Balancing of the Distributed Electrical Network by Method of Digital Regulation

Abstract

A three-phase distribution electrical network operating in an asymmetric mode is considered. As is known, the factor of asymmetry of phase currents leads to significant losses of active power in the network and transformer substations, as well as to the failure of household appliances and industrial installations. For the symmetry of distributed networks, a number of technologies have been proposed that have not found wide practical application because of their complexity and insufficient efficiency. In the traditional automated information and measuring systems of commercial electricity metering, the functions of data collection from a group of electricity meters installed at the network subscribers are realized, and, in general, the tasks of commercial metering of electricity are being solved. At the same time, in these systems, the optimization of the operating modes of distribution networks is not carried out. One of the possible approaches to solving the problem of balancing a three-phase network based on controlling the flow of electricity between the phases of the network is by switching single-phase electric receivers from a more loaded phase to a less loaded one. The implementation of this approach is implemented by introducing into the structure of the existing automated informative electric power accounting system an additional control subsystem - a digital controller that performs the functions of generating the appropriate control signals for switching electronic meters of electricity connected to the loads of the distribution network. The quality of control processes is evaluated by the objective (criterial) function, which characterizes the loss of active power in the network due to the asymmetry factor. A condition is obtained, the fulfillment of which guarantees the reduction of the value of the chosen indicator of system efficiency in a guaranteed way. A procedure for synthesizing a digital regulator has been developed that provides a reduction in the level of unbalance of phase currents based on the identification of the network load model and minimization of the selected criterial function. The obtained results make it possible to build information and control systems in place of the traditional automated informative electric power accounting systems, which are related to the class of information and measurement systems, which allow increasing the technical and economic performance of distribution companies.