JPS60148302A - Brake control device for electric vehicles - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in a braking system for an electric vehicle, and particularly to a braking system suitable for an induction motor type electric vehicle.

[Background of the invention]

Recently, in order to increase the regenerative power of electric vehicles, braking force has been generated close to the limit of the adhesive performance of electric vehicles (
Not only 'prail cars' but also trailer cars.
Brake control systems that also bear the braking force of vehicles (N Cars) have come to be adopted. FIG. 1 shows a conceptual diagram of the above-mentioned brake control system. The horizontal axis is the brake command and the vertical axis is the brake torque. For example, one electric vehicle (Motor Car), one accompanying vehicle (Train)
Car) Let us express the brake control method for one MT train. Here, TM represents the relationship between the brake command and brake torque of the electric vehicle, and TT represents the relationship between the brake command and brake torque of the accompanying vehicle. The brake force of the electric vehicle alone is used to decelerate the vehicle up to the maximum braking force that can be covered by the Tsumushimi vehicle, and if an even larger brake command is received, the supplementary amount is covered by the air brake force of the accompanying vehicle. It is a method. In this way, the electric braking force of the electric vehicle can be used effectively, and if a regenerative brake is used as the electric brake, the regenerative power can be increased.

However, in the case of a regenerative electric vehicle, it is not always possible to control it with the characteristics shown in FIG. This is because the regenerated power of an electric car will increase the overhead line voltage more than necessary if there is no load car to consume the regenerated power at that time, so the electric braking force has to be generated according to the power consumption of the load car. This is because you don't get it.

Therefore, even in the brake control system having the characteristics shown in FIG. 1, if the regenerative brake torque cannot be generated in accordance with the brake command, it is necessary to supplement the torque with air brake force. At this time, if a plurality of electric brake control systems are provided independently, the wheels of the electric vehicle may slip.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to prevent wheel slippage in an electric vehicle configured to compensate for the lack of electric brakes with mechanical brakes.

[Summary of the invention]

The present invention is characterized in that the electric brake force of at least one of the plurality of electric brake control systems is detected, and the brake force of the other electric brake control system is adjusted in accordance with the detected force.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram schematically showing the entire braking system for an electric vehicle according to the present invention.

In an MT formation consisting of an electric vehicle 1 and an accompanying vehicle 2, two types of control devices, a first control device 3 and a second control device 4, are connected to drive wheels 5, 6, and 7.8, respectively. This shows the case of controlling a motor.

It is also assumed that the brake control method is controlled according to the characteristics shown in FIG. In this case as well, when the electric brake force cannot be generated in accordance with the brake command, supplementary force is provided by the air brake, but the disadvantages when this air brake force extends to the electric vehicle will be explained. Since the brake pedal is controlled by two separate controllers, there is usually a difference in the braking force of the two controllers. If the supplementary air brakes are applied uniformly to each driving wheel in this state, there is a risk that the wheels on which a large electric braking force is acting may slip. In particular, when the load is low during regeneration and sufficient electric brake force cannot be generated, control is performed to reduce the electric brake force according to the overhead line voltage, but the amount of reduction of the electric brake force with respect to this overhead line voltage is extremely steep. Therefore, there is actually a large difference in electric and mechanical braking forces between the two control devices. For example, if the overhead line voltage is 750V, the electric brake force will start to be reduced when the overhead line voltage during regeneration is about 850V.
Although the electric brake is controlled to be completely braked at about 900V, there is a risk that the electric brake force will be unbalanced because the overhead wire voltage detection device usually has an error of 1% or more. Tsumashi, even though one control device is outputting full electric brake force, the other control device has 66%.
In some cases, only the electric braking force of If the air braking force is supplemented in such a state, a large braking force will be applied to the wheels on which the electric braking force is fully applied, and the adhesion coefficient between the wheels and the rail will be exceeded, causing the vehicle to skid. It's put away.

Therefore, as shown in FIG. 2, the electric brake force signals EBI and EB2 are transmitted between the control device 3 and the control device 4.
Take the ya υ. At this time, assuming that the electric brake force of the control device 3 is T1, the electric brake force of the control device 4 is T2, and the speed of the train is V, the regenerated electric powers R and P can be expressed by the following equations.

几P=K (T 1 + T 2 ) V Here, K is a proportionality constant. At this time, the regenerated power can be considered as the power consumption of other electric vehicles that are the load at that time, so the regenerative power can be fully utilized by controlling the electric brake force to the average value of the electric brake forces T1 and T2. It is possible to generate electric power in 10 seconds, and it is also possible to equalize the electric braking force of the two control devices.

FIG. 3 shows an embodiment in which the braking system shown in FIG. 2 is applied to an inverter device that controls an induction motor. The induction motors 9 to 12 drive the driving wheels 5 to 8 shown in FIG. , , 11 and 12 are controlled to be supplied with power by the control device 4. Each of the control devices 3 and 4 includes PWM inverter control devices 13 and 14, respectively, which will be described later in FIG.

The brake command B applied to the terminal 15 is applied to the PWM inverter control devices 13 and 14 via calculation units 16 and 17, respectively, thereby configuring two sets of regenerative brake control systems. The braking force generated by each brake control system is detected electrically. That is, motor currents IMI and IM2,
Motor voltages EMI and EM2 are detected, respectively, and generated brake force signals J', B1 and EB2 are obtained by brake force calculation units 18 and 19, respectively. These brake force signals FBI and EB2 are added by an adder 20.21, and further, an average value calculation unit 22.23 calculates the average brake force of both systems.

The calculation units 16 and 17 input the above-mentioned brake force command and the average brake force signal, and calculate brake commands DPI and Bp2 for equalizing the brake forces generated in both systems, and output them to the PWM inverter control device 13.14. This is what is input to.

Figure 4 shows the PWM control device 13 in Figure 3.
(or 14) is a configuration diagram. The current and slip frequency pattern generating section 24 inputs the brake command Bp+ (t or BF2) and outputs a current pattern Ip and a slip frequency turn fsp in accordance with the brake command Bp+ (t or BF2). The current pattern Ip is compared with the motor current IN and their deviation Δ
The IM is applied to a current control system that adjusts the frequency.

The overall frequency command f adjusted by this current control system
s is subtracted from the vehicle speed signal f during regenerative braking. As a result, the frequency command fXNV of 25 is set.

On the other hand, in this example, the output voltage V of the inverter is controlled in proportion to the frequency. That is, the frequency command flNI of the inverter is set to V/f constant (the modulation degree command γ of the inverter is calculated through the D calculation section 26. The frequency command fINV and the modulation degree command γ are input to the PWM modulation modulator 27, and 25 is controlled by pulse width modulation. Reference numeral 28 is a DC overhead wire, and 29 is a pantograph.

Therefore, the induction motors 9 and 10 connected to the inverter 25 generate regenerative braking force commensurate with the brake command Bpl.

It is desirable to detect the speed signal f of the vehicle by attaching a speed detector 31 to the trailing wheel 30, which has no risk of skidding.

FIG. 5 shows another embodiment of the present invention in comparison with FIG. 2, in which the electric brake force signal EB2 from the control device 4 is transmitted to the control device 3, and the control device 3 transmits the electric brake force signal E
It is controlled to output the same electric brake force as B2. Even in this case, it is possible to make the electric braking forces of the two control devices equal.

FIG. 6 shows the application of FIG. 5 to an inverter device for controlling an induction motor in comparison with FIG. 3. The electric brake force signal EB2 from the second control device 4 is transmitted to the calculation unit 1.
6 to the first PWM inverter control device 13 to equalize the braking forces generated in both systems.

As described above, according to this embodiment, even in an induction motor type electric vehicle where it is difficult to supply power from a single inverter to a large number of induction motors that drive the driving wheels of an electric vehicle, there is a low possibility of skidding during braking. A brake method can be provided.

〔Effect of the invention〕

As explained above, by applying the present invention, when two control devices are controlled by one air brake control system, it is possible to prevent skidding caused by an imbalance in the electric brake forces of the two control devices. Therefore, it is possible to provide a braking system for electric vehicles that provides a comfortable ride.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a braking system for an electric vehicle suitable for applying the present invention, FIGS. 2, 3, and 4 are examples of the present invention, and FIGS. 5 and 6 are illustrations of the present invention. It is a block diagram which shows another Example of. DESCRIPTION OF SYMBOLS 1... Electric vehicle, 2... Accompanying vehicle, 3... First electric brake control device, 4... Second electric brake control device. Agent Patent Attorney Akio Takahashi Chapter 10 Section 2 (2) Section 3 (2)

Claims (1)

[Claims] 1. In an electric car that compensates for the lack of electric brakes with mechanical brakes, the electric brake force generated by a plurality of electric brake control systems and at least one electric brake control system is detected. A braking system for an electric vehicle that includes a means and a means for adjusting the braking force of the other electric brake control system according to the detected force. 2. Claim 1, wherein the electric brake control system is a braking system for electric vehicles that includes an inverter and an induction motor connected to the inverter.