JPH0442884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for an electric vehicle, and particularly to a control device with a regenerative brake that regularly uses a regenerative brake for descending on a downhill slope.

[Background of the invention]

For example, "Hitachi Hyoron" September 1976, Volume 58, No. 9
A conventional device such as that described in "Recent Hitachi Vehicle Field Chopper Control Device" will be described.

FIG. 4 is a main circuit connection diagram when regenerative brake control is performed using a separately excited field motor in an electric vehicle.

FIG. 5 shows its notch curve diagram, and FIG. 6 shows its control block diagram.

When controlling power running and regenerative braking using a separately excited field electric motor, it is clear from Figure 5 that power running and regenerative brake control can be performed only by increasing or decreasing the separately excited field current. it is obvious. That is, in FIG. 5, if the speed is N ₁ and the separately excited field current is 10%, it will be at point A, and the power running current IaP ₁ will flow and power running will be performed.

Increase the separately excited field current by 50% at speed N ₁
If so, the state will be at point B, the regenerative current _IaB1 will flow, and regenerative brake control will be performed.

In this electric vehicle control device, control of the speed-reducing regenerative rake when descending on a downhill slope will be explained.

Figure 5 shows the characteristics necessary for _an electric vehicle when descending down gradients _of ^200/00 and ^300/00 .

In other words, if you try to descend a downward slope of ^200/00 at _a speed _N2 , by keeping the separately excited field current at 20%, a regenerative current _IaB2 will flow, and the acceleration force on the downward slope and the traction motor will be reduced. The resulting braking force matches, and the electric car can descend downhill at a constant speed of _N2 . Furthermore, by keeping the separately excited field current at 30%, a regenerative current _IaB3 flows, and the electric vehicle can descend at a constant speed _N2 on _a ^300/00 downward slope.

The control during slow braking will be explained in detail with reference to FIG.

A restraining brake command is issued from the driver's cab 22. Generally, the restraining brake command is given as a plurality of speed commands depending on how many km/n the driver wishes to lower the vehicle in accordance with the travel speed limit.

In FIG. 6, two commands, speed N ₂ and speed N ₃ , are shown as being given.

Assume that a restraining brake command _N2 is given from the driver's cab. As the restraining brake command _N2 is given, a command to close the main circuit current breaker 7, a separate field circuit breaker 4 closing command, and a brake control command are given, and the regenerative brake is applied to the electric vehicle. do. The regenerative braking force is commanded by the speed control command generation circuit 19 so that the separately excited field current is kept constant at 20%. When the separately excited field current is maintained at 20%, the electric vehicle is balanced at the speed N ₂ and the regenerative brake IaB ₂ shown at point C in FIG. 5, and in this state it can descend the downhill slope.

When the restraining brake command N ₃ is given from the driver's cab 22, the separately excited field current is kept constant at 30%, and the speed N ₂ and regenerative braking current IaB ₂ shown at point D in Figure 5 are increased.
You can balance yourself and descend downhill in this state. In addition, in a controlled vehicle with a regenerative brake, a brake force detector 20 is provided to perform blending control with the air brake during stop braking.

The brake force detector outputs an output during stop braking, and is cut off during slow braking.

The above control is a very common control method using a control device with a regenerative brake using a shunt motor.

Now, let's consider the case where the regenerative load disappears during the holding brake control. When there is no regenerative load, there is no regenerative current and no regenerative braking force.

Since electric cars do not have brakes, their speed increases due to the acceleration force generated by the downhill slope. Due to the increase in speed, the driver turns off the slowdown command and issues a stop brake command. The stop brake command applies air brakes to the electric vehicle, reducing the speed of the electric vehicle.

That is, in the conventional control system, when there is no regenerative load, the driver needs to confirm that there is no regenerative load and then switch the driving operation mode from holding brake to stopping brake.

Next, let's consider the case where slow brake control is performed on an electric car made up of two units.

In addition to differences in main motor characteristics and wheel diameters, differences in set values (separately excited field current 20
18% or 22% intend to set it to a constant percentage.
It can be like %. ) etc. occur. The situation in which there is a difference between the two units is shown by the notch curve in FIG.

When the unit runs alone, the balance speed of the first unit changes to balance speed N ₂₁ according to characteristic 28, and the balance speed of the second unit changes to balance speed N ₂₂ according to characteristic 29, and the balance speed changes to the target value. There is no problem except that it changes with respect to . However, when two units with different characteristics are assembled, the two units have the same co-speed. At this time, the balance state is the speed _N20 as shown in FIG. 7, and the regenerative braking current is IaB ₂₁ for the first unit and IaB ₂₂ for the second unit, so IaB ₂₁ <IaB ₂₂ . That is,
It can be seen that the burden on the first unit is light, and the burden on the second unit is heavy.

The case where this imbalance is greatest is when the regeneration circuit of either unit is turned off. (In the case of regenerative brake control, it is possible that regeneration is turned off in only one of the units in the formation due to an overvoltage limiter setting error, etc.) At this time, the load of the entire formation is borne by only the unit with a healthy regeneration circuit. It's going to happen. Stopping brake characteristics are 30
The balance speed will be N ₂₃ and the regenerative current of a healthy vehicle will increase as IaB ₂₃ .

As described above, in the conventional control system, when the vehicle is traveling by unit, the driver must switch the driving handling mode because the regenerative load is eliminated. Furthermore, when traveling in a formation of two or more units, there is a problem in that an imbalance occurs in the amount of braking force applied between the units.

[Purpose of the invention]

The purpose of the present invention is to add a simple circuit device,
To provide a control device which can lighten the burden on a driver and prevent an imbalance in braking force loads among units forming a train formation.

[Summary of the invention]

The key point of the present invention is that by specifying the braking force with the restraining brake command from the driver's cab, it is possible to automatically shift to air braking even during restraining braking when the regenerative load disappears, and the braking force of each unit in the train is changed. The aim is to keep the imbalance within a certain limit.

[Embodiments of the invention]

FIG. 1 shows a control block diagram of the present invention.

Let us explain about Figure 1. In FIG. 1, compared to FIG. 6, the restraint control command generation circuit 19 is removed, and the restraint brake command is directly given to the brake control command unit 18 by designating a brake force.

The difference is that the output of the brake force detector 20 is applied to the air brake device 25 even during slow braking, so that blending control can be performed.

A case where the speed control command _N2 is issued from the driver's cab 22 will be explained.

The main circuit circuit breaker 7 and the separately excited field circuit circuit breaker 4 are turned on and regenerative brake control is started, as in the conventional case.

A restraining brake command N ₂ (for example, brake force 200 Kg/M) from the driver's cab 22 is transmitted from the brake control command 18 to the current control command generator 17.
The electric motor control device 200 is controlled by the current command corresponding to the brake control command, and the main electric motor 300 is thereby driven to obtain a regenerative braking force equivalent to 200 kg/M.

The restraining brake command also instructs the air brake device 25 to generate an air brake force equivalent to 200 kg/M.

In the air brake device 25, the brake force detector 2
Since 0 output is given, if the regenerative braking force is produced by the blending action at a predetermined value of 200 kg/M, no air braking force will be applied.

The state of control at this time is shown in FIG.

It will be seen that when the restraining brake command N ₂ is given from the driver's cab 22, the balance is achieved at the speed N ₂ at point C.

Now, let's consider the case where there is no regenerative load. In the present invention, the regenerative brake and the air brake are controlled by blending, so even if the regenerative braking force is lost, it is automatically supplemented with the air braking force.In other words, the air brake compensates for the lack of regenerative braking force. As an electric vehicle, a constant braking force is always applied, so a balanced state is maintained.

Therefore, there is no need for the driver to switch the driving operation mode depending on the presence or absence of regenerative load.

Next, consider the imbalance between units.

In the present invention, since the braking force is specified, there is no need to consider differences in main motor characteristics and wheel diameters, and only the error in setting the control pattern of each unit appears.

Figure 2 shows the characteristics when the second unit deviates from the specified value of 200 kg/M to 220 kg/M.
The balance speed is N _2a , but the first unit is
IaB ₂₁ and the second unit are balanced in the state of IaB ₂₂ , and the unbalance of the regenerative brake current becomes a very small value. Furthermore, it can be seen that even if the regenerative circuit of the first unit is opened, the air brake force is supplemented by the first unit, and the regenerative current of the second unit, which continues regenerative brake control, remains at IaB ₂₂ .

The above description has been made for the case where the M car is alone, but if there is an accompanying car in the formation, the air brake of the T car can also be controlled to be completely released when there is sufficient regenerative load. A control block diagram when this control is performed is shown in FIG.

Compared to Figure 1, Fig. 3 shows the output of the other brake force detector, where the M car is shown as 32 and the T car is shown as 33, and the restraining brake command value, and the output of the air brake system of the T car is turned on. A comparison amplifier circuit for OFF control is provided. The comparison amplifier 26 is set to turn on and off when the regenerative braking force is several tens of percent of the commanded braking force. Of course, if the regenerative braking force is above the set value, the air braking force of the T car is turned off, and if the regenerative braking force is below the set value, the air braking force of the T car is turned on. Note that even if the comparison amount of the comparison amplifier is not the regenerative brake torque itself but the regenerative current value, the effect intended by the present invention can be obtained.

Further, although the present invention has been described with respect to a separately excited field motor, it is of course applicable to a case where speed-reducing regenerative braking is performed using a series motor, a compound motor, or an induction motor.

In the figure, 1 is a pantograph, 2 is a main circuit disconnector, 3 is an overcurrent relay, 5 is a separately excited field current control device, 6 is a traction motor separately excited field winding, and 8 is a main circuit current control device. , 9 is the main motor armature, 10 is the earthing switch, 11 is the voltage limiting resistor for the overhead line voltage detector, 1
2 is an overhead line voltage detector, 13 is a power running command circuit, 14
15 is a stop brake command circuit, 15 is a restraining brake command circuit, 16 is a circuit breaker closing command circuit for the main circuit and other excitation magnetic circuits, 17 is a current control command generation circuit, 1
8 is a brake control command circuit, 21 is a signal circuit for output ON during braking, 23 is a control current feedback signal, 24 is an air brake command signal, 25 is an air brake device, 27 is a slow braking characteristic, 3
1 is the regenerative braking force characteristic.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the burden on the driver and at the same time eliminate imbalance in the braking forces of each unit in the formation.

[Brief explanation of drawings]

FIG. 1 is a control block diagram of an embodiment of the present invention.
Fig. 2 is a notch curve diagram when controlled by the present invention, Fig. 3 is a control block diagram of another embodiment of the present invention, Fig. 4 is a main circuit connection diagram with regenerative brake control, and Fig. 5 is a notch curve. 6 is a control block diagram of the prior art, and FIG. 7 is a notch curve diagram showing differences in main motor characteristics. 6...Main motor separately excited field winding, 7...Main circuit current breaker, 8...Main circuit current control device, 9...Main motor armature, 10...Earthing switch, 13...Power running Command circuit, 14... Stop brake command circuit, 15
... Suppression brake command circuit, 16 ... Breaker closing command circuit for main circuit and externally excited field circuit, 17 ... Current control command generation circuit, 18 ... Brake control command circuit, 21 ... Output during braking ON signal circuit,
25...Air brake device, 100...Suppression brake command device, 200...Electric motor control device, 30
0... Main electric motor, 400... Air brake control device.

Claims (1)

[Scope of Claims] 1. A restraining brake control device for an electric vehicle, comprising a restraining brake command device 100, a current command generating device 17, a brake force detector 20, and an air brake control device 400, comprising: The vehicle is controlled to run by an electric motor 300 controlled by an electric motor control device 200, and uses regenerative braking as a restraint brake for descending a downhill slope. The current command generating device 17 receives the output of the restraining brake command device 100 and outputs a current command according to this command to the motor control device 200. The brake force detector 20 detects the brake force output by the electric motor 300, and the air brake control device 400 inputs the holding brake command and the output of the brake force detector 20,
When the brake force detected by the brake force detector 20 is insufficient than the restraining brake command, a signal is output to control the air brake so as to generate the brake force corresponding to the shortage. Suppression brake control device for electric vehicles. 2 Electric cars are equipped with an air brake system 2 during vehicle formation.
The air brake control device 400 outputs a signal to turn off the operation of the air brake device 25 when the output of the brake force detector 20 is equal to or higher than a predetermined value. A restraining brake control device for an electric vehicle according to claim 1.