51304163-300

3.PLC控制系统中电磁干扰的主要来源有哪些呢？

  (1)来自空间的辐射干扰

  空间的辐射电磁场（EMI）主要是由电力网络、电气设备的暂态过程、雷电、无线电广播、电视、雷达、高频感应加热设备等产生的，通常称为辐射干扰，其分布极为复杂。若PLC系统置于所射频场内，就回收到辐射干扰，其影响主要通过两条路径；一是直接对PLC内部的辐射，由电路感应产生干扰；而是对PLC通信内网络的辐射，由通信线路的感应引入干扰。辐射干扰与现场设备布置及设备所产生的电磁场大小，特别是频率有关，一般通过设置屏蔽电缆和PLC局部屏蔽及高压泄放元件进行保护。

  (2)来自系统外引线的干扰

  主要通过电源和信号线引入，通常称为传导干扰。这种干扰在我国工业现场较严重。

  (3)来自电源的干扰

  实践证明，因电源引入的干扰造成PLC控制系统故障的情况很多，笔者在某工程调试中遇到过，后更换隔离性能更高的PLC电源，问题才得到解决。

  PLC系统的正常供电电源均由电网供电。由于电网覆盖范围广，将受到所有空间电磁干扰而在线路上感应电压和电路。尤其是电网内部的变化，入开关操作浪涌、大型电力设备起停、交直流转动装置引起的谐波、电网短路暂态冲击等，都通过输电线路到电源边。PLC电源通常采用隔离电源，但其机构及制造工艺因素使其隔离性并不理想。实际上，由于分布参数特别是分布电容的存在，隔离是不可能的。

  (4)来自信号线引入的干扰

  与PLC控制系统连接的各类信号传输线，除了传输有效的各类信号之外，总会有外部干扰信号侵入。此干扰主要有两种途径：一是通过变送器或共用信号仪表的供电电源串入的电网干扰，这往往被忽略；二是信号线受空间电磁辐射感应的干扰，即信号线上的外部感应干扰，这是很严重的。由信号引入干扰会引起I/O信号工作异常和测量精度大大降低，严重时将引起元器件损伤。对于隔离性能差的系统，还将导致信号间互相干扰，引起共地系统总线回流，造成逻辑数据变化、误动和死机。PLC控制系统因信号引入干扰造成I/O模件损坏数相当严重，由此引起系统故障的情况也很多。

Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Fanuc A06B-6102-H226 Servo Amplifier Fast ship with warranty
Brand New
   33  326  85
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-6150-H030 Tested in Good condition
Pre-Owned
   33  319  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW ABB Variable Frequency ACS800-01-0070-3+P901 Fast Ship
Brand New
   33  290  71
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Yaskawa SGMGH-30ACA6C+SGDM-30ADA Fast Ship
Brand New
   33  283  06
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Mitsubishi HF302BS-A48 Fast Ship
Brand New
   33  282  92
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Fanuc A02B-0281-C071 LCD Unit Fast ship with warranty
Brand New
   33  157  96
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A16B-2202-0435 Tested in Good condition
Pre-Owned
   33  093  33
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Cisco WS-X6824-SFP-2T Tested in Good Conditon Fast Ship
Pre-Owned
   33  053  72
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-6100-H003
Pre-Owned
   33  048  16
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    SIEMENS SINUMERIK 810D CCU2 6FC5410-0AX02-1AA0
Pre-Owned
   32  884  83
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6FC5410-0AY03-0AA1 Tested In Good Condition
Pre-Owned
   32  882  05
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW IN BOX FANUC A06B-1498-B103 Fast ship with warranty
Brand New
   32  877  19
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW IN BOX FANUC A06B-6112-H022 Fast ship with warranty
Brand New
   32  756  96
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW MP8-3X-3X-00 ASTEC D/C:11+ MODULE
   32  734  72
  
+   20  85 shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    YASKAWA SGMGH-75DCA21/SGMGH-75DCA2S Tested in Good Condition
Pre-Owned
   32  664  52
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New ABB DSAI130 / 57120001-P Fast Ship
Brand New
   32  664  45
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Yaskawa SGM7G-1EAFC61 Fast Ship
Brand New
   32  651  32
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    ABB DSQC601 3HAC12815-1 Tested in Good condition Fast Ship
Pre-Owned
   32  643  25
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New A02B-0238-B542 FANUC A02B0238B542 Fast ship with warranty
Brand New
   32  617  96
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC servo motor A06B-0314-B563#0008 Tested in Good Condition
Pre-Owned
   32  600  65
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW ATOS KZGO-A-031/100 Fast Ship
Brand New
   32  587  93
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New In Box KEYENCE CV-5002 Fast Ship
Brand New
   32  586  89
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-0853-B300 Tested in Good condition
Pre-Owned
   32  555  41
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Rexroth HDS02  2-W040N-HS45-01-FW HDS02  2W040NHS4501FW Fast Ship
Pre-Owned
   32  528  44
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PC 6FC5371-0AA30-0AB0 Siemens NEW IN BOX Original CNC motherboard MODULE
Brand New
   32  525  45
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    LENZE servo drive EVS9330-ES Fast Ship
Pre-Owned
   32  511  48
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC PLC System 0i-MC A02B-0309-B522 Tested in Good condition
Pre-Owned
   32  484  52
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW IN BOX FANUC A04B-0231-H200 Fast ship with warranty
Brand New
   32  389  31
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Mitsubishi HG-SR421J Fast Ship
Brand New
   32  358  59
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New DUNGS DMV-DLE5080/11 Fast Ship
Brand New
   32  358  59
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW IN BOX Mitsubishi HG-JR503 Fast Ship
Brand New
   32  355  95
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Siemens 6ES7 416-3XL04-0AB0 Fast Ship
Brand New
   32  316  82
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New Sick Safety Laser Scanner S30A-6011BA Fast Ship
Brand New
   32  290  62
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A05B-2255-C103#EAW Tested in Good Condition Fast Ship
Pre-Owned
   32  222  99
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-1409-B150 Tested It In Good Condition
Pre-Owned
   32  214  86
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A06B-6141-H045
Pre-Owned
   32  212  08
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6SE7031-0TE60-Z (G41+G93+K80+M20+) Tested in Good condition
Pre-Owned
   32  184  98
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A06B-6164-H332#H580 Tested in Good Condition Fast Ship
Pre-Owned
   32  133  06
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New In Box KEYENCE CV-5001
Brand New
   32  130  77
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Fanuc A06B-6141-H030#H580 Servo Amplifier Fast Ship
Brand New
   32  056  13
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW HA-LP11K2B HALP11K2B MITSUBISHI SERVO MOTOR
   31  993  86
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Mitsubishi servo amplifier MDS-C1-V1-10 Fast Ship
Brand New
   31  969  39
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-0247-B805 Tested in Good condition
Pre-Owned
   31  951  46
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New In Box Siemens 6ES7317-7TK10-0AB0 6ES7 317-7TK10-0AB0
Brand New
   31  898  64
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FUJI V812IS Tested in Good Conditon Fast Ship
   31  893  08
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Siemens LMV51   100C2 Fast Ship
Brand New
   31  852  29