SU651988A1 - Apparatus for automatic control of braking effort of electric rolling stock - Google Patents

Description

This invention relates to the field of electric rolling control with electric braking.

A device for automatically controlling the braking force of an electric rolling stock is known, which contains T-motors for the independent excitation of direct current; The independent excitation windings of which are connected in series and connected to the rectifying installation, and the main windings of the motors are connected in series with the brake resistors. The current sensors of korea are connected via an OR gate to one of the inputs of the comparison element, the current signal of the core, the output of which is connected via the phase regulator to the input of the rectifying excitation unit, the current sensor is excited and connected through a functional converter to the input of the specified comparison element byKty MtypWr braking force from stopping and pre-braking setting devices on rectifying bridges, choosing the maximum one. From incoming signals, signal setting device and speed sensor awns

connected to a signal element by a speed that has a transistor amplifier, and if the given speed is greater than the real one, then the output transistor is open and fully compensates for the signal that sets the braking force, and the braking force is zero.

At a given speed equal to zero. Braking takes place with a maximum force up to a stop, since in this case the output transistor of the reference element is closed all the time. When the actual speed is greater than the set one, the braking is carried out only up to a given speed of movement, and then the braking force decreases to zero 1. The disadvantage of this device is that undesirable reactions occur in areas with a complex profile of the track in the train’s automatic couplings which may, under certain unfavorable conditions, lead to the hatching of the composition. This is explained by the fact that when the locomotive leaves the slope to the site, due to the equality of the actual and set speed and

no rolling force, the resilient braking system resets the braking force to zero. In this case, the coupling is weakened and the composition is stretched. During the transition of the electric locomotive to the subsequent slope, first the composition accelerates, then the rheostatic brake is activated, and, due to the railing of the rear cars, there are sharp dynamic shocks in front of the train.

The purpose of the invention is to increase the smoothness of the change in braking force in a wide range of speeds.

This goal is achieved by the fact that a transistor amplifier is connected between the braking force adjuster and the current comparison element of the core current, and a sensor and a speed reference are connected to the comparison element at the input of the amplifier.

The diagram shows a device for automatic control of the braking force of an electric locomotive VL-8OT.

Anchors of traction motors 1, 2, 3, 4 are connected to individual unregulated brake resistors 5, 6, 7, 8. The windings of independent excitation 9, 10, 11, 12 are interconnected in series and connected to the output of the rectifier excitation unit 13. In The main circuits of each motor include current sensors 14, 15, 16, 17. The outputs of these sensors are connected to the input of the logic element OR 18. The output of the element OR is connected to the first input of the element of the signal comparison 19. The excitation current sensor 20, which serves to feed back feedback excitation current , Connected in series with field windings. The output of the excitation current sensor is connected to the input of the functional converter 21, the output of which is connected to the second input of the reference element 19. The third input of the comparison element is connected to the outputs of the setpoint brake force 22 through a rectifying bridge 23 and the collector circuit of the transistor 24. The pre-braking unit 25 through the rectifier the bridge 26 is also connected to the third input of the signal comparison element, the output of which includes a phase regulator 27. The value, proportional to a given speed, is allocated on the resistor 28, which ory connected to the output speed set point 29. The magnitude proportional to the actual velocity, is allocated to the resistor 30 which is connected to the output speed sensor 31.

The device for automatic regulation of the braking force operates in two modes: in the mode of stopping braking and in the mode of stabilizing the speed on the descent. In the stop braking mode, the speed setpoint is 0. The brake knob of the controller is first set to the pre-brake position, and then, after some time has passed, it is switched to the braking mode. At the same time, the brake brake force setting device 22 is switched on. Since the signal from the setpoint speed is O, the transistor 24 will always be opened by a signal from the speed sensor and the input of the comparison element 19 will receive the maximum of two signals (from the setpoint brake force 22 and the setpoint pre-brake 25). The selection of the maximum of two signals is produced by the OR element, which is formed from two bridges 23 and 26 when the transistor 24 is open. The signal from the converter 21 arrives at the other input of the comparison element. The function converter converts the signal from the excitation current sensor to voltage. from the field current in such a way that, when it is algebraically summed with the setpoint voltage of the braking force, a voltage is obtained that is proportional to the specified value of the current, cor. The first input of the comparison element receives a signal from the current sensor cor. In the comparison element, depending on the incoming signals, a signal is generated, the magnitude of which determines the phase of the output signal of the phase regulator 27. This signal is fed to the control electrodes of the thyristors of the excitation unit 13. The phase of the control pulse will be such as to provide the corresponding excitation current and current cor according to the characteristic of the functional converter. The target brake will be maintained almost to a complete stop.

Claims (1)

If, however, the driving mode provides for stabilization of the speed on the descent, then a certain amount of speed of movement is set by the speed adjuster. As long as the target speed is less than the actual speed, the braking process will proceed as described above. But as soon as the actual speed becomes lower, the set one, the transistor 24 will close and turn off the brake force adjuster. The braking force drops, but not to zero, but to the level of the pre-braking value, ensuring the composition is kept in a compressed state. As soon as the composition starts to accelerate again (which may be at the transition to a new slope) and, therefore, the actual speed of movement will become greater than the set speed, the transistor opens with a signal from the speed sensor. When the transistor is open, the bridges 23 and 26 form an OR circuit, the input of which receives signals from the setpoint of braking force and from the setpoint of preliminary braking, and the larger one appears at the output. This large signal will be the signal from the brake force adjuster. Braking force will increase to the target. But it will increase not from zero, but from levels of preliminary braking. Thus, the composition will be in a compressed state regardless of the ratio of speeds and, therefore, undesirable reactions in the train's automatic couplings when moving along a pealing profile. The invention The device for automatic control of the braking force of an electric rolling stock during electric braking, contains DC traction motors, the main windings of which are connected with brake resistors in series, and the field windings are connected in series and connected to the rectifier installation of the excitation unit, the braking force of the stopping and preliminary braking, to the output of which rectifying bridges are connected, setpoint adjuster and speed sensor are connected to the elem. This compares signals with a speed having a transistor amplifier, Korean current sensors connected via an OR element to one of the inputs of a current signal comparison element, the core, the output of which is connected through a phase controller to the input of a rectifier excitation unit, an excitation current sensor connected via a functional Converter to another input of the specified element of the comparison of the current of the core, characterized in that, in order to increase the smoothness of the change in braking force in a wide range of speeds, A transistor amplifier is connected between the braking force adjuster and the element comparing signals to the current of the core, and a sensor and a speed controller are connected to the comparison element at the input of the amplifier. Sources of information taken into account in the examination I. Electrical and thermal performance, “Transport, No. 6, 1972, p. 20-25. Jf