SU88940A1 - Device for increasing the stability of the arc of excitation of mercury rectifiers - Google Patents

Description

Mercury rectifiers are increasingly used in electric drive circuits. However, it is observed that the rectifiers, which work reliably at the: 1-nal mode, have the excitation of the excitation arc under peak loads. Unstable burning of the excitation arc and its extinction in one cylinder lead to an increase in the load of the remaining cycled engines, and with the extinction of several cylinders it can lead to the failure of the entire unit. Jogasanp of the excitation arc is especially often observed at large control angles and large current jolts.

In order to increase the stability of the furnace: an excitation arc of a mercury rectifier proposes a device, characterized in that a serial-type transformer is connected to the main anode of the mercury rectifier in series. Its secondary winding, in turn, is connected in series to the excitation circuit and creates a voltage that is summed with the voltage of the DC or AC source that supplies the excitation circuit.

The drawing shows a circuit diagram of the device.

A series FT transformer is connected in series to the main anode A of a mercury rectifier, the secondary winding of which is connected in series to the excitation circuit (rectifier CB and excitation transformer TB).

The excitation current forcing occurs automatically at the time of the current of the working anode, i.e., at the most adverse moment from the point of view of arc sustainability.

When current is excited, the main anode automatically decreases.

No. 88940-2 -

excitation current, therefore, its average value does not increase against existing systems without excitation forcing.

To implement an automatic rise and fall of the excitation current, a forcing seriax transformer is included in the excitation circuit, the primary winding of which is connected in series to the main current circuit.

At the occurrence of the main anode current in the excitation circuit, due to the presence of the forcing transformer, an opposing voltage is induced, which for a short time reduces the excitation current to almost zero.

Then, when the main anode current decreases by the end of the burning period, the excitation current rises and reaches a value (peak) equal to almost twice the average current.

After the attenuation of the main current, the serial transformer acts as a choke in the excitation circuit, as a result of which the excitation current slowly drops to its average value.

A decrease in the excitation current with an increase in the main current does not affect the stability of the arc, however, this decrease can be largely limited by switching on the selenium rectifier parallel to the secondary winding of the force transformer.

Excitation forcing can also be applied when activating an AC rectifier.

Subject invention

A device for increasing the stability of the arc of excitation of a mercury rectifier, characterized in that a serial-type transformer is connected to the main anode in series, the secondary winding of which is connected in series to the excitation circuit creates a voltage that is summed with the voltage of the source of direct or alternating current feeding excitation circuit.

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