holding unit 523,
Thereafter, the control unit again turns off (interrupted state), and prevents the detection result of the addition / subtraction unit 521 from being output to the hold unit 523.

The hold unit 523 holds the value of the sticking current difference Δi _1q every time the sticking current difference Δi _1q is output via the switch 522, and holds the temporarily held sticking current difference Δi _1q.
The value of i _1q is constantly output to the addition / subtraction unit 524.

The addition / subtraction unit 524 includes a torque current component i _{1q_1} of the primary current flowing into the three-phase induction motor 21 and a torque current component i of the primary current flowing into the three-phase induction motor 22.
_{1q_2} is constantly calculated, and the adhesive current difference Δi output from the hold unit 523 is calculated from the torque current difference.
_{Subtract 1q} . As a result, the torque current difference can be corrected in consideration of the adhesion-time current difference Δi _1q . And
The addition / subtraction unit 524 outputs the corrected torque current difference (hereinafter “i _1q
^WD ". ) Is output to the comparator 525 at the subsequent stage.

The comparator 525 has a predetermined threshold (for example, 3
0 [A]) is stored, and it is determined whether or not the absolute value of the corrected torque current difference i _1q ^WD output from the adder / subtractor 524 has exceeded the threshold value. Then, when it is determined that the absolute value of the torque current difference i _1q ^WD exceeds the threshold, a detection signal is output to the command unit 53 at the subsequent stage. In this way, wheel slip or gliding is detected, and the command unit 53 is notified of that.

That is, the idling / sliding detecting section 52 is a three-phase induction
Torque current i flowing into motor 21 _{1q_1}And three-phase induction
Torque current i flowing into motive 22_{1q_2}Difference (relative value)
From the adhesive current difference Δi_1qCurrent difference i obtained by subtracting
_1q ^WDBased on whether the absolute value of
Detect wheel idling or skidding.

Therefore, based on only the difference between the torque current i _{1q — 1} flowing into the three-phase induction motor 21 and the torque current i _{1q — 2} flowing into the three-phase induction motor 22, the idling or the sliding is detected as compared with the conventional case. As a result, the influence on the idling detection caused by the wheel diameter difference is canceled. Further, since the characteristic difference between the three-phase induction motors 21 and 22 is also reflected in the adhesion-time current difference Δi _1q , even if a characteristic difference occurs between the three-phase induction motors 21 and 22, the characteristic is not affected. The effect of the difference on slip detection is canceled.

Further, it is possible to solve the problem that the idling or gliding is excessively detected due to the difference in the wheel diameter, and conversely, it takes more time to detect the slipping or sliding than when there is no difference in the wheel diameter. The problem of the detection time is, for example, a problem that rebounds as a ride comfort for passengers on a train. Therefore, the significance of the present invention is also significant in this regard.

When the detection signal is input from the slip / slide detection unit 52, the command unit 53 outputs a given ratio (for example,
By outputting the torque current control command increasing at 1000 [A / sec]) to the adder / subtractor 60, the torque command value input to the vector control calculator 40 is reduced, and the idle wheel is re-adhered to the track. . In the process, the command unit 53 calculates a return current value to be described later, and when the wheel that has slipped is re-adhered, the torque current value is increased to the return current value by a given ratio (for example, 1000 [A / sec]). ]) To return.

Hereinafter, a method of calculating the return current value will be described. First, the state equation of the drive system including the three-phase induction motors 21 and 22 is expressed by the following equations (2) to (4).

[0052]

(Equation 2)

[0053]

[Equation 3]

[0054]

(Equation 4) However,

(Equation 5)

Here, I ₁ : primary current vector, V ₁ : 1
Secondary voltage vector, Φ ₂ : secondary flux linkage vector, ω ₁ : 1
Secondary angular frequency, ω _2n : rotor angular frequency, ω _s : slip angular frequency, r ₁ : primary resistance, r ₂ : secondary resistance, L ₁ : primary inductance, L ₂ : secondary inductance, M: mutual Inductance, J: drive system inertia moment.

From the equation (2), the three-phase induction motor 22 (IM
_2), the load torque corresponding to the tangential force between the wheel and the track (rail) is expressed by the following equation (5).

[0057]

(Equation 6)

In the equation (5), the generated torque τ _{e —} 2 of the three-phase induction motor 22 can be approximated by using the following equation (6). Φ _2d ^* is a magnetic flux command value.

[0059]

(Equation 7)

In the equation (5), dω_{r_2}/ Dt
Is the rotation speed ω by the speed sensor _rNot detect
From the following equation (7).

[0061]

(Equation 8)

[0062] Slip angular frequency omega _{s_2,} during adhesive running is expressed by the relation of the following equation (8).

[0063]

(Equation 9)

After a wheel driven by the three-phase induction motor 22 idles or slides, Φ _{2d_2} hardly changes in a short period of time until the slip or sliding is detected. Therefore, the differential form of the slip frequency ω _{s_2} can be approximated by the following equation (9).

[0065]

(Equation 10)

When the equations (6) to (8) are applied to the equation (5), the load torque τ _{l — 2} ′ of the three-phase induction motor 22 changed by slipping or sliding can be estimated. Then, the load torque τ _{l — 2} ′ of the three-phase induction motor 22 and the generated torque τ
The following equation (10) representing the relationship between _{e_2,} can be calculated generated torque tau _{e_2} of the three-phase induction motor 22.

(Equation 11) Here, ω ₁ is the frequency of the inverter 10.

[0067] Thus, the following equation (11) representing the relationship between the three-phase induction generator torque tau _{e_2} the return time of the torque current value of the electric motor 22 (the return current value) i _1q, be obtained the return current it can.

(Equation 12)

The operation of the motor control device 1 will now be described with reference to FIG.
Refer to the simulation results shown in (a) and (b).
I will explain. FIG. 6A illustrates a three-phase induction motor 21.
Speed V of the driven wheel_{t_1}And three-phase induction motor
Speed V of the wheels driven by the machine 22_{t_2}Behavior
The horizontal axis indicates time [sec], and the vertical axis indicates speed [k].
m / h]. FIG. 6B shows a three-phase induction motor.
21 generated torque τ _{e_1}, Actual load torque
τ_{l_1}, Torque current i_{1q_1}, Exciting current i_{1d_1}, Three-phase invitation
Torque τ generated by conductive motive device 22_{e_2}The actual load torque
Τ_{l_2}, Torque current i _{1q_2}, Exciting current i_{1d_2}Behavior
The horizontal axis represents time [sec], and the vertical axis represents torque.
[N-m] and current [A].

FIG. 6 shows that the diameter of the wheel driven by the three-phase induction motor 21 is 814 [mm] and the diameter of the wheel driven by the three-phase induction motor 22 is 820 [mm]. It is a simulation result when a diameter difference of 6 [mm] occurs. In addition, the train car is 2.1
A constant acceleration motion is performed at an acceleration of [km / h / sec].

In both FIGS. 6A and 6B, 0.0 [sec] is set when the vehicle speed is 30 [km / h].
At 1.0 [sec], idling occurs. First, before the idling, the train is running immediately after driving, and the generated torque, the actual load torque, the torque current, and the exciting current are stable at constant values. However, a certain difference occurs in each of the generated torque, the actual load torque, the torque current, and the excitation current due to the wheel diameter difference. At this time, control means (not shown) turns on the switch 522 (connected state). This allows
The difference between i _{1q_1} and i _{1q_2} during sticking travel, ie, Δi _1q
Are held by the hold unit 523.

In the figure, from 0.0 [sec] to 1.0
Until [sec], since the train is sticking, the current difference i _1q ^WD corrected by the addition / subtraction unit 524 during this time.
Does not exceed the threshold value (30 [A]) stored by the comparator 525.

Next, at the time of 1.0 [sec],
When a wheel driven by the three-phase induction motor 22 idles, the rotation speed _{Vt_2 of the} wheel driven by the three-phase induction motor 22 fluctuates sharply, and the tangential force (load torque) τ _{l_2 of the} wheel is 15%. To a degree. Then
The absolute value of the corrected torque current difference i _1q ^WD is equal to the threshold value 30 [A].
Therefore, the comparator 525 detects the idling of the wheel, and outputs a detection signal to the command unit 53. Thereby, the command unit 5
3, the torque current component of the three-phase induction motor 22 becomes 10
It is narrowed down at a rate of 00 [A / sec]. In addition, when the detection signal is input, the command unit 53 loads the torque τ _{l — 2} ′
(See equation (10)), and a return current value is calculated based on this (see equation (11)).

After the idling wheel is again adhered to the rail due to the torque current being reduced, the command unit 53 sets
Until the torque current component flowing into the phase induction motor 22 reaches the return current value, it is increased at a rate of 1000 [A / sec].

Here, the determination as to whether or not the idle wheel has adhered to the rail again may be made by a known method. That is, since the determination of the sticking itself in the sticking control is not the purpose of the present invention, any method can be applied. For example, a method of estimating that the current has been re-adhered by lowering the current for a certain period may be used.

As described above, according to the motor control device 1 of the present embodiment, the following effects can be obtained. (1) The idling / sliding detection unit 52 corrects the torque current difference flowing into each three-phase induction motor in consideration of the wheel diameter difference, and calculates the wheel current based on the corrected torque current difference i _1q ^WD. Is detected, the influence of the diameter difference on the idling detection is canceled. Furthermore, since Δi _1q also reflects the characteristic difference between the three-phase induction motors 21 and 22, even if a characteristic difference occurs between the three-phase induction motors 21 and 22, the difference is caused by the characteristic difference. The effect on slip detection is canceled. Therefore, re-adhesion control can be performed accurately.

(2) Δi _1q held by the hold unit 523
Is updated each time the switch 522 is turned on (connected state) by control means (not shown).
The slide detection unit 52 can always correct the torque current difference with the optimum Δi _1q according to the angular velocity region of each of the three-phase induction motors 21 and 22. In addition, the difference in wheel diameter and the difference in characteristics of each induction motor are not always constant but change over time.
Since i _1q is updated, it is possible to prevent the sensitivity of idling detection from deteriorating due to the change.

(3) Since the vector control arithmetic unit 40 performs constant current control, the wheels on the three-phase induction motor 22 side idle,
When the torque current i _{1q — 2 of the} three-phase induction motor 22 decreases, the torque current i _{1q — 1} flowing into the three-phase induction motor 21 increases accordingly. However, the idling / sliding detection unit 52 considers the wheel diameter difference. By doing so, the idling is quickly detected and the period during which the torque τ _{e_1 of the} adhesive shaft increases is set to about 0.1.
[Sec] or less (see FIG. 6B). Therefore, in the re-adhesion control of a wheel that has slipped or slid, it is possible to accurately avoid all-axis idling caused by applying excessive torque to the adhesive shaft.

The description in the present embodiment is a preferred example of the motor control device according to the present invention, and the present invention is not limited to this. For example, in this embodiment, and it can be timely or periodically updated during the adhesive traveling .DELTA.i _1q which hold unit 523 holds, the .DELTA.i _1q
Thus, the torque current difference is corrected, but the method of correcting the torque current difference in consideration of the wheel diameter difference is not particularly limited to this, and the correction value can be obtained as follows. .

That is, for example, in a high-speed region, since the influence of the wheel diameter difference on the magnetic flux is small, the current difference Δi _1q with respect to the torque current command value i _1q ^* has an approximately proportional relationship. Specifically, assuming that the current difference Δi _1q when the torque current command value i _1q ^* is α [A] is Δα, the torque current command value i
Δβ which is the current difference Δi _1q when _1q ^* is β [A] is (β /
α) · Δα can be easily obtained. In this case, the hold unit 523 and the addition / subtraction unit 524
The operation can be realized by providing an operation means for performing the operation and outputting the operation result to the addition / subtraction unit 524 during the operation. However, this can be realized by software processing. When the slip / slide detection unit is configured in this manner, the reference correction value Δ
Once α has been obtained, it is no longer necessary to open and close the switch 522 in a timely or regular manner.

Further, from the torque current difference during sticking running,
A wheel diameter difference including a characteristic difference of the phase induction motor may be obtained, and a correction value may be obtained based on a steady characteristic at the wheel diameter difference. In this case, the first table in which the relationship between the torque current difference value and the wheel diameter difference during sticking traveling is defined in advance, and the steady-state characteristics (the relationship between the inverter output current value and the correction value Δi _{1q) at} each wheel diameter difference value ) Is stored in the slip / slide detection unit 52 in advance.

Thus, the idling / sliding detecting section 52 recognizes the current wheel diameter difference corresponding to the torque current difference by referring to the first table, and refers to the second table to determine the current wheel diameter. Since the steady-state characteristics in the diameter difference can be recognized, the correction value Δi _1q corresponding to the current inverter output current value can be obtained. The above processing can also be realized by software.

A more specific description will be given. When the T-type equivalent circuit of the induction motor is used, the relationship between the primary current and the slip S is obtained by the following equation (12).

(Equation 13) Here, x ₁ is the primary leakage reactance, x ₂ is the secondary leakage reactance, the x _m indicates an excitation reactance.

[0083] (12) By using the equation, slip _{S _1} of the electric motor, it is possible to obtain the _{S _2.} Where S
_{_1} and _{S_2} may be held in advance as a data table, or a solution may be derived using Newton's method or the like.

[0084] Then, _{S _1} was determined, by _{S _2,} is determined the following values.

[Equation 14]

Here, ω _2n is the rotor angular velocity, ω _e is the power supply frequency, D is the wheel diameter, ω _s is the slip frequency, and γ is the wheel diameter ratio. From equation (13), the slip frequency ω of each motor
_{s_1} and _{ωs_2} are obtained, and an arbitrary correction value Δi _1q is obtained.

Further, when each three-phase induction motor is in an excited state, the torque current of each three-phase induction motor is determined, the slip frequency is determined based on the torque current, and the three-phase induction motor is determined based on the slip frequency. Find the difference between the rotation speeds of
A wheel diameter difference may be determined from the difference in rotation speed, and a correction value Δi _1q at a predetermined inverter current may be determined based on the wheel diameter difference. This processing can also be easily realized by software processing.

A more specific description will be given. While coasting, one
Adjust the shaft slip to zero. For example, if one axis slip is 0
If there is a wheel diameter difference, i _{1q_1} is 0 [A], i
_{1q_2} becomes I [A], and a constant torque current is generated in two axes. Therefore, the angular motor speed is obtained as ω _2n — ₁ = ω _e and ω _{2n —2} = ω _e + Δω _s . For this reason,

(Equation 15) Is obtained.

Here, ω _{2n_1} ′, torque current command value i
Consider when you give _1q ^* . If the wheel diameter ratio γ is used, (1
Ω _{2n — 2} ′ is obtained by using the expression 5).

(Equation 16)

The inverter angular frequency ω _e is given by ω _e = ω _{2n — 1}
'+ Ω _s ^* and focusing on the second axis, (1
6) Formula can be derived.

[Equation 17]

As described above, the correction value Δi _1q may be obtained.

[0091] Further, by calculation or the like shown in (13), slip frequency omega _{s_1} of the electric motor, can be estimated omega _{s _2,}
Based on the estimated value, it is possible to estimate and calculate a wheel diameter difference (such as aging) and manage the wheel diameter difference. Also, Δ
It is also possible to obtain the wheel diameter ratio γ from i _1q , Δω _{s and the} like, and manage the wheel diameter difference.

In this embodiment, a vehicle in which two motors are driven by one inverter ("1C2M")
It is called. ), The present invention can be similarly applied to a vehicle (referred to as “1C4M”) in which one inverter drives four motors.

The present invention can be applied to not only trains, but also electric vehicles, machine tools, elevators, and the like, and the same effects can be obtained. In addition, it goes without saying that the detailed configuration and operation of the motor control device 1 can be appropriately changed without departing from the spirit of the present invention.

[0094]

According to the present invention, the influence of the wheel diameter difference on the idling detection and the steady characteristic difference between the induction motors are canceled, so that the wheel diameter difference is considered in the speed sensorless vector control. High-precision idling / sliding detection can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a motor control device according to an embodiment.

FIG. 2 is a diagram showing a behavior of a primary current vector when there is no diameter difference and no slippage.

FIG. 3 is a diagram showing a behavior of a primary current vector in a case where idling occurs on a wheel on a three-phase induction motor 22 side in FIG. 2;

FIG. 4 is a diagram showing the behavior of a primary current vector when there is no slippage but there is a diameter difference.

FIG. 5 is a block diagram showing a configuration of a readhesion control arithmetic unit in FIG. 1;

FIG. 6 is a simulation result showing a response during idling.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 motor control device 21, 22 three-phase induction motor 31, 32 current sensor 50 re-adhesion control calculator 51 coordinate conversion unit 52 idling / sliding detection unit 521, 524 addition / subtraction unit 522 switch 523 hold unit 525 comparison unit 53 command unit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Michihiro Yamashita 2-8-8 Hikaricho, Kokubunji-shi, Tokyo 38 Inside the Railway Technical Research Institute (72) Inventor Yasushi Matsumoto 2-2-1 Nagasaka, Yokosuka City, Kanagawa Prefecture Inside Fuji Electric R & D Co., Ltd. (72) Satoru Ozaki 2-2-1 Nagasaka, Yokosuka City, Kanagawa Prefecture Inside Fuji Electric R & D Co., Ltd. (72) Inventor Atsuo Kawamura 2-Green Garden, Izumi-ku, Yokohama, Kanagawa Prefecture 23-3 F term (reference) 5H115 PC02 PI03 PI29 PU09 PV09 QE08 QE14 QN03 QN09 RB11 RB26 SE03 5H572 AA01 BB10 CC01 DD02 FF01 GG04 HB08 HC01 HC08 JJ03 JJ04 JJ06 JJ07 LL22 5H576 AA01 AA02 BB01 A01 GG01 JJ04 JJ09 LL14 LL22 LL30 LL38

Claims (13)

[Claims] 1. A motor control device for controlling a plurality of induction motors connected in parallel to a power supply line by power supply by vector control, wherein the motors flow into at least two of the plurality of induction motors. Current measuring means for measuring the current to be performed, for the induction motor to be measured by the current measuring means, holding means for holding a normal current value, and while performing correction based on the normal current value held by the holding means, Based on the relative value of the current measured by the current measuring means, among the drive shafts driven by each of the plurality of induction motors, a slip / skid detecting means for detecting occurrence of slip or gliding on any of the drive shafts; An electric motor control device comprising: 2. The holding means according to claim 1, wherein
The relative value of the current flowing into the induction motor to be measured is held, and the slip / skid detecting unit determines whether the relative value of the current measured by the current measuring unit exceeds a predetermined threshold value. Alternatively, when the occurrence of skidding is detected, the relative value of the current measured by the current measuring means or the predetermined threshold value is corrected by the normal current value at the time of detection. An electric motor control device as described in the above. 3. The motor control device according to claim 1, wherein the holding unit updates the held normal current value based on the current measured by the current measuring unit. 4. The apparatus according to claim 1, wherein said slip / skid detecting means includes means for performing a given re-adhesion control when slipping or skidding is detected. Motor control device. 5. The method according to claim 1, wherein the slippage detection unit holds a correction value at a predetermined power supply current value, and performs the correction based on the held correction value and a change amount of the power supply current value. The electric motor control device according to any one of claims 1 to 4. 6. The slippage detecting means includes: first means for obtaining a slip frequency of the induction motor to be measured based on the current measured by the current measuring means; and a correction value based on the slip frequency. 5. The motor control device according to claim 1, further comprising: a second unit that obtains the correction value; and performing the correction based on the correction value obtained by the second means. 7. An electric motor control device for controlling a plurality of induction motors connected in parallel to a power supply line by power supply by vector control, wherein the motors flow into at least two of the plurality of induction motors. Current measuring means for measuring a current to be measured, and estimating means for estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured based on the current measured by the current measuring means. Characteristic motor control device. 8. An estimating means for estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured based on the current measured by the current measuring means. The motor control device according to any one of claims 1 to 4, wherein the slippage detection unit performs the correction based on a diameter difference or a diameter ratio between the wheels. 9. The apparatus according to claim 5, wherein the estimating means estimates a diameter difference or a diameter ratio between the wheels based on a difference in current measured by the current measuring means at a predetermined power supply current value. Or the motor control device according to 6. 10. The measuring device according to claim 1, wherein the estimating means obtains a slip frequency of the induction motor based on a torque current difference of the induction motor when the induction motor is in an excited state. 7. The motor control device according to claim 5, wherein a diameter difference or a diameter ratio between wheels driven by the induction motor is estimated. 11. A motor control method for controlling a plurality of induction motors connected in parallel to a power supply line by power supply by vector control, wherein the method comprises: flowing into at least two of the plurality of induction motors. A current measuring step of measuring a current to be performed, and for the induction motor to be measured, each of the plurality of induction motors is driven based on a relative value of the measured current while performing correction based on a normal current value. A slipping / sliding detecting step of detecting occurrence of slipping or skidding in any of the drive shafts. 12. The method according to claim 12, further comprising the step of: setting the relative value of the current flowing into the induction motor to be measured as the normal current value. Based on whether or not exceeds, the occurrence of slip or gliding is detected, at the time of detection, in the step of correcting the relative value of the measured current, or the predetermined threshold, by the normal current value The electric motor control method according to claim 11, wherein 13. An electric motor control method for controlling a plurality of induction motors connected in parallel to a power supply line by electric power supply by vector control, wherein at least two of the plurality of induction motors flow into the induction motors. A motor measuring method for measuring a current to be measured, and an estimating step for estimating a diameter difference or a diameter ratio between wheels driven by the induction motor to be measured based on the measured current.