SU1151841A1 - Device for determination of electric locomotive traction force - Google Patents

Abstract

A DEVICE FOR DETERMINING THE ELECTRIC POWER EQUIPMENT, containing a counting unit with a recorder and a speed sensor and voltage and current sensors of an electric motor connected to it, in order to improve the accuracy by processing the measurement information in a pulsed form, the speed sensor is complete In the form of an electric locomotive speed converter into a pulse frequency, and a counting-decisive block contains a stable pulse generator, a pulse frequency converter in eg ix converter current pulse duration and the voltage converter to the pulse repetition frequency which is stable through a pulse generator coupled to a current converter in the pulse width, which move through vyW recorder soy-tdiven yield transducer pulse repetition frequency in the voltage.

Description

eleven

The invention relates to a measurement technique and can be used to measure the traction or braking force generated by a direct current electric locomotive.

A device for determining locomotive tractive effort is known, containing a recorder l,

The drawbacks of the device are the complexity of its mechanical part and the need to use special coupling units.

The closest in technical essence to the present invention is a device for determining the tractive effort of an electric locomotive containing a calculating unit with a recorder and speed sensors and voltage and current sensors of an electric locomotive electric motor 2j connected to it.

A disadvantage of the known device is low accuracy.

The purpose of the invention is to improve the accuracy by processing the measurement information in pulsed form.

The goal is achieved by the fact that in the device for determining the tractive effort of an electric locomotive containing a calculating unit with a recorder and a speed sensor and voltage and current sensors of an electric locomotive motor connected to it, the speed sensor is implemented as a speed converter of an electric locomotive to a pulse frequency, and the calculating unit contains a generator of stable pulses, a frequency converter of the pulse following in voltage, a current converter in the duration of pulses and a converter pulse to pulse frequency, which through a generator of stable pulses is connected to a current-to-pulse converter, the output of which through a recorder is connected to the output of a pulse-to-voltage frequency converter.

Fig. 1 shows a block diagram of the device; Fig. 2 is a schematic diagram of the calculating unit, and Fig. 3 - diagrams of currents and voltages.

The device for determining the tractive effort of an electric locomotive contains sensors 1 and 2, respectively voltage and current of an electric motor of an electric locomotive, sensor 3 of the speed of an electric locomotive, calculating unit 4 and 18412

The horn 5, voltage sensor 1, is a resistor voltage divider. The current sensor 2 can be made in the form of an ohmic shunt, in which case it is connected to the calculating unit 4 via an operational amplifier 6.

The sensor 3 of the speed of an electric locomotive can be made in the form of two rolls of cheeks installed at a given distance i3 from each other under the body of the electric locomotive along the direction of motion with the possibility of inductive communication with inductors mounted on an iron canvas

roads are at regular intervals determined by working conditions. The power supply of the inductors can be carried out from the generator of sinusoidal oscillations.

0 frequency.

The counting unit 4 (FIG. 2) contains a generator of stable pulses 7, a converter 8 of the pulse frequency into voltage,

5 current-to-current converter 9 impulse voltage converter 10 to pulse frequency,., To the input of voltage converter 10 to the following frequency

0 pulses sensor 1 is connected

voltage, and to the output - the input of the generator 7 stable pulses, which is connected with the converter 9 current in the duration of the pulses, the input

which is connected to the operational amplifier 6, and the output through the recorder 5 is connected to the output of the converter 8 of the pulse frequency to voltage, the input of which is connected to the sensor 3 of the speed of the locomotive.

Stable pulse generator 7 includes reactor 11, capacitance 12, diode 13, thyristor 14 and

g pulse, transformer 15. The converter 8 of the pulse frequency to voltage contains a trigger 16, a transistor 17, a current regulator 18, a diode 19 and two capacitors 20 and 21.

The current-to-pulse converter 9 comprises transistors 22-24, a current stabilizer 25, diodes 26 and 27, a capacitor 28, and resistors 29-32.

The voltage converter 10 to the pulse pulse frequency comprises a dynistor 33, a pulse trans3

formator 34, capacitor 35 and resistor 36.

The device works as follows.

The voltage I from the output of the voltage sensor 1 through the resistor 36 is supplied to the capacitor 35. As a result, the capacitor 35 also charges the voltage Up, on it according to the diagram in FIG. 3 is increased to a value equal to the switching voltage of the dynistor 33. The dynistor unlocking generates a current ij, which enters the thyristor control transition circuit 14 via a pulse transformer 34. When the thyristor 14 is unlocked, transistors 23 and 24 are locked, and transistor 22 is unlocked by negative the half-wave voltage Od on the secondary winding of the pulse transformer 15, the duration of which is equal to the period To the natural oscillations of the circuit formed by the capacitor 12 and the reactor 11. at this time The switch 28 is charged to a voltage (proportional to the current of the motors 3.

After completion of the oscillation cycle of circuit C 12, 11, voltage Uq on diode 13 and thyristor 14 is restored, and a positive voltage is applied to resistors 24 and 23 through resistors 31 and 32. At the same time, transistor 24 unlocks current i- Li. The transistor 23 remains locked under the influence of negative voltage on the capacitor 28. The transistor 23 will be in the locked state until the capacitor 28 is discharged. After the discharge of the latter, the transistor 23 opens and loses the current -i through the recorder 5 and the resistor 30.

Under the action of the electric locomotive speed sensor 3, the voltage on the capacitor 21, equal to the maximum voltage value on the capacitor 20, varies directly proportional to the duration of the negative pulse at the base of transistor 17 and the time interval ui: between the pulses generated by the electric locomotive speed sensor 3.

The magnitude of the voltage on the capacitor 21 in the device in question is determined by the expression

151841

vt

U - 3

w 8 sgo

where About ft - the current at the output of the stabilizer 18 current ut the time interval between

impulses generated by the sensor 3 speed locomotive;

 - capacitor capacitance 20. The current through the recorder 5 in the proposed device can be determined by the formula

Icr ,,. It

. {t

(2)

h 7

where f is the pulse repetition frequency

unlock thyristor 14; TC - current pulse duration

through the recorder 5 and transistor 24;

 the resistance of the resistor 30. The pulse repetition frequency of the current A of the device thyristor 14 is determined

at

s

(3)

G7er)

(J

Where

- output voltage

1I sensor

one

pep - switching voltage

dynistor 20,

35 capacitor capacitance 35J resistor resistance

36

The duration of the current pulse through the recorder 5 devices can be determined by the formula

t, t (four)

st

25

where TQ is the period of natural oscillations

the circuit containing the capacitor 12 and the reactor 11, 3 - the current at the output of the sensor 2 or the operational amplifier 6

with the output of the stabilizer 25 current.

Substituting vfazheni (3) and (4) in formula 2, we get

-Tc

STG

i-z-bt

s

I (,, o-M6 -

or

IcT, 8, Mr.-7G

 r1. .with .,(}

SG25 er 3fe W

where is the capacitance of the capacitor 12/4, is the inductance of the reactor

eleven.

From expressions (5) and (6) it follows that the current through the recorder 5 of the device is proportional to the product of voltage, current and time interval at the outputs of sensors 1-3 and is directly proportional to the force generated by the electric locomotive, since

U.I-7-ut

., () -ir

where F is the thrust force of the electric locomotive, it is the time interval for which the electric locomotive will move on the path .IS (distance between the coils of the speed sensor);

U is the voltage across the motors x 3 is the current through the engines of the locomotive.

Thus, the implementation of the invention makes it possible to increase the accuracy of determining the tractive effort of an electric locomotive and to enable the automation of control of an electric locomotive both in and in regenerative braking mode.

Sch1

"

S

Q

one

h

Claims (1)

DEVICE FOR DETERMINING THE ELECTRIC Locomotive Traction Force, comprising a counting and decisive unit with a registrar and connected to it a speed sensor and voltage and current sensors of an electric locomotive electric motor, characterized in that, in order to increase accuracy by processing the measurement information in pulsed form, the speed sensor is made in the form a converter of the speed of an electric locomotive to a pulse repetition rate, and the counting-decisive block contains a stable pulse generator, a pulse repetition rate converter in voltage Converter current pulse duration and the voltage converter to the pulse repetition frequency which is stable over the pulse generator is connected to a current converter in pulse duration, output of which through a recorder connected to the output pulse frequency-to-voltage converter. 1 1151841 2