腾达机械厂降压变电所的设计

2012届毕业设计（论文）腾达机械厂降压变电所的设计系、部：电气与信息工程系学生姓名：指导教师：职称：专业：班级：学号：2012年5月2摘要电能是现代工业生产的主要能源和动力。机械厂供电系统的核心部分是变电所。变电所主接线设计是否合理，关系到整个电力系统的安全、灵活和经济运行。本设计在给定机械厂具体资料的基础上，根据本厂所能取得的电源及本厂用电负荷的实际情况，并适当考虑到工厂生产的发展按照安全可靠技术先进经济合理的要求确定变电所的位置，确定变电所主变压器的台数和容量类型选择变电所主接线方案及高低压设备和进出线确定二次回路方案，选择整定继电保护装置，确定防雷和接地装置，最后按照要求写出设计说明书。关键词：电能；变电所；二次回路；变压器3ABSTRACTTheelectricityismodernindustrialproductionofmainsourcesofenergyandmotiveforce.Thecoreofthepowersupplysystemofmachineryfactoryissubstation.Thewiringisreasonabledesignsubstation,relatedtothewholepowersystemsecurity,flexibleandeconomicoperation.Thisdesigninagivenmachineryfactoryconcretematerialfoundation,accordingtoourfactorywillachievethepowerandtheactualsituationofourelectricityload,andappropriateconsiderationtothefactorytothedevelopmentoftheproductionaccordingtothesafeandreliabletechnologyadvancedeconomicandreasonablerequiredthepositionofthesubstation,determinethemaintransformersubstationNumbersandcapacitytypechoiceLordwiringschemesandhighorlowvoltagesubstationequipmentanddeterminetheoutletandthesecondarycircuitsolutions,choosethesettingrelayprotectiondevice,determinethelightningprotectionandgroundingdevice,finallyaccordingtotherequestandwritethedesignspecification。Keywords：power；substation；Thesecondarycircuit；transformer4目录1绪论··························································11.1工厂供电的意义和要求·······································11.2工厂供电设计的一般原则·····································21.3本机械厂变电所的设计内容及依据·····························22负荷计算和无功功率计算及补偿补偿································42.1负荷计算概述···············································42.2负荷计算的方法·············································52.3无功功率的补偿·············································83变电所主变压器及主结线方案的选择································93.1变电所的概述···············································93.2变电所主接线选择···········································93.3高压线路导线的选择·········································103.4低压线路导线的选择·········································104变电所变压器和主接线方案的选择··································114.1年耗电量的估算·············································114.2主变压器台数的选择·········································114.3变电所主变压器容量的选择···································115短路电流的计算··················································135.1短路的原因及后果···········································135.2本设计采用标幺制法进行短路计算·····························136变电所一次设备的选择与校验······································166.1一次设备的选择与校验的原则·································166.2变电所高压侧一次设备的选择·································176.3变电所高压侧一次设备的校验·································176.4变电所低压侧一次设备的选择·································186.5变电所低压侧一次设备的校验································187变电所低压干线、支线上的熔丝及型号······························197.1保护电力线路的熔断器熔体电流的选择·························197.2保护电力变压器的熔断器熔体电流的选择·······················207.3保护电压互感器的熔断熔体电流的选择·························207.4熔断器的选择与校验·········································2057.5熔断器保护灵敏度的校验·····································218变电所二次回路方案的选择积极电保护的整定························228.1二次回路方案的选择·········································228.2继电保护的整定·············································229变电站的防雷保护和接地保护······································269.1防雷保护的概述·············································269.2接地保护的概述·············································2710设计总结与体会··················································2911参考文献························································3012致谢··························································3161绪论1.1工厂供电的意义和要求工厂供电就是指工厂供电所需电能的供应和分配，亦称工厂配电。众所周知，电能是现代工业声场的主要能源和动力。电能既易于由其他姓氏的能量转换而来，又易于转换为其他形式的能量以供应用；电能的输送和分配既简单经济，又便于控制、调节和测量，有利于实现生产过程自动化。现代社会的信息技术和其他高新科技都是建立在电能应用的基础上，因此，电能在现代工业生产及整个国民经济生活中应用极为广泛。在工厂里，电能虽然是工业生产的主要能源和动力，但它在产品成本中所占的比重一般很小（除电化工业外）。例如在机械工业中，电费开支仅占产品成本的5%左右。从投资额来看，一般机械工厂在供电设备上的投资，也仅占总投资的5%左右。因此电能在工业生产中的重要性，并不在于它在产品成本中或投资总额中所占的比重多少，而在于工业生产实现电气化以后，可以大大增加产量，提高产品质量，提高劳动生产率，降低生产成本，减轻工业人的劳动强度，改善工人的劳动条件，有利于实现生产过程自动化。从另一方面来说，如果供电突然中断，则对工业生产可能造成严重的后果。例如某些对供电可靠性要求很高的工厂，即使是极短时间的停电，也会引起重大设备损坏，或引起大量产品报废，甚至可能发生人身伤亡事故，给国家和人民带来经济上甚至生态环境上或政治上的重大损失。因此，做好工厂供电工作对于发展工业生产、实现工业现代化，具有十分重要的意义。工厂供电工作要很好的为工业服务，切实保证工厂生产和生活用电的需要，并做好节能和环保工作，就必须达到下列基本要求：（1）安全在电能的供应、分配和使用中，不应发生人身事故和设备事故。（2）可靠应满足电能用户对供电可靠性即连续供电的要求。（3）优质应满足电能用户对电压和频率等质量的要求。（4）经济供电系统的投资要省，运行费用要低，并尽可能的节约电能和减少有色金属消耗量此外，在供电工作中，应合理地处理局部和全局，当前和长远等关系，既要照顾局部和当前的利益，又要有全局观点，能顾全大局，适应发展。例如计划用电问题，就不能只考虑一个单位的局部利益，更要有全局观点。71.2工厂供电设计的一般原则按照国家标准GB50052-95《供配电系统设计规范》、GB50053-94《10kV及以下设计规范》、GB50054-95《低压配电设计规范》、JGJ16-2008《民用建筑电气设计规范》等的规定，进行变电所设计必须遵循以下原则：1、遵守规程、执行政策必须遵守国家的有关规定及标准，执行国家的有关方针政策，包括节约能源，节约有色金属等技术经济政策。2、安全可靠、先进合理应做到保障人身和设备的安全，供电可靠，电能质量合格，技术先进和经济合理，采用效率高、能耗低和性能先进的电气产品。3、近期为主、考虑发展应根据工作特点、规模和发展规划，正确处理近期建设与远期发展的关系，做到远近结合，适当考虑扩建的可能性。4、全局出发、统筹兼顾按负荷性质、用电容量、工程特点和地区供电条件等，合理确定设计方案。工厂供电设计是整个工厂设计中的重要组成部分。工厂供电设计的质量直接影响到工厂的生产及发展。作为从事工厂供电工作的人员，有必要了解和掌握工厂供电设计的有关知识，以便适应设计工作的需要。1.3本机械厂变电所的设计内容及依据1、供用电协议本厂与电业部门所签定的供用点协议主要内容如下：（1）从电业部门某10千伏变电所用10千伏架空线路向本厂供电，该所在距本厂8KM处。（2）电业部门变电做配出线路定时限过电流保护装置的整定时间为1．7秒。（3）在总配变电所10千伏侧计量。（4）要求本厂的功率因数值在0.9以上。（5）供电系统技术数据：电业部门变电所10千伏母线，为无限大电源系统，