15 research outputs found
Analysis of subâsynchronous resonance between DCâside dynamics of largeâscale PV plants and nearby synchronous generators shaft
Abstract This paper investigates the dynamic interactions between largeâscale PV plants and nearby synchronous generators. To this end, a comprehensive model of a PV plant, including the PV arrays characteristic and their voltage controller, DC/DC converter, DCâlink dynamic, DC/AC inverter controllers, and output filter, is obtained. Then, the eigenvalues of the PV plant model are calculated, and it is revealed that the PV plant has a dynamic mode in the subâsynchronous oscillations (SSOs) range. Furthermore, the modal analysis method is employed, and it is shown that the inductance of the DC/DC converter and the DCâlink capacitor significantly contribute to the PV subâsynchronous mode. Also, it is shown that this mode oscillations penetrate the grid and increase the risk of subâsynchronous resonance (SSR). Then, the mechanism of dynamic interactions between largeâscale PV plants and torsional modes of nearby synchronous generators is revealed. This paper also investigates the required conditions for these interactions and shows that solar irradiation level and the DCâlink capacitance are the essential factors that can intensify these interactions