【正文】 .......... 25 處理器選擇 ............................................. 26 LCD 液晶顯示器選擇 ..................................... 27 采樣電路設(shè)計(jì) ........................................... 31 AD 時(shí)序設(shè)計(jì) ............................................ 32 測(cè)頻電路設(shè)計(jì) ........................................... 39 控制輸出設(shè)計(jì) ........................................... 40 串口通信接口設(shè)計(jì) ....................................... 41 鍵盤(pán)設(shè)計(jì) ............................................... 42 低電壓直流電源設(shè)計(jì) ..................................... 46 看門(mén)狗電路設(shè)計(jì) ........................................ 46 時(shí)鐘信號(hào)及電源監(jiān)視電路設(shè)計(jì) ............................ 47 ......................................... 48 ............................................... 49 隔離措施 ............................................... 49 屏蔽 ................................................... 49 通道干擾處理 ........................................... 49 ..................................................... 49 4 裝置軟件設(shè)計(jì) ....................................................... 50 ........................................... 50 主 流程圖 ................................................. 50 ................................................. 51 初始化模 塊 ............................................. 51 數(shù)據(jù)采集模塊 ........................................... 52 數(shù)據(jù)處理模塊 ........................................... 53 故障分析模塊 ........................................... 53 ............................................... 54 ..................................................... 55 5 結(jié)論 ............................................................... 56 參考文獻(xiàn) ............................................................. 49 附錄 ................................................................. 52 致 謝 ................................................ 錯(cuò)誤 !未定義書(shū)簽。 step response。 ABSTRACT Neutral nongrounded and Petersencoil grounded systems which are also called neutral uneffectual grounded systems (NUGS), are widely used in the highvoltage electricity work of coal mine in China. The fault rate of singlephasetoground of NUGS is high, but its fault line selection has not been well solved yet. It is mainly because that the fault current is small and the fault traits are not obvious. With the improvement of the level of automation in the distribution work, the fault line selection needs to be solved urgently. Based on summaries of the existing fault line selection methods, the method of line selection by obtaining the step response of the lines is adopted. According to the theoretical analysis, the spectrum characters are very different between the fault line and the normal lines: the amplitudefrequency characteristic of the fault line is more obvious than that of the normal lines, and the phasefrequency characteristic of the fault line is reverse to the normal ones. So the foundation of line selection is confirmed as a result of the theory analysis result. Based on the principle of modularized designing, this paper focuses on designation of the hardware circuit and software flow chart of the line selection device for the 6kV power system of coal mine, offering the principle for IC device selection, the scheme for the system designing and its way of realization. A datasampling system with DSP and CPLD as well as a control system based on them is successfully designed. Software flow chart is given。最后 簡(jiǎn)單分析了軟件抗干擾的重要性，給出了一些軟件抗干擾的方法。 理論分析表明 ，故障線(xiàn)路和非故障線(xiàn)路階躍響應(yīng)頻譜特性表現(xiàn)出較大的差異：故障線(xiàn)路幅頻特性比非故障線(xiàn)路 明顯 ， 且相頻特性相反 。隨著配電網(wǎng)自動(dòng)化水平的提高，小電流接地系統(tǒng)單相接地故障選線(xiàn)問(wèn)題迫切需要解決。 X X X X 大 學(xué) 本科生畢業(yè)設(shè) 計(jì) 姓 名： XXX 學(xué) 號(hào) ： 04041228 學(xué) 院： XXXXXXXXXXXXXX 專(zhuān) 業(yè)： 電氣 XXXXXXXXXXXX 設(shè)計(jì)題目： 煤礦 6kV 電網(wǎng)接地選 線(xiàn) 裝置設(shè)計(jì) 專(zhuān) 題： 指導(dǎo)教師： 職 稱(chēng)： 200X 年 6 月 XXXX 大學(xué)畢業(yè)設(shè)計(jì)指導(dǎo)教師評(píng)閱書(shū) 指導(dǎo)教師評(píng)語(yǔ) （①基礎(chǔ)理論及基本技能的掌握； ② 獨(dú)立解決實(shí)際問(wèn)題的能力；③研究?jī)?nèi)容的 理論依據(jù)和技術(shù)方法；④取得的主要成果及創(chuàng)新點(diǎn)；⑤ 工作態(tài)度 及工作量；⑥總體評(píng)價(jià)及建議成績(jī)；⑦存在問(wèn)題； ⑧ 是否同意答辯等）： 成 績(jī)： 指 導(dǎo)教師簽字 年 月 日 XXXX 大學(xué)畢業(yè)設(shè)計(jì)評(píng)閱教師評(píng)閱書(shū) 評(píng)閱教師評(píng)語(yǔ) （ ①選題的意義； ② 基礎(chǔ)理論及基本技能的掌握；③綜合運(yùn)用所學(xué)知識(shí)解決實(shí)際問(wèn)題的能力； ④ 工作量的大??； ⑤ 取得的主要成果及創(chuàng)新點(diǎn)； ⑥ 寫(xiě)作的規(guī)范程度； ⑦ 總體評(píng)價(jià)及建議成績(jī)； ⑧ 存在問(wèn)題； ⑨ 是否同意答辯等 ）： 成 績(jī)： 評(píng)閱教師簽字： 年 月 日 XXXX 大學(xué)畢業(yè)設(shè)計(jì)答辯及綜合成績(jī) 答 辯 情 況 提 出 問(wèn) 題 回 答 問(wèn) 題 正 確 基本 正確 有一般性錯(cuò)誤 有原則性錯(cuò)誤 沒(méi)有 回答 答辯委員會(huì)評(píng)語(yǔ)及建議成績(jī)： 答辯委員會(huì)主任簽字： 年 月 日 學(xué)院領(lǐng)導(dǎo)小組綜合評(píng)定成績(jī)：