SU1553416A1 - Device for braking independent vehicle with dc electric drive - Google Patents

Abstract

FIELD: transport. The purpose of the invention is to increase efficiency and reliability. A traction generator 1 with excitation winding 1.1 and core winding 1.2 is rotated by a heat engine, such as a diesel engine. The traction motor 2 with the excitation winding 2.1 and the winding 2.2 bp when braking the vehicle operates in generator mode. The winding 1.2 of the generator 1 generator is connected to its winding 2.2 through the braking resistor 3. The braking current is set by the setting device 7 and is maintained by the constant regulator 5 of the excitation current according to the comparison result in the comparison element 6 with the actual value from the current sensor 8. The frequency of rotation of generator 1 depends on the frequency of rotation of the diesel and is set by its regulator. Depending on the actual rotation frequency of the generator 1, measured by the sensor 9, the excitation current of the traction generator for its operation in motor mode is maintained by means of functional converters 10 and 11 of the comparison element 12 and the current regulator 4. As a result, part of the braking energy is used to cover the loads of the own needs of the heat engine. 6 Il.

Description

Phage.1

This invention relates to transport, in particular, to devices for braking autonomous vehicles with direct current electric drives.

The purpose of the invention is to increase efficiency and reliability.

Figure 1 shows the functional diagram of the device; JQ in figure 2 - characteristic diesel; on fig.Z - characteristic of one of the functional transducers; Fig. 4 is an electrical circuit of one of the functional transducers 15 on the example of one of the specific embodiments; on fig.Z - characteristic of another functional converter; 6 is an electrical schematic diagram of another functional converter using the example of one of the specific embodiments.

The device (Fig. 1) contains a traction generator 1 driven by a heat engine, for example, a 25 diesel engine (not shown), and having an excitation winding 1.1 and a main winding 1.2, and a traction motor 2 also having an excitation winding 2.1 and a root winding 2.2. -JQ Their core windings 1.2 and 2.2 are connected via a braking resistor 3. The excitation windings 1.1 and 2.1 are connected to the regulators 4 and 5 of the excitation current. Element 6 is a comparison of sub-keys with an output to the input of current regulator 5, one input to current setting device 7, and another input to current sensor 8. The sensor 9 of the rotational speed of the generator 1 is connected to the inputs of the functional transducers 10 and 11. The output of the converter 1.0 is connected to the third input of the comparison element b. The output of the converter 11 is connected to one of the inputs of the comparison element 45 T2, the other input of which is connected via the valve 13 to the output of the comparison element 6.

The characteristic of a diesel engine (Fig. 2) is represented by the curve a, which expresses the dependence of the moment M on the shaft of the diesel engine on the frequency of its rotation. Values Could and S0OGr limit the range of operation of a diesel engine when the generator is operating in motor mode.

The characteristic of functional converter 11 (Fig. 3) is represented by curve b, which displays the dependence of the output voltage.

UBblXi (from the voltage U 6) m at its input.

A converter 11 (FIG. 4) is provided on an amplifier 14, resistors 15-18, a zener diode 19, and a power source 20.

The characteristic of the functional converter 10 (FIG. 3) is represented by a curve in which displays the dependence of the output voltage. from the voltage U I1 at its input.

The Converter 10 (6) is made on the resistor 21 and the Zener diode 22.

The device works as follows.

When the driver presses the brake pedal, a signal appears at the output of the setting device 7, which provides the excitation current of the electric motor 2 at the output of the regulator 5. As the vehicle moves, the engine 2 rotates, developing an emf that together with the emf of the generator 1 determines the current in the circuit: winding 22 core of electric motor 2 - core winding 1.2 of generator 1 - current sensor 8 - brake resistor 3. This current is opposite in direction to the current of the traction mode due to the fact that the EMF of the electric motor 2 exceeds the EMF of generator 1.

The motor current 2 is maintained at a predetermined level due to negative current feedback, the signal from sensor 8 is compared with a predetermined signal in element 6. Signal mismatch is amplified by regulator 5, which has a large gain factor. The output of regulator 5 determines the excitation current, the emf and the winding current 22 of the core of the electric motor 2. Therefore, the error cannot be large until the magnetic circuits of the electric motor 2 are saturated. The output signal of the reference element 12 is the difference between the functional converter signal 11 and the error signal arriving at the input of the element 12 through the valve 3,

The signal at the output of the element 12 provides the maximum excitation current of the generator 1 by means of the regulator 2. The generator 1 develops the motor torque, and the rotational speed of the diesel generator exceeds

set in the diesel controller, which leads to automatic shutdown of the fuel supply. The preset rotational frequency in the diesel engine is determined by the position of the pedal to control the traction mode. Diesel and own vehicle loads are then rotated by generator 1 operating in the engine sector.

in

mode, which corresponds to the work of the second square (figure 2) of the mechanical characteristics of the diesel. When exceeding the frequency of rotation of the diesel value

The output signal of the functional converter 11 decreases (FIG. 10), which reduces the excitation of the generator 1, decreases the engine torque of the generator 1 and limits the frequency of rotation of the diesel. If the frequency of rotation of diesel 1 exceeds W0rp (FIG. 4), then the signal at the output of the functional converter 10, which reduces the signal at the output of the regulator 5 of the excitation current of the electric motor 2, limits the emf of the electric motor 2 and the current, and hence the motor torque of the generator I. If the error is between the sensor signal 7 and the feedback signal of sensor 8 become large and positive (due to saturation of the magnetic circuit of the electric motor at low speeds, for example), the passage through the valve 13, the error signal reduces the excitation of the generator 1 using controller 2. At the signal mismatch

5534166

control signal 2, which can lead to an over-speed of the diesel generator 1.

The proposed device makes it possible to use the energy reserve of the braking vehicle for its own needs, which, without the expense of fuel, ensures the operation of the units and systems.

ten

15

20

25

thirty

35

The device simplifies the scheme of the power circuits of electrotransmission during braking, allows to expand the range of regulation of the braking current at low speeds of movement. The device allows a smooth transition from the thrust mode to the deceleration mode due to a change in the excitation currents.

Claims (1)

Invention Formula A device for braking an autonomous vehicle with a direct current traction motor, comprising an excitation current regulator connected by an output to the excitation winding of a traction generator driven by a heat engine, the root of which is connected via a braking resistor to the winding of the motor, Comparison element, one input of which is connected to the current sensor of the main winding of the traction motor, and the other input to the setting device, characterized in that, in order to increase efficiency and reliability, it is equipped with a date 45 The higher the signal from the output of the rotational speed of the generator, the converter 11, the regulator 2 changes the direction of the excitation current of the generator 1, which leads to the transfer of the generator 1 to the generator mode. The diesel is loaded with generator 1, reduces its rotational speed and goes into fuel-fed mode (the first square of the mechanical characteristic of Fig. 2). In this case, the set value of the braking current is maintained by the generator 1 with the help of the controller 2 at a level lower than the value specified by the sensor 7 by the magnitude of the signal from the output of the function converter 11. Valve 13 prevents negative mismatch from passing to adder 12 and exceeding input 50 55 functional converters. a valve, an additional element of comparison and an additional current regulator, connected by an output to the excitation winding of the traction motor, and by an input to the output of the comparison element and through a valve to one of the inputs of the additional reference element, the other input which is connected to the output of one of functional converters, and the output - with the regulator input of the excitation days, while the inputs of one and the other functional converters are connected to the sensor of the rotation frequency of the thrust generator, and the output of the other functional the third converter to the third input of the comparison element. tick generator frequency, functional converters. a valve, an additional element of comparison and an additional current regulator, connected by an output to the excitation winding of the traction motor, and by an input to the output of a comparison element and through a valve to one of the inputs of an additional comparison element, the other input of which is connected to the output of one of the functional converters, and the output is connected to the input of the excitation controller, while the inputs of one and the other functional transducers are connected to the rotation frequency sensor of the traction generator, and the output of the other function the transducer to the third input of the reference element. N Oh CJ,  orp CO, / V q VTN  X  # Wy (Ogr Fig.Z Фа2.2 m Unum W & sixteen 15 U8M1 Uvsh1 -0 if