摘要
为了满足高压脉冲电场(PEF)液体食品灭菌对脉冲电源的特殊要求,该文首先基于传统Marx电路提出了新的拓扑结构,以减少半导体开关的使用数量,设计了用于多样性负载残余电荷的放电回路,通过对双极性脉冲电路中半导体开关导通时序的控制,实现对双极性脉冲波形的陡化,并基于此设计搭建出可供液体食品灭菌实验用的双极性方波脉冲电源;其次,利用OrCAD仿真软件对电路进行可行性分析,验证了电源在阻容性负载下输出波形依然是方波,以及电路的钳位功能;最后,设计并搭建了3级双极性方波脉冲电源的实验样机。测试结果表明,双极性脉冲电源实现了±6 kV、50~500 Hz的高压脉冲输出,输出脉冲宽度达2~20µs,正、负极性脉冲上升沿与下降沿在300ns内。通过设计回路对负载及时放电,显著陡化了脉冲拖尾,具有良好的负载适应性。利用搭建的双极性方波脉冲电源灭菌实验平台对生鸡蛋清进行灭菌实验,结果表明,提高双极性方波脉冲输出的电压幅值、频率和宽度均可以增强对液体食品的灭菌效果,且脉冲电压幅值的提高对灭菌效果的提升更加显著,但脉冲电压幅值、频率和脉冲宽度的提高均会使液体食品温度升高从而导致异常放电,因此需要合理地调控三个参数来控制液体食品的温升以获得更好的灭菌效果。该文可为双极性方波脉冲液体灭菌技术提供理论和技术支持。
Pulsed electric fields(PEF)sterilization technology has the advantages of low energy consumption,short sterilization time,high efficiency,and low processing temperature.The high-voltage pulsed electric field acts on the biofilm of the cell to form a transmembrane voltage.When the trans-mode voltage exceeds a certain critical value,cells rupture and ultimately die completely.The sterilization technology has a small temperature rise and can maximize the retention of food nutrition and flavor taste.This non-thermal sterilization technology has received extensive attention.At present,the bipolar pulse power supply solves the tailing phenomenon in the sterilization of liquid food by means of discharge circuit and controlling the conduction time of solid state switch,but the tailing phenomenon still exists,which will cause the temperature of the treated liquid to rise,damage food nutrition,affect taste,and lead to the abnormal discharge of the treated liquid.A new topology structure based on Marx circuit is proposed.This topology reduces the number of semiconductor switches used.A discharge circuit for residual charges of diverse loads is designed.The working process of the new topology circuit is introduced in detail.Combined with the control of the conduction sequence of the semiconductor switch in the bipolar pulse circuit,the output of the bipolar square wave pulse is realized.The feasibility analysis of the three-stage bipolar square wave pulse circuit is carried out by using OrCAD simulation software.It is verified by simulation that the output waveform of the power supply is still a square wave under the resistance-capacitance load,which realizes the steepening of the bipolar square wave pulse waveform.At the same time,it is verified that the circuit has clamping function.The experimental prototype of a three-stage bipolar square wave pulse power supply is designed and built.The performance index of the pulse power supply prototype and the selection of the main components are given.The solid-state switch uses ABB's 5SNE0800E330100 module containing an anti-parallel diode and a separate diode module.The module can make the power supply structure more compact,reduce the inductance component of the circuit,and improve the rising edge of the bipolar square wave pulse.The test results show that the bipolar pulse power supply achieves a high-voltage pulse output of±6 kV and 50~500 Hz.The output pulse width is 2~20μs.The rising edge and falling edge of the positive and negative pulses are within 300 ns.By designing a circuit to discharge the load in a timely manner,the pulse tail is significantly steepened,and it has good load adaptability.A bipolar square wave pulse power supply sterilization experimental platform was established.The high voltage pulse sterilization system platform is mainly composed of bipolar square wave pulse power supply,liquid device to be treated,water pump,degassing treatment room,sterilization treatment room,liquid device after treatment,temperature control device and measuring device.Taking the bacteria naturally existing in raw egg white as an example,the sterilization experiment was carried out to study the sterilization effect under different amplitude,frequency and pulse width of high voltage pulse power supply output.The results show that increasing the voltage amplitude,frequency and width of bipolar square wave pulse output can enhance the sterilization effect of liquid food,and the increase of pulse voltage amplitude can improve the sterilization effect more significantly.However,the increase of pulse voltage amplitude,frequency and pulse width will lead to the temperature rise of liquid food and lead to abnormal discharge.Therefore,it is necessary to adjust three parameters reasonably to control the temperature rise of liquid food in order to achieve better sterilization effect.
作者
朱博
马成勇
吴国延
苏贺
魏新劳
Zhu Bo;Ma Chengyong;Wu Guoyan;Su He;Wei Xinlao(Key Laboratory of Engineering Dielectrics and Its Application Ministry of Education,Harbin University of Science and Technology,Harbin 150080,China;Huaneng Guanyun Clean Energy Power Generation Co.Ltd,Lianyungang 222228,China)
出处
《电工技术学报》
EI
CSCD
北大核心
2024年第16期5121-5133,共13页
Transactions of China Electrotechnical Society
关键词
高压脉冲电场
脉冲灭菌
双极性方波
MARX电路
High voltage pulse electric field
pulse sterilization
bipolar square wave
Marx circuit
