CS205437B1 - Connexion for measuring of angular and amplitude error of voltage and current converters - Google Patents

Description

The invention relates to a circuit for measuring the angular and amplitude bends of voltage and current transducers, for example voltage and current measuring transformers, measuring and circuit breakers, and the like.

The voltage and current transducers are used to convert the measured quantity to a level suitable for further processing, i.e., measuring, milling, and controlling electrical circuits. For this measurement, adjustment and regulation to be reliable, it is necessary to know, among other things, the magnitude of the angular and amplitude bends of these converters.

Until now, to measure the angular and amplitude bends of voltage and current transducers, bridge devices have been used which require laborious balancing and are relatively expensive because they contain a large number of precision circuit elements such as resistors and capacitors.

These disadvantages are eliminated by the wiring for measuring the angular and amplitude bends of the voltage and current transducers according to the invention, which is based on the fact that the inputs of a normal load carrying a nominal load and the inputs of the tested load carrying a nominal load are connected to a common voltage source. n * ground is connected and its second outlet is connected to the input of the first former, through the phase shifter to the input of the second former, directly or via a voltage divider

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205 437 the first output of the test transducer, whose second output is connected via the wire to the first input of the first switching detector and to the first input of the second switching detector, both outputs of the tested transducer are counter-phase to both outputs of the noxal converter. the control input of the first switching detector and the output for connecting the amplitude error indicator of the test transducer and the output of the second former are connected to the control input of the second switching detector with the output for connecting the angular bend indicator of the test transducer.

The advantage of the connection according to the invention is its simple operation, so that the measurement can be performed also by the operator with lower qualifications, it is possible to simultaneously measure angular and amplitude bends of multi-transducers using a single standard. serial production of converters. In long-term testing, the angular and amplitude bend measurements of the transmitters can be performed automatically, unattended, using a recorder or mass data acquisition.

An example of a circuit for measuring the angular and amplitude bends of voltage and current transducers is shown in the accompanying drawings, in which Fig. 1 represents a block diagram of the angular and amplitude bending measurement of voltage transformers. current transformer.

The primary winding of the normal voltage transformer TRBh (FIG. 1) is connected by a first input 11 to a voltage source 11 not shown and a second input 12 to ground, while its secondary winding is connected by a first output 012 to ground and a second output 011 through a voltage divider of the first resistor Rl and the second resistor R2 and which simultaneously forms its nominal load to the ground, both to the input 51 of the first shaping TVI both to the input 61 of the phase shifter P ^ · Primary winding test measuring ^one voltage transformer market js connected to the first input 21 to the same a voltage source 11 (not shown) and a second input 22 to ground, while the secondary winding is connected by a first output 021 to the center of a voltage divider consisting of a first resistor 51 and a second resistor R2 and a second output 022 to a first input 31 of the amplifier J. a third resistor R3 such as ih The second input 32 of the amplifier J is connected to ground, while its output 031 is connected to the first input 41 of the first splitter detector SP1 and to the first input 81 of the second switching detector 8D2. The output 051 of the first molding apparatus T1 is connected to the control input 42 of the first switch detector SP1 and the output 041 for connecting the real bend component indicator (not shown), i.e. the aperture bends of the test transformer to be tested. Phase shifter output 061 is input to input 21 of second former TV2. whose output 071 is connected to the control input 18 of the second switching detector 3D2 with the output 081 for connecting an imaginary error component indicator (not shown), i.e., the angular bends of the tested voltage transformer TRZn.

The magnitude of the first and second resistors R 1, R 2 of the divider are chosen such that the voltage at the second resistor R 2 corresponds to the nominal voltage at the secondary winding of the voltage transformer TRZn under test. wherein the secondary winding of the test voltage transformer

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TRZn is connected in such a way that its voltage is in phase and voltage at the second resistor R2 of the divider. Thus, if the two rated voltages are the same, the second output 011 of the secondary winding of the normal voltage transformer TRNn is connected directly to the first output 021 of the tested voltage transformer TRZn. Otherwise, another suitable divider can be used as a voltage divider ·

As indicators of the real component of the bends, as well as 1 imaginary component of the bends, Izo use micro-ammeters, recorders with a list and the like. This makes it possible to automatically record the dependence of the bending 1 under various conditions of operation or long-term testing.

The connection for measuring the angular and amplitude error of the current transformers of Fig. 2 differs from that of Fig. 1 only in the connection of both the TRNp and TRZp current transformers. Their primary windings are connected in series and connected to a common voltage source U not shown resistors R4 and R5 as rated load ·

Any potential difference in instantaneous voltage value that occurs between the second output 022 of the secondary winding of the test voltage transformer TRZn or current TRZp and the ground ee is amplified in the amplifier Z, from where it is brought to the inputs of the switching detectors SP1 and SD2. The first switching detector SP1 is controlled by a pulse reference voltage from the first TVI former, derived directly from the output voltage of the normal measuring transformer, the voltage ΪΕΙίη or the current TRNp, and which is in phase with the source voltage. The SP2 is a pulse reference voltage from the second TV2 contactor. which is shifted by a quarter of the period by the PP phase slider. The real component of the instantaneous voltage difference is directly proportional to the amplitude bending of the TRZn or TRZp current measurement transformer and the imaginary component of the instantaneous voltage difference is proportional to the angle error of the TRZn voltage or TRZp current measurement transformer.

The circuitry of the invention can be used to measure the angular and amplitude bends of any voltage and current transducers.

Claims (1)

SUBJECT OF THE INVENTION Circuit for measuring angular and amplitude error of voltage and current transducers characterized in that the inputs (11, 12) of the normal transducer loaded with a nominal load and the inputs (21, 22) of the test transducer loaded with a nominal load are connected to a common voltage source (JJ). ), wherein the first output (012) of the normal converter is connected to ground and its second output (011) is connected to the input (51) of the first former (TV1), via a phase shifter (PP) to the input (71) of the second former (TV2) and directly or via a voltage divider (R1, R2) to the first output (021) of the test transducer, the second output (022) of which is connected via an amplifier (Z) to the first input (41) of the first switching detector (SB1) and to the first input ( 81) a second switching detector (SD2), both outputs (021, 022) of the tested converter 205 437 are connected in counter-counter to both outputs of the normal converter, the output (051) of the first former (TV1) is connected to the control input (42) of the first switching detector (SD1) β output (041) for connecting the amplitude bend indicator the test transducer and the outlet (071) of the second molder (TV2) is connected to the control input (82) of the second switch detector (SD2) and the output (081) for connecting the angle bend indicator of the test transducer.