Contributions to the power flow control of distributed generation systems integrated energy storage schemes.
Contributions to the power flow control of distributed generation systems integrated energy storage apparatus
The increasing insertion of renewable energy sources, connected to the power grid through
power converters, can cause instabilities due to the non-dispatchable nature of these
power systems. The integration of energy storage systems (ESS) to the distributed generator
(DG) inverter can smooth power injection at the point of common coupling (PCC)
with the electrical grid, contributing to the voltage and frequency stability of the electrical
system. In this work, a cooperative control strategy is proposed for regulating the DC
bus voltage of the grid-connected inverter, integrated with an ESS, in order to minimize
possible fluctuations of voltage and frequency in the PCC of a low voltage electrical grid.
Comparisons are made with traditional control methods to evaluate the effectiveness of
the proposed method. The strategy validation is performed through experimental results,
in a wind emulation platform composed of a permanent magnetic synchronous generator
(PMSG) and a battery bank. It was verified that the inclusion of the storage allowed the
increase of the system stability margin, the reduction in the DC bus oscillation, the smoothing
of the active power delivered and the mitigation of the voltage fluctuations in the
PCC.