配电网监控主机的软件设计.doc

山东科技大学学士学位论文 摘要 摘要摘要 配电所自动化系统近年来发展迅速 但是主要着眼于 110kV 和 35kV 电压等级 10kV 配电所多处于送电终端 事故影响面较小 配电所自动 化发展相对缓慢 此外 由于城市低压配电所所处的地理环境复杂 针对 供电部门的实际需要 需要开发一套低压配电所自动化监控系统 该系统 利用方便的通讯方式可以实现对配电所的遥信 遥测和遥控 有效地提高 城市低压网安全运行和供电可靠性 在吸收目前国内外流行的监控软件的优点和特点的基础上 本文针对 配电网系统运行原理 研究开发了一个电力监控系统软件 实现了监控系 统所需的基本功能 本系统以 WIN XP 为开发平台 以 V B 6 0 为开发工 具 数据库部分使用的是 Microsoft Office Access 2003 以面向对象技术作 为设计思想 采用模块化程序设计方法 具有一定的通用性 关键词 关键词 监控系统 模块化设计 数据库 山东科技大学学士学位论文 摘要 ABSTRACT The electric distribution station automation technology develops rapidly recent years but the technology lays stress upon 110kV and 35kV level distribution station 10kV distribution stations are often located at electric distribution terminals and the domain of accident influence is little so 10kV distribution stations automation technology develops slowly In addition because the geographic environment of the station is complicate a low voltage distribution station automation supervisory and control system is necessary for power supply 另一方面要求能接受站内运行人员的控制命令 将其下发给 现场装置 实现遥控 遥调操作 而同时监控系统还在变电站与监控中心 的关系中担任着上传数据信息 下达命令的角色 配电网监控系统是直接 面对变电站站内的运行人员 提供给运行人员直观 简便和快捷的途径对 变电站的运行进行控制 使运行人员通过对计算机的操作实现对整个配电 网的监视 测量和遥控等作业 提高变电站运行的可靠性 经济性和易维 护性 可以使值班人员和系统调度人员把握安全控制 事故处理的主动性 减少和避免误操作 误判断 缩短事故停电时间 同时可以提高电网的运 行管理水平 减少变 配电损失 提高供电质量 因此监控软件在配电所 乃至电网自动化系统中都起到重要的作用 本课题的监控软件可以被看成实时数据库和历史数据库的应用程序 6 是调度员监视电网运行状态 调整运行方式的主要界面 应该能够把反映 电网状态的信息用许多实时画面 表格 趋势曲线等形式显示 以便能够 方便的操作 本系统主要对历史数据库的显示 报表的生成 配电网的一 次主接线图等方面做了具体的研究 以下图 4 3 为系统欢迎界面 山东科技大学学士学位论文 监控主机系统软件设计及代码实现 19 图 4 3 系统欢迎界面 4 3 2 配电网监控主机的一次主接线图及其模块设计配电网监控主机的一次主接线图及其模块设计 监控界面是重要的人机界面接口 是运行人员了解电站运行情况的窗 口 实时数据要以最快速度在界面上得到更新 该模块为各级用户提供了 灵活的实时监视图形界面 可以显示变电站一次主接线 实时运行数据等 如 图 4 4 所示为一次主接线图 山东科技大学学士学位论文 监控主机系统软件设计及代码实现 20 图 4 4 配电网监控主机的一次主接线图 当任何一个断路器的报警信号被采集并通过串行通信进入数据库后 监控主机就能调用这个信息 反应在主界面上的实时现象就是 断路器的 状态监测灯都会由绿色变为红色 同时进行记录到故障报警库中 点击遥 控按钮管理员可以对断路器进行开关的操作 1 系统监视和报警功能的内容如下 事件顺序记录 当变电站重要设备发生事故或其运行状态发生变化 时 监控系统立即做出的反应 并记录事故发生时间 状态变化的设备名 山东科技大学学士学位论文 监控主机系统软件设计及代码实现 21 称 内容等 若有多个事件相继发生 则按发生时间先后顺序记录 故障报警 当变电站重要设备发生故障时 监控系统立即报警提 示并作相应处理 同时记录故障类型和发生时间 多个故障同时发生 则 按时间顺序报警和记录 参数越限报警 运行设备参数越过其设定限值时 立即进行报警 恢复时进行复限提示 操作记录 对于变电站优化调度操作 按先后顺序进行记录 并 以汉字显示方式报告运行人员 图中断路器开断的主要代码为 varSource SELECT FROM 表 1 cnn ConnectionString Provider Microsoft Jet OLEDB 4 0 Data Source C Documents and Settings Administrator 设计 01 mdb cnn Open Set rs1 ActiveConnection cnn rs1 Open varSource t1 rs1 Fields 1 If t1 1 Then Text10 BackColor Data Source C Documents and Settings Administrator My Documents 设计 一次接 线图 01 mdb cnn Open Set rs1 ActiveConnection cnn rs1 Open varSource t1 rs1 Fields 1 If t1 1 Then Text10 BackColor and in terms of the filter design the 3 order Butterworth low pass filter is designed according to the simulation results of the measurement signal The test result indicates that the presented system can be use in the measurement of the moving object electric field Keywords electric field measurement electrode filter Introduction Aerial moving object can be charged electrically because of friction and inducting process the electric charging of moving object causes an electric field which is transported by the moving object 1 it is difficult to be removed completely Because of the concurrence of charge and discharge during object 山东科技大学学士学位论文 附录 2 翻 译 54 moving the object electric field isn t a proper electrostatic field it is a quasi electric field The tests of various moving objects show that the electric field varies in an extreme low frequency 2 the frequency spectrum is from DC to kilo HZ The electric field parameter of the moving object can be measured by using the electrostatic measurement device on the ground To the ground electrostatic measurement device the electric field can be measured as an electrostatic field DESIGN ON THE MEASUREMENT SYSTEM There are two ways to measure the charge quantity of the moving object the one is that the electrode is joined with a charge amplifier the output of the charge amplifier is in proportion to the charge quantity of the electrode surface but it is infeasible because in the open space application condition of the electrostatic measurement it is difficult to realize the absolute insulation between the electrode and the earth 1 Another method is that according to the electrostatic theory the electrode of the electrostatic measurement device inducts the charge of moving object in certain distance range because of the movement of the object the induction charge of the electrode is varies with the object distance that means the charge quantity of the electrode is the function of the object distance thereby it is the function of time so the characteristic of induction charge which is varying with the moving object distance is utilized in electrostatic measurement system design the charge quantity of the electrode surface is gained by measuring the current of the electrode The schematic diagram of the electrostatic measurement system is shown in Fig 1 山东科技大学学士学位论文 附录 2 翻 译 55 Fig 1 The schematic diagram of the measurement system A Design of the Electrode Shape The spherical electrode is selected in the electrostatic measurement system the reasons are 1 It is easy to estimate the influence of the electrode to the measured electric field calculate the surface charge of the electrode and the electric field distortion is less 3 2 Analyzing qualitatively the spherical electrode is isotropic but the induction of the plate electrode is influenced by the angle which is the pitch angle of the moving object and the plate electrode B Design of the Measurement Circuit The induction charge of the spherical electrode is influenced by various weather conditions and interference in the open the high sensitive and anti jamming performance circuit is designed in the electrostatic weak signal measurement The low impedance circuit couples less interference comparing with the high impedance circuit In order to measuring the current of nA or pA level the weak current I V transform circuit is designed in the measurement system 4 the operational amplifier OPA128 with ultra low biased current is adopted the biased current of operational amplifier OPA128 is less than 0 075pA the typical value is 0 04pA In terms of the weak current measurement circuit design the common design rules in engineering practice are adopted to improve the 山东科技大学学士学位论文 附录 2 翻 译 56 performance of the circuit effectively 5 the T type network is adopted to reduce the noise of the resistor the metal film resister which is influenced less by the environment is used in feedback element a small capacitance is connected in parallel with the feedback resistor to avoid the time lag inconsistent of different frequency caused by the indeterminacy of the parasitic capacitance Fig 2 The curve of the signal simulation of the electrostatic measurement circuit C Design of the Filter The low pass filter is the important part to insure the electrostatic measurement system work normally as it filters the high frequency interference of the system and the environment The filter parameter can be estimated by signal simulation of the electrostatic measurement system in filter design Fig 2 is the curve of the signal simulation of the electrostatic measurement circuit based on the typical charged moving object Fig 3 is the graph of the spectrum analysis of the simulation signal 山东科技大学学士学位论文 附录 2 翻 译 57 Fig 3 Graph of spectrum analysis of the simulation signal The result is derived from the simulation the energy of the out put signal of the current measurement circuit is concentrated in low frequency band which is less than 50 HZ Because of the high gain parameter of the weak current measurement circuit the noise of the circuit is amplified especially in the condition of 50Hz AC work frequency the circuit is influenced severely So the pass band of the low pass filter is designed as 0 40HZ According to the measurement system demands the measurement signal distortion can not be caused by the designed filter so the filter with flat amplitude frequency response and constant delay phase frequency response characteristics in the pass band is adopted the low pass Butterworth filer matches the presented demands A three order Butterworth low pass filter circuit is designed to match the specific demands of the measurement system by using Filter CAD software the schematic diagram of the filter circuit is shown in Fig 4 and it is a switch capacitance filter 山东科技大学学士学位论文 附录 2 翻 译 58 Fig 4 The schematic diagram of the filter circuit The curve of the filer amplitude frequency response is shown in Fig 5 山东科技大学学士学位论文 附录 2 翻 译 59 Fig 5 The curve of the filer amplitude frequency response TEST AND RESULT The lab and aeromodelling test are carried out to prove the performance of the designed measurement system The measurement test device in the lab is consisted of a metallic spherical electrode weak current measurement circuit low pass filter and output instrument The wave shown in Fig 6 is the output of oscillograph when a charged sphere is moving over the metallic spherical electrode The test result proves that electric field of the aerial moving object can be measured by using this designed measurement system Fig 6 The measurement wave of the lab test 山东科技大学学士学位论文 附录 2 翻 译 60 CONCLUSION The investigations about electric field measurement of the moving object demonstrate that it can be successful to measure the moving object electric field by using the designed electrostatic measurement system The results of experiment prove the performance of the measurement system and correctness of the measurement signal simulation Further investigation is ongoing to improve the measurement precision of the designed measurement system REFERENCE 1 H Trinks Electric Field Detection and Ranging of Aircraft IEEE on Aerospace and Electric system Vol AES 18 No 3 May 1982 2 David M Hill Time varying Electrostatic Modeling Techniques ADA358654 1999 3 ZhangWeidong Cui Xiang Research on Optical Fibre Transient Electric Field Sensor Measurement and Control Technology 2003 Vol 23 4 Qian Guofei Foundation and Application of Integration Operation Amplifier Shanghai Jiao Tong University Press 1992 5 Wu xingyuan Wu Fei Discussion on Improvement of the Amplification Noise Electroacoustics Technology 1994 10 山东科技大学毕业设计 论文 说明书 附录 2 翻 译 61 关于运动物体电场的测量系统的设计关于运动物体电场的测量系统的设计 陈熙 贾雍洪 毕军健 徐厉辛 中国北京 机械工程学校 北京科技学院 电话 010 58915044 邮箱 chenxi 摘要摘要 本文这个测量系统是用来研究运动物体电场测量的有效手段 电极被使用在测量系统用来引导由移动的对象运输的电场 并且电场 参量由被设计的当前的测量电路测量 球状电极和微弱的潮流 I V 变换电路被设计在测量系统 并且根据过滤器设计 根据测量信号的 模仿结果设计三等级巴特沃思低通滤波器 测试结果表明 被提出的 系统可以用在移动的对象电场的测量 主题词主题词 电场测量 电极 过滤器 导言 空中移动的对象可能由于摩擦并且引导过程充电 这种的充电移 动对象导致一个移动的电场 1 它难完全地被去除 由于充电和放电 同时发生在对象运动期间 对象电场不是一个适当的静电场 这是一 个半电场 各种各样的移动的对象试验证明 电场变化在极端低的频 率中 2 频率光谱是从直流电到交流电 移动的对象的电场参量可 以在地面使用测量静电测量设备测量 对地面静电测量设备来说 这 种电场能够作为一个静电场被测量 山东科技大学毕业设计 论文 说明书 附录 2 翻 译 62 关于测量系统的设计 有二种方式测量移动的对象的充电数量 一种是电极被加入到充 电放大器 充电放大器的输出量是与电极表面的充电数量成比例的 但它是不能实行的 因为静电测量应用条件是在露天场所 在电极和 地球之间的材料不可能会绝对绝缘 2 另一种方法是 根据静电 理论 静电测量设备的电极在某一距离范围引导移动的对象充电 由 于对象的运动 电极感应电荷是随对象距离变化而变化的 这就意味 着电极的充电数量是与对象距离的有关 因此是时间的作用 所以随 移动的对象距离变化的感应电荷的特征被运用在静电测量系统设计 电极表面的充电数量由测量获取电极的潮流 静电测量系统的概要图 被显示在图 1 图 1 测量系统的概要图 A 电极形状的设计电极形状的设计 球状电极被选择在静电测量系统 原因是 1 它容易估计对被测量的电场的电极的影响 容易计算电极的 表面充电 并且电场畸变是较少 3 2 定性地分析 球状电极是各向同性的 但金属电极的感应现 象被移动的对象和金属电极的角度影响 B 测量电路的设计测量电路的设计 山东科技大学毕业设计 论文 说明书 附录 2 翻 译 63 球状电极的感应电荷在户外被各种各样的天气情况影响和干涉 高敏感和反阻塞的表现电路被设计在静电微弱的信号测量 低阻抗电 路结合较少干涉和高阻抗电路相比 为了测量达到 nA 或 pA 水平 在测量系统中设计了弱电流 I V 转换 4 采取具有极端微弱的偏流 的运算放大器 OPA128