電子、電氣產(chǎn)品的設(shè)計(jì)，必須保證在一定的電磁環(huán)境中能正常工作，既滿足標(biāo)準(zhǔn)規(guī)定的抗干擾極限值要求，在受到一定的電磁干擾時(shí)，無性能降級(jí)或故障；又要滿足標(biāo)準(zhǔn)規(guī)定的電磁輻射極限值的要求，對(duì)電磁環(huán)境不構(gòu)成污染。所以，產(chǎn)品設(shè)計(jì)之初，就要從分析產(chǎn)品預(yù)期的電磁環(huán)境、干擾源、耦合途徑和敏感部件入手，采用相應(yīng)的技術(shù)措施，抑制干擾源、切斷或削弱耦合途徑，增強(qiáng)敏感部件的抗干擾能力等。文中詳細(xì)介紹了一款485通訊隔離產(chǎn)品從輻射超標(biāo)到順利通過FCC CLASS B認(rèn)證，在原理設(shè)計(jì)、PCB制板等多方面所做的各項(xiàng)改進(jìn)措施。文中所提到的方法及規(guī)則，對(duì)產(chǎn)品EMC設(shè)計(jì)具有很大的參考及指導(dǎo)意義。
為了改變目前電網(wǎng)現(xiàn)場(chǎng)作業(yè)管理的變電巡檢、變電檢修試驗(yàn)、輸電線路巡檢檢修等管理系統(tǒng)各自獨(dú)立運(yùn)行，信息不能共享，功能、效率受限，建設(shè)和維護(hù)成本高的現(xiàn)狀，提出了采用B/S+C/S構(gòu)架模式，將各現(xiàn)場(chǎng)作業(yè)管理模塊和生產(chǎn)MIS（管理系統(tǒng)）集成為一體的現(xiàn)場(chǎng)作業(yè)管理系統(tǒng)的設(shè)計(jì)方案，做到各子系統(tǒng)和生產(chǎn)MIS軟硬資源共享，做到同一數(shù)據(jù)唯一入口、一處錄入多處使用。各子系統(tǒng)設(shè)備人員等基礎(chǔ)信息來源于生產(chǎn)管理系統(tǒng)，各子系統(tǒng)又是生產(chǎn)管理系統(tǒng)的作業(yè)數(shù)據(jù)、缺陷信息的重要來源。經(jīng)過研究試用成功和推廣應(yīng)用，目前該系統(tǒng)已在江西電網(wǎng)220 kV及以上變電站全面應(yīng)用。
Abstract:
In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
When a system designer specifies a nonisolated dc/dc powermodule, considering the needed input voltage range isequally as important as considering the required performanceattributes and features. Generally, nonisolated moduleshave either a narrow or a wide input voltage range. Narrowinputmodules typically have a nominal input voltage of3.3, 5, or 12 V. For systems that operate from a tightlyregulated input bus—such as those that do not use batterybackup—a narrow-input module is often adequate sincethe input remains fairly stable.Offering greater flexibility, wide-input modules operatewithin a range of 7 to 36 V, which includes the popular12- or 24-V industrial bus. This enables a single module tobe used for generating multiple voltages. These modulesare ideal for industrial controls, HVAC systems, vehicles,medical instrumentation, and other applications that usea loosely regulated distribution bus. In addition, systemspowered by a rectifier/battery charger with lead-acidbattery backup almost always require wide-input modules.System designers who choose power supplies may wantto take a close look at the latest generation of wide-inputdc/dc modules.
