Micro-Grid Inrush Current Stability Analysis

Abstract

Transient currents can severely impact the operation of weak or islanded grids. Inrush current electromagnetic compatibility challenges, due to their unpredictable and intermittent nature, are very difficult to identify. Using multi-point synchronised measurements, analysis is performed on an inverter. The supply powers various loads that are observed during cold start as well as under load switching conditions. Inrush event triggered failure probability is linked to non linear and average load levels.

On the Importance of Power Quality in Solar Home Systems for Energy Access

“…by power electronics, problems with power quality can occur. Furthermore, turning loads on and off can cause significant transients, as a result of the inrush currents [6]. Besides, power quality issues occur by cause of loads connected to the dc bus which can propagate in the system.…”

Superposition of Transient Switching Currents for Non-Linear Devices

“…To make the data clearer, the average waveform for each test suite number of LEDs is plotted. The firing angle of the voltage has a large impact on the current peak and waveform shape [7]. The average per cluster waveform plot in Fig.…”

“…Inrush currents may reach such a degree that protection systems are activated, the power supply components are damaged [5] as well as causing severe voltage sags, swells or flicker effects compromising EMC [6]. In [7] it is shown that connecting a small SPEC load component, which is a fraction of the nominal capacity of an inverter, has the ability to disable the system, requiring restart and severely impacting the reliability of the system. Electromagnetic interference (EMI) caused by the superposition of many small inrush currents, create large net peak currents with high crest factor (CF) which can be equal to or exceed the effect of single higher power devices.…”