Transient States Modeling in Power Supply Systems with Lower Electrical Energy Quality and with Distributed Generation Plants

Under current conditions, power consumers can create efficient distributed generation (DG) plants. DG plants can be connected to electrical power systems ( EPS) via direct current (DC) links, based on power electronics elements. This allows ensuring high power quality and power supply reliability, and limiting the short circuit (SC) power in the DG sources buses. DG plants operating on the basis of synchronous generators allow developing a sufficiently large power. The efficiency of such plants in various modes depends on the settings of the automatic speed regulator (ASR) of rotor spinning systems and generator automatic voltage regulator (AVR). Currently, many tuning methods and algorithms for the operation of regulators of synchronous generators are offered. At the same time, the operation of ASR and AVR of DG plants under conditions of lower power quality and their impact on the electrical energy quality are not sufficiently studied. The article presents modelling results for transient states in microgrids designed for power supply of AC railroads non-traction consumers. The studies were conducted in the MATLAB system using the Simulink and SimPowerSystems software packages. The following events were considered as transitional modes: microgrid main power supply shutdown and activation of backup power supply; connecting an additional traction load that deteriorates the quality of electrical energy in the microgrid. The results of the DG plant and DC link influence on the electrical energy quality are presented, according to which it was established that the DG plants can be used to improve power quality.