Lei Qi, Zhiyuan Shen, Jianjian Gao, Guoliang Zhao, Xiang Cui and Wei Kang
This paper aims to establish the wideband model of a sub-module in a modular multilevel converter (MMC) and analyze the switch transients of the sub-module.
Abstract
Purpose
This paper aims to establish the wideband model of a sub-module in a modular multilevel converter (MMC) and analyze the switch transients of the sub-module.
Design/methodology/approach
The paper builds an MMC sub-module test circuit and conducts dynamic tests both with and without the bypass thyristor. Then, it builds the wideband model of the MMC sub-module and extracts the model parameters. Finally, based on the wideband model, it simulates the switch transients and analyzes the oscillation mechanism.
Findings
The dynamic testing shows the bypass thyristor will add oscillations during switch transients, especially during the turn-on process. The thyristor acts like a small capacitor and reduces the total capacitor in the turn-on circuit loop, thus causing under-damped oscillations.
Originality/value
This paper found that the bypass thyristor will influence the MMC sub-module switch transients under certain circumstances. This paper proposes a partial inductance extraction procedure for the MMC sub-module and builds a wideband model of the sub-module. The wideband model is used to analyze and explain the switch transients, and can be further used for insulated gate bipolar transistor switch oscillation inhibition and sub-module design optimization.
Details
Keywords
Qi Yao, Chao Hu and Jianjian Du
To provide theoretical guidance on improving luxury brands’ marketing performance, this study aims to examine the impact mechanism and boundary conditions of luxury brand buyers’…
Abstract
Purpose
To provide theoretical guidance on improving luxury brands’ marketing performance, this study aims to examine the impact mechanism and boundary conditions of luxury brand buyers’ consumption resources on observers’ brand attitudes from the perspective of consumers’ power distance beliefs (PDBs).
Design/methodology/approach
Four experimental studies were conducted. Study 1 examined the influence of the interaction of consumption resources and PDBs on luxury brand attitudes; Study 2 examined the mediating role of prestige perception. Study 3 excluded alternative explanations of (dis)association motivation and envy. Finally, Study 4 examined the moderating effect of brand relationship norms.
Findings
Consumers with low PDBs had lower attitudes towards luxury brands when consumption resources were acquired through luck (rather than effort). However, no significant difference in luxury brand attitudes was found between these two consumer groups when PDBs were high. Consumers’ perceptions of prestige played a mediating role in the main effect, whereas brand relationship norms moderated the main effect.
Originality/value
First, this study reveals the unique role of PDBs in shaping consumer attitudes towards luxury brands. Second, it uses consumption resources as a signal for luxury consumption and identifies a way to influence consumers’ attitudes towards luxury brands, namely, their perceptions of prestige. Third, it uncovers the influence of consumers’ brand relationship norms on the formation of luxury brand attitudes.