Open AccessPerformance analysis and capacitor design of three‐phase uncontrolled rectifier in slightly unbalanced grid
Author(s) -
Fang ZhiJian,
Cai Tao,
Duan ShanXu,
Chen Changsong,
Ren ChengDa
Publication year - 2015
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2014.0421
Subject(s) - rectifier (neural networks) , harmonics , peak inverse voltage , precision rectifier , voltage , control theory (sociology) , harmonic , capacitor , three phase , grid , pwm rectifier , power factor , computer science , voltage source , voltage droop , engineering , electrical engineering , mathematics , physics , control (management) , acoustics , geometry , stochastic neural network , artificial intelligence , recurrent neural network , artificial neural network , machine learning
Slightly unbalanced grid voltage can cause large unbalanced current and non‐characteristic harmonics in three‐phase uncontrolled rectifier. This study proposes an accurate model to analyse the performance of three‐phase uncontrolled rectifier in slightly unbalanced grid. Three appreciative operation modes (three‐phase rectifier, double‐phase rectifier and single‐phase rectifier with discontinuous rectifier current) in slightly unbalanced grid are discussed in detail in this study. Moreover, the closed‐form analytical expressions for boundaries of modes are also derived. To further aid the designer, the curves of current unbalance, third harmonic current, output average voltage, output voltage droop and output voltage harmonic as function of loads under the condition of 2% voltage imbalance are illustrated. Then the design procedure of capacitor is given considering the influence of unbalance and harmonics in slightly unbalanced grid. Finally, a design case is expressed. The design results are realised in a 5 kW three‐phase uncontrolled rectifier to verify the accuracy of the proposed models. The proposed model provides a tool for rapidly and accurately judging the impact of various loads on the rectifier performance in slightly unbalanced grid.