准Z源逆变器直流链电压跌落的判断和抑制方法  

Judgment and Suppression Methods for DC-Link Voltage Sag of Quasi Z-Source Inverter

作　　者：许宇豪 肖海峰 马昭 高文 贺昱曜[2] Xu Yuhao;Xiao Haifeng;Ma Zhao;Gao Wen;He Yuyao(School of Electronics Engineering Xi’an Aeronautical University,Xi’an 710077 China;School of Marine Science and Technology Northwestern Polytechnical University,Xi’an 710072 China)

机构地区：[1]西安航空学院电子工程学院,西安710077 [2]西北工业大学航海学院,西安710072

出　　处：《电工技术学报》2022年第14期3688-3700,共13页Transactions of China Electrotechnical Society

基　　金：陕西省科技厅项目(2020JM-632);陕西省教育厅项目(21JX012,21JK0704)资助。

摘　　要：准Z源逆变器是一种允许桥臂直通的特殊升压变换器,在新能源电动汽车、光伏和风电等分布式发电系统中具有广泛应用前景。准Z源逆变器直流链电压泵升时存在一个潜在问题,若直流侧电感储能不足会使二极管电流断续,从而导致直流链电压发生跌落,严重降低了准Z源逆变器的输出性能和安全可靠性。针对该问题,首先,该文定义电压跌落深度的概念来计算和衡量直流链电压升高和降低的幅值。然后,在综合分析造成二极管电流断续因素的基础上,提出直流链电压跌落判断方法,可根据当前系统参数和状态预判直流链电压是否发生跌落。最后,为了防止准Z源逆变器出现非正常状态,基于系统协调控制的思想提出了直流链电压跌落抑制方法。结果表明,所提出的方法能够准确预测直流链电压跌落的条件,并能够有效防止直流链电压跌落。The quasi Z-source inverter is a special boost converter with ability of short-circuiting the bridge arm in the same phase.It has a wide application prospect in new energy electric vehicles and distributed generation systems,such as photovoltaic and wind power systems.However,there is a potential problem when the DC-link voltage is boosted,i.e.,the inductor on the dc-side of inverter with insufficient energy storage will make the diode current discontinuous.This will lead to DC-link voltage sag,a phenomenon that seriously reduces the output performance and safety and reliability of the quasi Z-source inverter.To solve this problem,the definition of voltage sag depth is firstly proposed to calculate and measure the rise and fall amplitude of DC-link voltage.Secondly,based on the comprehensive analysis of the factors causing the diode current interruption,a method for judging DC-link voltage sag is proposed.It can be used to predict whether DC-link voltage drops or not according to the system parameters and state.Thirdly,to prevent the quasi Z-source inverter from operating in the abnormal state,a method for suppressing DC-link voltage sag is proposed based on the idea of system coordinated control.The results indicate that the proposed method can accurately predict the conditions of DC-link voltage sag and effectively avoid DC-link voltage sag.

关 键 词：准 Z 源逆变器 直流链电压 电压跌落深度 二极管电流断续 

分 类 号：TM13[电气工程—电工理论与新技术]