电动汽车充电站

电动汽车充电站 基于以太网的电动汽车充电站监管计费系统 的与实现 ,, 摘要:针对电动汽车充电站的智能化管理，推进其商业化应用推广，通过系统功能和运营 需要设计了系统的总体结构，基于以太网架构了远程后台与充电桩的监控管理网络;通过系统 硬件的模块化设计和软件支撑实现充电实时监控、计费计量、充电桩运营管理、网络内数据交 换和转发等功能;采用VB6.0可视化编程语言Winsock控件、ADO技术实现数据通信和充电站 后台数据库的应用。经过实践运行证明，该系统可靠性高，通信速度快，可达到无人或少人值 守，实现充电设施经济、安全、高效运行，有着广泛的应用前景。 关键字:电动汽车 充电站 智能 以太网 监控管理 计量计费 Research and Design of Monitoring and Charging System for Electric Vehicle Charging Stations Base on Ethernet SUN Jun-xiang (1.College of Computer Engineering of Weifang University , Weifang ,261061,China) Abstract: In order to improve the electric vehicle charging station intelligent management and promote its commercial application, an monitoring and management system is designed, in which monitoring communication network is designed based on the Ethernet network, and each function module which supported with hardware and software, such as charging real-time monitoring, measuring and billing, charging station operational management, data exchange and forward, are mainly included. The application of this control and monitoring system, including data communication and charging stations database application, is achieved on the base of VB6.0, Winsock Controls, and ADO technology. Practice proved that it has high reliability and high communication speed，ultimately realize no or few people unattended electric vehicle charging stations，guaranteeing the economical，safe and efficient operation of electric vehicle charging stations(It has a broad prospect of application. Key words: electric vehicle; charging station; intelligent; Ethernet; monitoring and management; measuring and charging 0引言 近年电动汽车因其以电力为驱动动力而具有的环保节能特点广受推崇，并逐渐成为各国政 府和汽车制造商关注的焦点;由于我国特殊的能源结构和社会经济发展现状，决定了电动汽车[1]在我国具有广阔的发展空间，在未来必将逐渐取代燃油汽车而成为市场的主流。 电动汽车充电站是电动汽车大规模商业化后不可缺少的电动汽车能源服务基础设施，针对 [2]目前广泛认同的三种充电模式——交流充电方式、直流充电方式和快速换电方式，已有相应 的电动汽车充电站监控系统的初步研究成果;但是目前的诸多研究中尚无针对计费运营的 监控系统研究，滞缓了电动汽车充电站的进一步发展。 本文针对上述问，首先分析了电动汽车充电站的功能需求，根据商业运营特点设计了电 动汽车充电站建设的一般模式，并进一步设计了系统的监控管理方案，通过运行该系统可以实 现安全的充电管理，为电动汽车用户提供便捷的充电服务，保障系统的运行可靠性，提高电动 汽车充电设施与电网资源的高效利用，从而实现本领域研究向应用发展的推进。 2--per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After dilution to 1000mL. 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL water bottle; 5mL iodine stock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetate buffer (PH5.3): dissolve 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a small amount of water. volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5mol/L sodium chloride: 14.5 g of sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure before use should determine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beaker in the, added 80~90mL distilled water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keep micro-boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 ? water bath in the makes solution reached this temperature, and in 40 ? Shi with distilled water (40 ?) set capacity, this starch solution placed 40 ? thermostat water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath: (40+-0.2) 0C. B) spectrophotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample 1电动汽车充电站监控系统整体设计 1.1面向应用的充电站建设模式 [3]目前，电动汽车电能供给主要有3种典型方式:交流充电、直流充电和电池更换。其中，电池更换方式要求电动汽车蓄电池具有化的统一接口和相关参数，暂时尚无相关标准出台以规范电动汽车市场，不具有商用基础;直流充电方式功率大，输出电流、电压变化范围宽， [4]充电效率高，适用于大型专用电动汽车的充电;交流充电方式由车载充电机给动力蓄电池充 [5]电，适用于小型纯电动汽车和可外接充电式混合动力电动汽车，一般功率较小，充电时间长。 综上所述，并结合当前电动汽车的发展现状，本文归纳了面向应用的充电站建设模式: 由数个智能计费交流充电桩和监控管理系统组成，适用于居民区、街道和商业区的停车场，为小型纯电动汽车、小型混合动力汽车提供稳定可靠的充电服务。 1.2充电站监控管理系统需求分析 根据面向应用的充电桩建设模式设计，本系统最重要的任务是完成对充电桩运行和计费计量的监控，保障充电桩稳定运行、精确计费管理和可靠的通信传输。其主要功能模块结构图如图1所示。 电动汽车充电站监控管理系统 数据运行计费故障图形管理配电采集监控计量处理界面应用监控通信模块模块模块处理模块模块模块 负责系统采集各出现故障监测，计监测站内管理维护充电桩数后显示报费信息管实现充电桩运营充电据并处理对充电站警画面，理，充电设备运行桩的消费后台监控配电设备的状态给充电桩桩故障处状态参数和充电桩情况和进行监控和运行发送控制理和实时的显示之间的电量计量参数显示运行指令数据传输状态 图1系统功能模块图 Fig.1 The function module chart 运行监控模块的对象为充电桩交流输出接口的状态，如电流、电压、开关状态、保护状态等，以及充电桩智能系统运行反馈的状态，如时间、充电用户卡号、充电时间、充电金额等信息。 计费计量模块主要功能是将采集的电能表实时电量信息处理并存储，并于充电结束后传回所消费的金额;各个充电桩的充电电量和计费信息存储到数据库服务器中。为完善系统应用，计费费率可更改并对意外断开充电连接、结账失败等情况进行判断与进一步处理并存储。同时，为保证系统计量计费的可靠性，监控系统需要有对时功能，可自动或手工进行时钟校测或对电能表进行校时。 数据采集模块直接面向充电桩终端，对其运行数据进行收集和管理，按照相关通信规约定义数据帧以供传输。通信传输网络采用《广东电网公司深圳供电局电动汽车充电设备通信规约》 boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -micro e, added 80~90mL distilled water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keepin th efore use should determine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beakerium chloride: 14.5 g of sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure b/L sodmall amount of water. volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5molffer (PH5.3): dissolve 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a ste bur bottle; 5mL iodine stock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetadilution to 1000mL. 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL wate per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After--20.2) 0C. B) spectrophotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample-: (40+ thermostat water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath?laced 40 ) set capacity, this starch solution p? Shi with distilled water (40 ?the makes solution reached this temperature, and in 40 water bath in ?2 作为数据传输协议，为实现监控管理系统对充电桩的实时数据采集以及相关控制提供通信保障。管理应用模块面向系统使用者，涵盖了监控信息处理显示功能、充电桩运行信息查询功能、数据库管理以及故障警告和处理等功能。 2电动汽车充电站监控管理系统的实现 2.1系统硬件环境设计 该监控系统整体包括充电桩、监控计算机、数据服务器、通讯转换设备等硬件。其中充电桩监控由检测电路、保护电路、脉冲电路、数据采集电路、智能通信接口和单片机系统组成，其中以太网通信接口由独立控制器组成，提供与PC机的通信服务;监控计算机与数据服务器主要是对处理系统数据，完成监控任务的软件设计;通讯转换设备应用于各硬件层之间的异构数据转换，采用现有产品。 图2为系统结构图，按照硬件归类划分为自成体系的三层: 监数 据控 服计控制层 务算 器机 通信层 充充充??????????????终端设备层电电电 桩桩桩 图2 电动汽车充电桩监控系统结构图 Fig.2 The Monitoring and Charging System diagram 控制层主要由数据服务器、监控主机组成，主要完成充电桩运行数据的采集、处理、存储、显示，计量计费信息的存储与处理，以及遥控、负荷分流、故障处理等控制功能。通信层主要由通信管理机、数据集中器、安全防护器等组成，主要完成数据的转发与控制命令的下达功能。终端设备层主要由充电桩、保护测控装置、安全防护设备等组成，负责对原始数据的采集、就地操作的执行。通过系统各层次分别架构与整体融合，实现各层次间的相对独立性，数据的采集转化在各层次内部完成，精简层与层之间的异构信息交互以保证监控系统高稳定性的安全运行。 2.2系统通信网络搭建 充电桩的应用通常为居民小区、停车场、沿街道停车位等较为分散的场所，各分散充电桩通过以太网交换机建立工业级别带有冗余的通信网络，当工作网络出现故障时迅速启用冗余网络，防止数据丢失;采用工业以太网建立监控计算机、数据服务器与以太网交换机之间的通信网络，以完成大量实时数据的可靠传输。 通信传输网络采用以太网TCP/IP协议进行信息的传送。Socket接口是TCP/IP网络的API函数接口，充电桩与监控系统之间的连接建立、数据传输等操作都是通过该Socket接口实现的。Socket接口中定义了许多函数，可以加快应用程序的开发。 通信传输网络采用《广东电网公司深圳供电局电动汽车充电设备通信规约》作为数据传输协议，对应用层的帧格式做了明确的规定，具体格式如表1所示: L distrmine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beaker in the, added 80~90mof sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure before use should dete.5 g volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5mol/L sodium chloride: 14 e 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a small amount of water.ssolvstock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetate buffer (PH5.3): di 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL water bottle; 5mL iodineon to 1000mL. per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After diluti--2hotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample0.2) 0C. B) spectrop-water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath: (40+ thermostat?) set capacity, this starch solution placed 40 ? Shi with distilled water (40 ?ached this temperature, and in 40 he makes solution re water bath in t?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -illed water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keep micro3 表1 监控系统与充电桩通信协议帧格式 Table 1 The frame format communication protocol of monitoring system and Vehicle Charging Stations 说明 对应代码 字节数 帧起始符 68H 1 终端逻辑地址 RTUA 4 主站地址与命令序号 MSTA&SEQ 2 帧起始符 68H 1 控制码 C 1 数据长度 L 2 数据域 DATA 变长 校验符 CS 1 结束符 16H 1 在本系统中，采用VB6.0中的Winsock控件实现以太网通信。本控件对用户不可见，可以访问TCP和UDP网络服务。后台监控系统和充电桩之间的数据通信采用C/S(服务端/客户端)的模式，后台监控系统定义为服务端，充电桩定义为客户端。图3显示了系统通信连接的建立流程。 建立Winsock控件Listener建立客户端 开始监听 建立新的Winsock控件向服务器端发送连接请求Sock相应连接 与后台监控系统进行通信与充电桩进行数据通信 Sock关闭连接，Listen 继续处于监听状态 Listener关闭，服务器关闭客户端关闭连接 图3通信流程图 Fig.3 The Communication flow chart 3系统软件设计与实现 监控管理系统利用可视化的编程语言VB6.0开发，其界面设计功能强，具有良好的图形用户接口，并且具有结构化的时间驱动编程模式，使编程效率得到提高，应用功能得到增强。 在软件设计中，电动汽车充电桩监控系统可分为五部分来实现:运行监控子系统、计量计费子系统、信息查询子系统、安防监控子系统以及配电监控子系统。子模块设计结构图如图4所示: Shi with distilled water (40 ?the makes solution reached this temperature, and in 40 water bath in ?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -micro e, added 80~90mL distilled water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keepin th efore use should determine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beakerium chloride: 14.5 g of sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure b/L sodmall amount of water. volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5molffer (PH5.3): dissolve 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a ste bur bottle; 5mL iodine stock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetadilution to 1000mL. 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL wate per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After--20.2) 0C. B) spectrophotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample-: (40+ thermostat water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath?laced 40 ) set capacity, this starch solution p?4 电动汽车充电桩监控系统 安防监控计量计费配电监控信息查询运行监控 系统系统系统系统系统 历故保运 电消时数史障报视图报数护设行数远 能费钟据记记表频像表据信备状据程 计结校存录录打监处管采息管态存控 查查处管量算时储印控理理集理储制 询询理理 图4子模块设计结构图 Fig.4 The submodule design structure diagram 3.1充电运行监控系统 充电运行监控系统是充电站监控系统的核心功能，主要实现对充电桩的监视和控制。运行监控系统主要完成的功能有:1)监控所有充电桩的交流输出接口的运行数据，如电压、电流等。2)提供充电桩远程控制功能:设置充电桩的运行参数，如电压、电流的阈值，远程控制充电桩开关机等。3)提供所有充电桩紧急停机功能。4)数据记录及相应报表打印功能。5)对充电桩的运行状态进行实时监视，例如故障信息报警等。6)将电压电流的实时数据通过图形的方式表现出来，更好的实现人机交互。 图5是充电桩充电监控系统主界面。 图5 充电桩监控系统主界面 Fig.5 The main interface of monitoring and charging system 3.2 计量计费系统 计量计费系统的主要功能是显示电动汽车在充电过程中消耗的电能，并实时给出所消费的金额等信息。充电站内由用电采集终端负责采集各个充电桩内的电能表的实时电量信息，通过 ached this temperature, and in 40 he makes solution re water bath in t?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -illed water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keep microL distrmine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beaker in the, added 80~90mof sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure before use should dete.5 g volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5mol/L sodium chloride: 14 e 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a small amount of water.ssolvstock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetate buffer (PH5.3): di 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL water bottle; 5mL iodineon to 1000mL. per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After diluti--2hotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample0.2) 0C. B) spectrop-water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath: (40+ thermostat?) set capacity, this starch solution placed 40 ? Shi with distilled water (40 ?5 本地工业以太网与计量计费系统通讯，将整个充电站的各充电机的每次充电电量传送到后台计量计费系统进行处理，并把电量和计费信息存储到数据库服务器中。同时，为保证系统计量计费的可靠性，监控系统需要有对时功能，系统可以自动或手工进行时钟召测对电能表进行校时。图6是计费计量系统主界面。 图6 计费计量系统主界面 Fig.6 The main interface of Charging system 3.3信息查询系统 在本系统中，查询功能主要分为两部分，一部分是电动汽车充电历史记录查询，主要是从充电桩编号、用户卡号、充电时间等方面进行查询。第二部分是报警信息查询，可以通过故障时间和故障原因两方面进行查询。同时，本系统支持报表打印和数据导出功能，可以按照要求将数据导出到excel表格中。图7是充电桩监控系统信息记录查询系统主界面。 图7信息查询系统主界面 Fig.7 The main interface of Information query 3.4安防监控系统 电动汽车充电站的安防监控系统充电站视频监控和监控中心组成，视频监控由图像监控系统、安防报警系统组成，将分散在充电站各单元的视频监控连接起来，安防监控设有媒体服务器、计算机系统等设备，并对这些设备对监控单元所提供的视频监控进行管理并跟踪监视。 3.5配电监控系统 配电监控系统实现对电动汽车充电站内的配电设备的监控，实现对数据的管理及共享。可 ?the makes solution reached this temperature, and in 40 water bath in ?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -micro e, added 80~90mL distilled water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keepin th efore use should determine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beakerium chloride: 14.5 g of sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure b/L sodmall amount of water. volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5molffer (PH5.3): dissolve 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a ste bur bottle; 5mL iodine stock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetadilution to 1000mL. 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL wate per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After--20.2) 0C. B) spectrophotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample-: (40+ thermostat water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath?laced 40 ) set capacity, this starch solution p? Shi with distilled water (40 6 以实现对采集电压、电流、功率、周波、温度等模拟量;采集断路器位置、刀闸位置、各类预告报警信号、设备状态信号等的数据采集;实现对保护开关状态量处理、保护定值等保护信息的处理;同时，以图形界面的方式显示出来，方便直观。 系统运行主界面，是系统与用户之间的人机交互接口，本系统具有用户权限管理功能，该功能可以实现通过监控计算机创建或修改用户名及密码。用户按可操作安全区分为若干级别，以控制用户系统权限，在通过登录界面登录系统时，系统可以根据输入的用户名来判断该用户的权限，相应权限的用户只能操作对应其权限的操作，使对系统的操作控制更具有针对性和安全性。 在信息查询系统中需要建立数据库，本系统使用的是SQL server 2000作为数据库支持软件，ADO技术为二者的数据接口。SQL server 2000数据库是一种关系型数据库，具备客户机/服务器体系结构，图形化用户界面，以及丰富的编程接口，可以独立开发数据库系统，也可以作为后台数据库与VB等，高级语言综合使用。ADO是当前访问数据库的一种主流技术。在VB6.0中，通过利用工程自身的Adodc控件，通过连接字符串的方式连接到指定的数据库。利用VB6.0中的DataGrid控件与数据库绑定。在应用程序界面上实时显示接收到的充电桩的信息，对接收到的数据进行实时的存储。 4结束语 本文基于VB6.0软件设计开发了采用以太网作为通信网络的电动汽车充电桩监控计费系统，通过以太网通信网络实现方案，计量计费系统、充电监控系统以及信息查询系统共同完成系统功能的实现。本系统可以完成了对交流充电桩的运行监控和历史充电记录的跟踪、查询、打印功能。经过实践运行证明，该系统可靠性高、通信速度快，具有良好的人机交互功能，为充电安全提供了技术保障，能够提高充电设施的智能化、自动化水平，达到无人或少人值守运行，实现充电设施经济、安全、高效运行。 参考文献 [1] 严辉，李庚银，赵磊等(电动汽车充电站监控系统的设计与实现[J](电网技术,2009, 33(12):16,19( YAN Hui, LI Geng-yin, ZHAO Lei. Development of Supervisory Control System for Electric Vehicle Charging Station[J] .Power System Technology, 2009, 33(12):16,19( [2] 冯冬青，赵洪蕊，王迎迎(电动汽车充电站智能监控管理系统设计[J](计算机测量与控制,2011,19(7):1619,1621( Feng Dong-qing, Zhao Hong-rui, Wang Ying-ying. Design of Intelligent Monitoring and Management System for Charging Station[J]. Computer Measurement & Control, 2011,19(7):1619,1621( [3] 申超群，王晓侃，孙忠良(电动汽车充电站智能监控系统研究与设计[J](华东电力,2011,39(6):1000,1003( SHEN Chao-qun, Wang Xiao-kan, SUN Zhong-liang. Research and Design of Intelligent Monitoring System for Electric Vehicle Charging Station[J]. East China Electric Power, 2011,39(6):1000,1003( [4] 刘永相，惠富会，徐瑞林等(基于LabVIEW和CAN总线的电动汽车充电站监控系统设计[J](电测与仪表，2011,11:41,44 LIU Yong- xiang, HUI Fu- hui, XU Rui- lin. Design of Supervisory Control System for Electric Vehicle charge-station Based on LabVIEW and CAN Bus. Electrical Measurement & Instrumentation, 2011,11:41,44 [5]刘艺，聂一雄，王星华等(基于GPRS的低压配电网监控系统下行控制信号通信研究,J,(电力系统保护与控制,2010,38( 11) :147,150( LIU Yi,NIE Yi-xiong,WANG Xing-Hua. Research on the down communication of remote control signal of low voltage distribution supervisory and control system based on GPRS. Power System Protection and Control, Shi with distilled water (40 ?ached this temperature, and in 40 he makes solution re water bath in t?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -illed water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keep microL distrmine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beaker in the, added 80~90mof sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure before use should dete.5 g volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5mol/L sodium chloride: 14 e 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a small amount of water.ssolvstock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetate buffer (PH5.3): di 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL water bottle; 5mL iodineon to 1000mL. per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After diluti--2hotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample0.2) 0C. B) spectrop-water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath: (40+ thermostat?) set capacity, this starch solution placed 40 ?7 ,38( 11) :147,150( 2010 water bath in ?boiling 3min, stamped and cooling to at room temperature, transfer to 100mL capacity bottle in the, into 40 -micro e, added 80~90mL distilled water, Yu asbestos online in constantly mixing Xia quickly heating to boiling, then with fire keepin th efore use should determine its value. Accurate said take amount starch (equivalent to dry state 1g) Yu 250mL high type beakerium chloride: 14.5 g of sodium chloride dissolved in boiled water, and constant volume to 500mL. 1.1.5 soluble starch: pure b/L sodmall amount of water. volume and then mixing the two together and add water to 500mL, using regulation to PH5.3. 1.1.4 0.5molffer (PH5.3): dissolve 87g sodium acetate (CH3COONa • 3H2O) 400mL water and 10.5mL in glacial acetic acid is dissolved in a ste bur bottle; 5mL iodine stock solution, and then diluted to scale and mix. This solution every other day to prepare. 1.1.3 acetadilution to 1000mL. 1.1.2 0.000 35mol/L iodine solution: dissolve 20 g of potassium iodide in Cheng You (30~40) 500mL mL wate per ml sodium hydroxide [c (NaOH) =1.000 mol/L] potassium hydrogen phthalate standard solution of quality g. ... After--20.2) 0C. B) spectrophotometer. 1.3 procedures 1.3.1 preparation of samples: weighing 50mL 10G sample-: (40+ thermostat water bath in the for determination samples with. 1.2 the instrument a) constant temperature water bath?laced 40 ) set capacity, this starch solution p? Shi with distilled water (40 ?the makes solution reached this temperature, and in 40 8