中文摘要：

将周期性扩频技术用于变换器中来抑制其电磁干扰和噪声已经得到了论证并被广泛的应用，但却忽略了其中的非线性现象．在分析了周期性扩频技术和单相SPWM．H桥正弦逆变器的精确频闪映射模型的基础上，研究了采用周期性扩频技术的单相H桥正弦逆变器的分岔和混沌现象，建立了H桥正弦逆变器扩频后的离散模型，通过时域图、折叠图、分岔图及李雅亚普诺夫指数谱对其非线性现象进行了分析．研究表明，扩频后的H桥正弦逆变器在进入非线性区域后更容易进入混沌区，并且周期扩频的频率会对系统产生初始分岔点的位置产生影响．

英文摘要：

The periodic spread spectrum technologies used in converter to suppress its electromagnetic interference and noise have been applied widely, while the nonlinear phenomenon is ignored. Based on the analysis of the periodic spread spectrum technology and single-phase H bridge converter accurate stroboscopic map model, the bifurcation and chaos phenomenon of the single-phase H bridge circuit is studied and the discrete model of the H bridge sine inverter is established by means of periodic spread spectrum technology. The nonlinear phenomenon is analyzed using the time domain chart, folding map, bifurcation diagram and Lyapunov index spectrum. Results show that the H bridge sine inverter based on the spread spectrum technology can go into the chaotic region more easily when it is in the nonlinear region, and it is concluded that the frequency of cycle spread spectrum has important effect on the initial branch point position of system.