This paper analyses and compares different methodologies for supporting system frequency in low inertia power systems using HVDC interconnectors. Reduced system inertia, caused by the massive integration of converter-interfaced renewables and the displacement of conventional synchronous generation, can result in high values of rate of change of frequency (ROCOF), increasing the risk of frequenc...

The purpose of this note is to mechanistically derive the logistic population growth models from the well tested and received Droop equation. 1. A mechanistic derivation of the logistic equation. Population growth involves and often is determined by the birth and death processes. Most of the existing studies focus on birth process on the combined birth and death processes (the growth process). ...

This paper presents a distributed hierarchical control framework to ensure reliable operation of dc microgrid (MG) clusters. In this hierarchy, primary control is used to regulate the common bus voltage inside each MG locally. An adaptive droop method is proposed for this level, which determines droop coefficients according to the state-of-charge (SOC) of batteries automatically. A small-signal...

Software defined radio has find important place in modern communication systems where majority of signal processing is performed in the digital domain using programmable DSPs.Digital down conversion (DDC) is one of the core technologies in SDR, as well as an important component of digital intermediate frequency receiver system. DDC use CIC decimation filters for sample rate decimation. CIC deci...

1 Introduction GaN-based light-emitting diodes (LEDs) deliver the desired high efficiency only at relatively low injection current density [1]. At the elevated current densities required in practical high-brightness applications , the efficiency is substantially reduced. This efficiency droop phenomenon has been intensely investigated for a number of years, but the physical mechanisms behind it...

In this work a mechanistic explanation of the classical algae growth model built by M. R. Droop in the late sixties is proposed. We first recall the history of the construction of the "predictive" variable yield Droop model as well as the meaning of the introduced cell quota. We then introduce some theoretical hypotheses on the biological phenomena involved in nutrient storage by the algae that...

The expected path of an open system, which is a big Poincaré system, has been found in this paper. This path has been obtained from the actual and from the expected droop of the open system. The actual droop has been reconstructed from the variations in the power and in the frequency of the open system. The expected droop has been found as a function of rotation from the expected potential ener...

Volt/var control (VVC) of smart PV inverter is becoming one of the most popular solutions to address the voltage challenges associated with high PV penetration. This work focuses on the slope sensitive local droop VVC recommended by integration standard IEEE1547, rule21 and addresses their major challenges i.e. vulnerability to instability (or voltage oscillations), significant steady state err...