JPS611202A - Induction motor driven electric railcar - Google Patents

Abstract

PURPOSE:To increase the tension force and the brake force of an electric railcar by providing a parallel circuit of impedance elements and switches in series with a power supply path of induction motor groups of odd and even number axle positions. CONSTITUTION:Electric railcars of axle drive supported at bodies by two sets of 2-axle bogie trucks are divided into induction motor groups 21, 23 group for driving dynamic wheels 11, 13 axles of odd numbers and induction motor groups 22, 24 for driving dynamic wheels 12, 14 axles of even numbers. Impedance elements 31-33 and switches 37-39, impedance elements 34-36 and switches 40- 42 connected in parallel are respectively inserted between the inverter 8 and motors 21, 23 and 22, 24. When the induction motor currents exceed a set value at electric railcar accelerating/decelerating times, switches 37-39, 40-41 are opened or closed in response to the axial movements occurred during the acceleration or deceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to increasing the pulling force or braking force of an electric vehicle driven by an induction motor.

[Conventional technology]

Both Fig. 2 and Fig. 3 are diagrams of an example of a conventional induction motor-driven electric vehicle, and Fig. 2 mainly shows the power system and the third
The figure is a side view showing the mechanical configuration, and shows a very general configuration.

The induction motor-driven electric vehicle with each shaft driven, in which the car body 1 is supported by two sets of two-shaft bogie bogie frames 2 and 3, is powered by four induction motors 21 to 21 that are supplied with power from a variable voltage variable frequency inverter 7. 24.

The induction motors 21 to 24 drive the driving wheels 11 to 14, respectively, and the two driving wheels 11 to 12 have a distance between their axes.
and 13 and 14 are rotatably fixed to the bogie frames 2 and 3, respectively, and run on the rails 4.

The transmission point of tensile force between the car body 1 and the bogie frames 2 and 3 is assumed to proceed in the direction shown by the arrow, and couplers 5 and 6 are installed at positions of height H from the rail 4 surface before and after the direction of movement of the car body 1. The rear coupler 6 is used to tow an accompanying vehicle (not shown).

In the case of an electric vehicle configured in this way, the height H of the coupler 6
and a tensile force transmission point 2a between the car body 1 and the bogie frames 2 and 3,
It is well known that because the height h of the electric vehicle 3a is not zero and these positions do not coincide with the surface of the rail 4, an axle load shift between the driving wheel axles of an electric vehicle occurs.

That is, if the axle positions of the driving wheel axles of the driving wheels 11 to 14 are N[11 to positive 4 in order from the leading side in the direction of travel, then as a result of this axle load shift, the axle load of each driving wheel axle of the electric vehicle is Nnl during acceleration. The shaft becomes the lightest and the following is Nn3. hh2. The order will be the four axes of the squad.

Also, during deceleration, the 4th floor axis is the lightest and is less than m2. m3.
The order is IVhl axis.

Therefore, for example, if we consider during acceleration, the wheels 11 to 1
4 and the rail 4 are the same, the limit frictional force between the wheel and the rail, expressed as the product of the axle load and the friction coefficient, is the smallest for the N11 axis and 3゜m2. The order is Nn4 axes.

Nnl-NnThe wheel circumference tensile force of the four axes is pj-F, respectively.
4, if the tensile force around any of the wheels exceeds the above limit friction force while the electric car is accelerating, the driving wheels will spin and cause problems in operation, so the maximum tensile force of the electric car is is constrained by the critical frictional force of

Similarly, during deceleration, if the circumferential braking force of any wheel exceeds the limit frictional force, the driving wheel will slide, causing trouble in driving.

Since the time of deceleration can be considered in the same way as the time of acceleration, the following explanation will be made regarding the time of acceleration.

[Problem that the invention seeks to solve]

As mentioned above, the tensile force ΣF of the electric vehicle is limited by the limit frictional force so as not to cause the driving wheels to spin.

In the conventional induction motor driven electric vehicle shown in FIGS. 2 and 3, the induction motors 21 to 24 that drive the four axles N111 to N111 are all fed power in parallel by one inverter 7, The circumferential tensile forces F1 to F4 are equal for each axis, and the limit tensile force for one electric car in the coupler 6 (maximum tensile force ΣF that does not cause slipping) is the limit friction at the Nll axis where the axle load is the lightest. The force is four times that of the Nnl axis (for 4 axes), and although the other axles, which have heavier axle loads than this Nnl axis, have enough margin to reach the limit frictional force, they have the disadvantage of not being able to be used as a tensile force for electric cars. .

The present invention improves the above-mentioned drawbacks and makes it possible to utilize the tensile force of an electric vehicle almost up to the limit frictional force.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes a plurality of induction motors that drive an electric vehicle, including a group of induction motors that drive odd-numbered driving wheel axles, and an induction motor group that drives even-numbered driving wheel axles. The system is divided into two groups: a group of induction motors, and an impedance element and a switch are connected in parallel between the variable voltage variable frequency inverter that supplies power to these groups and the group of induction motors. If the switch is closed and the induction motor current exceeds the set value during acceleration or deceleration of the electric vehicle, the axle load will be reduced in response to the axle load shift that occurs during acceleration or deceleration of the electric vehicle. The switch of the driving wheel axle group is opened to set the power supply path to the motor to the impedance element side, thereby reducing the motor current of this driving wheel axle group and reducing the tensile force around the wheels of the driving wheel axle group.

[Summary of the invention]

In an electric car driven by each axle, whose body is supported by two sets of two-axle bogies as shown in Fig. 3, the accompanying car (
When accelerating in the direction of the arrow while towing a vehicle (not shown), the axle loads on the ml, 1lh and 3 axles, which are odd-numbered axles counting from the leading axle in the direction of travel due to the axle load shift, will change as described above to the even-numbered axles. The axle load is smaller than that of the 11&12°+1&L4 axles, which are the axle positions.

As will be described later, the range in which the axle load decreases is approximately determined by the specifications of the vehicle. Select so that the ratio of motor torque and motor torque when not connected in series is approximately equal to the ratio that reduces the axle load. When the current supplied from the inverter to the electric motor exceeds a certain set value, an instruction is given to open the switches of the induction motor groups that drive the odd-numbered driving wheel axles. According to this command, an impedance element is inserted in series in the power supply path of the induction motor group at the odd numbered axis position, the current of the motor decreases, the torque decreases, and the driving wheels 11°13, that is, N11l,
The wheel circumferential tensile forces Fl and Fs of the Nn three axes are the driving wheels 12.
14 or Nn2. Nnd axis wheel circumference tensile force F2,
It is smaller than F4 by the above ratio, and IVII11~
All the axles of Nn4 generate a wheel circumferential tensile force that is approximately equal to the limit frictional force corresponding to each axle load.

Strictly speaking, there is a difference in the axle load of each axle from M1 to floor 4, but the difference in axle load between the N111 axle and Na3 axle and the NCLZ
Since the difference in axle load between the axle and the N[14 axle is generally small, the present invention aims to simplify the device by collectively controlling the N111 axis, the Nn3 axis, the positive 2 axis, and the positive 4 axis, respectively. It is something that exists.

That is, by increasing the wheel circumferential tensile forces F2 and F4 of the driving wheels 12 and 14 of the Nn2 and m4 axes until they become approximately equal to the limit frictional force of the FkL2 axes, the electric vehicle 1 which is the sum of all the wheel circumferential tensile forces F1 to F4 is generated. The ultimate tensile force for both parts can be made larger than that of conventional electric cars.

The setting value of the current that gives the instruction to open the switch is explained based on Figure 3.The axle load is reduced by -1.
, the set value is set to a value slightly lower than the motor current at which the wheel circumference tensile force generated by the NcLa shaft reaches the limit frictional force.

This allows the impedance element to be inserted by opening the switch only when a large acceleration force is required, such as during startup, and to avoid the intervention of the impedance element when the acceleration force is small, such as when re-accelerating at high speed. I can do it.

In addition, when an electric vehicle decelerates, the axle load of the even-numbered driving wheel axles decreases, contrary to the above-mentioned acceleration, so when the motor current exceeds a certain set value, the induction motor group that drives the driving wheel axles decreases. A similar effect can be achieved by commanding the switch to open and reducing the motor torque to increase the braking of the electric vehicle. Additionally, when the electric vehicle is traveling in the opposite direction, the same effect can be obtained by giving a completely opposite command to that described above.

Such switching of commands due to acceleration and deceleration, and switching of commands due to changes in the traveling direction can be easily performed by linking with the operation of the master controller.

〔Example〕

FIG. 1 is a side view showing a power system of an embodiment of an induction motor-driven electric vehicle according to the present invention, and the same reference numerals as in FIGS. 2 and 3 indicate the same parts. Since the mechanical configuration is exactly the same as that shown in FIG. 3, this will be used for explanation.

The electric vehicle with each axis driven, in which the car body 1 is supported by two sets of two-axle bogies, has induction motor groups 21 and 23 that drive the odd-numbered driving wheels 11 and 13, and the even-numbered driving wheels 1.
2. It is divided into 22 and 24 groups of induction motors that drive 14 axes. Then, the inverter 8 and the induction motor 21
, 23 and 22. Impedance elements 31, 32, 33 and switches 37, 38 are connected in parallel between each other.
, 39 and impedance elements 34 , 35 , 36
and switches 40, 41 and 42 are inserted, respectively. Here, 43 is a motor current detector, and 44 is opened and closed according to instructions from a master controller (not shown) or the like when the electric vehicle accelerates, decelerates, and travels when the motor current exceeds a set value. containers 37 to 39 or switches 40 to 42
This is a controller that gives a command to open the circuit by selecting one of the following, or gives a command to close the circuit when the motor current falls below a set value. The switches 37 to 42 are normally open and perform opening and closing operations according to commands from the controller 44.

Thus, in an electric car configured as described above, when the electric car accelerates in the direction of the arrow, when the wheel circumferential tension reaches a certain value, that is, the motor current exceeds a set value, the first axle with the lightest axle load starts to spin idly. Therefore, when the current reaches the set value in order to prevent idling, the switches 37 to 39 are opened according to an instruction from the controller 44, the current is controlled by the impedance elements 31 to 33, and the FkLl
, 1Vha shaft electric motor torque is reduced, the tensile force around the wheels is also reduced, and driving can be continued without the driving wheels 11, 13 idling.

The specifications of the mechanical structure of the vehicle in this example are as follows.

Height of couplers 5 and 6 from the 4th rail surface H = 0.88m A tensile force transmission point 2a between the vehicle body 1 and the bogie frames 2 and 3.

Height from 4th rail of 3a h=0.6m A tensile force transmission point 2a between the vehicle body 1 and the bogie frames 2 and 3.

Distance L between 33 = 13.5m Distance J between driving wheels 11 and 12 and driving wheels 13 and 14 in bogie frames 2 and 3 = 2.1m Vehicle weight including passengers W+ = 48600Kg Others used in the following explanation The symbols to be used are as follows, including those explained above.

F1~Fi;Nnl-11hTension force around each wheel of 4 axes ΣF
; Tensile force of electric car = FJ +F2+F3+F4W
* -W4 ; Each axle load ΔW1 to ΔW of positive 1 to Nn4 axes
4 ; Weight movement of each axis of Nn 1 to Nn 4 axes When the mechanical configurations as described above are the same, the conventional power system shown in Fig. 2 and the power system of this embodiment shown in Fig. 1 Compare the ultimate tensile force of an electric car.

The amount of axle load movement at each axial position is expressed by the following formula. The direction in which the axle load becomes lighter is considered negative.

The axle load of each axis is Ws = Wt / 4+ΔWs
(5) W2 = Wt / 4+ΔW2
(6) Wa = Wt / 4+ΔWs
(7) W4 = Wt /
4+ΔW4 (8)(a)
In the case of a conventional power system The limit tensile force of the induction motor-driven electric vehicle with the conventional power system shown in FIG. 2 is calculated. All induction motors 21~
24 are supplied with power in parallel from a single inverter 7, the wheel circumference tensile forces F1 to F4 of each axis are all equal.

Fi = Ft =: Fs == Fa・°・F+
+ F2 = Fa + F4 = ΣF/2 This formula is (
Substituting into equations 1) to (4) and rearranging, we get ΣFbH−h ΔW3−2(7L) ΣF h H−h, ΔW4=+ , (7+ 7>]T, so ΔW1(0, ΔW2 :> Q, ΔWa < 0,
ΔW4 > 0 or 1ΔWs l ) lΔWa l Therefore, from equations (5) to (8), M1 to N [Nl in the L4 axis
The l-axis has the smallest axle load. Therefore, the first floor axle is most prone to slipping, and the tensile force around the wheels of the electric car is suppressed by the value of the axle load of the first floor axle.

To = 4 μc1 = 4 A (Wt / 4+Δ
Ws ) h H-h = μwt -2μΣF (7+-T-) Here, since To = ΣF, (b) In the case of the power system according to the present invention In a car, the limit tensile force is calculated when the acceleration force is large and the switches 37 to 39 are opened. Odd numbered axis position i.e. Nl
The induction motors 11 and 13 that drive the l and rha axes are supplied with power in parallel from the inverter 8 via impedance elements 31 to 33, and the even numbered axes, that is,
The induction motor 12.14 that drives the 114 axis is supplied with power from the inverter 8 in parallel with the impedance elements 34 to 36 short-circuited, so Fr = F3Fl = F4, °, Ft + F2 = Fs + Fa - ΣF/2
Substituting this formula into (1) to (4) and rearranging it, ΣF h
H−h ΔW・=−7(7+7) ΔW2 =+＾p(h−T7−) 7L ΣF h t(−h Δ”= 2(l L) ΣF h H−h lWa −+7(7+−T7− ) This is the same as the case with the conventional power system described above, so ΔW+ < 0, ΔW2 ) O, ΔW2 < 0
, lWa > 0 or 1ΔWs l ) lΔWs l , ΔW2 (Δ
Since W4, from equations (5) to (8), N11 at odd numbered axis positions.
The axle load on the l-axis is small, and at even-numbered axles, the axle load on the second axle is small. Therefore, the limit tensile force of an electric vehicle is restricted by the values of the axle loads of the first and second axles.

However, here Since it can be considered that ΔWs in ΔW1, ΔW4 in ΔW2 and therefore Wl, +W3. W2+W4 You can think about it.

The friction coefficients between wheels 11 to 14 and rail 4 are all equal.
If μ=0.25, the limit tensile force TN for one electric vehicle according to the present invention is TN, =2μWt + 2μW2 =2μ(Wt/4+ΔW1) + 2μ(Wt/4+Δ
W2) ΣFhH-h ΣFhH-h =μWt+2μ-ding(70-■-)+7(7--T-)
=μWt -2μΣF(H-h)/L Here, since TN""ΣF, μWt TN= = 12024Kg1+2
μ(H-h)/L Also, W4 ΣF h H-h F+ =t, iW+ =μ, -■(7-) =2
576KgW4 ΣF h H-h 1' = Anchor' = μ 4 + 2 (/L) = 34
36xgI2576 π-πi=0・750 Therefore, in the case of this embodiment, an impedance element that generates an average motor torque of 75 cm of the induction motor of even numbered shafts is provided in the power supply path of the induction motor of odd numbered shafts. By inserting, the limit tensile force To =
With respect to 10536Kg, the limit tensile force TN=12024Kg of the electric car according to the present invention becomes 'rN12024 To=10536='', which can be increased by 14 inches.

[Effect of the invention] As shown in the above explanation and calculation examples in the examples,
The induction motor-driven electric vehicle according to the present invention connects impedance elements in series to the power supply paths of the odd-numbered induction motor groups and the even-numbered induction motor groups, and short-circuits the impedance elements. The direction and acceleration of the electric car.

By opening and closing switches in response to deceleration, the axle load of each axle can be used effectively and the pulling force and braking force of the electric vehicle can be increased, improving the acceleration and deceleration characteristics of the electric vehicle. It can contribute to

[Brief explanation of drawings]

FIG. 1 is a side view showing a power system of an embodiment of an induction motor driven electric vehicle according to the present invention, FIG. 2 is a side view showing a power system of a conventional induction motor driven electric vehicle, and FIG. 3 is a side view showing a power system of a conventional induction motor driven electric vehicle. FIG. 2 is a side view showing the mechanical configuration of an induction motor-driven electric vehicle. 1...car body, 2,3...bogie frame, 4...
Rail, 5.6...Coupler, 7.8...Inverter, 11-14 - Driving wheel, 21-24...-Induction motor, 31-36 - Impedance element, 37-42
・・Switch.

Claims (1)

[Claims] 1. A variable voltage variable frequency inverter, a plurality of induction motors supplied with power from this inverter, and a two-shaft bogie truck equipped with a plurality of driving wheel axles driven by the induction motors, each axle drive supporting the vehicle body. In the electric vehicle, the plurality of induction motors are divided into an induction motor group that drives the odd-numbered driving wheel axles of the electric vehicle and an induction motor group that drives the even-numbered driving wheel axles, and the variable An impedance element and a switch connected in parallel are interposed between the voltage variable frequency inverter and each of the induction motor groups, and when the induction motor current exceeds a set value during acceleration or deceleration of the electric vehicle, an impedance element and a switch are provided. An induction motor-driven electric vehicle characterized in that the switch is opened and closed in response to an axle load shift that occurs in the vehicle.