Adaptive Active Power Sharing Techniques for DC and AC Voltage Control in a Hybrid DC/AC Microgrid

Abstract

This paper deals with the AC and DC dynamic voltage control in a hybrid DC/AC Microgrid (MG) with central and distributed Battery Energy Storage Systems (BESSs), applying a power sharing mechanism between the different devices in the MG. The MG is composed by a multiport transformation center and two fixed frequency 3 phase AC Nanogrids (NGs) coupled to a DC bus through 3-phase Power Electronic Converters (PECs). The system pursues to minimize the dependence on the utility grid and the stress in the MGs central BESS, while increasing the power handling capability and the overall system stability during islanding condition. In order to approach the proposed aim, two main concerns are studied in this paper: an adaptive power sharing mechanism between the DC bus and the AC NGs for DC voltage control, and the design and implementation of an AC dynamic local voltage compensator based on Distributed Energy Storage System (DESS). The proposed techniques are validated through simulations and experimental results.

Design and Control of a Modular 48/400V Power Converter for the Grid Integration of Energy Storage Systems

“…2) Voltage Control: The voltage regulator has been designed using the Quadratic Voltage Control proposed in [22]. Where the expression that defines the system is given by (20).…”

“…Since the disturbance introduced by the TPDAB is related with the demanded or delivered load power, and considering there are no losses, the relationship between the current through the inductor and the power through the capacitor is given by (22). Because the I pDC is not measured, P in is estimated as the power demanded by the TPDAB, P F LOW .…”

Adaptive active power sharing techniques for DC and AC voltage control in a hybrid DC/AC microgrid

“…In order to obtain the transient window, a transient detection method, based on the presented in [22], is proposed for its application to the LVDC voltage. The method, defined by equation (24), is based on the squared correlation of the measured LVDC voltage (v dc ), with a signal of period T and zero average (sin 2πt T ).…”

“…This paper follows the study presented in [24]. The changes incorporated respect to the conference paper are the improvement of the adaptive power sharing algorithm and the experimental verification of the proposed methods.…”

“…Simulation results: system performance using the proposed methods. a) LVDC Voltage; b) N G 1 voltage magnitude in p.u., c) N G 2 voltage magnitude in p.u., d) transient window obtained by(24), and sharing coefficients, e) Power shared by the elements participating in the active power control, f) Load drawn by the CPLs located in the NGs.…”