轧钢设备的故障信号有数字量和模拟量之分,PLC采用不同的方法对这两种信号对应的故障进行诊断。
2.1基于数字量信号的故障诊断
PLC对数字量信号的识别是通过其数字量输入模块完成的。PLC控制轧钢生产设备时,设备中的压力、温度、液位、行程数字及操作按钮等数字量传感器与PLC的输入端子相连,每个输入端子在PLC的数据区中分配有一个“位”,每个“位”在内存中为一个地址。读取PLC输入位的状态值可作为识别数字量故障信号的根据。诊断数字量故障的过程,实质就是将PLC正常的输入位状态值与相应的输入位的实际状态值相比较的过程。如果二者比较的结果是一致的,则表明设备处于正常工况,不一致则表明对应输入位的设备部位处于故障工况。这就是PLC诊断基于数字量信号故障的基本原理。这种诊断方法,故障定位准确,可进行实时在线诊断。通过PLC的图形功能块编程,还可将故障诊断融入过程控制,达到保护轧钢设备的目的。
2.2基于模拟量信号的故障诊断
PLC对模拟量信号的识别是通过PLC的模拟量输入输出模块来完成的。模拟量输入输出模块采用A/D转换原理,输入端接收来自传感器或变送器的模拟信号,输出端输出的模拟信号作用于PLC的控制对象。PLC诊断模拟量故障的过程,实质就是将在相应A/D通道读到的监测信号的模拟量的实际值与系统允许的极限值相比较的过程。如果比较的结果是实际值远离极限值,则表明轧钢生产设备对应的受监控部位处于正常状态,如果实际值接近或达到极限值,则为不正常状态。判断故障发生与否的极限值根据实际系统相应的参数变化范围确定,利用PLC上的模拟量设定开关可精确设置该极限值。
当模拟量的实际值达到模拟量设定开关的设定值,PLC还能按照一定的逻辑关系启动开关量模块上的输出位,或者从PLC的通讯口主动发起通讯,从而输出故障诊断的结果,并据此实现对轧钢生产设备的控制。
2.3基于中断方式的故障诊断
PLC的中断方式有:
(1)输入中断;
(2)间隔定时器中断;
(3)高速计数器中断。其中,输入中断特别适合于轧钢生产设备的故障诊断。它对应于工业操作站的硬中断,属于外部中断,但PLC的输入中断可用PLC的外部指令来屏蔽。将轧钢生产设备的故障信号作为PLC的输入中断源,一旦出现故障信号,CPU立即响应,停止正在执行的程序,转到中断子程序中去,即可方便地对故障进行处理。它与直接利用PLC的内部逻辑完成故障诊断的不同之处在于:采用输入中断处理故障时,可停止PLC主程序的执行过程,而直接利用PLC的输入和内部逻辑处理故障时,PLC的主程序仍处于运行状态。因此,要根据故障对轧钢生产设备的影响程度选择合适的故障诊断方式。PLC的输入中断方式对后果严重的突发故障的处理特别有用。3PLC在故障诊断系统中的作用
故障诊断系统是典型的人机系统,根据系统中的信息流向和功能划分的结果[1],基于操作站智能化的故障诊断系统,如图2所示。
系统的输入模块要完成轧钢生产设备故障检测信号、控制指令和专家知识的接收工作。处理模块要求能自动实现特征参数提取、控制指令代码转换的功能。专家知识的整理和表达由领域专家和系统专家协作完成。控制模块是故障诊断系统的核心,它根据控制指令,利用专家知识,完成从故障特征到故障原因的识别工作。控制模块的功能越完善,故障诊断系统的智能化程度越高。输出模块通过声光报警装置和人机界面,给出故障定位、预报和解释的结果。其中,人机界面还能提供排除故障的技术路线。实现信息源从输入模块到输出模块的全自动流向,减少人在其中的干预作用,是轧钢生产设备对其故障诊断系统的要求。采用PLC的故障诊断系统,有助于实现故障诊断过程的自动化。
MERLIN GERIN 1A-TYPE D C60N MULTI9 1-POLE CIRCUIT BREAKER 913CB
GENERAL ELECTRIC 30A 240VAC 3 POLE INDUSTRIAL CIRCUIT BREAKER TEB132030WL
ALEN BRADLEY CIRCUIT BREAKER SERIES C 1492-SP1D010
GENERAL ELECTRIC CIRCUIT BREAKER 225A 2P 240VAC TQD22225
GENERAL ELECTRIC * CIRCUIT BREAKER * 3P 100A T
SIEMENS-ALLIS 1200A A.C. HIGH VOLTAGE CIRCUIT BREAKER TYPE 5-3AF-250-1200-?58
MITSUBISHI ELECTRIC 600VAC 75A 3-POLE CIRCUIT BREAKER NF100-CS NNB
SQUARE D LAL2640036MV800?2 400 AMP CIRCUIT BREAKER
ALLEN BRADLEY 2 POLE CIRCUIT BREAKER 1492-SP
WESTINGHOUSE 20A 600VAC 3-POLE CIRCUIT BREAKER FD 25K / FD3020
SIEMENS CIRCUIT BREAKER 400A 600V 3P HJXD63B400H HJXD6-A
MERLIN GERIN 5A TYPE D 240VAC 2-POLE CIRCUIT BREAKER C60N 60157
ALLEN BRADLEY SINGLE-POLE 4A CIRCUIT BREAKER 1492-CB1G040 SER. B *LOT OF 10*
CUTLER HAMMER 2 POLE TYPE BA 50AMP CIRCUIT BREAKER
WESTINGHOUSE 600VAC 3-POLE 3A CIRCUIT BREAKER MCP0322CR / 2607D80G02
SCE ENCLOSURE SCE-604CH
HITACHI 15A 220V 1-POLE CIRCUIT BREAKER CP31-F A60L-0001-0143/?15AH
WESTINGHOUSE 3-POLE, 600VAC, 800A CIRCUIT BREAKER HLM3800F W/ 600A PLUG
FUJI ELECTRIC FA 240VAC 50A 3-POLE CIRCUIT BREAKER SG53RCUL
SQUARE D CIRCUIT BREAKER 20 AMP LOT OD 2 TYPE QOB L-2236
SQUARE D 600V 100AMP MOLDED CASE CIRCUIT BREAKER FH36100
FUJI ELECTRIC 3-POLE 30A CIRCUIT PROTECTOR CP 33E/30
SQUARE D 30A 10KA CIRCUIT BREAKER LOT OF 4 L-5669
SIEMENS BQ1B030 30 AMP CIRCUIT BREAKER, NNB
ALLEN BRADLEY BREAKER SER A BULLETIN 1492 STYLE GH
GE TYPE TEY CIRCUIT BREAKER 3 POLE 480VAC 20 AMP
SQUARE D 600VAC 400A 3-POLE CIRCUIT BREAKER LAL3640036M1021 *CHIPPED PLASTIC*
ALLEN BRADLEY 25A 5HP CIRCUIT BREAKER SER.C 1492-CB1H250
TELEMECANIQUE 6.3A MOTOR CIRCUIT PROTECTOR GV2-L10
FUJI ELECTRIC 2-POLE 10A CIRCUIT BREAKER CP32E/10
ABB SINGLE POLE 16A 230/400V CIRCUIT BREAKER S 281 K 16A
ETA 1.2A CIRCUIT BREAKER LOT OF 3 43-200-MO
GE 800A FUSED LOW VOLTAGE POWER CIRCUIT BREAKER AKRU-7D-30 *NO TRIP UNIT*
GENERAL ELECTRIC 30A 2 POLE CIRCUIT BREAKER TYPE THQL
3-POLE 600V 40/120A CIRCUIT BREAKER HH 83XB 422 NIB
ALLEN BRADLEY CIRCUIT BREAKER 1492-SP1B040
GENERAL ELCTRIC 100A 480VAC CIRCUIT BREAKER TED124100
POTTER & BRUMFIELD 20A CIRCUIT BREAKER W90-X112-20 *LOT OF 3*
GE 400A 600V 3POLE CIRCUIT BREAKER TJK436F000
FEDERAL PACIFIC ELECTRIC CIRCUIT BREAKER NJJ231400 3 POLE 400 AMP 240 VAC
MITSUBISHI 70A 480VAC 3 POLE NO FUSE CIRCUIT BREAKER NF-SF
I-T-E TYPE QP 240VAC 3-POLE CIRCUIT BREAKER Q390
ALLEN BRADLEY CIRCUIT BREAKER 1492-GS2G050 SER.A
GENERAL ELECTRIC 2 POLE 30 AMP CIRCUIT BREAKER
I-T-E 600VAC 50A 3-PLES frame-F ETI CIRCUIT BREAKER ET4064
WESTINGHOUSE 3-POLE 90A 600VAC INDUSTRIAL CIRCUIT BREAKER FDB3090 SER. C
SQUARE D 600VAC 400A 3-POLE CIRCUIT BREAKER LAF3640032MV102?7
SYNDEVCO CPB SN-03 MACHINED SERIES COMPACT POWER BLOCK, NNB
ALLEN BRADLEY SINGLE POLE 2A CIRCUIT BREAKER 1492-CB1 H020 *LOT OF 15*
SQUARE D 277VAC 5A SINGLE POLE CIRCUIT BREAKER FY-14015-B
GE CIRCUIT BREAKER SERIES G LOT OF 7 C4 V/099-007104 622303
ALLEN BRADLEY CIRCUIT BREAKER 2P 3A 1492-CB2 H030
EATON HEINEMANN 250VAC 20A CIRCUIT BREAKER AM3R-A3-LC07T-A?-20-2 NIB LOT OF 3
WESTINGHOUSE 150A 240VAC 3-POLE CIRCUIT BREAKER CA3150W
MOELLER SINGLE-POLE 4A CIRCUIT BREAKER FAZ G4A-CNA *LOT OF 5*
MERLIN GERIN 25A 3-POLE CIRCUIT BREAKER NS100L / TM 25 D
ALLEN BRADLEY SINGLE POLE 7A CIRCUIT BREAKER 1492-CB1 G070 SER. B *LOT OF 10*
MITSUBISHI 20A 3-POLE 480Y/277VAC CIRCUIT BREAKER NF100-SWU
MERLIN GERIN MULTI 9 2A-TYPE C 3-POLE 480VAC MINIATURE CIRCUIT BREAKER C60N
SQUARE D 600V 30A 50HZ 0.05KVA TRANSFORMER LR21455 9070TF50D1
GENERAL ELECTRIC 600VAC 70A 3 POLE CIRCUIT BREAKER, THED136070
MITSUBISHI CIRCUIT PROTECTOR CP30-BA AC 15AMP 3 POLE NNB
GENERAL ELECTRIC 2 POLE 25A CIRCUIT BREAKER
SQUARE D CIRCUIT BREAKER 20 AMPS LOT OF 3 MG-9518 TYPE QOB
ALLEN BRADLEY SINGLE POLE 15A CIRCUIT BREAKER 1492-CB1 H150 SER. B *LOT OF 10*
WESTINGHOUSE QUICKLAG 15A CIRCUIT BREAKER BAB-1015 *LOT OF 4*
CUTLER HAMMER 20A 2 POLE 120/240VAC CIRCUIT BREAKER CLASS CTL TYPE CH
WESTINGHOUSE 20AMP 1 POLE CIRCUIT BREAKER QBGFEP1020
ALLEN BRADLEY CIRCUIT BREAKER 1498-CB2G400 SER B
SQUARE D HACR 20A 10KA CIRCUIT BREAKER LOT OF 3 HOM P-2276
SIEMENS 13A 1-POLE CIRCUIT BREAKER LOT OF 5 5SX21 C13
MERLIN GERIN 3 POLE 40AMP MULTI 9 CIRCUIT BREAKER C60 24544
WESTINGHOUSE 3-POLE 600VAC 30A CIRCUIT BREAKER FD3030L 103864
SIEMENS 4A 230/400V CIRCUIT BREAKER LOT OF 5 5SX21 C4
CHALLENGER CIRCUIT BREAKER TYPE C2100 120/240V AC 2 POLE 100 AMP
FUJI ELECTRIC 220VAC 30A 2 POLE CIRCUIT BREAKER, EA52B
FUJI ELECTRIC 220VAC 30A 2 POLE CIRCUIT BREAKER, SA52BT
MITSUBISHI ELECTRIC 2-POLE 15A NO-FUSE CIRCUIT BREAKER NF30-FAU
SIEMENS 2.5-4.0A MOTOR STARTER PROTECTOR MSP10J
GENERAL ELECTRIC 2 POLE HACR 60A CIRCUIT BREAKER TYPE RT-692
GENERAL ELECTRIC 50A 480V CIRCUIT BREAKER TED134050
CUTLER-HAMMER EATON 30A 600VAC 250VDC 3-POLE TYPE 12(3R) SAFETY SWITCH DH361UDK
WESTINGHOUSE 25A 600VAC 3 POLE CIRCUIT BREAKER 1375D86G20
MITSUBISHI 1A SINGLE POLE CIRCUIT BREAKER CP30-BA
SQUARE D 240V 175A 3 POLE MOLDED CASE CIRCUIT BREAKER, Q232175H
FPE 2 POLE 15 AMP CIRCUIT BREAKER 240VAC CU-AL
SQUARE D TYPE QOB 2 POLE 30AMP CIRCUIT BREAKER
CUTLER HAMMER 2 POLE 30AMP TYPE BA CIRCUIT BREAKER
WESTINGHOUSE 100A 600VAC 3-POLES 40°C CIRCUIT BREAKER FB3100L / 4992D46G44
FUJI ELECTRIC 220VAC 20A 3-POLE AUTO BREAKER SA33B BB3ASB-020
SIEMENS SIRIUS 3R .22-.32A MOTOR PROTECTION CIRCUIT BREAKER 3RV1011-0DA10
HYUNDAI 15AMP 3P, 660V CIRCUIT BREAKER HBH103,LBK00Y NIB
FUJI ELECTRIC 220VAC 30A 2 POLE CIRCUIT BREAKER, EA52A
WESTINGHOUSE 600V 300A 3 POLE CIRCUIT BREAKER LBB3300W
GENERAL ELECTRIC 2-POLE 20A CIRUIT BREAKER THQP HID
FUJI ELECTRIC 220VAC 5A 3-POLE CIRCUIT BREAKER EA53B / BB3BEB-005W
AMP A63L-0001-0428
MITSUBISHI 10A 2-POLE CIRCUIT BREAKER LOT OF 5 NF30-FA B0103
SQUARE D 1 POLE 10A TYPE QOB CIRCUIT BREAKER MJ-1704
SQUARE D CIRCUIT BREAKER 20 AMP SER. 2 FHB36020
BACO 16A 10mA CIRCUIT BREAKER 0660 002 *LOT OF 3*
GENERAL ELECTRIC 25A 600VAC 3 POLE CIRCUIT BREAKER TED136025
ALLEN BRADLEY 2-POLE 2A CIRCUIT BREAKER 1492-CB2 G020 SER. B LOT OF 5
SQUARE D 30 AMP CLASS A CIRCUIT BREAKER AD-561
TOYOZUMI TRANSFORMER SD21-01KB
WESTINGHOUSE 10A 600VAC 250VDC 3-POLE CIRCUIT BREAKER 454D676G23
SQUARE D 3-POLE 20A THERMAL MAGNETIC CIRCUIT BREAKER FAL34020
SQUARE D CIRCUIT BREAKER 20 AMP 1 POLE LOT OF 2 TYPE Q0 LL-750
ALLEN BRADLEY 16A 2-POLE CIRCUIT BREAKER 1492-CB2 G160 *LOT OF 5*
SQUARE D 2 POLE 40 AMP TYPE QOU CIRCUIT BREAKER
FUJI ELECTRIC 220VAC 24A 3-POLE CIRCUIT BREAKER EA53BM / BM3BEB-024 NIB
CHALLENGER TYPE C260 2 POLE 60AMP CIRCUIT BREAKER
GENERAL ELECTRIC V-LINE 277/480VAC 4A CIRCUIT BREAKERS, V07104, LOT OF 5
MERLIN GERIN 3A 277VAC SINGLE POLE CIRCUIT BREAKER C60N 3A-TYPE C
SIEMENS 2 POLE 30AMP TYPE QP CIRCUIT BREAKER
SQUARE D CIRCUIT BREAKER NIB 15A 120/240V QOU115
I-T-E 600VAC 50A 3-POLE CIRCUIT BREAKER EF3-L050
ITE 2 POLE 15AMP TYPE BQ CIRCUIT BREAKER BQ2B015
MERLIN GERIN MULTI-9 C60N 8A CIRCUIT BREAKER *LOT OF 2*
GENERAL ELECTRIC V LINE 2 POLE C10AMPS CIRCUIT BREAKER
WESTINGHOUSE 30 AMP 2POLECIRCUIT BREAKER HACR TYPE CU/AL
FUJI ELECTRIC * 250 AMP 3 POLE CIRCUIT BREAKER * BU-JSA3250
FUJI ELECTRIC, 10A, 240V, 2 POLE, CIRCUIT BREAKER BU-ECA2010
SIEMENS 30 AMP 1 POLE 60HZ CIRCUIT BREAKER MODEL B130
GE CIRCUIT BREAKER 30A 2P LOT OF 5 HACR
CUTLER HAMMER CIRCUIT BREAKER 120/240V I POLE UNIT M1641 E11713
MITSUBISHI ELECTRIC 3-POLE, 600VAC, 15A NO-FUSE BREAKER NF30-SS
ALLEN BRADLEY 10A 1-POLE CIRCUIT BREAKER SER.B LOT OF 5 1492-CB1G100
FUJI ELECTRIC BU-ESB3020 CIRCUIT BREAKER, NIB
ALLEN BRADLEY 65VDC 0.5A SINGLE POLE CIRCUIT BREAKER 1492-GS1G005 SER. A
I-T-E 1-POLE 20A 277VAC 125VDC CIRCUIT BREAKER E41B020
ITE 20A 2 POLE 220/240VAC HACR CIRCUIT BREAKER TYPE QP
ABB 480VAC 500VDC 3 POLE CIRCUIT BREAKER RV-2296
GENERAL ELECTRIC 3-POLE 300A TRI-BREAK CIRCUIT BREAKER TB 43F
SQUARE D CIRCUIT BREAKER 15 AMP LOT OF 2 AB-4961 TYPE TIPO QO
DAYKIN 1000VA TRANSFORMER DISConNECT LTFS-05
WESTINGHOUSE 800A, 600VAC, 3-POLE LOW-VOLTAGE CIRCUIT BREAKER DSL-206, BARRIER
WESTINGHOUSE 240VAC 100A 3POLE CIRCUIT BREAKER 4990D03G44
WESTINGHOUSE 240VAC 60A 3POLE CIRCUIT BREAKER 4990D03G41
ITE 2 POLE TYPE BQ 15AMP CIRCUIT BREAKER BQ2B015
GENERAL ELECTRIC 30AMP TYPE RT-660 2 POLE CIRCUIT BREAKER TYPE THQB LOT OF 2
GENERAL ELECTRIC 30AMP TYPE RT-660 2 POLE CIRCUIT BREAKER TYPE THQB LOT OF 2
SQUARE D * CIRCUIT BREAKER 30AMP * 999330
ALLEN BRADLEY 10A 2HP SINGLE POLE CIRCUIT BREAKER 1492-CB1 G100 *LOT OF 10*
GOULD 3 POLE CIRCUIT BREAKER 100A 480V E43B100
ALLEN BRADLEY 16A SINGLE POLE CIRCUIT BREAKER G160 1492-CB1 SERIES B *LOT OF 25*
EATON ITAP362 DS SWITCH POW-R-WAY PLUG BUS DUCT 60AMP 60 VOLTS AC 3 PHASE 3WIRE
ALTECH ABLSURSUM SINGLE-POLE 3A CIRCUIT BREAKER V-EA G 3A IGU3 *LOT OF 3*
SQUARE D 120/240VAC 200A CIRCUIT BREAKER QOM2
ALLEN BRADLEY SINGLE POLE 10A CIRCUIT BREAKER 1492-CB1 G100 *LOT OF 19*
SQUARE-D * PUSH BUTTON NIB * 9001SKR1G
FUJI ELECTRIC 220VAC 24A 3-POLE AUTO BREAKER CIRCUIT BREAKER EA53BM / BM3BEB-024
GE GENERAL ELECTRIC 120/240VAC 50A 2-POLE CIRCUIT BREAKER TQB2150
SQUARE D 15AMP CIRCUIT BREAKER LOT OF 2 9080 GCB150 SER C 99621
ALLEN BRADLEY 1492-CB2G200 20 Amp CIRCUIT BREAKER NIB
GE 20A 1-POLE CIRCUIT BREAKER LOT OF 5 TQC1120 / KH-652
RELIANCE ELECTRIC CUTLER-HAMMER DC ConTACTOR 417690-4R / 6702ED591
GENERAL ELECTRIC C4 4A SINGLE POLE CIRCUIT BREAKERS V/099-007104 SER. G LOT OF 5
ALLEN BRADLEY 16A 3-POLE CIRCUIT BREAKER AS168X-CB3 H160 W/ AS168X-ACB H1
MERLIN GERIN 80A 3-POLE CIRCUIT BREAKER NS160L / TM 80 D
WESTINGHOUSE * CIRCUIT BREAKER 20A MP 1 POLE * BR120R
KLOCKNER-MOELLE?R 3 POLE 50AMP CIRCUIT BREAKER FAZN C50
TELEMECANIQUE INTEGRAL 63 63A 690V CIRCUIT BREAKER ConTACTOR LD1 LD030
SQUARE D CIRCUIT BREAKER LOT OF 3 NE-2676 TYPE QO
WESTINGHOUSE 600V 800A 3 POLE SELTRonIC CIRCUIT BREAKER, MC3800F
SQUARE D 3-POLE 400A INSTANTANEOUS TRIP CIRCUIT BREAKER LAP3640036MMTV6?283
SQUARE D 1 POLE 120/240 VAC CIRCUIT BREAKER LOT OF 4 MG-6025 TYPE QO
SQUARE-D * 20A CIRCUIT BREAKER LOT OF 2 * UNKNOWN PART #
SQUARE D 600VAC 15A THERMAL-MAGNETI?C CIRCUIT BREAKER FHB36015 SER. 2
ITE 3POLE 600VAC F frame ETI CIRCUIT BREAKER 4064
TELEMECANIQUE 100A CIRCUIT BREAKER GV7-RE100
SQUARE D 700AMP 3 POLE 600VAC 250VDC CIRCUIT BREAKER MH36700
CUTLER HAMMER 70A 3 POLE CIRCUIT BREAKER BAB3070H
I-T-E GOULD 400A 3-POLE CIRCUIT BREAKER
SQUARE-D * 20A 120V 50/60HZ 1-POLE CIRCUIT BREAKER NIB * QOB120K
SIEMENS 120/240VAC SINGLE POLE 50A CIRCUIT BREAKER TYPE BQ ZD-6121 *LOT OF 3*
SIEMENS 15 AMP 3POLE 480VAC CIRCUIT BREAKER ED43B015
SQUARE D 2 POLE CIRCUIT BREAKER LOT OF 2 LL-7585 TYPE HACR
GENERAL ELECTRIC 60A 600VAC 250VDC MODEL-7 CIRCUIT BREAKER TH3362
EATON HEINEMANN 250VAC 20A 2-POLE CIRCUIT BREAKER AN3R-A3-LC07T-A?-20-2
GENERAL ELECTRIC CIRCUIT BREAKER 2P 120/240VAC E11592B
WESTINGHOUSE 15A 600VAC CIRCUIT BREAKER MCP03150R
FUJI ELECTRIC 600VAC 150A 2-POLE CIRCUIT BREAKER BU-FSB2150
SIEMENS SENTRON SERIES CIRCUIT BREAKER 3P 600A LXD63B600
ALLEN BRADLEY 10A SINGLE POLE CIRCUIT BREAKER 1489-A1C100
GENERAL ELECTRIC CIRCUIT BREAKER THED113020
FUJI ELECTRIC 480VAC 15A 2-POLE INDUSTRIAL CIRCUIT BREAKER BU2EHC-015L
MITSUBISHI ELECTRIC 240VAC 125A 3-POLE NO-FUSE BREAKER NF225-CWU3
FUJI ELECTRIC 3-POLE 20A EARTH LEAKAGE CIRCUIT BREAKER SGH63