Turbomachinery Mechanical Oscillations Analysis and Active Compensation Design by EESS in Thermal Power Plant

There are analyzed a turbomachinery mechanical oscillations which are excited in the synchronous generator caused by electrical transients in the electrical grid. The higher voltage harmonics and interharmonics affecting the mechanical stability are identified and discussed. Then, there is presented a methodology using Fourier harmonic analysis of the generator voltage to identify potentially harmful frequencies of the voltage. Moreover, there is presented design of active protection system using Electronic Energy Storage System (EESS) which is a specifically designed Battery Energy Storage System (BESS) extended by superior control unit handling mathematical model of turbomachinery and control algorithms commanding directly the power converter. The EESS is connected to the point of common coupling (PCC) with the synchronous generator. The protection system generates electric currents based on the designed methodology to compensate identified harmful voltage frequencies. The state of the art of the project and the future development is summarized in the conclusion.