  This paper proposes a novel control strategy in which Renewable Energy
Sources (RES) considered in a new Dynamic Virtual Power Plant (DVPP) concept
directly participate to Secondary Frequency Control (SFC). This allows full
participation of these generators to SFC, i.e., in the same manner as classic
synchronous generators by fulfilling identical specifications from both control
and contractual points of view. An internal real-time redispatch has been
proposed to account in DVPP in order to determine the amount of active power
injection by each RES unit for provision of frequency support in secondary
level. The whole control scheme is designed to take into account both rapid and
slow dynamics of modern power systems which contain both classic synchronous
generators and rapid power electronics for renawable energy sources in which
DVPP is supposed to be inserted. The performance of secondary frequency control
strategy has been validated through simulation studies on a two-area benchmark
with mixed wind power plants and classic synchronous generators. This work is
part of the H2020 POSYTYF project (https://posytyf-h2020.eu/).
