SU68664A1 - Device for parallel operation of the motor-generator and mercury-rectifying units - Google Patents

Description

Device for parallel operation of the motor-generator and mercury-rectifying units

Filed July 12, 1940 to the People's Commissariat of Railways of the USSR

No. 3154 (342745)

Published June 30, 1947

The difference in the external characteristics of the motor-generator and the mercury rectifier and the dependence of the electromotive force of the mercury rectifier on the supply voltage make it difficult to use these units for parallel operation.

With frequent changes in the supply voltage and full utilization of the power of the units, their parallel operation becomes impossible, due to the inadequate distribution of the loads between them.

In order to ensure proper distribution of the loads, it is necessary to interconnect the two units so that the electromotive force of one of them follows the changes in the electromotive force of the other.

The difference between the electromotive forces of the motor-generator and the mercury rectifier creates an equalizing current in the circuit composed of them. If this equalizing current is passed through the ballast resistance, then there is some potential difference across the terminals of these resistances. It will be proportional to the equalizing current and will coincide with it in sign, therefore, will be proportional to the difference of the electromotive forces of both units.

Including ballast resistances in series with the motor-generator winding circuit, it is possible to make the motor-generator electromotive force dependent on the difference between the motor-generator motor-electromotive forces and the rectifier and to allow the motor-generator and the mercury-rectifying units to work in parallel.

For this, according to the invention, one of the excitation windings of the generator driver (or generators) is included in the circuit of the equalization wire.

The invention is illustrated in the drawing, which shows a schematic electrical diagram of the proposed device.

Here: MG - generators of generator-generating units, RV is a mercury rectifier operating in parallel with motor-generators, g -

245

the ballast resistances used to create a potential difference corresponding to the equalizing current, p the excitation windings of the MG generators, e is the generator pathogen, and one of its excitation windings, E and Ep is the emf. units of MG and PB, / g and / r - current strengths

of these units, / is the external load current.

Naturally, in all cases x / g4- / p- If / gf / p, then a current fa will flow in the equalization wire. The excitation current / in the MG unit is set so that, under the mode

current ia was zero.

Then, if / g 1p, the resulting current ia will demagnetize the pathogen e, as a result of which the excitation current / in will decrease, thereby automatically reducing the emf. Eg And leveling the load distribution between the MG and PB units. At / g / r, the voltage ia of the current is reversed and the balancing current will bias the driver e, automatically increasing 1c, ee and / g, i.e., the load distribution between the units will be equalized.

In the device, the introduction of current ia into the serial winding of the excitation exciter has the advantage over introducing it directly into the excitation circuit of the MG unit, since the losses in the circuit consisting of the resistance r and winding a are reduced due to the decrease in the resistance r. The disadvantage of this circuit is its inertial action, since an intermediate magnetic system of the exciter is introduced into the work; However, this deficiency is insignificant and will be felt only with abrupt changes in the voltage of the mercury rectifier.

Subject invention

A device for parallel operation of the motor-generator and mercury-reinforcing units with automatic redistribution of loads by changing the excitation of the generator (or generators) with an equalizing wire, o and so that one of the excitation windings of the exciter generator is included in the balancing wire.

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