[工学]110KV降压变电所的设计.doc

摘 要 本设计是平东110KV降压变电所的电气一次部分设计。本变电所有两个电压等级为110KV、10KV，在设计中要考虑主接线的选择，主变压器的选择，电器设备的选择等。并要进行大量的短路计算以及变压器保护的整定计算工作。 在设计中考虑变压器保护的设计，根据变压器继电保护配置原则，采用差动保护，瓦斯保护，过电流保护，过负荷，零序保护等。 电力变压器作为电力系统和广大企业用户广泛应用的电气设备，在联络电网，电力的输送、分配和使用过程中发挥着核心关键作用，而变压器风冷控制系统则是保证其安全正常运行的重要部分。传统的变压器风冷装置，由于控制系统主要由机械触点逻辑电路实现，安全隐患多，自动化程度低，不能适应当今无人值守变电站的需要，因此新的控制系统的设计方案势在必行。 本文针对传统变压器风冷控制系统存在的控制回路复杂、可靠性低、风机的保护方式简单、控制误差大、故障率高、维护工作量大、无法实现远程通讯等问题，经过多方面的技术分析和调研，设计开发了以单片机为核心的变压器风冷控制系统，该系统充分利用软件资源，在保证控制系统可靠性的基础上尽量简化装置的硬件电路，彻底摒弃继电器逻辑处理方式，完善了变压器风冷控制系统的功能。系统以变压器顶层油温及负荷等参数作为被控量，采用具有延迟裕度的投、切温度阈值的控制策略和按风机累计运行时间自动均衡投切风机的控制方法来实现风机的自动控制。 关键词：主接线；变压器，单片机，风冷系统，自动控制 Abstract This design was float,east of 110 kv step-down substation electrical part design at a time.The voltage substation are two levels of 110 KV, 35KV, 10KV., in the design to be considered the main wiring options, the choice of main transformer, electrical equipment selection. And conduct extensive calculation of short circuit and transformer protection setting. Considered in the design of the transformer protection design, distribution transformer protection principles, use of differential protection, gas protection, over-current protection, overload, zero-sequence protection. As electrical equipment, power transformer is widely used in power systems and enterprise users. It contacts network, converts the power supply network voltage to voltage that electrical equipments or devices can use directly and plays a key role in power transmission, distribution and use process. Transformer cooling control system is an important part to ensure its safety of normal operation. The traditional transformer cooling control system, due to the control system consisting of logic circuit of mechanical contacts, high security hidden hazards, low automatization, cannot adapt to the needs of todays unattended substation, so the new control system design is imperative. For the existing transformer cooling control system has many shortcomings, such as the compl