SU66792A1 - Device for controlling traction motors - Google Patents

Description

The modern tram car has a great deal of attention during start-up, which demands a high starting and automatic control, and the acceleration at THIS is brought to such an extent that the tractive force on the rim of the wheel is much closer to its grip limit.

In connection with these features, in all (the latest schemes of tram cars both abroad (RCC, Brill) and in the USSR (oheMia BKT in serial and compound versions, developed by the Dynamo Kirov plant), the absence of serial-parallel switching of year-old engines and, as a result, the absence of a full-bodied running bore (Steve of the car. This is a circumstance under the condition of great smoothness and automatic start with great acceleration greatly simplifies the circuit and equipment of the car and. However, on the other hand, for the same environmental equipment and power supply, the lack of a serial connection of the Vigatels is a serious defect in the scheme in terms of its operation in northern cities, where winter is accompanied by strong snowstorms and snowfalls It is known that snow drifts, even with a relatively small thickness of the snow layer, greatly increase the resistance to movement of the car. Usually in such cases, powering on a parallel connection of engines is prohibited. This facilitates the operation of the engines, reducing the I1X overheating, prevents overloading the equipment and the wiring of the cars and reduces their damage. On the other hand, this measure prevents overload from the power supply system. As experience shows, in DNI1 of snow drifts, the load of substations when driving is prohibited on a parallel connection of traction engines is approximately equal to the load under normal conditions when driving is performed, as a rule, on a parallel connection.

Thus, for the climatic conditions of the northern cities, reduced running speed is necessary, since otherwise large reserves of power would be required, as in

electrical equipment on; D1vizhnogo composition, and in energGO (C1H; abzheniiI used lshsh in the days of snowdrifts.

The solution to this problem by the use of adjusting the two-way traction control is not radical.

The device (for controlling the engines of three wagons operating on a parallel connection, ipemaer the question of combining the ability to start without a series-parallel switching of engines and driving both the Parallel and Hia series of engines.

To this end, according to the invention, a manual, (with direct or remote drive) switch is inserted into the engine power supply circuit, which translates - in case of a de-energized circuit - a circuit to the series connection of the engines for the operation of the tram installation; on this connection of the engines (i.e., at lower speeds).

This manual switch is an apparatus that acts, as mentioned above, only when it is de-energized) of the Common circuit and allows, in advance of dispatch, to include traction engines (or groups of such) in series or in parallel, giving those themselves the opportunity to choose the automatic characteristic on which the wagon will operate.

The principle of operation of the proposed device is explained in part; 1 which depicts the electrical circuit of the device, l FIG. 2 - the table of positions of contactors.

In the diagram shown in FIG. 1 of the drawing, a manual switch, the fingers and segments of which are indicated by the RP, are assumed to be in the form of a drum-type switch, which does not exclude other embodiments as, (vaprim-re, switch-over switch, etc.

In the diagram, the switch shows the p position of a parallel motor connection. The scheme is left without any changes for a four-axle car with (engines, rated; half of the mains voltage and connected in two groups by a de-engine in series.

The action of the switch in motoiphoM mode is easily seen from the diagram.

Rheostatic braking when driving on a parallel connection of engines is carried out in a well-known way - opening contactors LK. and TI and the closure of the contactors T, Ta and Tz.

KoiHTaiKTop T and a battery are associated with the necessity of weakly independent excitation of one of the machines with a floating control system.

Pr, and driving on a series connection of engines, resistal braking is carried out according to the same cxeiMe as when driving on a parallel connection, but with some features.

The connection between the excitation winding of the motor I and its core, broken by the DF switch, necessary for the formation of a cross-circuit, is made by the Gz contactor, which is appropriately switched for this purpose when the DF switch is turned in position of the serial series of the motors. When the switch is in the serial position, the end of the starting resistor R is permanently connected (wire / s of the output terminal of the motor excitation winding //).

In this way, switching on the contactors TZ and Tz and turning off the linear contactor LK leads to the formation of the same brake circuit | as in the case of parallel connection of motors. The contactor TI, riding on the engine series connection, is excluded from the power circuit of the car.

However, the formation of a brake circuit does not yet provide braking.

In fact, after driving on the D1 motors serial connection, the flow of residual magnetism in the second engine // n1P is equal to; according to the CURRENT of the motor mode flowing through the field winding in the direction from MMz to MZ. Meanwhile, in order to excite the machines in a generator mode according to this scheme, the opposite direction of the residual O (magnetic field of the second engine II) is necessary, which occurs after driving on the parallel connection of the engines.

To excite the machine, it is therefore necessary to remagnetize the second engine.

As can be seen from the diagram, this is accomplished with the aid of a battery.

When switching to rheostatic braking, the contactor T connected by means of the switch RP to the output M of the motor field winding // and the current from the battery, flowing through it in the direction from MZ to MMz, remag, depletes the machine.

In the long-range, contactor T and battery are performed. already functions of the independent excitation circuit of one of the machines, necessary, as indicated above, with a floating control system.

Thus, the reversal of the second motor to the floating control system does not require any special equipment. Moreover, the circuit can be, generally speaking, completed in such a way that it does not even require switching the independent excitation circuit when switching from parallel to

series motor connection.

Thus, as follows. From the foregoing, the manual switch is designed to proactively select the characteristic on which the car will operate. As a rule, the switch is in the position of parallel connection of engines, and the driver controls the car: as if the latter has only a parallel connection of engines.

With snow drifts, or even with the likelihood of prolonged movement at low speed for some reason, the driver sets the switch to the serial connection of the engines and further) Sprays the Car as if the latter only has this series connection, and no difference the manipulation of controls compared with the previous CFHs pet.

(Subject invention

A device for controlling tramway engines always operating in parallel connection, characterized in that a manual switch is inserted in the engine power supply circuit, which transfers, in a de-energized circuit, a circuit to the serial connection of the engines for the implementation of the tram installation only on this connection engines (i.e., at lower speeds) in the case of snow drifts, etc.,

FIG. 2