Application of the Operational Method for Calculating the Mode of the Electrical Grid Circuit with Distributed Loads

Abstract

The development of the renewable source component for electricity production leads to an increase in the number of sources connected to the low voltage network and to difficulties in calculating the transient regime. The purpose of this paper is to present a new way of applying the operational method for calculating the regime in circuits with the distributed load, which is not limited by the order of the differential equation and that describes the dynamic processes in the analyzed circuit. As a method of calculating currents in the circuit of a network with tasks and sources of distributed generation, the method of loop currents was selected. The method allows the equations of the voltage balance to be drawn up, so that in each of loop circuit there is only one element of the transverse chains connected in the network power outlets. This ensures that the values of the loop currents with the currents in the respective transverse element coincide, whether we consider the connected load or the distributed source of generation. Knowing the values of currents in the loop of the circuit allows calculation of all derived parameters: voltage drop, loss of power, examination the regime in the natural evolution course in the network, so from the transient regime to the permanent regime. It has been shown that, for the topology of the electrical networks with active-inductive components, the roots of the characteristic equation of the differential equations describing the equilibrium state of the instantaneous voltages in the network circuits can be determined without great difficulties. The analytical solutions allow for calculating the instantaneous values of the loop currents and the voltage drops in the connection nodes of the load and the sources of generation distributed at the low voltage network. The proposed method of applying the operational method is robust both for determining the characteristics of the transient regime at any point of the supply network, and for the parameters of the permanent regime.