JPS5827728B2 - electric car control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric vehicle control device that improves the series-parallel or parallel-series connection of an electric vehicle having a plurality of electric motors.

In an electric vehicle having a plurality of electric motors, the series and parallel sides of two groups of electric motors are often operated during electric operation.

Furthermore, in many electric vehicles using compound-wound motors, parallel-series return control is performed during regenerative braking to widen the speed and night range in which regenerative braking is effective.

The purpose of the present invention is to select between series-parallel or parallel-series
To provide an electric vehicle control device which is particularly effective when applied to parallel-to-series crossing during regenerative braking, where the value of armature current changes greatly during crossing, and which can also be applied to series-to-parallel crossing during electric operation. be.

Conventionally, in an electric vehicle with regenerative brakes using a plurality of compound motors, the plurality of motors are divided into two groups, and during regenerative braking, the two groups of motors are connected in parallel at high speeds and in series at low speeds.

In this case, when changing the connection from parallel to series during regeneration, it is common practice to reuse the starting resistor used at starting.

To switch the above two groups of motors from parallel to series, first, at the end of the parallel state, a resistor is connected in parallel to the motor circuit I of the second group, and then the motor circuit of the second group and the resistor are connected in series. Then, short-circuit the resistors one after another.

In this case, it is desirable to have almost no difference in regenerative braking force before and after switching from parallel to series, and to do so, the resistance value must be such that the armature current hardly changes before and after switching from parallel to series. After the adjustment has been made, the contactors forming the parallel circuit can be opened.

For this reason, in order to smoothly control this crossing, devices have already been developed in which the resistor is slightly shorted depending on the magnitude of the commanded brake force, and then the contactor forming the parallel circuit is opened, and the armature current is Devices have been proposed that open when the currents flowing through the resistors become equal.

However, with regenerative braking, it cannot be said that the regenerative braking force that is equal to the commanded braking force always acts.
As r becomes higher, the regenerative braking force is limited, and in devices that add air brakes, the commanded braking force (
Therefore, it cannot be said that it is sufficient to control the opening timing of the contactor for parallel four-way configuration.

In addition, the method of opening when the armature current and the current flowing through the resistor become equal is sometimes used for series-parallel side (goods) in electric motors, but the current detector tends to be large and expensive. It is.

The present invention eliminates the drawbacks of the conventional devices as described above and provides a small and lightweight electric vehicle.

A control device can be obtained.

The present invention will be explained below based on the drawings.

Figures 1 to 4 are main circuit connection diagrams during regenerative braking used in compound motors, and Figure 1 shows two groups of motors in parallel,
Figure 2 shows a state in which a resistor is first connected in parallel with the motor in order to switch the two groups of motors from parallel to series, Figure 3 shows a state in which two groups of motors are connected in series and a resistor is inserted, and Figure 4 shows a state in which a resistor is inserted. This shows a state in which the resistor is short-circuited and regenerative braking is effectively applied to two groups of motors in series.

In Figures 1 to 4, I) N is a pantograph, Ml
, F2. Sl are the armature, series-wound field, and shunt-wound field of the first group of the motor, respectively, and M2. F2. S2 is the armature of the second group of the motor, a series winding field, and a quarter winding field, respectively.

R,1,R2 are resistors whose resistance values are the camshaft controller,
Controlled by electromagnetic contactors, electropneumatic contactors, etc.

S. P and G are contactors, and PR is a shunt field regulator.

To perform parallel-series switching of motor groups during regenerative braking, first, when contactors P and G are closed and S is open and the two motor groups are connected in parallel (Fig. 1), contact 8iS is closed. One series path of resistors R1 and R2 is connected in parallel to the motor group (FIG. 2).

In this case, the actual regenerative current decreases, but the regenerative braking force remains unchanged.

Next, open the contactors P and G and connect the motor 2 group to the resistor R1,
(Fig. 3), then connect the resistor R
1, R2 are short-circuited in sequence and the resistance value is finally set to zero (4th
figure).

In the present invention, when switching between two groups of motors in parallel, the resistor Ri
, when R72 reaches an appropriate reduction value, the contactor P,
This is related to the control to open G.

Next, the above period will be explained.

5 and 6 are characteristic curves showing the relationship between speed and armature current during regenerative braking, assuming that the overhead line voltage is constant.

In the figure, A and B are characteristic curves when two groups of motors are connected in parallel, curve A is the case where the shunt field current is maximum, and curve B is when the shunt field current is small.

Further, curves C and D are characteristic curves when the regenerative braking force is constant in parallel, and the curve C is the characteristic of the brake state, and the curved line is the characteristic of the brake state.

Curves E, F, and G in the broom diagram 6 are the characteristics when connected in series,
Curve E? F + (The total resistance value of resistors R1 and R2 is small in the order of J.

For example, in Fig. 6, the armature current is 11 or ■2.
When the motor group is connected from parallel to series (Fig. 3), the armature current suddenly changes to the current value of curve E 5 F 2 (J-hi) in Fig. There must be.

If the current value decreases from ■1 to the current value of curve E, the amount of decrease will be small, but if the current value decreases from ■1 to the current value of curve E, the amount of decrease in 11jf will be too strong, which is not preferable.

(2) In the case of 1, it is preferable to select the combined resistance value so that the current value changes to the curve F or G.

The combined resistance value is the value when all or part of the starting resistor is shorted.

Usually, it is at the maximum value at first, and then it is short-circuited one after another.

Therefore, it is better to open the contactors P and G when the resistor is shorted to the required value.

Although not particularly shown in FIGS. 1 to 4, there is usually a current detector at least in the armature or series field part for controlling electric vehicles.1. In addition, a detector is added to detect the current in the contactor S portion of Fig. 2, and when the detected value of this detector becomes equal to the detected value of the armature current detector, contacts RBP and G are activated. This is how to open it.

This method has disadvantages such as the large size of the additional detector and the increased amount of main circuit wiring.

As an alternative to this, the armature current is predicted in advance based on the brake command value, and after some of the resistors R1 and R2 in FIG. 2 are short-circuited depending on the magnitude of the command value, the contactor 1 However, as mentioned above, when the overhead line voltage changes depending on the amount of regenerative load, such as with the σ regenerative brake, or when the overhead line voltage rises, this latter method is used to limit the regenerative current. The method cannot always be expected to provide good parallel-to-serial switching.

The present invention solves the above-mentioned problems, and the contactor P
, which changes the opening timing of G.

7 to 9 are control circuit connection diagrams showing the control method.

In Figures 7 to 9, the same symbols indicate the same equipment, SO is the power supply, C1, C2, C3, and C4 are the contacts of the camshaft controller CA, which are closed at the hatched cam position shown in the figure. .

p. a and b indicate the positions of the camshaft control 5CA, p is the parallel position, a is the first stage position in series, and b is the position where the resistors are connected in series and are slightly short-circuited.

Sc, Pc, and Gc are the contactors S, P, and G in Figures 1 to 4.
This is the operating coil.

CP is an armature current discriminator. CPa is a contact point of a relay attached to the current discriminator.

TD is a time limit device, and TDb is a contact point of a relay attached to the time limit device.

Sa is an interlocking contact of the contactor S, and is a so-called A contact that closes simultaneously when the main contact of the contactor S closes.

First, FIG. 7 will be explained.

When the cam @1 is in the parallel stage p position, the contact C1 is open, the contact C2 is closed, and the contactors P and G are energized. be.

Although the gear advance control section of the camshaft controller CA is not shown in the drawings, it is advanced from the position p to the serial position of the position a during parallel-series switching.

When the contact CPa of the armature current discriminator is open, the contactors P and G are demagnetized at position a, and when the contact CPa is closed, the contactors P and G are energized at position a, and the connection advances to position. Contact begins when contact C3 opens "lap 5 G
is demagnetized.

When armature current discriminator CP is small, contact CPa
is open, and the contact CPa is configured to be closed when the armature current is large.

In FIG. 8, while the contact CPa of the discriminator CP is closed, the contactors P and G continue to be excited.

The armature current discrimination value of the armature current discriminator CP is the camshaft m
When the signal at contact C4 of lJ controller CA is applied once, it is configured to be raised by a certain predetermined value.

For example, if the unique discriminant value is 30OA and the armature current is 30OA,
If the current is 0 A or less, the contact CPa remains open even if no signal is applied to the contact C4.

Contactors P and G are therefore demagnetized when contact C2 is opened.

Assuming that the armature current is 4.0 OA, and the above-mentioned predetermined value 0 is 15 OA, when the camshaft controller CA reaches the position 1 from position a, the signal at contact C4 is output to the electromagnetic current discriminator CP. As a result of the comparison between this value and the armature current of 400 A, the contact CPa of the armature current discriminator CP opens and the contactors P and G are demagnetized.

In Figure 3, contact C4 closes only once between positions a and b, but in a multi-stage controller, the number of resistance short circuits is increased, and contact C4 closes only once between positions a and b.
4 may be opened and closed several times.

Further, since the normal camshaft aiSCA has an intermediate feed contact, the armature current discriminator CP can be sequentially pulled up every time the intermediate feed contact is closed after the contactor S is closed.

For example, in the above example, if the armature current is 300A, contactor P and G are demagnetized at position a, and if it is 400A, the next stage after position a is 500A.
If it is 2 steps after position a, if it is 600A, it will be 3 steps or 4 steps after position a (1300 people in 600A-300 will be 150
Since it is exactly twice A, the armature current discriminator CP is the contact point CPa.
will open either 3 steps after position a or 4 steps after position a.

) can be changed as follows.

The one in Figure 9 is armature current discrimination '15 in Figures 7 and 8.
A timing device TD is used instead of cP.

When the value of the armature current is small, there is almost no time element, and when the armature current is large, there is a long time element, which is what is called a programmable time element.

After the contactor S is energized and the contact Sa is closed, the contact T D
l) opens immediately, the contactors P and G are connected to the cam [shaft 1451
J box] is demagnetized when the contact C2 of the box CA is opened.

If the armature current is large, the opening of the contact T D b is delayed, for example, when the camshaft controller CA reaches its position, the contactor G is demagnetized.

The method shown in Figure 9 is a contactor ■). This has the advantage that the purpose can be achieved with a simple timer when there are small variations in the release time of G and the rotational speed of the camshaft restrictor CA.

Although the present invention has been described above as being applied to parallel-to-series braking during regenerative braking, it can also be similarly applied to series-to-parallel braking during electric braking.

In this case, the difference is that instead of opening the contactors P and G after the contactor S is closed, the contactor S is opened after the contactors P and G are closed.

In addition, in the actual circuit configuration, for example, changes such as whether to control the contactor directly by contact C2 or to excite the contactor via a non-contact device or other relay with the signal from contact C2 are required as design changes. range.

As described in detail below, in the present invention, by using components comparable to conventional commanded brake force quantity discriminators, changes in armature current caused by both fluctuations in overhead line voltage and fluctuations in commanded brake force can be ignored. However, it is possible to provide a control device that can provide a good ride comfort, and its effects are outstanding.

[Brief explanation of the drawing]

Figures 1 to 4 are connection diagrams at each stage of parallel-series interruption of motor groups during regenerative braking. Figure 5 is a characteristic diagram of the relationship between regenerative braking current and speed when motor groups are connected in parallel. FIG. 6 shows the relational characteristics when the motor groups are connected in series and the final characteristics of the parallel connection when a series resistor is inserted, and FIGS. 7 to 9 are control circuit connection diagrams according to the present invention. Ml, M2... Armature, Fl, T'2''' series winding field, 81°S2... shunt winding field, R1, R, 2...
・Resistor, s, p. G... Contactor, FR... Shunt field regulator, C1, C
2゜C3, C4...Camshaft controller contacts, Sc,
Pc. Gc... contactor operation coil, CP... armature current discriminator, TD... time limit device.

Claims (1)

[Claims] 1. In an electric vehicle having a plurality of electric motors, the magnitude of the motor armature current value relative to a predetermined value is determined during series-parallel bridge crossing during electric power or parallel-series crossing during regenerative braking. An electric vehicle control device characterized in that the opening timing of a bridging contactor is changed depending on the presence or absence of an output from a discriminator. 2 By sequentially increasing the discrimination value of the discriminator according to the camshaft advancement stage after reaching the transition stage, the bridge crossing contactor is opened when the discrimination word output disappears. An electric vehicle control device according to claim 1, wherein the electric vehicle control device is configured to: 3. A patent in which a timer whose time limit changes depending on the value of the armature current is used in place of the discriminator, and the bridging contactor is opened after the time limit of the timer reaches the crossing step. An electric vehicle control device according to claim 1.