摘要
目前锁相环方法有过零点检测法,低通滤波器开环锁相法,dq变换闭环锁相法和增强型锁相(EPLL)法。对于前3种方法分别存在过零点畸变,动态响应慢和存在二次谐波等缺点。EPLL系统可以结合对称分量法解决上述问题,但输入电压谐波含量的变化导致其抑制谐波能力也会变化,自适应能力差。在EPLL基础上,采用归一化方法提出一种自适应数字锁相环,可以降低锁相环对输入谐波的敏感度,适应谐波含量在大范围内变化,并给出在F2812上的实现方案。最终,通过实验结果验证改进方法的可行性。
At present, the available PLL methods are zero-crossing, open-loop PLL with low-pass filter, closed- loop PLL with dq transformation and enhancement PLL （EPLL）. There are several shortcomings in the first three methods, such as zero- crossing distortion, slow dynamic response and the presence of second harmonic. For EPLL system,symmetrical component method can be combined to make up for these shortcomings. However, the ability of EPLL harmonic suppression will be changed with changes in the harmonic content, resulting in adaptive ability is poor. Based on EPLL, an adaptive digital PLL was presented,using normalization method,which can reduce the sensitivity of input voltage harmonic and adapt to change within a wide range of harmonic. Implementation is given based on F2812. Finally, experiment results show the feasibility of improved method.
出处
《电气传动》
北大核心
2013年第1期52-55,共4页
Electric Drive
