SU1393672A1 - Apparatus for electrodynamic braking of rail vehicles - Google Patents

Abstract

The invention relates to electrical engineering, in particular to a direct current drive, and can be applied to electric vehicles. The purpose of the invention is to increase reliability. In the mode of electric braking, self-excitation of the traction motors occurs and rheostatic braking is performed. If the EMF of the traction motors exceeds the voltage of the power supply source 16, the recovery diode 15 is opened and the regenerative-stopping braking mode is implemented. At the same time, during the whole period of braking, the excitation current of the traction motors is controlled by varying the resistance of the braking resistor 1, which provides the braking force in a wide range of braking speed. When the rolling stock speed decreases, when the EMF of the traction motors becomes less than the voltage of the power supply source 16, the recovery diode 15 is closed and a rheostatic braking mode is implemented. If the insulation breaks at the junction point of the windings 8 and 9 of Korea and 6 and 7 of the excitation of traction motors, a short circuit opens and the high-speed contactor 10 is opened, the limiting resistor 11 and the primary winding of the pulse transformer 12 are introduced into the circuit of the generating Korean traction motors. the secondary winding of the pulse transformer 12 forms a triggering pulse on the thyristor 13, which is unlocked and forms a softening circuit of the windings 4.5 of the motor korya excitation of the motors and a loop of the current decay of the windings 8.9 excitation. . 1 il. SP

Description

The invention relates to electro.

technology, in particular for electric drive-I do DC, and can be used on an electrically movable device.

The purpose of the invention is to increase reliability.

The drawing shows a schematic diagram of the proposed device.

The device contains a braking resistor 1, included: between the connection point of the windings 4 and 5 of the armature 2 and 3 of the excitation of the first group of motors 15 and the connection point of the windings 8 and 9! anchors 6 and 7 of the excitation of the second group of traction motors, fast-speed; smell a contactor 10, one contact of which is connected to a limiting resistor 11 connected to a pulse transformer 12 connected to a control electrode of a thyristor 13 connected to an additional resistor 14 connected to the cathode of a recovery diode 25 15 connected to a power supply 16.

The device operates as follows.

At the initial moment of braking, self-excitation of the traction motors occurs. In this case, the current of the windings of the anchors 2 and 3 of the first group of traction motors increases through the windings 8 and 9 of the excitation of the second group of traction 25 engines, and the current of the windings of the anchors 6 and 7 of the second group of traction motors increases through the windings of 4 and 5 of the excitation of the first group of traction motors And through closed high-speed dd contactor 10. The current of both groups of traction motors flows through the braking resistor and rheostatic Braking is implemented.

If the EMF of the traction motors exceeds the voltage of the power source 16, then the recovery diode 15 is unlocked and the regenerative-rheostatic braking mode is implemented. In this case, the recovery current 1p flows through the circuit: the beginning of the windings of the anchors 2 and 3 - an additional resistor 14 - diode 15 of the recovery, the walkie-talkie - the source 16 of the power supply - a high-speed contactor 10 - the windings of the Anchors 6 and 7 - the braking resistor 1 The end of the windings of the anchors 2 and 3 , The excitation current of $ 1 _B flows through the circuit: the beginning of the windings of the anchors 2 and 3 (6 and 7) of the first (second) group of traction motors - the windings 8 and 9 (4 and 5) of the excitation of the second (first) group of traction motors .

A current flowing through the braking resistor I is equal to the sum of the excitation currents 1 _{& of} both drive traction motors and 1p recovery.

In the steady state, the electromagnetic processes in the device circuits are described by the system of equations 2E = (Ip + I _ft ) 2R ₄ + I _e 2R _e + (I _P + 2I _B ) R _r ; 4E = (Ip + 2I _e ) R _r + (Ip + I _e ) 4R _s + IpR + U;

I _T ^S I _F + I _e (1) where U is the voltage of the power source 16;

E - EMF rotation of one engine;

RjjjRg is the active resistance of the armature windings and the excitation of one traction motor, respectively;

R _T , R - resistance of the braking and additional resistors.

The dependence of the excitation current on the main parameters of the device from (1) has the form

-g = (R-Rt) ^e R + R _T + 4R _e ^{5 1} 'and the velocities ν- Ir (R _T + 2R _A ) + I _e , (R _T + 2R _B ) 2СФ' ^k 'where Ф is magnetic excitation flow;

C is a constant depending on engine parameters.

Maintaining the braking force, and therefore the braking current during the entire braking period, is carried out by reducing the resistance of the braking resistor 1 in proportion to the speed. Thus, as seen from (2) simultaneous excitation current control 1 _and the minimum value corresponding to the fully inserted braking resistor 1 to a maximum value corresponding to the minimum value of the braking resistor 1, which provides a constant braking force over a wide range of braking velocity.

With a decrease in the speed of the rolling stock, when the EMF of the traction motors becomes lower than the voltage of the power source 16, the recovery diode 15 is locked and rheostatic braking is performed.

Insulation failure at the junction point of windings 8 and 9 of anchors 6 and 7 of the excitation of the second group of traction motors forms a short circuit of the armature current: the beginning of the armature windings 6 and 7 - the negative terminal of the power supply 16 - contactor 10 - the end of the armature windings 6 and 7. With increasing short-circuit current, the high-speed contactor 10 opens, and a limiting resistor 11 and the primary winding of the pulse transformer 12 are introduced into the circuit of the generating windings of the anchors 6 and 7 of the traction motors. On the secondary winding of the pulse transformer and 12, an unlocking pulse 15 is formed on the thyristor 13, which opens and forms the demagnetization circuit of the windings 4 and 5. Excitation by the current of the windings of the armature 2 and 3 of the traction motors: the beginning of the armature windings 2 and 20 3 - the thyristor 13 - the windings 4 and 5 of the excitation - the end of the windings anchors 2 and 3,. and also the circuit for decreasing the current of the windings and 7 excitations through the negative terminal of the power supply and the junction point 25 of the windings of the armature 6 and 7 of the excitation of the second group of traction motors.

Claims (1)

The claims ι „30 Device for electrodynamic braking of rolling stock, containing two groups of traction motors, a power source and a braking resistor, included by the method of dots. connecting the armature windings and subsequently connected field windings of the first and second groups of traction motors, while the beginning of the armature windings of the first group of traction motors is connected to the beginning of the excitation windings of the second group of traction motors, characterized in that, in order to increase reliability, it is equipped a high-speed contactor, limiting the resistor, a pulse transformer and a circuit from a series-connected recovery diode, an additional resistor and a thyristor, the cathode of the recovery diode connected to one of the poles of the power source, and the common connection point of the additional resistor and the thyristor anode is connected to the beginning of the armature windings of the first group of traction motors, the end of the excitation windings of which is connected to one of the contacts of the high-speed contactor, the other pole of the power source and to the cathode of the thyristor, to the control electrode of which is connected to the secondary winding of a pulse transformer, the primary winding of which is connected by one output to one of the contacts of a high-speed contactor, and d another conclusion through the limiting resistor - with the common point of connection of another contact of the high-speed contactor and the end of the windings of the anchors of the second group of traction motors.