SU751673A1 - Apparatus for stabilizing the rotation frequency of electric drive at rheostatic braking - Google Patents

Description

The outputs and inputs of the adder are connected respectively to the input of the excitation current controller and the outputs of 3anoMjnia elements and current sensors of the core and excitation windings, and the ground of the non-switch is connected between the outputs of the current sensors and the inputs of the corresponding storage elements and between the output of the setting element of the minimum of the braking moment and the input of the element of the comparison of the channel of limiting the braking moment, and the deputy the whip is between the output of the master element of the braking torque maximum and the input of the said comparison element and between the output of the adder and the input of the field current regulator.

The drawing shows a functional diagram of the device for stabilizing the frequency of rotation of the electric drive during resistive braking, made for the regime of resistive braking of the electron-twist mixture.

The armature 1 of the traction machines is connected to the brake resistors 2, and the excitation windings 3 are connected to the output of the excitation current controller - exciter 4. Sensors 5 of the current core and excitation windings 6 are connected respectively to the selective element 7 and agree to the element 8. Element 7 is directly connected to the inputs of the elements 9 and 10 of the comparison and through the contact 11 of the non-switch of the braking modes - to the input of the recording element 12 of the current box. The element 8 is connected directly to the input of the comparison element 13 and through the non-switch mode contact 14 is decelerated - to the memory element 15 of the excitation current. The outputs of elements 10 and 13 compare the keys to the input of the element 16 comparing the differences between the recorded and current values of the currents, the output of which is connected to the driver 4 through the contact 17 of the deceleration mode switch. The output of the element 9 compares to the second input of the driver 4. The elements of comparison 10, 13, 16 form an adder.

A signal proportional to the currents / koreas enters the control unit from sensor 5 through element 7, the output of which is the discharge of Ua proportional to the largest of the currents / d. The excitation current / V is measured by sensor 6 and supplied to the device through element 8, in which it is converted into voltage U proportional to current / in. The incidence U in the comparison element 9 is compared with the output voltage of one of the driver elements 18 or 19. The incision with the rear. the outputs are fed to the input of element 9 through the contacts of the two-lane braking mode switch, shown in

the drawing in the position corresponding to the mode of stabilization of the rotation frequency of the traction gear. The manifestation of Ly. The output of the comparison element 9 is applied to the input of the exciter 4 and provides a change in the current 1 c to the value, and with which .n. L / hell value. Element 19 can be formed so that the braking torque or all rotational frequencies of the drive and the driver do not exceed the required limits and element 18 so that the braking torque corresponds to the minimum necessary for fixing the corresponding values of the currents / and / in. This causes the drive to overload in the mode of stabilizing the rotational frequency and provides the necessary mode of operation in the process and intermittent switching on.

In the preliminary braking mode, the resulting signal by contact 17 is disconnected from the input of the exciter 4, and in elements 8, 10, 12, 13, 15, 16 the information necessary for stabilization is accumulated;

rotational speed and the required level. In the mode of pre-preloading braking, 6 6 is fed through pin 11 to the input of the storage element 12 1 a core, the output of which is like ground until the 1st

is preserved for example. φ, equal to the input voltage at the moment of opening the contact 11. In the element 10, a comparison of the fsirovany value of the charge O ". j subtracts the current value of the voltage

b, and forming a difference DL, is given to the input of the comparison element 16. Elements 8, 15, 13 form a similar contour of comparison, the input signal for which is the value of the shock current. It is obvious that in the mode of preliminary deceleration and closed contacts And 14, the values of D0 and Db are zero. Therefore, the zero is the output of L / y, f the output of the element 16 comparing the difference of currents.

However, in transient modes, the possible voltage deviations & U, i and D (UV from the pool, and therefore it is advisable to disconnect the output voltage of the element 16 from the exciter 4 in all modes, except for the stabilization of the frequency of rotation, which is carried out by contact 17.

During pre-braking, the braking torque is determined by the output of the driver element 19.

The transition to the mode of stabilization of the frequency of rotation of the drive to the input of the comparison element 9 connects the output voltage of the driver element 19, which corresponds to the limit at this frequency

rotational braking torque. Therefore, the signal Ly. It rises again to the largest, which could lead to an increase in the current / to the maximum. value. However, at the same time, a device for stabilizing the frequency of rotation of the drive begins to work, limiting the change in currents at a constant frequency of rotation of the electric machines.

From the functional diagram it follows that

uf - .f - - а.ф + vPri when a sufficiently large gain factor of the exciter is 4, the cohesion voltage Uy, f is significantly less than the voltage C / and St. therefore, we can assume that the value (Vy. f is equal to i. South

, and ..- and, .c.

The constant C is determined by the moment of current i and i, which are proportional to the values of ivf and 0, which are not predetermined for switching to the oscillation mode of the drive rotation frequency. f. Obviously, after switching to the speed rotation mode, the difference between these currents should be preserved, since in the opposite case a large signal Uy would appear. φ which returns the system to its original position, therefore, the previous values of the currents of the EC and the HC are also preserved.

Since the rotational speed of the traction machines changed, then with a change in current IB, the current must change accordingly. The device operation causes a corresponding change and the current Jt, i in this way, this device provides a simultaneous change in the current Korea and the coupling wall with a constant value of their difference, - and this corresponds to a hard characteristic of rheostatic braking, in particular, when IB- / a U, a characteristic of rheostatic braking with self-excitation, having a great rigidity, is obtained.

Studies of the device made according to the invention on a physical model with real 10H1V1 machines showed that it provides good stabilization of the frequency of rotation of the drive at a given level with the relatively simple design of all the elements included in it. In this case, the overall design of the resist brake system, in particular of electric rolling stock, is greatly simplified.

Claims (2)

Invention Formula j stroizzo to stabilize the rotational speed of the electric drive during rheostatic braking of electric machines with independent arresting and unstable resistance of the jurusable resistor, containing the auto-current regulator, the current sensors Cor 11 ohm is impaired, dripping braking torque limiter and adder, about 1 vl li h This is so that, in order to unbrain the equipment of the brake rheostat1O and to increase the reliability of its work and the stability of the characteristics in the mode of rotation frequency, it is equipped with a mode switch deceleration and disturbing elements of currents xcr and immobilization of immobilization associated with the output of the current sensors through co-tacts of the transducer, the output of the braking modes, and the output and the inputs of the adder are connected with the input of the current regulator currents and with the outputs of the coupling elements and the cortex input and the outputs of the accumulator currents and the outputs of the current regulator; vozdezhdeii, and open group koptakgov said switch is connected between the outputs of the sensors currents and inputs soogvetstvuyuschih storage elemeitov and between the output of the master eleme1gga lpschimuma braking MREs meita and input elemeiga comparing the channel limitations as brake torque, and closed - between the output of the master maximum braking torque member and the inlet uiom iutogo comparing element and between the output of the adder and the input of the regulator of the charging current. Sources of information, sources for examination 1. tanners B. A. 1 question about the application of the electrode 1P amic braking on a diesel locomotive. B kn. “Collection of Leningrad Institute of Railway Engineers. B. Yu, M., Trans. Ildornsdat, 1958, p. 189-197. 2. Tulupov V.D. Avtomatcheskoe regulating the force of traction and braking of electric rolling stock. M., “Transport, 1976, p. 153-154, 162-189.