Integrated network distributing transformer with error compensating mutual inductor

Abstract

The invention relates to an integrated network distributing transformer with an error compensating mutual inductor. By adopting a method of a built-in type no-load and load error characteristic compensating mutual inductor, the high-accuracy stimulating measurement of primary side current and voltage of a transformer is realized, and the electric energy consumption transmitted by the transformer is really recorded for real-time comparison with the electric energy consumption metered by a high-voltage winding power metering device and a low-voltage side electric meter so as to discover the generation of an electricity stealing phenomenon in time; in the compensating ways of a voltage inducting type principle, a phase shift technology, current mutual inductors, and the like, the error performance of the voltage mutual inductor is adjusted for ensuring that the accuracy of the mutual inductor is more than 0.2 grade so as to meet the requirements of power metering, voltage and current monitoring, relay protection and harmonic measurement; and the integrated network distributing transformer with the error compensating mutual inductor can be also combined with other equipment to form a miniature transformer substation, and the precision of the miniature transformer substation has great improvement space.

Description

technical field [0001] The invention relates to an integrated distribution network transformer with an error compensation transformer, in particular to an integrated distribution network transformer equipped with no-load and load error characteristic compensation transformers, belonging to the technical field of electric energy measurement and metering in the electric power industry. Background technique [0002] The distribution network transformer is the node of the power system facing the user. The integration of primary equipment (miniaturization, integration, and multi-function) is the development trend of power grid planning and construction. High-voltage equipment such as integrated transformers and transformers, It is conducive to the safety and reliability of the power grid, is conducive to reducing the overall cost, and is conducive to monitoring the phenomenon of power theft in the distribution network. [0003] The integrated distribution network transformer with...

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Problems solved by technology

[0004] In the existing known integrated transformer with transformer, the current transformer is to measure the secondary current with a CT with an annular iron core built in or placed outside the oil tank, and the voltage signal is directly taken from the secondary side outgoing line. The Chinese utility model patent "Measurement Substation transformer" (application number: 200520057371.X application date: 2005-04-16), "metering integrated distribution transformer" (application number: 02276149.7 application date: 2002-08-16) is the structure adopted , due to the excitation current I of the transformer 0 with load current I 2 Compared with the proportion is also very small, and the excitation current I 0 Relatively stable, the load current (also known as transformer secondary measurement current) I 2 with the primary side current I 1 The relationship is proportional to the relationship, so the secondary winding through the current transformer coil CT can obtain a higher accuracy of the primary side current conversion value; but from the transformer "T" type equivalent diagram (attached figure 1 ) It can be seen that due to the load Z B The resulting load current I 2 and transformer excitation current I 0 In the primary winding impedance Z 1 and the secondary winding impedance Z 2 , resulting in the secondary voltage U 2 and primary voltage U 1 There are differences between them. The secondary output voltage cannot reflect the primary voltage in proportion. For 35kV, 20kV and 10kV series distribution network transformers, according to the different capacity and structure, the secondary voltage and the primary voltage are different under no-load and full-load conditions. The deviation can reach 5% to 8%, which makes it difficult to measure the primary side voltage with high accuracy. If simple and reliable measures can be taken, a set of deviations less than 0.2% can be output at the secondary end of the transformer by means of compensation. The primary-side voltage measurement signal port and the secondary-side current signal port form a high-accuracy analog primary-side voltage and secondary-side current signal, monitor the power transmission of the transformer, and realize a high-precision integrated distribution with built-in transformer function. Network transformer function, and can guide higher voltage level transformers to add transformer function

[0005] A similar built-in integrated method and device for measuring the current and voltage of the primary side of the transformer through high-accuracy analogue monitoring of the power transmission of the transformer has not been seen in the existing patent literature

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