High Voltage Electric Pulse Discharge And Its Application In Industry

Electrostatic dust removal is a main method to reduce industrial gas.Due to the continuous improvement of the emission standard,the traditional electrostatic precipitator can't meet the demand and must to be optimized.The traditional electrostatic precipitator is generally supplied by DC high-voltage power with low electric field breakdown and has no spark discharge control function.The high voltage pulse power supply and its application in dust removal are studied in this paper.The main research work and innovation points are as follows:(1)The principle of electrostatic dust removal is studied in this paper to propose that the best way to increase the collection efficiency is to strengthen the corona discharge by increasing the power supply voltage.However,if the voltage is too high,electric field will breakdown and the discharge mode will change from corona discharge to spark discharge,which will reduce the collection efficiency and damage the equipment.Because of the high breakdown field intensity of high voltage pulse,the DC overlapped pulse power supply can increase the dust removal voltage and reduce the effects of spark discharge.(2)A pulse power supply circuit topology is designed in this paper based on the high voltage semiconductor switch.The pulse is generated by LC resonance,and most of the electric energy can be recovered in the negative half cycle.The pulse voltage and pulse width can be adjusted.The pulse generator platform produces the narrowest pulse width of 85 us and the experiment has showed that it can be used to remove dust.(3)The spark tracking control is designed in this paper according to the optimal pulse voltage.The spark tracking control can automatically adjust spark frequency according to the intensity of spark discharge.Compared with the traditional control,spark tracking control can adapt to different work conditions and the average voltage is higher so that it can increase the collection efficiency.(4)The time domain and frequency domain characteristics of spark discharge voice are analyzed and the BP neural network is established to identify spark discharge in this paper.The short-time energy(STE),short-time zero crossing rate(ZCR),linear prediction cepstrum coefficient(LPCC)or MEL frequency cepstrum coefficient(MFCC)are taken as the inputs of BP neural network.MFCC combining STE and ZCR can get the highest recognition rate.The spark sample has been optimized to enhance the anti-interference ability and robustness of the system by using two high energy frames at the moment of spark discharge.As a result,the comprehensive recognition rate reaches more than 97%.This paper also divides the intensity of spark discharge into strong,neutral and weak by the numerical boundary of STE and ZCR.(5)Based on the Internet of things,a remote monitoring system of spark discharge is composed of lower computer,server and client.The lower computer includes pulse voltage control circuit,PDM digital microphone circuit and Ethernet circuit,is mainly responsible for spark tracking control,sound signal acquisition and data interaction with the server.The server designed by JAVA language and SSM framework is C/S architecture with Mysql database,mainly runs the audio recognition algorithm of spark discharge and communicates with the lower computer and the client.The client designed for Android mobile phone provides an human-machine interface for convenient monitoring.The high voltage pulse power dust removal system designed in this paper has the functions of sound detection of spark discharge,spark tracking control and remote monitoring.The system has the advantages of good dust removal effect,high intelligent level,strong adaptive ability,friendly human-machine interface,can facilitate the later management and maintenance and promote the development of dust removal power supply.