Prompt determination of the static stability margins in electrical energy systems equipped with distributed generation plants

Yu N Bulatov,A V Kryukov,K V Suslov,A V Cherepanov,V Breskich,Y Dreizis,A Zheltenkov

doi:10.1051/e3sconf/202022402004

Abstract

The wide use of distributed generation (DG) technologies in electrical energy systems (EES) requires development of new control algorithms in normal, emergency and postemergency modes. The issues of determining the static aperiodic stability (SAS) margin in EES equipped with DG plants are of particular relevance. These plants can be removed from the consumption centers, which can lead to SAS reserves depletion. The article presents the results of studies aimed at the developing SAS reserves express calculation methods in EES equipped with DG plants. An effective technique to determine stability margins was proposed based on one of the modifications of limiting modes equations. The results of determining SAS for an electrical network with distributed generation plants are presented. Additionally, the simulation of transient processes in the studied EES for various points in the space of the mode’s controlled parameters has been carried out in the Matlab system.

Highlights

IntroductionThe issues of determining limit load modes and static aperiodic stability (SAS) margins [13] are relevant when designing and operating electrical energy systems (EES) and have both independent significance and are an integral part of other electrical energy issues related to providing a required level of EES reliability [4]
The results obtained allow us to conclude that an efficient technique for analyzing static aperiodic stability in an energy systems (EES) equipped with distributed generation (DG) plants can be implemented on the limit loads equations (LLE) basis, which is applicable in design problems, as well as operational and emergency control (OC and EC)
The DG plants synchronous generators were simulated by the standard unit of the SymPowerSystems package of the MATLAB – Synchronous Machine pu Fundamental system, with the unit having the following parameters: rated power – 24 MVA; electric line voltage 6 kV; generator voltage and current frequency – 50 Hz; stator resistance per phase Rs = 0.008979 r.u.; stator leakage inductance Ll = 0.05 r.u.; direct-axis magnetizing inductance viewed from stator Lmd = 2.35 r.u.; quadrature-axis magnetizing inductance viewed from stator Lmq = 1.72 r.u.; field resistance Rf = 0.0021 r.u.; field leakage inductance Llfd = 0.511 r.u.; inertia coefficient H = 2.8485 s; friction factor F = 0.0092 r.u.; number of pole pairs p = 3

Summary

Introduction

The issues of determining limit load modes and static aperiodic stability (SAS) margins [13] are relevant when designing and operating electrical energy systems (EES) and have both independent significance and are an integral part of other electrical energy issues related to providing a required level of EES reliability [4]. The issues of determining SAS reserves are of particular relevance in power supply systems equipped with distributed generation (DG) plants, in particular, implemented on the basis of non-traditional renewable energy sources [5,6,7,8,9,10,11,12,13,14,15,16,17,18]. Such plants, as mini hydropower plants and offshore windmill farms can be in a remote location from consumption centers, which leads to SAS reserves depletion [19, 20].

Problem formulation

R ΔR V

F F F ΔX F

U2 6 kV

Transient processes simulation results

Conclusions