English Original Reader for Technical Students. Power transformers: short-circuit testing, monitoring systems (Smart Grid) - страница 2

Шрифт
Интервал


Keywords: Intellectual Networks; Smart Grid; Monitoring System; Electrical Equipment; Information-Measuring System; Frequency Response Analysis; Transformer Winding Fault Diagnostic; Low Voltage Impulse Method; Short-Circuit Inductive Reactance Measurement

1.1. Introduction

Joint Stock Company “Federal Grid Company of Unified Energy System” is the operator of the United National Electrical Network of Russia. The total extent of electrical power transmission lines is 121.7 thousand km, the number of substations is 805, and the class of voltage is 220–750 kV. The five-year investment program includes the construction of 73 new substations.

The switch to “clever power engineering” (Smart Grid) realized by Federal Grid Company, will make it possible not only substantially change today’s energy landscape, but also further develop the electrotechnical industry, mastering new technologies and creating new electrical equipment. Novel methods are to be incorporated both in plants and in scientific design institutes, stimulating the professional growth of Russian scientists.

In Saint-Petersburg International Economic Forum that took place some years ago, it was declared that one of the results of the conversions, conducted today by Federal Grid Company, must be the creation of the components of “intellectual networks” (Smart Grid), which will solve the existing tasks of the power electrical engineering providing for increase of effectiveness of its work and creating conditions for increasing the competitive ability of the economy of Russia on the basis of new innovation solutions and technologies.

1.2. Smart Grid Information-Measuring System for Control of Inductance Value Transformer’s Winding

The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring of the parameters of the electrical equipment. The residual winding’s deformations of power transformers during short circuits appear practically instantly, not leaving time to analysis of the results of diagnostic measurements, demanding to switch off the transformer as fast as possible in order to avert or, at least, reduce the necessary consequent repair of the electrical equipment.

Information-measuring systems (IMS), which are described in this paper, were proposed to transformer winding control. Rapid digital protection against short-circuit regimes in transformer windings is used with IMS. The instantaneous and average values of inductance have been calculated. This calculation showed that using IMS for inductance control allows to decrease the number of failures and expenditures for repair.