【作者】 孙建军；

【导师】 徐建源；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2006， 硕士

【摘要】 变压器是电力系统和配电网络中昂贵且最重要的设备之一,其状态的好坏对保证供电网络的可靠运行意义重大。在当前的变压器状态监测中,虽然继电保护系统和定期维修能对变压器提供有效的保障,但是一方面影响电网的可靠性,降低电能质量,达不到降低维护成本的目的;另一方面这些传统方法属于常规的试验和检测,仅仅能够提供变压器故障或事故后的滞后信息,不能满足对变压器进行实时状态监测的需要。 根据对变压器绕组信号特点的理论分析,本文设计了一种基于嵌入式实时操作系统的多通道变压器并行数据采集硬件装置。在硬件电路实现上,注意选择电流电压变送器,合理设计了信号调理电路,采用了32位嵌入式微控制器和16位高精度A/D构成的硬件平台。在进行多通道数据采集时,克服了用一片A/D在速度上受到的限制问题,介绍了多通道、高速并行数据采集技术,并设计了数据采集电路和大容量的存储电路;制作了硬件电路的PCB板以及标准的金属封闭式机箱。并将此信号采集电路与嵌入式操作系统相连接,对采集的电流电压信号的进一步处理后与上位机通信。 在以往的变电站自动化系统与变压器保护装置之间的联系,绝大部分采用串口通信方式(RS-232,485总线等),其通信速率和资源共享程度均受到限制。本文详细描述了CAN现场总线通讯单元的上下位机软硬件开发过程,并利用CAN总线实现设备的检测处理及与上层监测主机的通信,实现变压器监测系统对通信的实时性要求。 本文设计的数据采集系统,设计思想的新颖之处是利用现场总线技术,大大降低了网络流量,降低了传输延迟,采用通用的ARM7TDMI内核的LPC2294系统板,完成数据并行采集、监控及通讯功能软件编写,并且移植了嵌入式实时uC/OS-Ⅱ操作系统,增加了系统的稳定性、实时性和可靠性,降低了开发成本,这在网络化工业管理控制中有着一定的应用前景。更多还原

【Abstract】 Transformer is one of the important and costly equipments in electric power system and distribution network, and the running states of transformer are of great importance for ensuring the security of electric power system network running. The system of relay protection and scheduled maintenance methods are most frequently studied in the protection of transformers, however, one these methods affect the reliability of the network and increase the maintenance expense, the either these tradition methods are the conventional trials and test which cannot meet the needs of state maintenance and real-time states monitoring of transformer.According to the theoretic analysis to windings monitoring characteristic of transformer, this paper proposes one of high speed and multi-channel data acquisition device based on embedded real-time operating system. In hardware circuit implementation, notice to choose signal sensors, signals magnify circuit and filter circuit are reasonably designed. In this scheme, the hardware platform composed by advanced 32-bit embedded microprocessor unit. At the same time, the multi-channel parallel data acquisition technique and high-precision 16-bit A/D converter are introduced, and large capability storage circuits are designed, overcame the problem that the speed is limited by use of one A/D converter to sample the multi-channel signals. At last, this paper designing hardware circuit board and standard metal enclose cabinet for acquisition device. Then the data sampling circuit is connected with embedded operating development system to process signals and communicate further.Previously, the communication mode control mainly adopts RS-232 or RS485 serial communication bus to continue substation automation system with transformer protection equipment, which the rate of communication and resource sharing are limited. This paper adopts distributed field CAN bus to design the development process of hardware and the communication software. At last, this paper makes use of CAN bus to realize the detection of the equipment and the units communication between equipment layer and monitoring layer, realized the real-time require of the transformers communication.This paper designs the data acquisition system of transformers greatly reducing network flow and transmission delay based on CAN field bus. Developing data sampling and communication function gating through exploiting the LPC2294 processor system plate of Advanced RISC Machines (ARM7) kernel and transplanting embedded uC/OS-II operation system. This method based on multi task real-time operating system increasing the high reliability and real-time, being apt to develop and maintain and upgrade and extend and so on.更多还原