直流侧电压高二次纹波率条件下的单相逆变器谐波削弱调制  

Harmonic Reduction Modulation Strategy of Single-phase Inverter with High Second-order Ripple Rate of Voltage on DC Side

作　　者：徐辰华[1] 伍建松 刘斌[1] 陈延明[1] 陆益民[1] 吕智林[1] XU Chenhua;WU Jiansong;LIU Bin;CHEN Yanming;LU Yimin;LYU Zhilin(School of Electrical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学电气工程学院

出　　处：《电力系统自动化》2020年第3期176-184,共9页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目（61863003）;湖南省自然科学基金资助项目（2018JJ3690）~~

摘　　要：传统的单极性与双极性单相逆变调制方法的推演是基于直流母线电压为理想恒定直流量的前提。在实际的单相系统中,交直流功率的耦合使得单相逆变器直流母线电压含大量二倍交流电压频率的纹波分量。若采取传统逆变调制,二次纹波分量又使得交流输出侧的三次谐波含量增加,影响交流输出侧的电能质量。文中采用双重傅里叶变换从理论上对输出电压的谐波特性进行评估,从而提出了一种在直流侧电压高二次纹波率条件下的单相逆变器谐波削弱调制方法。利用基于三阶广义积分器的增强型锁相环提取直流母线上的二次纹波分量,并通过在逆变调制系数中注入相反二次分量的方法,达到削弱输出侧三次谐波,降低交流总谐波畸变率的目的。最后,通过实验验证了所提主动调制方法的合理性和可行性。The derivation of the traditional modulation strategy for unipolar and bipolar single-phase inverters is based on the assumption that the DC bus voltage is an ideal constant DC parameter.However,due to the DC/AC power coupling,the DC bus voltage of the single-phase inverter contains a large amount of ripple component of double AC voltage frequency in the practical single-phase inverter.With the traditional modulation strategy,the second-order ripple component causes the increase of the third-order harmonic on the AC side,and impacts the power quality of AC output voltage.By means of the double Fourier transform method,the harmonic characteristics of output voltage are theoretically evaluated.Then,this paper proposes a harmonic reduction modulation strategy of single-phase inverter with a high second-order ripple rate of voltage on the DC side.Based on the third-order generalized integrator,the second-order ripple component in the DC bus voltage is extracted by the enhanced phase-locked loop(PLL).By injecting the opposite second-order components into the modulation coefficient,the third harmonic and the total harmonic distortion(THD)of the output voltage have been reduced.Finally,the rationality and feasibility of the active modulation strategy are verified by experiments.

关 键 词：单极性调制 直流母线电压纹波 三次谐波 三阶广义积分器 双重傅里叶分析 

分 类 号：TM464[电气工程—电器]