JPH01286702A - Readhesively controlling method for inverter electric vehicle at slipping/sliding time - Google Patents

Abstract

PURPOSE:To readhesively control an inverter electric vehicle at the time of finely slipping/sliding by detecting the slip/slide by the compared result of the speed of each drive wheels with a reference speed calculated from the acceleration/deceleration of an electric train. CONSTITUTION:A reference speed calculator 6n outputs a reference speed 2 and a rotating frequency 21 on the basis of an output of an accelerometer 4 and rotating frequency signals f1-f4 of drive wheels 3a-3d. A slip/slide detector 16 outputs a slip/slide detection signal 17 when the speed differences v1- f4 between the speeds v1-v4 of the wheels 3a-3d obtained by the signals f1-f4 and the speed 2 are predetermined value or more. A subtractor 19 normally outputs a reference slip frequency and a slip frequency reduced by a predetermined amount from a reference slip frequency during a period in which the signal 17 is outputting. An adder 23 adds a rotating frequency 21 and a slip frequency 20, and outputs an inverter frequency command 24.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a readhesion control method for increasing the coefficient of adhesion during slipping and skidding that occurs on the driving wheels and track surfaces of an inverter electric vehicle using an induction motor. It is something.

[Conventional technology]

First, with reference to FIGS. 4 and 5, a conventional re-adhesion control means when an inverter electric vehicle is idling or skidding will be explained. In Fig. 4, l is the body of the electric car, 2 is the track, and 3a to 3
d is the driving wheel of the induction motor. Reference numerals 11 to 44 are rotational frequency detectors that detect the rotational frequency of each driving wheel.

7 and fI to r4 are outputs of each rotation frequency of each driving wheel. 6. Input each rotational frequency of each driving wheel, and during the process, set the minimum value of each rotational frequency as the reference frequency of the driving wheel. Also,
During regeneration, the comparison circuit uses the maximum value of each driving wheel as the reference frequency of the driving wheels. 10° is the amount of change in each rotational frequency of each driving wheel (
This circuit calculates the differential value a r7a t). The output of the amount of change in each rotational frequency is detected by the OR of diodes, which are semiconductor elements, to detect the maximum value of the amount of change.
It is output to.

The maximum value of this change is compared with 15', which is the output of the 14° slipping/sliding edge setting device, and if it is greater than the set value, it is judged as slipping/sliding and a detection signal is sent to 17. Output. °18 is a standard pattern of the slip frequency of an induction motor that corresponds to the variable load of an electric vehicle. Reference numeral 19 denotes a subtracter that narrows down the standard pattern of the slip frequency during the period when the slip/skid detection signal is output. The result of this subtraction is used as the slip frequency (fs) of the induction motor, and the current of the induction motor is controlled during slipping or skidding to achieve readhesion.

21 is the output of the reference frequency (f,) of the driving wheels obtained from each rotational frequency of each driving wheel, and is added to the previous slip frequency by 23. 24 is the output of the adder 23, and the inverter frequency (f r, 1v-r, I ±rm)
In the formula 0, the (+) indicates the ka line, and the (-) indicates the time of regeneration.

The conventional readhesion control means when an inverter electric vehicle is idling or skidding is constructed as described above, and is a readhesion control method as shown in FIG. FIG. 5 explains the case where each driving wheel idles at the same time and has the same size. In FIG. 5, 7 indicates each rotational frequency of each driving wheel shaft, 13° indicates the maximum value of the amount of change (acceleration) of each rotational frequency, and 15° indicates the setting level of the slip detection sensitivity. 17 is an idle detection signal.

20 is the slip frequency (f,) of the induction motor, and when slipping occurs and the detection sensitivity is exceeded and slipping is detected, the slip frequency of 20 is narrowed down as shown at point E, and the slipping wheel is made to re-stick. It acts on However, the wheel slip detection signal is output only during the period when the wheel slip detection sensitivity level is higher than the wheel slip detection sensitivity level.

Furthermore, the detection signals are demagnetized when each rotational frequency tends to decelerate.

Therefore, the slip frequency recovers to its original value. Therefore,
Each driving wheel cannot be re-adhesive, and as shown in 7, it spins around! This results in a continuation.

In this way, with the means for detecting based on the amount of change in each rotational frequency of each driving wheel, when a slight slip (slight slip) occurs, it is not detected and continues for a long time. Therefore, if it is assumed that the vehicle travels on the broken line unless idling occurs at each rotational frequency in FIG. 5, the damage caused by hitting the track and each driving wheel in FIG. 4 will be large. Also, if all driving wheels spin or skid,
The inverter frequency (f+, v) in Figure 4 that controls the inverter of the electric car is because the reference frequency (f,) in Figure 4 increases in the case of slipping and decreases in the case of skidding. As a result, there is a disadvantage that all the driving wheels are encouraged to spin and slide.

[Problem to be solved by the invention]

In the conventional inverter electric vehicle as described above, readhesion control means at the time of slipping and skidding, that is, each driving wheel (3a
) to (3d), the rotational frequency detector (11
) to (44) of each rotational frequency (7) obtained from (fl
) to (([4)] Due to the magnitude of the change (differential value)
In the skid detection method, if a slight slip or skid occurs that does not reach the detection sensitivity (15'), the distance between the base line and each driving wheel is on the broken line shown in (7) in Figure 5, that is, when no slip occurs. This tends to increase the speed difference. In addition, as shown in (17) in Figure 5, the detection signal when slipping or skidding is detected is demagnetized before re-adhesion, so the slip frequency (20
) is narrowed down once, but immediately recovers to its original value.

For this reason, the driving wheels that have spun or skid are unable to re-adhere, and the state of ° continues with a certain speed difference, and re-adhesion is only expected when the adhesion between the driving wheels and the track increases. No, the coefficient of adhesion between the track and the driving wheels will decrease significantly, and the
When two driving wheels are idling and skidding at the same time, the reference frequency (21) (rx) of the driving wheels in Fig. 4 increases when idling and decreases when skidding, so the inverter electric vehicle is controlled. There was a problem that it could not work properly.

[Means to solve the problem]

The present invention eliminates the above-mentioned drawbacks, and a method for controlling readhesion when an inverter electric vehicle is idling or skidding is based on the relative speed difference between the reference speed calculated from an accelerometer installed in the same vehicle body and the speed of each driving wheel. When the speed difference exceeds a certain value (for example, 2 km/h), it is detected as slipping or skidding.
Immediately narrow down the slip frequency of the induction motor by a certain amount,
Controls the current flowing through the induction motor to promote readhesion.

In addition, the detection signal continues until complete re-adhesion occurs, and the
The purpose of this invention is to obtain a re-adhesion control method that takes measures to prevent re-sliding and increases the available adhesion coefficient between the driving wheels and the track.

[Effect]

In this invention, the reference speed is calculated from the acceleration/deceleration of the train using an accelerometer, so it can be calculated regardless of whether the train is slipping or skidding. Since skidding can be detected, re-adhesion control is possible at the point of slight slippage or slight skidding. Further, if this reference speed is converted to the reference frequency of the driving wheels and used as the rotor frequency of the induction motor, stable control of the inverter of the electric vehicle is possible even when the electric vehicle is idling or skidding. [Embodiment] An embodiment of the present invention will be described with reference to the drawings. First, in Figure 1, the horizontal axis is time (t), and the vertical axis is the output (5) (α) of the accelerometer when the electric car is moving, and the (α) of this accelerometer output (5). (V, ) of the reference speed (12) is calculated by the pro-sensor (α×sampling time). Reference speed (
(VS) of 12) is calculated and integrated from (α) of the output (5) of the accelerometer that is input every sampling. At point (A) of the accelerometer output (5), the train enters an uphill slope and (α) of the accelerometer output (5) decreases.
This shows a state in which (Vs) of the reference speed (12) is gently controlled. Further, point B of the output (5) of the accelerometer indicates the state during coasting. (V,) of the reference speed (12) during coasting is the addition (m) due to gradient changes, etc.
It is controlled according to changes in speed. In this way, the reference speed (12) (V,) in Figure 1 uses the accelerometer (4) in Figure 2 instead of the rotational frequency of the electric car's driving wheels, so the Next, we will explain the re-adhesion control method when an inverter electric vehicle slips or skids using this reference speed (V,). As shown in Figure 2, (1) is the vehicle body, (2) ) is the track, and (3a), (3b), (3c), and (3d) are the driving wheels of the induction motor. The speed of each driving wheel is detected by each driving wheel (3a), ~
Rotational frequency detector (11) (2) attached to (3d)
2) Rotational frequency output of (33) (44) (7)
(r+)<fl)Cf2)<14), (4) is an accelerometer to obtain (V, ) of the reference velocity (12) and (f, I) of the reference frequency (21). (5) is the output of the accelerometer (4). (6) inputs the output (5) of the accelerometer (4), and calculates the (Vs) of the reference speed (12) and the reference frequency (21) during car travel and regeneration.
This is a circuit that calculates (fN). Also, during coasting, (f,
) to (f4) are input, and corrections are made to (V, ) of the reference speed (12) and the diameters of the driving wheels (3a) to (3d). (8) inputs (fl) to (r,) of the rotational frequency (7) of each driving wheel (3a) to (3d), and
) ~ (3d) speed (V+)'' (V, ) is calculated. (9) is each driving wheel (3a) ~ (3d) (D speed output (v+) ~ (V4), (10) is (6
) of the reference speed (12) which is the output of (V, ) and each driving wheel (
3a) ~ (3d) Speed output (9) (■1) ~ (V
, ) to detect the relative speed difference. The speed difference (Δ■) during traveling is detected by subtracting (V,) of the reference speed (12) from each of the driving wheel speeds (9) (vl) to (v4).

The speed difference (ΔV) during regeneration is (Vs
) is detected by subtracting (vl) to (■4) of driving wheel speed (9). (13) is the output of the speed differences (ΔVl) to (ΔVa) that were compared and calculated in (1o). (14) is a speed difference sensitivity setting device for detecting slipping and skidding. (15)
is the output of the sensitivity setter (14). (16) is idle/
This is a skid detection circuit, and each driving wheel (3a) in (13)
Compare the speed difference (ΔV+) to (ΔV4) in (3d) with the detection sensitivity for slipping/sliding (for example, 2 km/h), and if the detection sensitivity is higher than the detection sensitivity, it is determined that the vehicle is slipping/sliding, and the detection signal (1
7) is output. The detection signal (17) is transmitted from each driving wheel (3a) to
(3d) is readhesion, that is, velocity difference (ΔVl) ~ (ΔV
The process continues until the value of 4) becomes zero. (1
8) is the standard pattern (r□) of the slip frequency corresponding to the load response of the electric vehicle. (19) is the slip frequency pattern (18) during the period when the slipping and skidding detection signal (17) is output. This is a subtracter that narrows down the standard pattern ((sr) by a certain amount.

(20) is the output of the subtractor (19) as the slip frequency (f, ) of the induction motor, and this slip frequency (20)
(f,) reduces the current flowing to the induction motor by a certain amount during slipping/sliding to promote readhesion. Also,
(f,) of the slip frequency (20) is positive (+
), and has a negative (-) effect during regeneration.

(21) is an output (fM) which is the rotor frequency of the induction motor by converting the reference speed of the reference speed calculation circuit (6) into the reference frequency of the driving wheels. (23) is an adder. (21
), that is, the rotor frequency (r9) and (20
) is added to the inverter frequency (fINV) - (fx) ±(f,
), (- indicates regeneration), the inverter of the electric car is controlled at this inverter frequency (r +, 1w>).
By doing so, even when idling or sliding (21)
The reference frequency, that is, the rotor frequency, is stable and stable control is possible. The embodiment will be explained in detail with reference to FIG. 3 as follows. The explanation basically shows the case where four driving wheels (3a) to (3d) spin at the same time with the same size. (12) is the second wheel obtained from the accelerometer.
The reference speed (V 5) (9) in Figure (L2) is (vl) to (v4) of the speed (9) of each driving wheel (3a) to (3d) in Figure 2.
), (20) is the slip frequency (f, ), (
13) is the speed difference (ΔV) in Fig. 2 (13) caused by the idling of the reference speed (12) (V$) and the driving wheel speed (9) ” (Vt ) ~ (V4) (V
t) is shown. (15) is the level of wheel slip detection sensitivity. (17) indicates a state in which the speed difference (ΔV) exceeds the slip detection level (15) and a detection signal is output.
4) is continued until it reaches the reference speed (12) (Vs), that is, until the readhesion point. Based on the detection signal (17), the slip frequency (20) is narrowed down by a certain amount as shown at the 0 point, and the current flowing through the induction motor is reduced to achieve readhesion. Point D of the driving wheel speed (9) is
In the above-mentioned embodiment showing the readhesion point obtained by the readhesion control method according to the present invention, the difference in the diameter of each drive wheel is caused by the difference in wear between the drive wheels, so the correction of the diameter of each drive wheel is performed during coasting. It is necessary that the detection level of the slipping/skidding detection circuit shown in FIG. 2 (14) be a predetermined value or can be changed arbitrarily. Furthermore, since the polarity of the output (5) of the accelerometer (4) changes depending on whether the vehicle is moving forward, regenerating, forward, or backward, it is necessary to take care that the output (5) is always set in the same direction (positive) using an external signal. By adopting the above-mentioned configuration, this invention uses the reference speed compared with the conventional rotational frequency of each driving wheel as a reference frequency, controls the inverter of an electric vehicle, and also prevents slipping and
By using an accelerometer to calculate a reliable reference speed and reference frequency without using a method to detect skidding, and by detecting slipping and skidding based on the relative speed difference between the reference speed and the speed of each driving wheel, inverter electric vehicles Measures to prevent re-adhesion during slipping or skidding can be taken early to increase the available adhesion coefficient and enable stable control.

〔Effect of the invention〕

As explained in the above embodiment, this invention calculates a reference speed using an accelerometer, and compares it with the speed of each driving wheel determined from the rotational frequency obtained from the rotational frequency detector attached to each driving wheel. Since the maximum adhesion force can be obtained by detecting slipping or skidding and performing re-adhesion control of the inverter electric vehicle, the ride comfort during slipping or skidding can be improved by 1. Furthermore, since an accelerometer is used to detect the reference speed, it has the advantage of being able to cope with gradient changes.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the principle of an embodiment of the present invention. Fig. 2 is a side view and circuit diagram of an electric car showing an embodiment of the present invention, Fig. 3 is an explanatory diagram of a re-adhesive Ha left method showing an embodiment of the invention, and Fig. 4 is a diagram of a conventional electric car. A side view and a circuit diagram of an electric vehicle showing the readhesion control means, and FIG. 5 is an explanatory diagram of the readhesion control means of the conventional electric vehicle. (1)...Car body (2)--Race surface (3a
)~(3d)...-Each driving wheel (4)...-Accelerometer (5)...Accelerometer output (6)-
・−・−Reference speed calculation circuit (6°)−−・Reference frequency comparison circuit (7)・・・・One rotation frequency (8)−・
・−Speed rendition circuit (9)−・・・Driving wheel speed (10)
・-・・−Speed difference detection circuit (10')・～・Rotational frequency change detection circuit (12), (■t)・−・−
・Reference speed (13) --- Output of speed difference (13
°)...- Output of change in frequency per rotation (14)...
-Setter for speed difference detection sensitivity (14°)...Setter for change detection sensitivity (15') -Speed difference detection sensitivity (15°)...Setter for change detection sensitivity (16) )−
...Slip and skid detection (17) ---Slip and skid detection signal (18) --- Standard pattern of slip frequency (19) --- Subtractor (20) ---
... - Slip frequency (21) ... Driving wheel reference frequency (23) ... Comparator (24) ...
Inverter frequency (11), (22), (33). (44)...-Rotational frequency detector for each driving wheel (α)・
---Acceleration (f,) ~ (f4) ---Rotational frequency of each axis (vl) ~ (■4) --- Speed of each driving wheel
(ΔV+)～(ΔV4)・−・Speed difference between each driving wheel (1
)・・・・・Time (A)・・・・・−Output of the accelerometer needle during uphill slope (B)・・・・Output of the accelerometer during coasting
(C)・−・−・Narrowing down the slip frequency by a certain amount (D
)--Re-adhesion point (E)--Narrowing down the slip frequency Patent applicant Railway Technology Research Institute Figure 1 Figure 3 ff14 Figure

Claims (1)

[Claims] The standard speed of the train and the reference frequency as the rotor frequency of the induction motor are calculated from the accelerometer installed in the same car body, and when the train is slipping or skidding, this reference speed is compared with the speed of the power transmission shaft in the same car body. The calculation is performed, and based on the magnitude of the relative speed difference, slipping or skidding is detected, and the slip frequency of the induction motor corresponding to the variable load of the electric car is controlled to the re-adhesion point, and the reference frequency is used to control the slipping frequency of the electric car. A readhesion control method for an inverter electric vehicle when it is idling or skidding, which is characterized by obtaining the maximum adhesion force between driving wheels and tracks by controlling an inverter.