SU1597742A1 - Current-to-voltage converter - Google Patents

Abstract

The invention relates to a technique for measuring alternating currents. The purpose of the invention is to expand the range of operating frequencies. The measured current flowing through the input winding 4 magnetizes the main 1 and N-1 additional 2.1, 2.2 ... 2.N-1 current transformers with cores. The current flowing through the load 6 and the output winding 5 demagnetizes the cores to the magnitude of the residual magnetic flux that induces a voltage in the measuring windings 7. The amplifiers 9 demagnetize a group of 8 cores covered by the compensation windings. Such a design leads to a reduction in the reactive components of the current converter. 1 il.

Description

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with

four

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ten

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The invention relates to electrical measuring equipment and can be used for large-scale AC conversion with galvanic isolation.

The purpose of the invention is to expand the range of operating frequencies.

The drawing shows a block diagram of a current to voltage converter.

The current converter contains the main transformer 1 of current ё with the core and p-1 of additional transformers 2.1, 2.2 ... 2P-1 Toka with cores 3.1, 3.2 ... Gp-1, input% and output 5 windings cover the core of the main transformer 1 current and cores 3.1v.-i3n-1 of additional transformers 2.1 ... 2n-1 of current, the output winding 5 is connected via terminals with load 6, each additional current transformer contains measuring one. and a compensatory winding 8 and an amplifier 9, the measuring winding 7 is connected to the input of the corresponding amplifier 9, the first output of each amplifier 9 is connected to the first input of the corresponding compensation winding 8, the second view of the windings 8 is connected to the second load terminal. 6, the first output of which is connected to the second terminals of the outputs of all amplifiers 9, each of the compensating windings 8 additional transformers, for example a compensating transformer 2.2, simultaneously cover all cores with large numbers, i.e. 31, 3i + 1, 3i + 2 ... and Зп-1-th cores of additional transformers 21 - 2.p-1 current.

The descending of a voltage-to-current converter is based on the unwinding of the current transformer cores.

The input current flowing through the input winding 4 magnetizes the main 1 and additional cores 3.1 ... 3.P-1. The current flowing through the load 6 and the output winding 5 demagnetizes all the cores to the magnitude of the residual magnetic flux, which in the measuring winding 7 emits an emf. Amplifier 9

i.

the number of turns of the output 5 and the compensation 8 windings, the output current of the additional transformer-current is equal to the deviation of the demagnetizing current, the stages in front of it from the magnetizing input current. The output currents of all BcnoMoraTejib current transformers 2.1 ... 2n-1 are fed to the load 6, where they are summed up with the output current of the main current transformer 1, as a result of which the conversion accuracy is high.

The known converter, when used, requires the use of n primary windings, n measuring

pp (p + 1).

compensate20

windings and 1

windings.

The proposed converter involves the use of a single primary winding, n measuring and n compensation windings. The number of 25 compensatory windings necessary for operation of the converter decreases to -.

, 2. Shp in k. 2

 {About, the number of primary windings decreases n times. In proportion to these values, the values introduced additionally by the windings of the parasitic capacitances of the circuit are reduced.

In the known converter, the output of the first amplifier is connected in series (n + 1) to compensate for the P1 windings. In the proposed Converter to the output of the amplifier; only one compensating winding is connected, which (n + 1) times reduces the magnitudes of the parasitic reactive and active components of the south load of the force of 45 bodies and expands the frequency range.

Claims (1)

Invention Formula  Current-to-voltage converter containing a main current transformer with a core, input and output windings, n-1 additional current transformers with cores, each of which contains 35 40 VO I MHrTVTTHnVeT unJU n tiJi - / I4cii-u i,., - - - .-, g „ GazG .. g.p.a, e „„ «“ 35 “eR„ .. only „..„ „to„ „e„ с ™ о „„. О. cores to the magnitude of the residual magnetic flux determined by the loop gain. With equal k and the measuring windings are connected to the corresponding input of n-1 amplifiers, to the first output as 0 five i. the number of turns of the output 5 and the compensation 8 windings, the output current of the additional transformer-current is equal to the deviation of the demagnetizing current, the stages in front of it from the magnetizing input current. The output currents of all BcnoMoraTejib current transformers 2.1 ... 2n-1 are fed to the load 6, where they are summed up with the output current of the main current transformer 1, as a result of which the conversion accuracy is high. The known converter, when used, requires the use of n primary windings, n measuring pp (p + 1). compensate0 windings and 1 windings. The proposed converter involves the use of a single primary winding, n measuring and n compensation windings. The number of 5 compensatory windings necessary for operation of the converter decreases to -. , 2. Shp in k. 2  {About, the number of primary windings decreases n times. In proportion to these values, the values introduced additionally by the windings of the parasitic capacitances of the circuit are reduced. In the known converter, the output of the first amplifier is connected in series (n + 1) to compensate for the P1 windings. In the proposed Converter to the output of the amplifier; only one compensating winding is connected, which (n + 1) times reduces the magnitudes of the parasitic reactive and active components of the south load of the force of 45 bodies and expands the frequency range. Invention Formula  Current-to-voltage converter containing a main current transformer with a core, input and output windings, n-1 additional current transformers with cores, each of which contains 35 40 / I4cii-u i., - - - .-, g „ 35 "eR„ .. e „..„ „to„ „„ e „с ™ о„ „. О. “ER„ .. e „„ .. „„ to „„ „e„ с ™ о „„. О. Moreover, the measuring windings are connected to the corresponding inputs of n-1 amplifiers, to the first output as-. 51597742 Because of which npHCoisAHHeHbi are the first, the corresponding compensation cores are made covering the cores. The i, i + 1, ..., n-1 additional windings, the second terminals of which are current transformers, the output winding, are combined, which is connected to the first and second terminals, so that in order to extend the range for connecting the load , the combination of operating frequencies, the input and output second compensation terminals on the windings are made covering the windings connected to the first terminal of the cores of all additional trans-components for connecting the load, and the current, combination and current amplifiers of the second amplifiers sensational The windings of each i-ro are connected to the second terminal for connecting an additional current transformer or load.