Testing of the valve system of the generator excitation of the EG2500 unit

Abstract

The article presents a comprehensive study and analysis of the implementation of a modern excitation system for gas turbine power plants of the EG2500 series. The relevance of the study is due to the current state of the energy sector of Ukraine, which is faced with a chronic deficit of electric power in the unified energy system. The article substantiates that under such conditions, the concept of decentralization and development of distributed generation facilities, capable of ensuring the autonomy of critical infrastructure and local power nodes, acquires strategic importance. The technical condition of the fleet of EG2500 mobile units, which are a key tool for maneuverable generation due to their mobility and ability to quickly start up, is considered in detail. A critical problem has been identified, according to which the long-term operation of these plants has led to deep moral and physical wear and tear of standard electromechanical excitation systems. Old electromechanical solutions do not provide the necessary accuracy of voltage regulation and speed in dynamic modes, which creates the risk of emergency stops and increases the cost of maintenance due to the shortage of spare parts. The central topic of the article is the implementation and testing of a new digital system for valve excitation of the SVG manufactured by Pluton IC LLC. The structural structure of the system, which consists of a thyristor rectifier cabinet and a switching and protection cabinet, is described. The functional capabilities of the microprocessor control system are analyzed in detail, including the implementation of the PID regulation law, automatic excitation forcing, overload limitation by time-dependent characteristics, and the possibility of integration into existing automatic control systems of stations. Special attention is paid to the method of experimental adjustment of the regulator parameters in the special "Pulse" mode. The proposed iterative method of experimental parameter selection is substantiated and applied, which allows achieving the optimal form of the transient process without self-oscillations. The practical part of the work presents the results of tests on a real object during a sharp start-up and load shedding of 1 MW. Comparative analysis showed a significant improvement in the indicators for stator voltage overregulation and mode establishment time. Additionally, the economic and operational effect of the introduction of the SVG is emphasized, in particular, an increase in the resource of the field extinguishing machine by switching the rectifier to inverter mode during regular stops.