一种矿用变频器滤波装置  

A mine-used frequency converter filter device

作　　者：荣相 史晗 蒋德智 眭先明 王越 RONG Xiang;SHI Han;JIANG Dezhi;SUI Xianming;WANG Yue(CCTEG Changzhou Research Institute,Changzhou 213015,China;Tiandi(Changzhou)Automation Co.,Ltd.,Changzhou 213015,China)

机构地区：[1]中煤科工集团常州研究院有限公司,江苏常州213015 [2]天地(常州)自动化股份有限公司,江苏常州213015

出　　处：《工矿自动化》2020年第5期76-81,共6页Journal Of Mine Automation

基　　金：天地科技股份有限公司科技创新创业资金专项资助项目(2018-TD-QN016)。

摘　　要：矿用变频器与电动机通过长线电缆连接,脉宽调制(PWM)脉冲在传输过程中存在电压反射现象,从而引起电动机端产生尖峰电压,严重影响变频驱动系统的运行可靠性。目前,矿用隔爆变频器一般采用串联输出电抗器的方式来抑制尖峰电压,但抑制效果有限;而采用RC滤波装置和LRC滤波装置抑制尖峰电压的方法主要针对380,660 V变频器,不能满足煤矿井下1140 V变频器对尖峰电压的抑制要求。针对长线电缆远距离传输引起的尖峰现象,分析了实际应用中电动机负载、PWM上升时间及电缆长度对尖峰电压的影响:长线电缆终端反射系数对电动机负载的变化不敏感,在滤波参数的设计过程中可忽略电动机负载的影响;PWM上升时间越长,电缆长度越短,则电动机端尖峰电压越小。根据上述分析,结合电缆长度和装置功率损耗,提出了一种适用于煤矿井下1140 V变频器的LRC滤波装置设计方案,在PWM脉冲信号传入长线电缆之前,利用该LRC滤波装置延长PWM上升时间,达到抑制尖峰电压和高du/dt的目的。仿真和试验结果验证了该滤波装置的有效性。The mine-used frequency converter is connected with motor through a long cable,and there is phenomenon of voltage reflection in transmission process of pulse width modulation(PWM)pulse,which causes spike voltage at the motor end and seriously affects operation reliability of frequency conversion driving system.At present,mine-used flame-proof frequency converter usually adopts series output reactor to suppress spike voltage,but suppression effect is limited.And the methods of suppressing spike voltage by using RC filter device and LRC filter device mainly aim at 380 V and 660 V frequency converter,which cannot meet requirement of suppressing spike voltage by 1140 V frequency converter in underground coal mine.In view of the spike phenomenon caused by long-distance transmission of long cable,the effects of motor load,PWM rising time and cable length on the spike voltage in practical application were analyzed.The reflection coefficient of long cable terminal is not sensitive to change of motor load,and influence of motor load can be ignored in design process of filter parameters.The longer the rising time of PWM and the shorter the cable length,the smaller the spike voltage at the end of the motor.According to the above analysis,combined with cable length and device power loss,a design scheme of LRC filter device suitable for 1140 V frequency converter in underground coal mine was proposed.Before PWM pulse signal is introduced into the long cable,the LRC filter device is used to delay PWM rising time,so as to achieve the purpose of suppressing spike voltage and high d u/d t.Simulation and experimental results verify effectiveness of the filter device.

关 键 词：1140 V矿用变频器 变频驱动 LRC滤波装置 长线电缆 尖峰电压 du/dt 脉宽调制 

分 类 号：TD608[矿业工程—矿山机电]