基于频率合成技术超声波电源的设计

Design of Ultrasonic Power Based on Direct Digital Synthesis Technique

针对传统超声电源采用模拟锁相电路进行频率跟踪时,存在锁相范围窄、元器件一致性差、在负载突变时易失锁等缺点。提出一种利用直接数字频率合成技术的频率跟踪方法,对其设计方法、工作原理进行了阐述。并进行了实验,结果表明该方法可很好地跟踪负载谐振的变化,显著地减小了功率器件的开关损耗并提高了电源效率。

Traditional frequency-tracking technique of ultrasonic power often adopts analog phase-locked loop circuit. But it has some defects, such as the narrow locked-in range, poor consistency of components and the tendency to lose phase-locked with a sudden change in load. Therefore, a control strategy by direct digital frequency synthesis technique is proposed, and an explanation to its working principle and design method are given. The experimental results show that the ultrasonic power using frequency synthesis technique has good characteristics of frequency-tracking. And this method significantly improves the efficiency of the power supply.