JPS61224804A - Controlling method for electric railcar - Google Patents

Abstract

PURPOSE:To improve the efficiency of a preliminary excitation by preliminarily exciting before closing a regenerative brake weakening switch. CONSTITUTION:When a brake command line 18 is energized by a brake command to close the interlock contact 16 of a brake converter, a coil 14a of a preliminary excitation switch 14 is energized. Thus, the preliminary excitation is performed in all field state. Then, since the contact 14b of the switch 14 is closed, the coil 9a of a disconnecting switch 9 of a main circuit is excited. Then, since the contact 9b of the switch 9 is closed, the coils 12a, 10a of a weakening switch 12 and a disconnecting switch 10 of a main circuit are energized. When a field current comes to the prescribed value or higher, the switch 14 is opened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling an electric vehicle, and particularly to a method for supplying a pre-excitation current to a traction motor immediately before applying regenerative braking in a chopper-controlled vehicle.

[Conventional technology]

When the vehicle decelerates, the main electric motor acts as a generator and regenerative braking is applied.The connection diagram of the main circuit of the chopper control vehicle is shown in Figure 1. In the same figure, (/1 is the armature of the main motor, (2) is the field coil, (, 71 is the main smoothing reactor, C4j) is the chopper device, (j) is the blocking diode, (1) is the filter capacitor, (7) is a filter reactor, (f) is a current collector, and (9) (
10) (//) is a current breaker in the main circuit. and,(/
ko) is a weakening switch, (/J) is a field weakening resistor, (/
$) is pre-excitation switch-in! , (/&) is a pre-excitation device. The series-connected weakening switch (1) and field-weakening resistor (tS) constitute a shunt circuit connected in parallel to the field coil (I/C), and the The pre-excitation switch (ta) and the pre-excitation device (/3) also constitute a pre-excitation means connected in parallel to the field coil (co).

Next, a conventional control method will be explained. The steady operation of regenerative brake control is well known.

The description will be omitted here, and the control method for steady regenerative braking @ until the brake is fully loaded will be explained.

The field rate of the traction motor when applying regenerative braking is generally set to 0, since regenerative braking does not work from a high-speed range. Turn on the weakening switch (1) of the shunt circuit connected in parallel to the magnetic coil (1), and connect the field weakening resistor (1) whose resistance value is determined to achieve a predetermined field rate.
/, 7) Dividing the K traction motor current. Therefore, when applying the regenerative brake, it is necessary to turn on the weakening switch (/2) in advance.

On the other hand, in order to stably start up the regenerative current even in the low speed range, a pre-excitation device (/S) is usually provided, and a pre-excitation switch (/S) is installed before the chopper device (41) operates.
), apply a preliminary excitation current to the field coil (J) of the main motor, sufficiently induce the main motor voltage IF-, and then start the chopper system.

The weakening switch (L) and the pre-excitation switch (C0) are turned on in the following order.

In other words, when receiving a brake command from the driver's cab.

The brake converter (not shown in Figure 1) that switches between the power line circuit and the brake circuit is switched to the brake side, forming the circuit shown in Figure 9, and the first weakening switch (1 piece) is turned on.
When the weakening switch (L) is turned on, each current interrupter 0)(
to) (tt) are turned on in a predetermined order, and at the same time, the preliminary excitation switch (/E) is also turned on.

A pre-excitation current flows through the field coil (K) of the main motor. When all of the current circuit breakers (v) (to>(tt)) in the main circuit are turned on, regenerative brake control by the chopper device (1) K starts.

Each switch was turned on in the order of ``brake command 1 weakening switch on → pre-excitation switch on''. In addition.

In FIG. 3, the operation of the flow breakers (de) (tO) (tt) is omitted.

[Problem that the invention seeks to solve]

In the conventional control method described above, even if the pre-excitation switch is turned on and the pre-excitation current flows, a portion of it flows to the field-weakening resistor side. This is shown in FIG. In Fig. 6, I is the pre-excitation current flowing from the pre-excitation device (tr), and IR is the field weakening resistor (/J
) side.

Engineering? is the current flowing to the field coil (C-) side, and the current nib that actually flows through the field coil (C) is Iy = 4-
Indicated by IR. Therefore, the excitation efficiency of the main motor voltage becomes poor, especially considering the capacity of the pre-excitation device (/3).

The lower the set field rate, the lower the value of the 1-weakening field resistor, so the IR shown in FIG. 6 becomes larger and the excitation efficiency deteriorates. For this reason.

(a) The pre-excitation device becomes large.

(b) There were problems such as the need to consider the capacity of the pre-excitation device every time the field rate changed.

This invention was made to solve the above-mentioned problems, and provides a control method that makes the excitation efficiency of a pre-excitation device independent of the field rate during braking, and also allows high excitation efficiency to be obtained. The purpose is to

[Means for solving problems]

In the control method according to the present invention, upon receiving a brake command,
After the brake circuit shown in the diagram was constructed, the pre-excitation S switch was first turned on to flow the pre-excitation current, and after the traction motor voltage was raised, the weakening switch was turned on.

[For production]

By applying pre-excitation a before the field-weakening switch forms the shunt circuit of the field-weakening resistor, all the output current of the pre-excitation device flows to the field coil, allowing efficient pre-excitation of the traction motor. can be done.

〔Example〕

FIG. 1 is a diagram showing the operation sequence of the control method of the present invention. That is, when a brake command is given, first the pre-excitation switch is turned on, and after the pre-excitation is sufficient, the
I turned on the weak switch.

Next, FIG. 1 shows the flow of the pre-excitation current when the operation order is as shown in FIG. In Figure 1, the weakening switch (saw) is open when the pre-excitation switch (ta) is turned on, so all current from the pre-excitation device (/) flows through the field coil (K).

In addition, an example of a cutting circuit that turns on the weakening switch (saw) shown in FIG. 2 and the preliminary excitation switch (saw) shown in FIG. z
(7a) (//a) are the closing coils of the main circuit breakers (q), (io), and (tt) shown in the diagram, respectively, and (9b)
(lOb) (//b) are each interlocking a contact, (lcomi) is the closing coil of the weakening switch (saw), (1 piece b)
is its slow wJa contact, (z4(a) is the pre-excitation switch (ha0 closing coil), (/111) is its interlocking a contact, (/4) constitutes the main circuit during braking as shown in the figure below. (/7) is an interlocking contact of a brake converter (not shown) that closes when the brake switch is switched to the brake side. The closing coil of the contact (not shown) works to cut off the pre-excitation when the field current exceeds a predetermined value. Note that (1g) is the brake command line that is pressurized by the brake command, and (lde) is the power supply line. It is a line.

In Fig. 3, the brake command 11 is caused by the brake command.
When 1 (/l> is pressurized, the brake converter switches to the brake side. k, the interlocking contact of the brake converter (/A)
is closed, and the closing coil (zl) of the pre-excitation switch (ta) is closed.
a) is energized, and the pre-excitation switch (
ie), pre-excitation is performed in a full field state. Next, when the interlocking A contact (tab) of the pre-excitation S switch (C0) is closed, the closing coil (9a) of the current interrupter 5 (9) in the main circuit is energized, and the current interrupter (9) is energized.
) is inserted. Next, the interlocking a contact (9) of the current interrupter (9)
b) is busy closing.

The closing coils (tea) of the main circuit weakening switch (saw) and current interrupter (/Q) are energized, and the first weakening switch (saw) and current interrupter (10) are turned on.

A shunt circuit is formed. As mentioned above, the interlocking contact (1) is opened when the field current exceeds a predetermined value, so at that point the closing coil (/la) of the pre-excitation switch (/4I) is demagnetized. , pre-excitation switch (t
a) is released. This causes the interlocking a contact (ta
b) is opened, but this interlocking a contact (tab) has 1
Since the interlocking A contacts (L and B) of the weakening switch (saw) are connected in series, the closing coil (9a
) continues to be excited.

Next, since the linked A contact (TAB) of the current interrupter (IO) is closed, the closing coil (//) of the current interrupter (//) in the main circuit is closed.
/a) is excited and the current interrupter (11) is turned on. That is, the flow breakers are turned on in the order of (?) → (10) → (//). When the flow interrupter (/l) is turned on, its linked a contact (/lb) is closed, and at the same time, a chopper start command is given, and regenerative brake control is performed by the chopper device (44>). You will be killed.

〔Effect of the invention〕

As described above, in the control method according to the present invention, pre-excitation is applied before turning on the weakening switch of the first regenerative brake, so the efficiency of pre-excitation is improved and the capacity of the pre-excitation device/child can be reduced. Furthermore, since the capacity of the pre-excitation device is not affected by the field rate, the pre-excitation device can be standardized, resulting in the advantage that the device is inexpensive and a more efficient control method can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the sequence of the control method according to the present invention, FIG. 1 is a diagram for explaining the control method according to the present invention,
Fig. 3 is a circuit diagram showing an example of a control circuit for carrying out the control method of the present invention, Fig. 9 is a connection diagram of the main circuit during regenerative braking to which this invention is applied, and Fig. 3 is a conventional control circuit. A diagram showing the sequence of the method, FIG. 6 is a circuit diagram for explaining the conventional control method of FIG. 3. In the figure, (1) is a weakening switch, (7, 7) is a field weakening resistor, (ta) is a pre-excitation switch, (/j)
is a pre-excitation device. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1 Flood Figure 4

Claims (1)

[Scope of Claims] Pre-excitation means comprising a pre-excitation device and a pre-excitation switch connected in series to supply a pre-excitation current to a field coil of a main motor, a field-weakening resistor and a pre-excitation switch connected in parallel to the field coil; In a chopper-controlled vehicle equipped with a shunt circuit in which weakening switches are connected in series, when a brake command is given, the pre-excitation switch is turned on to flow the pre-excitation current, and the main motor voltage is started up. An electric vehicle control method characterized in that the weakening switch is turned on to start regenerative brake control at a predetermined field weakening rate.