High-Frequency Oscillations and Their Leading Causes in DC Microgrids

Impact of resources distribution on high‐frequency behaviour of photovoltaic systems

“…Obviously, higher frequencies of the intersection, due to the LF nature of power systems, are preferable. In addition, smaller magnitudes of admittances, according to [13], will reduce the harmonic oscillations.…”

“…To specify the frequency-domain behaviour of infinite distributed CCIs, (12) and (13) obtain the limit of Y t − cl#n at very high-frequencies and LFs, respectively. It can be seen from (13) that in the presence of line impedances, R l plays a role in determining the LF behaviour…”

“…So far, the interaction of CCIs with the power grid has been the topic of plenty of studies [11][12][13][14][15][16]. In these studies, the interaction in an individual grid-connected CCI and also in grid-connected paralleled CCIs have been thoroughly addressed.…”

Phase Shaping Method for Negative Input Admittance of Buck Converter Based on Sliding Mode Disturbance Observer

“…When a single power converter directly supplies power to an independent CPL, the current harmonics of the load converter are suppressed by the filter inside the source converter, so no LC low-pass filter is needed between the two converters. For the instability of this cascade system, the damping factor estimation algorithm [11] and the negative impedance detection method [12] can be used to compensate for the system damping adaptively in real-time. Moreover, the fast state-plane-based source-end controller solves bus voltage oscillation caused by constant power load and improves the dynamic performance [13].…”

Analysis and mitigation of low‐frequency oscillations in hybrid AC/DC microgrids with dynamic loads

“…DERs with decentralised control approach‐based virtual voltage/frequency are used in [13], whereas virtual active/reactive control strategies are proposed in [14, 15] to damp power oscillations. A dynamic droop gain in association with a virtual impedance loop is used in a DC microgrid to damp low‐frequency power oscillations in [16–19]. Although the aforementioned approaches ensure improved power oscillation damping (POD) performance, they significantly affect the voltage profile and power sharing performance.…”