摘要
单相H桥逆变器由于其结构模块化、控制简单、易扩展特性,广泛应用于新能源并网技术并起到至关重要的作用。但其直流侧谐波会耦合到交流侧对交流系统造成影响,严重时会威胁系统的安全运行。本文基于H桥工作原理,结合采样方式建立SPWM调制模型,依据傅里叶级数分析法,推导逆变器输出电压的各次谐波表达式。通过建立逆变器输出电压与开关函数之间的数学关系,针对实际工况逆变器直流侧含有谐波源的情况,提出一种谐波传导定量分析方法,实现精确得到不同采样方式下逆变器直流侧含有谐波时输出交流电压的各次谐波表达式,以及揭示谐波从直流侧传递到交流侧机理的目的。
Single-phase H-bridge inverters are widely used in new energy grid-connected technology and play a vital role due to its characteristics of modular structure,simple control,and easy expansion.However,the harmonics on the DC side will be coupled to the AC side and affect the AC system.In severe cases,it will threaten the safe operation of the system.By introducing the working principle of the H-bridge inverter and the sampling modes of SPWM modulation,the Fourier series is deduced for quantitative evaluation harmonics.Through the analysis of the relationship between the inverter output voltage and the switching function,a quantitative analysis method for harmonics will be provided when the DC side of the inverter contains harmonic sources in practice.This method can give the accurate expression of each harmonic of the output voltage of the converter under different sampling methods.The different harmonic characteristics of inverter output voltage under different sampling modes will be explained in principle.It also can reveal the principle of harmonic transfer from the DC side to the AC side.
作者
全良臣
QUAN Liangchen(China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan Hubei 430000,China)
出处
《铁道建筑技术》
2023年第4期5-10,共6页
Railway Construction Technology
基金
中铁第四勘察设计院集团有限公司技术开发项目(TSYSDY-JLLCHSD[2020]-13)。
