大功率数字式超声电源设计

发布时间：2018-08-22 19:43

【摘要】：在中药萃取过程中，加入超声波对药物进行超声作用，可有效提高中药材的萃取量。受限于功率超声设备输出功率过小和超声电源在工业现场使用不便的特点，功率超声技术在中药萃取领域的应用一直都没有规模化和产业化。近几年，随着超声换能器工艺的改进和大功率数字式电源的出现，使功率超声设备在中药萃取领域的应用成为可能。本文主要对大功率数字式超声电源进行一些研究，以期对实际工业应用提供一定的帮助。本文对功率超声电源的匹配电路做了一些研究。舍弃了原有根据串联谐振频率Fs进行静态匹配的思路，采用新型动态匹配方式，将换能器与匹配电路等效为一个整体，公式推导得到整体系统的动态耦合频率，超声电源输出频率只需等于当前系统耦合频率，即可实现系统谐振。这为超声数字电源进行频率自动搜索和自动跟踪提供了理论依据。本文设计了一套适合数字式超声电源的控制算法。针对超声电源所作用负载的特性，本文采用积分分离PI控制算法在频率搜索阶段和频率跟踪阶段分别对通过换能器端的电流做恒流控制。在频率控制方面，提出采用变步长的方法进行谐振频率的搜索，针对负载变化程度的不同分别设计了相应的频率跟踪算法，并最终提出适用于各种负载变化情况的通用频率跟踪算法。本文所设计电源内嵌Modbus_RTU通信协议，利用此协议可实现计算机对多台超声电源的远程集中设置。本文所设计的功率超声设备已经在河南宛西制药厂的中药萃取生产中得到应用，结果表明，使用超声设备后可使某些中药材的出膏量较不使用超声设备之前有较大的提高。因此，，功率超声波技术在中药萃取领域的规模化应用具有广阔的前景。
[Abstract]:In the process of traditional Chinese medicine extraction, adding ultrasonic wave can effectively improve the extraction amount of traditional Chinese medicine. Limited by the characteristics that the output power of power ultrasonic equipment is too small and the ultrasonic power supply is inconvenient to be used in industrial field, the application of power ultrasonic technology in the field of traditional Chinese medicine extraction has not been large-scale and industrialized. In recent years, with the improvement of ultrasonic transducer technology and the emergence of high power digital power supply, the application of power ultrasonic equipment in the field of traditional Chinese medicine extraction has become possible. In this paper, some research on high power digital ultrasonic power supply is carried out in order to provide some help for practical industrial application. In this paper, the matching circuit of power ultrasonic power supply is studied. The dynamic coupling frequency of the whole system is obtained by using a new dynamic matching method, and the transducer and matching circuit are equivalent to a whole, and the dynamic coupling frequency of the whole system is derived by deducing the formula, which is based on the static matching method based on the series resonant frequency Fs. The output frequency of ultrasonic power supply only needs to be equal to the current system coupling frequency, and the system resonance can be realized. This provides a theoretical basis for automatic frequency search and automatic tracking of ultrasonic digital power supply. In this paper, a control algorithm suitable for digital ultrasonic power supply is designed. According to the characteristics of the load acting on the ultrasonic power supply, the integral separation Pi control algorithm is used to control the current passing through the transducer at the frequency searching stage and the frequency tracking stage, respectively. In the aspect of frequency control, the method of variable step size is proposed to search the resonant frequency, and the corresponding frequency tracking algorithms are designed according to the varying degree of load. Finally, a general frequency tracking algorithm suitable for various load variations is proposed. The Modbus_RTU communication protocol embedded in the power supply is designed in this paper, which can be used to realize the remote centralized setting of multiple ultrasonic power sources by computer. The power ultrasonic equipment designed in this paper has been used in the extraction production of traditional Chinese medicine in Henan Wanxi Pharmaceutical Factory. The results show that the quantity of extract of some traditional Chinese medicinal materials can be greatly increased after the use of ultrasonic equipment compared with that before the use of ultrasonic equipment. Therefore, the application of power ultrasonic technology in the field of traditional Chinese medicine extraction has a broad prospect.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB552

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