有关越级跳闸的资料

有关越级跳闸的资料 1 事故现象 河北省魏县某35kV变电站，曾经有一条10kV线路发生相间短路故障，由于10kV开关拒跳，而造成越级跳闸，使得一台主变停运。 2 原因分析 我们迅速赶到现场对事故原因进行分析，并对该10kV开关进行了全面检查。首先，用万能操作把手对开关进行合、跳闸操作，结果一切都正常，这说明开关的电气回路和机械操动部分没有问。我又检查了保护装置，合上开关，做传动保护试验，做了一次传动，开关正常跳闸，这又证明了保护装置也没有缺陷。这是怎么回事呢?用万能操作把手操作开关，开关能正常跳、合闸，并且开关的机械操动部分也没有卡死和不到位情况。经过进一步查看和分析，我认为问题还是出在保护装置上。确实，当我再一次做传动实验时，只是听到了过流继电器动作以及时间继电器的钟表机构转动，而开关没有跳闸。问题果然在继电器上面。我就逐个将过流、时间等继电器进行检查，发现时间继电器的触点连片松动、稍有弯曲。这样，当保护动作时，触点接触时而良好，时而接触不良。这就是为什么第一次做传动保护试验时开关能跳闸，而第二次开关却没有跳闸。同样，这也是开关越级跳闸的原因。 3 处理和启示 问题找出后，我就把时间继电器的触点处理了一下，紧固触点连片，把弯曲矫正过来，使触点接触时能牢固可靠，且有一定压力。我将修理好的继电器进行恢复，接着做了三次保护传动试验，开关都能正确跳闸。由此，我得到启发: (1)开关及其二次回路检修完毕，投入运行前，一定要对开关的保护装置做传动试验，证明继电器处于良好工作状态后，开关才能够投入运行。 (2)平时加强对继电器的检查和维护。继电器的可动系统必须动作灵活，触点接触牢固可靠。 (3)对一些故障的表面现象要深入细致地研究分析，以便查出故障的真正原因。往往一些表面现象容易转移我们的注意力，而影响我们快速及时地排除故障。 【简述】2006年4月15日13时30分，三马山110KV变电站三朱线断路器速断跳闸，引起朱衣35KV变电站停电18小时，造成了一次严重的停电事故。【事故经过】2006年4月15日13时30分，三马山110KV变电站三朱线断路器速断跳闸，引起朱衣35KV变电站停电18小时，造成了一次严重的停电事故。事故发生后供电所派出技术人员对35KV线路进行检查，未发现事故点，逐级检查到变电站发现无监视、保护，进一步检查直流电源电压已降到60V，直流充电机未工作。 【原因分析】 1、此次事故是因为朱黄线接地短路造成，由于朱衣变电站直流电源过放电未能使保护迅速切断故障线路而导致保护越级跳闸。2、运行人员对“两票三制”执行力度不够，值班人员没有认真进行设备巡视检查。交接班人员没有核对设备的运行情况。3、朱衣变电站采用综合自动化保护，保护、监控的直流电源采用18只12V100AH蓄电池组供操作、保护和监控的后备电源。由于直流充电机停机时间较长，导致蓄电池过放电。【防范措施】 1、加强设备巡视检查，加强运行人员对事故相关规定的学习和理解，建立严格的考核奖惩制度，关键要加大对管理者的考核，用制度来保障设备的安全，并以督促其对安全生产及其 设备的管理。值班负责人在工作安排时要交代清运行设备的安全注意事项。 2、加强职工的安全教育和业务技能的学习，提高安全责任感，严格执行设备巡回检查制度，落实安全生产责任制，定期进行安全知识讲座。 3、值长、班长是值班现场的安全生产第一责任人，要树立全局观念，安全生产工作要全面考虑，严格认真地安排巡视检查，建立安全生产互保机制。 1 事故情况 我局某新建60kV变电所在运行中多次发生越级跳闸。无论是哪条10kV线路故障，虽然其断路器跳闸，但都同时引发主变过流保护动作，造成越级跳闸，以至全所停电。这类事故给我们查找事故原因带来了很大困难。 2 查找经过 我局的继电保护人员去现场进行了全面的分析，估计有以下几种原因可能会引起主变油断路器越级跳闸:1)主变过流保护整定值与各分柜整定值配合不当;2)主变过流保护整定值校验不准，取值过小;3)各分柜过流保护整定值校验不准，取值过大;4)主变过流继电器线圈并联接成串联，以至整定值缩小一半;5)各分柜过流继电器线圈串联接成并联，以至整定值增大一倍;6)主变过流时间与各分柜过流时间配合不当。 根据对以上可能发生原因的逐一检查并结合断路器误跳闸前后的现象判定，上述原因基本上都可以排除。对主变和各分柜过流整定值进行了校验，都正确无误。对主变和各分柜过流继电器的线圈进行核对，亦完全正确。对主变过流时间(t=0.5s)继电器和各分柜过流时间(t=0.2s)继电器进行检验，也都正确无误。剩下的只有线路问题了。 3 故障点分析和查实 为了进一步地查明原因，我们做了下面的试验(如附图所示):在主变和任一分柜的电流互感器二次侧的试验端子排处，把两过流保护的交流回路串联起来，再串接这条10kV分柜的油断路器主接点，冲击地加入可使两过流保护都动作的电流值。 正常的话，这条10kV分柜经约0.2s跳闸后，由10kV分柜油断路器主接点断开试验交流电源(即模拟短路电流)，主变达不到0.5s而返回，不会跳闸。但事实是主变和这条10kV分柜都动作跳闸。因此判定问题出在主变保护回路的接线上。 把保护回路原理图和安装接线图结合起来分析，发现主变保护屏后，DS?1型时间继电器中的应接终止接点的线接在了滑动接点上。在这种情况下，时间继电器中的正电源，经滑that balances the sensitivity associated with the following factors: (1) the long arm of the scale, higher sensitivity, and (2) the beam of the scale is heavier, lower sensitivity, (3) pivot and the shorter the distance between the center of gravity, high sensitivity. But the sensitivity of the balance are not only associated with these three factors, while carrying heavy loads and balance beam deformation, agate cutters of the fulcrum and the load point of the contact point (that is, agate and knife blades sharp and smooth). So, balance beam made of triangular-ovate, hollowed out in the Middle, triangular-the sensitivity adjustment screw located on the top of a vertical, set two zero point adjusting screw in the horizontal direction, Fulcrum Onyx blade slightly below contains key Onyx blade's "Alice beams" type, and balance beam made of aluminium alloys or titanium alloys light metal alloy. V-shaped, "Alice beams" in order to reduce the impact deformation, knock out heavy and light metal materials to relieve beam measures sensitivity adjustment screw is to use the height to adjust the quality of the nut itself d the length of the horizontal zero-point adjustment screw is the distance from the fulcrum nut quality adjustment nut to adjust the size of the moment change the zero point. Balance of sensitivity General to signs of grid number to measure, that sensitivity = grid/mg but in actually often with "sense volume" to said: sense volume = mg/grid electro-optic balance of sense volume General adjustable into 1mg/grid, and 0.1mg/grid, and 0.01mg/grid, will signs made transparent film, loaded in pointer Shang, then, through optical zoom 10 times"illumination", "welding". 3, electricity lines: (1) electric line, required for overhead installation of resilient rubber sheathed cable or plastic. Adopted at the lane or road protection pipe buried underground, set up signs, connectors must be overhead or located connector box. (2) rubber cable portable power tools, lead length not more than 5 m from the switch box, without joints. (3) use mobile power tools and lighting are soft rubber cord, do not use plastic resin line instead. (4) temporary wiring installations, use a rubber or plastic insulated wires must be knob cables set up, switch set. 4, grounding and zeroing device: (1) grounding electrode available angles, steel of not less than two, depth of not less than 2 m and not less than 2.5 metres in distance between two grounding, grounding resistance is less than 4 ohm. (2) ground (neutral) wires using insulated copper wire, do not use aluminium wire for grounding (neutral) wire joints by welding, crimping a reliable electrical connection. (3) rubber cable core in the "black" or "green/Huang Shuang-color" line as the ground wire. 5, high voltage line protection: (1) in the vicinity of overhead power transmission line construction, erection of bamboo protection frame. (2) in the vicinity of high voltage cable erection Derrick (gantry), scaffolding outside power lines above the water, all safety nets (Booth). 6, handheld or mobile motor: switch box must have leakage protection devices, leakage current 30ma/0.1s, 15mA/0.1s wet job (includes the following equipment: vibration machine, polishing machine, ramming machines, submersible pumps, electric hand Planer, hand drills, grinders, cutters, 动触点(经检验亦为0.2s)使出口中间励磁而误动作，跳开主变油断路器，将时间继电器终止接点恢复正常接线后，就再也没发生该断路器误跳闸事故。 4 经验教训 (1)要教育施工安装人员保证工作质量，及时发现缺陷并改正。 (2)不论新建或扩建增容的变电所，全所的二次接线一定要认真检查，保证其正确无误。 (3)加强对电气试验人员的培训，提高其业务水平。要使电气试验人员明白，对任何一套保护做试验时，不但要做好各继电器的检验，还要认真做好整组试验。 (4)查二次接线故障时，要把控制、保护、信号回路原理图和安装接线图结合在一起分析，查找才能少走弯路。 断路器越级跳闸后应首先检查保护及断路器的动作情况。如果是保护动作，断路器拒绝跳闸造成越级，则应在拉开拒跳断路器两侧的隔离开关后，将其它非故障线路送电。 如果是因为保护未动作造成越级，则应将各线路断路器断开，再逐条线路试送电，发现故障线路后，将该线路停电，拉开断路器两侧的隔离开关，再将其它非故障线路送电。最后再查找断路器拒绝跳闸或保护拒动的原因。 电流速断保护越级跳闸问题在电网运行中是不容许存在的事故，它使电网停电范围扩大，造成国民经济和社会效益的重大损失。经过分析，我们认为造成电流速断保护越级跳闸的主要原因是继电保护整定失误造成的，为了防止它的发生，我们认为应做好以下几方面: 1 首先要明确电流速断保护的概念也就是要明确速断保护与过流保护的区分 (1) 从保护任务上分:速断保护是为了迅速地、有选择性地、自动地将电力系统中的短路故障切除。过流保护主要是为了负荷电流超过定值类似不正常工作状态时(也承担短路故障的后备保护)或发出信号告警或跳闸切除。 (2) 从切除故障的快速性上分:切除故障点速断保护是瞬时的，而过流保护是有时限的(有迟滞时间)。 (3) 从保护范围上分:速断保护的保护区是本级开始到下级保护之前，过流保护的范围可以延伸到整条线路的最末端。 (4) 从保证选择性上分:速断保护是以各级有各自的保护范围来保证选择性的，而过流保护是调整各级间不同动作时限来保证选择性。 (5) 从保护整定依据上分:速断保护的动作整定值是以最大运行方式时本级保护区末端的三相短路电流值为依据的;过流保护的整定是以本级保护以下整条线路的最大负荷(或额定负荷)为整定依据的。 2 三相短路电流简便计算 速断保护整定值的计算其核心是三相短路电流的计算。目前在计算短路电流时普遍用两种方法:一是标么法，它是取物理量对基准值的比值称为标么值，没有单位;另一种是有名法(亦称欧姆法)。有名法比较直观，所以下面计算都用有名法。 下面以策勒电网为例计算D1、D2点的三相短路电流，在计算前首先画出策勒电网的计算电路图。 附注:?相对策勒用电量把和田电网拟为无穷大计算。 ?D1为35kV短路点，D2为10kV短路点。 ?两小水电站容量太小，没能维持策勒电网的单线运行，因而不计。 (1) 计算D1短路点的三相短路电流。 已知:查有关数据得系统出口断路器的断流容量SdL=1200MVA; 查线路平均电抗值X0=0.4Ω/kM;计算电压UC1=35kV×105=36.75kV ?电力系统的电抗 X1=UC12/SCL2=36.752/1200=1.125Ω ?架空线路电抗: that balances the sensitivity associated with the following factors: (1) the long arm of the scale, higher sensitivity, and (2) the beam of the scale is heavier, lower sensitivity, (3) pivot and the shorter the distance between the center of gravity, high sensitivity. But the sensitivity of the balance are not only associated with these three factors, while carrying heavy loads and balance beam deformation, agate cutters of the fulcrum and the load point of the contact point (that is, agate and knife blades sharp and smooth). So, balance beam made of triangular-ovate, hollowed out in the Middle, triangular-the sensitivity adjustment screw located on the top of a vertical, set two zero point adjusting screw in the horizontal direction, Fulcrum Onyx blade slightly below contains key Onyx blade's "Alice beams" type, and balance beam made of aluminium alloys or titanium alloys light metal alloy. V-shaped, "Alice beams" in order to reduce the impact deformation, knock out heavy and light metal materials to relieve beam measures sensitivity adjustment screw is to use the height to adjust the quality of the nut itself d the length of the horizontal zero-point adjustment screw is the distance from the fulcrum nut quality adjustment nut to adjust the size of the moment change the zero point. Balance of sensitivity General to signs of grid number to measure, that sensitivity = grid/mg but in actually often with "sense volume" to said: sense volume = mg/grid electro-optic balance of sense volume General adjustable into 1mg/grid, and 0.1mg/grid, and 0.01mg/grid, will signs made transparent film, loaded in pointer Shang, then, through optical zoom 10 times"illumination", "welding". 3, electricity lines: (1) electric line, required for overhead installation of resilient rubber sheathed cable or plastic. Adopted at the lane or road protection pipe buried underground, set up signs, connectors must be overhead or located connector box. (2) rubber cable portable power tools, lead length not more than 5 m from the switch box, without joints. (3) use mobile power tools and lighting are soft rubber cord, do not use plastic resin line instead. (4) temporary wiring installations, use a rubber or plastic insulated wires must be knob cables set up, switch set. 4, grounding and zeroing device: (1) grounding electrode available angles, steel of not less than two, depth of not less than 2 m and not less than 2.5 metres in distance between two grounding, grounding resistance is less than 4 ohm. (2) ground (neutral) wires using insulated copper wire, do not use aluminium wire for grounding (neutral) wire joints by welding, crimping a reliable electrical connection. (3) rubber cable core in the "black" or "green/Huang Shuang-color" line as the ground wire. 5, high voltage line protection: (1) in the vicinity of overhead power transmission line construction, erection of bamboo protection frame. (2) in the vicinity of high voltage cable erection Derrick (gantry), scaffolding outside power lines above the water, all safety nets (Booth). 6, handheld or mobile motor: switch box must have leakage protection devices, leakage current 30ma/0.1s, 15mA/0.1s wet job (includes the following equipment: vibration machine, polishing machine, ramming machines, submersible pumps, electric hand Planer, hand drills, grinders, cutters, X2=X0?L=0.4Ω/kM×(104 60)=65.5Ω ?画出D1短路点的等效电路: D1短路点前的总电抗: X2=X1 X2=1.125 65.4=66.5Ω ?D1点的三相短路电流: ID1=UC1/ ?X?=36.75/(1.73×66.5)=0.319kA (2) 计算D2短路点的三相短路电流。 已知:SDL=1200MVA; 主变容量SB=3150kVA，主变短路电压UD=7.05，架空线路长104kM。 ?电力系统的电抗 X1=UC22/SDL1=10.52/1200=0.092Ω ?架空线路电抗: X2=X0?L?(UC2/UC1)2=0.4×104×(10.5/36.75)2=3.3Ω ?电力变压器的电抗: X3=UD/100×UC22/SB=7.5×100×(10.52/3150)2=2.4×10-3Ω ?画出D2短路点的等效电路: D2短路点前的总电抗: X?=X1 X2 X3=0.092 3.3 2.4×10-3=3.4Ω D2点的短电电流(三相): ID2=UC2/1.73X?=D=10.5/(1.73×3.4)=1.78kA 3 电流速断保护的整定 (1) 例中的D1短路点的电流速断整定值可按下式整定 Id=KKID1也就是说速断保护的动作电流可靠系数乘D1短路电流=1.2×0.319=0.383kA，这样整定值的整定可以保证保护的选择性，但存在有一定的保护死区，应设时限速断保护和过流保护为后备保护，这样设置的三段保护就能较好地完成该线的保护任务了。 (2) 例中D2点的电流速断保护的整定值计算: Id=KKID2 D2点速断保护整定值其动作电流应是 Id=1.2×1.785=2.14 但考虑到D2点的速断保护是属于电网的末级保护，不存在有选择性的问题，因而可以直接以计算的三相短路电流值或少于此值进行整定，实际Id,1.785，根据我们经验在这末级的速断整定可按过流整定值×2为宜。 由于这末级的速断整定值少于计算三相短路电流值，因而不存在有速断保护死区，在保护设置上只要有速断保护作主保护，过流保护作后备保护就行了，(不必设置时限速断保护)。 (3) 按计算的整定值对速断保护整定后，在运行实践中还应进行检验、调整，使之选择性、灵敏度、快速性、可靠性等诸项基本要求都能使人满意为好。 图1 策勒电网图 4 应普及继电保护的整定常识 在县级电力系统中，技术培训是经常的，可是我发现各级各次的培训班中，内容涉及继电保护的基本不讲，涉及整定的更是只字未提。问之，都回答说继电保护是上级专门机构的事，整定值是上级部门给定的，没必要。由于有上面这样的意识指导，在基层工作的电力人员对继电保护也就很少去学习，实践。说起来也多批次的派人到内地大专院校学习继电保护专业，但回来后基本上不能胜任，究其原因除了教学上的空对空外，可能也与学员有以上的认识有关。 在《西北电力系统继电保护管理规程》中6.5条“保护装置整定范围划分”的6.5.2中规定:变电所、发电厂内的设备原则上由设备所在单位的继电保护机构整定。在生产实践中我们也深感基层生产单位也应有自我整定的能力。 that balances the sensitivity associated with the following factors: (1) the long arm of the scale, higher sensitivity, and (2) the beam of the scale is heavier, lower sensitivity, (3) pivot and the shorter the distance between the center of gravity, high sensitivity. But the sensitivity of the balance are not only associated with these three factors, while carrying heavy loads and balance beam deformation, agate cutters of the fulcrum and the load point of the contact point (that is, agate and knife blades sharp and smooth). So, balance beam made of triangular-ovate, hollowed out in the Middle, triangular-the sensitivity adjustment screw located on the top of a vertical, set two zero point adjusting screw in the horizontal direction, Fulcrum Onyx blade slightly below contains key Onyx blade's "Alice beams" type, and balance beam made of aluminium alloys or titanium alloys light metal alloy. V-shaped, "Alice beams" in order to reduce the impact deformation, knock out heavy and light metal materials to relieve beam measures sensitivity adjustment screw is to use the height to adjust the quality of the nut itself d the length of the horizontal zero-point adjustment screw is the distance from the fulcrum nut quality adjustment nut to adjust the size of the moment change the zero point. Balance of sensitivity General to signs of grid number to measure, that sensitivity = grid/mg but in actually often with "sense volume" to said: sense volume = mg/grid electro-optic balance of sense volume General adjustable into 1mg/grid, and 0.1mg/grid, and 0.01mg/grid, will signs made transparent film, loaded in pointer Shang, then, through optical zoom 10 times"illumination", "welding". 3, electricity lines: (1) electric line, required for overhead installation of resilient rubber sheathed cable or plastic. Adopted at the lane or road protection pipe buried underground, set up signs, connectors must be overhead or located connector box. (2) rubber cable portable power tools, lead length not more than 5 m from the switch box, without joints. (3) use mobile power tools and lighting are soft rubber cord, do not use plastic resin line instead. (4) temporary wiring installations, use a rubber or plastic insulated wires must be knob cables set up, switch set. 4, grounding and zeroing device: (1) grounding electrode available angles, steel of not less than two, depth of not less than 2 m and not less than 2.5 metres in distance between two grounding, grounding resistance is less than 4 ohm. (2) ground (neutral) wires using insulated copper wire, do not use aluminium wire for grounding (neutral) wire joints by welding, crimping a reliable electrical connection. (3) rubber cable core in the "black" or "green/Huang Shuang-color" line as the ground wire. 5, high voltage line protection: (1) in the vicinity of overhead power transmission line construction, erection of bamboo protection frame. (2) in the vicinity of high voltage cable erection Derrick (gantry), scaffolding outside power lines above the water, all safety nets (Booth). 6, handheld or mobile motor: switch box must have leakage protection devices, leakage current 30ma/0.1s, 15mA/0.1s wet job (includes the following equipment: vibration machine, polishing machine, ramming machines, submersible pumps, electric hand Planer, hand drills, grinders, cutters, (1) 上面继电保护整定机构给的整定值是在一定时间一定的运行条件整定的，但运行参数是随时可能变化的。如线路的扩展延伸，电力设备的添置、更换、用户的增减等，这就需要继电保护作相对应的调整，虽然说基层只要上报上面就行了，但至少做到心中有数。 (2) 好多故障通过简单的整定计算就能大致断定故障的原因，如保护拒动，我们就可以通过整定的核算来判断出是整定不合理还是二次接线问题，或是操纵机构问题。 (3) 在上下级保护装置配合失调时，基层人员也可以通过自己的计算，迅速提出设想看法。提供给上级参考。 (4) 继电保护在目前的电力生产运行中是科技含量较高的专业范畴，如果能针对本单位实际继电保护设施进行专业培训，可能比派人员出去培训更为实用，更易普及，进而形成竞争机制，使基层生产运行人员素质普通提高，为电力生产的安全，高质保证了前提。 注: (1) 此文中的短路电流计算参考了刘介才编写的《工厂供电》(修正本)。 (2) 此文中的速断是指继电保护中的电流瞬时速断。 (收稿日期:2000—05—22) [摘要]本文结合电力大客户内部发生故障时越级到变电站开关跳闸的情况,通过对电力大客户继电保护装置的改进,消除了反时限保护装置的越级跳闸现象,在保障了电网安全运行的同时还提高了电力大客户的经济效益。 [关键词]反时限保护装置越级跳闸 一、引言 电力系统的不断发展和安全稳定运行给国民经济和社会发展带来了巨大的动力和效益。企业的电力系统安全运行就成为了重中之重。一旦发生故障,如果不能及时有效控制,就会越级到变电站扩大事故范围,造成大面积停电,给社会和企业造成直接的经济损失,甚至会产生锅炉爆炸、有毒气体排放等危及社会安全的危险后果。继电保护装置就是保证电力设备安全和防止及限制长时间大面积停电的最基本、最重要、最有效的技术手段。继电保护装置一旦不能正确动作,就会扩大事故范围,酿成严重后果。 供电企业已广泛应用集测量、保护、控制和通讯于一体的智能化微机型继电保护装置。但因为微机继电保护装置及配套措施价格昂贵,维护费用高。在大量的工矿企业、民用建筑等变电站和配电室中,还在大量使用电磁型反时限继电保护装置。这些继电保护装置设备老化、精度不够,尤其时间元件精度极差。当被保护线路内出现短路、过流等故障时,常会导致 保护时间元件不精准而造成越级跳闸现象。不但降低了对用户供电的可靠性,同时也给供电企业安全运行造成了重大隐患。 使用电磁型反时限继电保护装置的这些企业大多在经济市场化的浪潮中艰难生存,资金非常紧张。虽然对改造继电保护装置有主观的意愿,但是需投入的改造费用却不能落实到位。所以我们只有另辟蹊径,用最小的投入满足客户与供电企业的继电保护配合问题。以下是亨通精密铸造有限公司继电保护改造实例。 二、现状调查及存在问题 1.亨通精密铸造有限公司平均每年发生越级跳闸事故4次,而且给该厂供电专线上还T接有其他3家电力大客户。屡次越级跳闸事故的发生给该条线路上的4家电力大客户造成了极大的经济损失。仅亨通精密铸造有限公司一家因此造成的直接经济损失就高达近百万元。 2.经过对亨通精密铸造有限公司两年来的故障分析和现场实验判定,该厂内部故障屡次越级到变电站10KV出线越级跳闸的直接原因是该厂保护装置为电磁型反时限GL-11型电流继电器,时间元件精度差、动作时间不精确,根本无法达到与变电站微机保护时限相差0.2秒的配合,在给自己和其他电力大客户造成经济损失的同时也给我局安全运行构成了很大威胁。 3.该厂目前一次系统只有一条10KV电源进线,二次回路采用全交流系统。如选用交流微机保护装置则在发生故障时很可能失去保护电源而造成保护拒动,从而使故障越级到110KV变电站10KV出线间隔扩大故障范围。但如选用直流蓄电池系统,仅保护及配套措施直接费用需12~15万元,而且该厂配电室老旧,更换新设备必须对原配电室进行改建,加之新安装的设备后期维护保养费用等,厂家无力投资。 4.如更换新型微机保护装置及配套措施则需要改建配电室,安装间隔、增加直流系统、敷设电缆等项目,要用十天时间才能完成,企业停产期间直接经济损失很大,主观上也不愿意改造。 5.运行人员对新设备的运行管理不熟悉,短时间内不能胜任工作。 三、解决措施 在原保护装置的基础上。我们采用供电企业通用的dl-11型系列电流继电器和js系列数字式时间继电器更换原电磁型反时限继电器,从根本上解决保护动作时间问题,从而消除了越级故障的发生。并且不用改建配电室,不用增加间隔、不用敷设电缆、原运行人员也能立刻胜任工作,极大节省了资金和时间。 1.选用供电企业广泛应用的高精度集成块数字式js系列时间继电器ac220v,功率消耗?15w。即降低了费用,又达到了可靠、精准的保护装置动作时间。 2.用电力系统继电保护专用ups不间断电源供电,延长不间断时间,提高供电可靠性。由于电力系统专用ups不间断电源采用了优质、长寿命的阀控式免维护蓄电池,采用“可靠的直流”+“可靠的逆变电源”,从而提高了系统的可靠性,同时由于蓄电池组容量大,供电电源失电后可零时限提供较长时间的电源以供继电保护装置继续使用。若采用常规的ups,一是内部电源切换时间长,不能满足继电保护装置的用电需求,二是普通ups蓄电池经常出现蓄电池失效等问题,一但供电电源失电酱造成ups输出电力中断,使事故扩大。所以采用电力系统继电保护专用ups电源既提高了保护装置可靠性,也省去了昂贵的直流系统和直流系统维护费用。 3.原运行人员可直接胜任工作。 4.利用星期六一天进行改造工作,将企业的经济损失降低到最小。 四、具体实施及效果 2007年9月8日(周六)用时一天完成亨通精密铸造有限公司继电保护装置改造工作并试验合格,投入运行。我们对改造后的运行情况、以及维护情况、保护动作情况进行跟踪统计,that balances the sensitivity associated with the following factors: (1) the long arm of the scale, higher sensitivity, and (2) the beam of the scale is heavier, lower sensitivity, (3) pivot and the shorter the distance between the center of gravity, high sensitivity. But the sensitivity of the balance are not only associated with these three factors, while carrying heavy loads and balance beam deformation, agate cutters of the fulcrum and the load point of the contact point (that is, agate and knife blades sharp and smooth). So, balance beam made of triangular-ovate, hollowed out in the Middle, triangular-the sensitivity adjustment screw located on the top of a vertical, set two zero point adjusting screw in the horizontal direction, Fulcrum Onyx blade slightly below contains key Onyx blade's "Alice beams" type, and balance beam made of aluminium alloys or titanium alloys light metal alloy. V-shaped, "Alice beams" in order to reduce the impact deformation, knock out heavy and light metal materials to relieve beam measures sensitivity adjustment screw is to use the height to adjust the quality of the nut itself d the length of the horizontal zero-point adjustment screw is the distance from the fulcrum nut quality adjustment nut to adjust the size of the moment change the zero point. Balance of sensitivity General to signs of grid number to measure, that sensitivity = grid/mg but in actually often with "sense volume" to said: sense volume = mg/grid electro-optic balance of sense volume General adjustable into 1mg/grid, and 0.1mg/grid, and 0.01mg/grid, will signs made transparent film, loaded in pointer Shang, then, through optical zoom 10 times"illumination", "welding". 3, electricity lines: (1) electric line, required for overhead installation of resilient rubber sheathed cable or plastic. Adopted at the lane or road protection pipe buried underground, set up signs, connectors must be overhead or located connector box. (2) rubber cable portable power tools, lead length not more than 5 m from the switch box, without joints. (3) use mobile power tools and lighting are soft rubber cord, do not use plastic resin line instead. (4) temporary wiring installations, use a rubber or plastic insulated wires must be knob cables set up, switch set. 4, grounding and zeroing device: (1) grounding electrode available angles, steel of not less than two, depth of not less than 2 m and not less than 2.5 metres in distance between two grounding, grounding resistance is less than 4 ohm. (2) ground (neutral) wires using insulated copper wire, do not use aluminium wire for grounding (neutral) wire joints by welding, crimping a reliable electrical connection. (3) rubber cable core in the "black" or "green/Huang Shuang-color" line as the ground wire. 5, high voltage line protection: (1) in the vicinity of overhead power transmission line construction, erection of bamboo protection frame. (2) in the vicinity of high voltage cable erection Derrick (gantry), scaffolding outside power lines above the water, all safety nets (Booth). 6, handheld or mobile motor: switch box must have leakage protection devices, leakage current 30ma/0.1s, 15mA/0.1s wet job (includes the following equipment: vibration machine, polishing machine, ramming machines, submersible pumps, electric hand Planer, hand drills, grinders, cutters, 从2007年9月8日到2009年4月8日共动作6次,经过改进后的继电保护装置均可靠动作,成功的消除了越级跳闸事故,达到了预期目标。 五、效果及建议 如果企业的资金能落实到位,一定要选取整套的微机保护及其配套设施。但是对于生产不景气、资金困难的客户,则可以采取此种折中的办法,将电力事故限制到最小范围。通过这次保护装置改进工作,我们改变了固有的工作思路,充分调动了客户的积极性。用最小的投入满足了电力大客户与供电企业继电保护装置时限配合问题,有力保障了电网安全运行,取得了良好的效果。具有普遍的实用性和推广性。 继电保护 科技名词定义 中文名称: 继电保护 英文名称: relay protection 定义1: 对电力系统中发生的故障或异常情况进行检测，从而发出报警信号，或直接将故障 部分隔离、切除的一种重要措施。 所属学科: 电力(一级学科);继电保护与自动化(二级学科) 定义2: 对运行中电力系统的设备和线路，在一定范围内经常监测有无发生异常或事故情况， 并能发出跳闸命令或信号的自动装置。 所属学科: 水利科技(一级学科);水力发电(二级学科);水电站电气回路及变电设备(三 级学科)