Long Ju - IEEE Xplore Author Profile

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Harmonic resonance is increasingly observed in many European residential low-voltage networks, which can cause increased harmonic disturbance levels. An aggregated simulation model can be used to analyze the resonance phenomenon. Various literature has developed different frequency-domain aggregated representations of LV networks. But they are not realistic for harmonic resonance studies. To bridg...Show More
Harmonic resonance is increasingly observed in many European residential low-voltage networks, warranting its characterization and detection. Various simulation models of such networks were developed to perform harmonic studies, but they are not optimized to represent the varying harmonic resonance characteristics and the parameters it affects. To bridge this gap, a detailed simulation model in th...Show More
Importance of harmonic interactions between installations containing power-electronic based sources and loads has grown in recent years. Such interactions of voltage and current harmonics within a typical low-voltage network and an islanded microgrid with different LEDs are analyzed in this paper. The analysis is based on measurements of two laboratory setups representing a LV network and microgri...Show More
The increasing penetration of distributed generation in microgrids and the connection of different types of electronic loads cause significant levels of supraharmonic emission, especially in islanded microgrids. In this paper loads with different circuit topologies are connected to a laboratory microgrid, and supraharmonic voltages and currents are analyzed in both interconnected and islanded mode...Show More
Harmonic resonances are increasingly observed in various central European networks, which are impacted by complex parameters. This paper considers the impact of variation in both grid-side and customer-side parameters. The grid-side variations include a change in cable lengths and the distribution of customers. The customer-side variations include the time-dependent combination of various househol...Show More
Harmonic resonance is increasingly observed in public low-voltage (LV) networks of central European countries. Adverse effects, such as harmonic disturbance amplification, can be caused by harmonic resonance, which necessitates and emphasizes the importance of their continuous monitoring and detection. This article proposes a noninvasive harmonic resonance detection technique for public LV network...Show More
Harmonic resonance is increasingly observed in public networks in Germany and Europe. Adverse effects such as harmonic emission amplification can be caused by harmonic resonance, which necessitates and emphasizes the importance of continuous monitoring and detection of harmonic resonances. This paper proposes a non-invasive harmonic resonance detection methodology that relies only on the measureme...Show More
Harmonic analysis in an islanded microgrid is a significant research topic owing to its increased installation and increased power-electronics based loads. The characteristics of frequency-dependent harmonic impedance depend on various system parameters and have a direct impact on the voltage and current distortions. In this paper, impedance measurements carried out in a laboratory microgrid opera...Show More
Harmonic resonance in Low-Voltage networks is increasingly observed majorly caused due to increase in capacitive based modern power electronic equipment. This paper presents a systematic mathematical outlook on harmonic resonances and the effects of various parameters on its sensitivity. Frequency-domain based models for a single and multi-feeder network with distributed loads are considered for a...Show More
Harmonic resonance is a modern-age power quality issue. These issues are observed in public Low Voltage networks caused by increased penetration of diverse power electronic equipment using grid-side filter circuits and shunt capacitances. Harmonic resonance could result in stability issues or amplified harmonic levels in the network. The paper presents simulation results to emphasize on the import...Show More
Modular Multilevel Converter (MMC) are increasingly used in Medium Voltage and High Voltage industries for various applications. In this paper, averaging and circulating current control integrated with Selective Harmonic Elimination (SHE) modulation based on Nearest Level Control (NLC) is proposed in order to improve the performance of MMC in terms of stable operation and harmonic performance comp...Show More