A constraint-aware controller for renewable power plant operation under communication delays

Abstract

The control of reactive power at the point of interconnection in large wind farms and PV plants poses a significant challenge. With PV/Wind units scattered over several kilometers and numbering in the hundreds, coordinating them effectively becomes a complex task, especially when accounting for potential delays in communications with the central controller. This paper presents a method to address the coordination of generation units, ensuring a consistent level of reactive power globally while considering communication delays between units and the central controller. Moreover, once the control system is designed, a reference governor is introduced to dynamically manage the reactive power reference, ensuring compliance with operational constraints. The proposed approach is evaluated through simulations using highly detailed system models, demonstrating its advantages and effectiveness. In particular, for a power plant composed of five 1 MW generators, settling times of less than one second are achieved, as required by the network codes. In addition, fulfillment of all operating constraints is guaranteed.