JPS5829684B2 - Electric vehicle control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for supplying preliminary excitation current during flaking of an electric vehicle driven by a DC motor.

Recently, there has been a strong demand for reduced power consumption and labor-saving maintenance for electric vehicles, and advances in semiconductor technology have led to the rapid spread of chopper-controlled trains with regenerative brakes, especially in subways.

This main circuit system is shown in Figure 1a. As shown in Fig. 2b, a conventional DC series-wound motor is controlled, and as shown in Fig. 2a and b, an automatic variable field method is adopted to control a DC motor with two field windings. There is.

Conventionally, in each of these brake circuits, as shown in Figures 1 and 2, a pre-excitation current IEX is sent to the field winding of the main motor from the auxiliary power source of the electric vehicle through the pre-excitation device pEXD at the start of braking. Smoothly induces main motor voltage.

Here, the operation of the brake circuit in the automatic variable field chopper system shown in FIG. 2 is performed as follows.

That is, when the chopper CH turns on, the electromagnetic element A
- Field winding F1 - Main flat sliding axle MSL - Chopper C
H - Field winding F2 - Brake current I in the closed circuit of armature A
B flows.

At this time, the armature A, the field winding F1, and the field winding F2 are connected in series, and the same current IB flows through them, so that the field rate of the motor becomes a stronger field of F1+F2.

When chopper CH turns off, armature A - field winding F
1 - Main flat sliding axle MSL - Freewheeling diode FWD - Filter reactor FL - Pantograph P
The energy stored in the MSL etc. by the AN circuit becomes a regenerative current IR and flows out to the power source side via the overhead contact line (overhead line) L.

At this time, no power is supplied to the field winding F2 because the CH is off, and the field becomes weaker with only Fl.

When the chopper CH is repeatedly turned on and off in this circuit, the field rate of the main motor changes depending on the on/off ratio.

In other words, in the high-speed range where the on ratio is small, there is a weak field state,
In the low speed range where the ON ratio is large, the field becomes stronger.

Also, in the case of the circuit shown in FIG. 2a, the field winding F2 is connected in series with the freewheeling diode FWD, so the field is strong in the low speed range and weak in the high speed range.

Now, conventionally, in the brake circuit shown in Figure 1 and Figure 2,
In order for the brake current IB to start flowing smoothly, a pre-excitation current IEX is sent to the traction motor field winding from the auxiliary power supply of the electric vehicle via the pre-excitation device PEXD when a brake command is issued. Since this is the main circuit, the contents of the pre-excitation device PEXD include a power transformer Tr with high voltage insulation treatment as shown in Figure 3, a rectifier bridge Re,
A surge absorber consisting of a capacitor C and a resistance tube R, a series or parallel resistance tube R, and a high-voltage pre-excitation contactor EXK were required.

Moreover, since the pre-excitation current IEX requires a current of several + A, the capacity of the vehicle auxiliary power supply must be considerably large even though it is only used when braking is commanded, and transformers, rectifiers, resistance tubes, capacitors, etc. must also be used for high voltage. This required a fairly large product, which was disadvantageous in terms of price.

This invention was made in view of these circumstances, and allows a preliminary excitation current to flow directly from the overhead contact line using a simple circuit.

An embodiment of the present invention will be described below based on the drawings.

FIG. 4 shows the automatic variable field type brake main circuit according to the present invention.

Note that the same reference numerals as in FIGS. 2a and 2b indicate the same parts, but in this invention, the series body of the pre-excitation contactor EXK and the series resistor REX is a pantograph PAN in which the freewheeling diode FWD is used. and the chopper CH side of the field winding F2.

In other words, in the automatic variable field system, one field winding F2 of the traction motor is connected in series with the chopper CH, and one end is connected to the ground side, so the series resistor REX and pre-excitation are connected from the overhead contact line to the series resistor REX. Contactor EXK boiled pre-excitation current I
EX can be easily flowed.

Note that the regenerative braking operation is the same as that shown in FIG. 2, so a description thereof will be omitted.

As described above, according to the present invention, in an electric vehicle that performs automatic variable field type chopper control using a DC series motor having two field windings, only a pre-excitation contactor and a series resistor are required. By providing a pre-excitation current, it is possible to easily flow the pre-excitation current from the overhead contact line to the motor field winding, and unlike the conventional pre-excitation method, it is possible to easily flow the pre-excitation current from the contact line to the motor field winding. By eliminating the need for an absorber, the pre-excitation device can be made lighter, smaller, and lower in price.

[Brief explanation of the drawing]

Figures 1a and b are main circuit connection diagrams of the power and regenerative brakes of a chopper control vehicle that controls a general series-series motor, and Figures 2a and b are a DC series-wound motor with two field windings. Fig. 3 is a circuit connection diagram showing the standard configuration of a conventional preliminary excitation device, and Fig. 4 is a circuit connection diagram according to the present invention. FIG. 2 is a regenerative brake main circuit connection diagram of an automatically variable field type chopper control vehicle according to an embodiment. Note that the same reference numerals in the figures indicate the same or corresponding parts. In the figure, A is the armature, Fl, F2 are the field windings, CH is the chopper, FWD is the freewheeling diode, PAN is the pantograph, L is the contact line, EXK is the preliminary excitation contactor, R
EX is a series resistor.

Claims (1)

[Claims] 1. The field rate in both selling field windings is reduced by controlling the power supply state to one field winding of a DC series motor having two field windings with a chopper. In an electric vehicle in which voltage control and field rate control are performed simultaneously, an armature of the motor, a first field winding of the motor,
Freewheeling diodes are connected in series, and a regenerative current flows through the freewheeling diode to the power supply side through the electric wire during braking operation, and the armature and the first field winding of the motor. a second electric line connected in parallel to the chopper and a second field winding of the motor; A third electric line connected to the chopper side is provided, and when a brake command is issued, a preliminary excitation current is supplied from the main power source of the overhead contact line to the second field winding through the third electric line. An electric vehicle control system characterized by: 2. In the first electric circuit and the second electric circuit, the first field winding and the chopper are connected to the contact line side via the freewheeling diode. 2. The electric vehicle control system according to claim 1, wherein the armature of the electric motor and the second field winding are connected to a ground point side. 3. The electric vehicle control system according to claim 1, wherein a contactor and a resistor are connected in series to the third electric path.