SU1347155A1 - Test voltage former - Google Patents

Abstract

The invention can be used to reproduce real overvoltages affecting the insulation of ultra-high voltage electrical equipment. The test voltage driver contains transformers 1-3, which have equalizing windings 4-6, excitation windings 7-12 and secondary windings 13-15, source 16 of the mains voltage, frequency 18, regulator 17, filter 18, capacitive accumulators 19-21, The charging circuits of which contain resistors 22-24, adjusting autotransformers 25-27, charge capacitors 28-30 and diodes 31-36, and discharge circuits - reactors 37-39, controlled, switches 40-42, such as thyristors. The control circuits are powered from windings 43-45. 1 il. (About Ci: i- c with 4; -vi taoA SL 01 19 16 -k-1 7

Description

  13

The invention relates to electrical engineering, in particular, to a pulse technique, and can be used to reproduce real voltages acting on the insulation of a super high voltage electrical equipment.

The aim of the invention is to extend the functionality by ensuring the formation of test voltages with the imposition of -pulses in parameters that coincide with the pulses of real overvoltages,

The drawing shows an electrical circuit of the device by the example of a cascade of three test transformers.

Transformers 1-3, connected in cascade, have equalizing windings 4-6, excitation windings 7-12 and secondary windings 13-15, respectively. A source 16 of the mains voltage of the frequency frequency | through the regulator 17 and the filter 18 are connected to the winding 7. Capacitive accumulators 19-21 with charging circuits containing resistors 22-24, adjusting auto-transformers 25-27, charging capacitors 28-30 and diodes 31-36, as well as with discharge circuits, are connected to equalizing windings. containing reactors 37-39 and controllable switches 40-42, for example thyristors. The control circuits are powered from windings 43-45.

Depending on the magnitude of the operating voltage of the test object, the regulator 17 excites the corresponding voltage in the windings 7-11 of all three transformers.

For a given multiplicity of switching overvoltages, the charge voltage is adjusted with respect to the multiplication circuit with respect to the operating voltage of the auto-transformers 25-27. .

Operation of the device begins with charging capacitive accumulators 19-21 with the help of capacitors 28-30 and diodes 31 and 32, 33 and 34, respectively. Upon completion of charging at a given moment, the sinusoidal voltage in the field windings of the transformers is simultaneously triggered. switches 41-42, for example, thyristors The discharge current of capacitors passes through pe5

one

0 0 5

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five

0 5

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actors 37-39 and equalization windings 4-6, excite a voltage pulse in windings 13-15, i.e. a real form of operating stress is achieved. Resistors 22-24 serve to limit the discharge current through autotransformers 25-21 and the frequency filter 18, tuned to the frequency of the free voltage oscillations in the discharge, acts as a filter plug for these oscillations.

Connecting the capacitive charge circuits directly to the equalizing windings of the cascade transformers allows the capacitive drives to be charged when it is supplied from the cascade to the test object of the working voltage of its insulation, for example, 850 kV (effective value).

Then it is possible to reject the cumbersome disconnectors that are turned on when the charging voltage is applied from a source located on the ground potential and disconnected in order to insulate the stages of the cascade on the voltage that occurs when the capacitive drives are discharged.

Zar d capacitive storage By multiplying the voltage, for example, by doubling scheme, it is possible to obtain at the output of the cascade the required magnitude of the test voltage pulse, for example, 2100 kV (amplitude value) superimposed on the above operating voltage, which will be a complete simulation of the operational overvoltages stress class

Formula aa of oh brethren

A test voltage driver containing test transformers, the secondary windings of which are combined in a series circuit connected to the output terminals, each transformer contains the first and second field windings and parallel connected equalizing windings, to the points of connection of the equalizer windings of the corresponding transformer are connected to the discharge circuit from series-connected capacitive storage, reactor-. Pa and managed switch, each capacitive drive is connected to the corresponding charging circuit, and the first excitation winding of each end is 131347155

The test transformer capacitive storage tank contains

pa connected in parallel with the second voltage multiplier circuit, made by the excitation winding followed by the original on the diodes and capacitors, the outputs

a power transformer, about which is connected to a capacitive one that, with the storage tank, and the output through the optional extension of the functional ones, an autotransformer can be inserted

by providing equalization windings to the corresponding test voltages from the overlapping test transformer,

impulses on them, by parameters, the first excitation winding of the first

coincident with the pulses of the real test transformer, the connecting;

overvoltages, charging circuit with each source of mains voltage

Claims (1)

Form l. from acquisitions Test voltage shaper _? containing test transformers, secondary transformers, whose windings are connected in a series circuit connected to the output terminals, each transformer contains the first and second field windings and parallel equalizing windings, a discharge circuit from series-connected capacitive connected to the connection points of the terminals of the equalizing windings of the corresponding transformer drive, reactor and managed switch, each capacitive drive is connected to the corresponding charging circuit, and the first field winding of each previous test transformer is connected in parallel with the second field winding of the subsequent test transformer, characterized in that, in order to expand the functionality by providing the formation of test voltages with imposing pulses on them with parameters matching the pulses of real overvoltages, the charging circuit each capacitive storage contains a voltage multiplication circuit made on diodes and capacitors, the outputs of which are connected to the capacitive storage, and the output through an additionally introduced autotransformer to the equalizing windings of the corresponding test transformer, and the first field winding of the first test transformer is connected _; yen with mains voltage source