SU1381647A1 - Device for limiting the switching current inrush of single-phase transformer - Google Patents

Description

(21) 3839680 / 24-07

(22) 01/02/85

(46) 03/15/88. Bul Number 10

(71) Research and development, design and technological institute of power and semiconductor equipment of the Plant Electric generator

(72) V.N.R. Bov and E.P. Vasilyev (53) 621.316.925 (088.8)

(56) Patent of Germany No. 2432896, cl. H 02 H 9/02, 1978.

USSR Author's Certificate No. 1269755, cl. H 02 H 9/02, 1983.

(54) DEVICE FOR RESTRICTING CURRENT CURRENTS FOR SWITCHING ON A SINGLE-PHASE TRANSFORMER

(57) The invention relates to the field of electrical engineering. The purpose of the invention is to increase the reliability of the device. When applying AC voltage, the inrush current is limited by the resistor 1. At the same time, the capacitor 9 is charged. When the voltage across the capacitor 9 is turned up to a value equal to the switching value of the dynistor 10, the latter is turned on, the capacitor 9 is discharged to the primary winding of 6, A rectangular shaped impulse from the secondary winding of transformer 6 includes a switching element 3, which bypasses the resistor 1. 1 sludge.

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The invention relates to electrical engineering, specifically to devices for limiting inrush current of a single-phase transformer.

The purpose of the invention is to increase the reliability of the device.

The drawing shows a diagram of the device.

The device contains a current limiting resistor 1 connected in series with the primary winding of the transformer 2 and a shunted switching element 3, which is used as a simrist, the positive control output of which is connected through the control resistor 4 and to the beginning of the primary winding of the single-phase transformer 2, and through diode 5 to the beginning of the secondary winding of the pulse transformer 6, the end of the secondary winding of which is connected to the negative terminal of the switching device 3. The rectifying bridge 7 is clamped The alternating current is connected to the primary winding of a single-phase transformer 2, the output of bridge 7 is connected to an RC circuit composed of a resistor 8 and a capacitor 9, the upper plate of the capacitor 9 is connected through a dynistor 10. to the beginning of the primary winding of a pulse transformer 6, and the end of the secondary winding to the bottom plate of the capacitor 9.

The device works as follows.

In the initial state, the capacitor 9 is discharged, the switching element 3 (triac) is turned off.

When applying AC voltage, the inrush current of the transformer 2 is limited by the current limiting resistor 1. Simultaneously, the capacitor 9 is charged from the rectifying bridge 7 through the resistor 8. When the voltage on the capacitor 9 rises to a value equal to the switch-on voltage of the distributor 10, the latter is turned on, in which case the capacitor 9 is discharged to the primary winding of the transformer 6. A rectangular pulse is formed on the secondary winding of the transformer 6, a positive field p

the bone of which, via diode 5, is applied to the positive control terminal of the switching element 3, and negative to the negative terminal. With the arrival of the control pulse, the switching element 3 is turned on and remains open due to the holding current flowing through the control resistor 4. This ensures shunting of the current-limiting resistor 1.

This device has a simple and reliable scheme that does not require adjustment and adjustment.

Claims (1)

Invention Formula A device for limiting inrush current of a single-phase transformer, containing a current limiting resistor connected in series with the transformer primary winding, a switching element connected in parallel with the resistor, and a switching element control unit, characterized in that operation, the control unit is made of a valve bridge, the AC terminals of which are connected to the terminals for connecting the primary winding of a single-phase transformer, a KS circuit is connected to the DC terminals, the bottom plate of the capacitor which is connected to the negative terminal of the valve bridge and to the end of the primary winding of the pulse transformer; The top capacitor plate is connected to the anode of the dynistor whose cathode is connected to the beginning of the primary winding of the pulse transformer, the beginning of the secondary winding of the pulse transformer is connected via a serially connected diode to the positive control terminal of the switching element, which in turn is connected to the beginning of the primary winding of the single-phase transformer and the end of the secondary winding of the pulse transformer is connected to the negative input of the switching element.