JPS5928801A - Protecting method for electric motor coach - Google Patents

Abstract

PURPOSE:To protect an electric motor coach even if the direction of a start command is in error by comparing the direction of the start command of the coach with the rotating direction of a rotor of an induction motor and stopping a variable voltage/variable frequency inverter which drives a motor when both directions are different to each other. CONSTITUTION:A DC current collected by a pantograph 1 drives an induction motor 3 through a variable voltage/variable frequency inverter 2. A pulse sensor 6 is mounted on the rotor of the motor 3 to detect a signal of the rotating direction according to which of pulse elements 6a, 6b provided, for example, so that the distances therefrom to the center of rotation are different passes earlier through the detecting point. A controller 7 inputs a power drive or a brake command, forward or reverse drive command and a frequency fM from the sensor 6 and instructs so that the inverter 2 produces output voltages in the prescribed sequence of phases corresponding to the command. A comparator 8 compares the direction of the command with the rotating direction of the rotor to produce a signal for stopping the inverter 2 when different. In this manner, an electric motor coach can be protected.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for protecting an electric vehicle using an induction motor.

A conventional electric car was constructed as shown in Figure 1.

In the figure, (1) is a punk graph that collects DC voltage from overhead wires, (2) is a variable voltage variable frequency impark (hereinafter abbreviated as an inverter) composed of control rectifying elements such as Cyrisk, (3) ) is an induction motor (hereinafter abbreviated as IM) whose speed is controlled by impark (2):, (
4) is provided on the axis ν116 of IM (3) and has a rotational frequency (
The pulse sensor (5) that detects fhQ is activated by the forward and regenerative brake commands and the nf forward and reverse commands.
This is a control device that outputs an ignition command for impark (3).

In order for the electric vehicle 111 to travel in a predetermined direction in response to a forward or backward command from the electric vehicle, the driver, or the self-help driving device (hereinafter referred to as the driver),
The rotation direction of IM (3) is determined, and the rotation direction of IM (3) is determined.
so as to generate a rotating field in the same direction as the rotating direction of
The output voltage level of impark (2) (the order of magnitude is the control device (
5).

In addition, in order to change the rotation direction in 1) and 1 (3) to the opposite direction, it is sufficient to reverse the direction of the rotating field, so the phase relationship of the output voltage ゛ is changed between U - V - W l. This is achieved by reversing the concave or two outputs between the lines.

For example, in FIG. 1, if the digit order for forward motion is u-v-w, then reverse motion is achieved by changing the position to U-W, -V.

At the same time, the voltage and inertia of impark (2) are set in advance to be 1-lux according to the driver's power command. ! ! Ichiri 1i19) Inspector (5) Ichiri ω
V.

One step, slipping circumference? The torque (T) generated in the area where the skin relief (fs) is small (I), 1 (:3) is (
1) It7. .

T ==k (7 guns) 2f s medium, (
1) V: [1 gun! , j 'r LF fI : inverter frequency ie times) version field frequency fB , slip frequency? In this case, the slip frequency (f8), the impark frequency (fI), and the I M rotational frequency detected by the pulse sensor (4) and fed to the control device (5) (IM) and is expressed by equation (2).

f day = fl - fhs ... river (2) (1
) formula, in order for the slip frequency (fs) to be positive during forward operation, the re-impairing frequency (fI) is set higher than the IM rotation frequency fM), and a positive torque is applied to the mechanical M(3). generate.

Furthermore, when stopping the Denki East while it is running, the driver issues a brake command as well as a forward or reverse command. As a result, the regulating device f(5) i, j impark(2
), determine the beginning of the output voltage, and calculate the slip frequency (fs
) is negative! The engine is operated with the impark frequency lower than the 21 rotation frequency (fbQ), and IM(3)K generates negative torque to apply the electric brake.

However, when a restart or brake command is given while the electric train is coasting in a predetermined direction, if a command to proceed in the opposite direction is given, the slip frequency (fs) can be determined from equation (2), but the input Park frequency (fI) and IMM rotation frequency (fhQ) have opposite rotation directions, so
The inverter frequency (fl) and the IMM transfer frequency (fM) are opposite to each other. Therefore, the slip frequency a
Cfθ) As shown in equation (3), each frequency tj
! The absolute values of i(fI) and (fM) become different, resulting in excessive values.

l f s l = 1f I l -1-1f M
l...(3) In this case +lL (1
) formula j′: does not hold. This is generally detailed in the literature.
I'll omit it because it's short. As a result, the stall torque point (
A) ° or (B) is exceeded, and not only is it impossible to generate torque, but also the laminar flow becomes excessive and the process M (3)
There is a risk of burning out.

This IJJ was made in view of the above points,
If the direction of rotation of the rotor of one rotor is compared with the advance command that directs the forward or backward movement of the engine, and if the directions do not match, the operation of the inverter is stopped ( [Providing a way to praise Ui4 of Qi rlZ.

The figures will be explained below. In Figure 3, (1) to (
3) (τt f,'e is the same as rice. (6) is
(3) rotor (handle 1 = J keratah pulse sensor,
I L1 rotation position wave It! I(fht) and the signal 'W' in the direction of rotation and rotation of the rotation plate are constructed. The direction of rotation is detected by determining which of the hk pulse elements (6a) and (6b), which are provided at different distances from the center of the rotating circle, passes through the ejection point first.(7) )
This is a control device that issues an ignition command to the if in park (2), and outputs a power running brake command, an acceleration command, and a pulse sensor (6) to the engine rotational speed e, (f
ht) is manually operated, and the inverter (2
) gives a command to output voltage at the inner corner of the eye.

(8) 17 is the direction of the advance command and I M I! 21 Comparison of the turning direction signal and manual input 4.5 If both directions do not match, the control cape device (7) issues a command to stop the impark (2).
Output to.

'1 in Figure 3 (Kobuntun is, for example,
jfK IIJ, and when issuing a brake command during coasting, that is, while the rotor is rotating, if the forward command is incorrectly commanded to reverse, the comparator (8) ) compared with eight, nohi with disagreement in both directions!
! An impark stop command is issued from 2 ÷ (8), and the VV in operation is
The VF inverter (7) rises to a stop F in response to this interrupting and manually input inhalation stop command.

Figure 5 shows an example of Sennoji h (S), where the I M rotation frequency (f M) and the rotation speed of the M-times 1 plate are calculated using the J comparison circuit (
9), and compare the output of this comparison circuit (9) with 4(
+iii JJ! in the output table of 8). By providing a logic circuit (U) that issues an inverter stop command, the direction of the advance command is compared with the rotation direction of the rotor when the rotation speed of the rotor exceeds a predetermined value. Therefore, when driven in the fjfJj1M direction, the temporary retreat of 'f4fqi1j while the rotational torque reaches a predetermined value is not detected as a mismatch;
For example, if 5 Km/h is set as the default value, 5 Km/h
If the comparator circuit (9) is configured to output an output when the value exceeds the above, it is possible to prevent the tonne from being set back by a different level.

Based on this starting point J, compare the direction of the advance command and the direction of the 1st version of the 1st version of the seduction machine and find L where both directions do not match.
Since the advance command is canceled when the advance command is made, the tonne is maintained 1, ψ even if the direction of the advance command is incorrect.

[Brief explanation of drawings]

Figure 1 is the circuit configuration diagram of the conventional Ichikitun, Figure 2 is the circuit diagram of the conventional Ichikitun.
, FIG. 6 is a detailed view of another embodiment. In the figure, (2) is an inverter, (3) is an electric motor, (6) is a pulse sensor, (7) is a rifl river wholesale device, and (8) l-, j are comparators. The same number in the middle or (indicates the target part. Agent Kazuno Id- Figure 1 Figure 2 Figure 3 Figure 5

Claims (2)

[Claims] (1) In a method for protecting an electric vehicle that drives an induction motor with variable frequency impark, the direction of the advance command that commands the 1ifJ, IMAi, ti, and t i bases of the electric vehicle and Conductive! A method for protecting a tV air tank, characterized in that the rotation direction of the rotor of the I1II machine is compared with the direction of rotation of the rotor of the I1II machine, and when the two directions do not match, the variable frequency inverter is stopped. (2) The direction of the rotating field and the direction of the rotor are compared when the rotation speed of the rotor exceeds a predetermined value. A method for protecting an electric vehicle as described in item 1 of the box.