【正文】 the bubble volume on the liquid surface increases, causing the water level increased. Comprehensive two factors, after the step increase of the steam flow rate, the water level down has a time delay process, showing a up then down. 沈陽理工大學學士學位論文 30 The impact on the water level of water flow or steam flow stepping decreased has similar principle as above. As analysis can be seen as above, when the water flow or steam load change, the water level did not follow the change immediately, but there is an opposite process at first. This phenomenon is called false water level phenomenon. III. DESIGN OF WATER LEVEL FUZZY CONTROLLER The conventional PID controller has a poor control performance to the steam generator that exist “false water level” characteristics, showing a greater overshoot in the tracking time. But a welldesigned fuzzy controller is able to overe the false water level phenomenon, and has good control performance. A. Sstructure of Fuzzy Controller The structure showed in Figure 1. Figure 1. Structure of steam generator water level fuzzy controller Choose the water level error (e) and change rate of error (ec) as input of the fuzzy controller, the output of the fuzzy controller is the added value of the valve opening signal Δu. Meanwhile, use the steam flow feedforward to overe the false water level phenomenon, use water flow feedback to overe fluctuations in water supply side . k1, k2 were water flow and。 GS (s) for the effect of the steam flow (load) to the steam generator water level. The balance of the steam generator water level is maintained through the match between the water flow and steam flow. The process that water level changes with the steam flow or water flow changing can be regarded as a simple integration process, but impact of the water flow and steam flow ?s change on water level is different. A. Dynamics Characteristics under Water Flow Disturbance Suppose steam flow GS remains unchanged, and water flow GW step increases, on the o ne hand because the temperature of feed water is much lower than the temperature of saturated water in the steam generator, so that , when feed water entering, it will absorb a lot of extra heat, the vapor phase bubble contents will reduce, resulting in water level decreasing。 QS for the steam flow。 the steam generator?s water level must be controlled in a certain range. When the nuclear power plant is running, as the steam flow or the water flow changing, the amount of boiling bubbles in the steam generator will change due to local pressure or temperature change, the instantaneous water level showed “false water level” phenomenon . The existence of “false water level” made it difficult to control the water level. The introduction of feedforward control to the traditional singleloop PID control can, in a certain extent, overe the false water level phenomenon. But the conventional PID control method in the process of steam generator water level control has some shortings. To the steam generator that has highly plex, large timedelay and nonlinear timevarying characteristics, the PID parameters tuning is a tedious job and the control effect is very poor. Furthermore, to achieve good control performance still as conditions changing, it often needs to change the PID controller parameters. But the analog PID controller parameters are difficult to regulate online. Fuzzy control is a kind of nonlinear 沈陽理工大學學士學位論文 29 control strategy based on fuzzy reasoning, which express operating experience of skilled manipulation men and mon sense rules of inference through vague language. Fuzzy control do not need to know precise mathematical model of controlled object, is not sensitive to the change of process parameters, is highly robust and can overe nonlinear factors, so, fuzzy control has faster response and smaller ultra tone, can get better control effect. Based on understanding above, this paper design a steam generator water level fuzzy controller, the simulation shows that the controller has good control performance and practical value. II. DYNAMIC CHARACTERISTICS OF STEAM GENERATOR The transfer function of PWR steam generator?s mathematical model of the general form shows below: y(s)=GW(s)QW(s)+GS(s)QS(s) （ 1） where y is the steam generator water level。 沈陽理工大學學士學位論文 27 參考文獻 [1] 李剛民，曹巧媛 .單片機原理及使用技術 [M].北京：高等教育出版社， 20xx. [2] 徐愛鈞 .8051 單片機實踐教程 [M].北京：電子工業(yè)出版社， 20xx. [3] 胡漢才 .單片機原理及其接口技術 [M].2 版 .北京：清華大學出版社， 20xx. [4] 周潤景 .PROTEUS 入門實用教程 [M].北京：機械工業(yè)出版社， 20xx. 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[15] [德 ]克勞斯而且本系統(tǒng)采用 USB 接口供電，使系統(tǒng)的抗干擾能力比普通電池要較強一些。 該系統(tǒng)實現(xiàn) 了 水塔 水位檢測 、數(shù)碼管顯示當前水位功能以及蜂鳴器鳴笛 報警 ， 實現(xiàn)水位 過滿 報警 、水位過低和正常 警戒水位處理 的系統(tǒng)要求 。 沈陽理工大學學士學位論文 26 7 結論 此課題屬于設計類，在分析了設計任務后，查閱大量的資料和相關的書籍，最終選定了以 SCT89C52 單片機為核心控制器來進行系統(tǒng)設計。 (二 ).軟件問題及解決方案： 按鍵按一下會跳好幾個數(shù)字：這在軟件中叫做按鍵的抖動，因為按鍵機械結構的原因，不可能濾除的很好，那么只能軟件里 防范 .檢測到按鍵后延時一個 15ms 的時間，然后再一次檢測，如果按鍵確實按下，執(zhí)行按鍵按下命令。 。一是要查看蜂鳴器是否接反。主要查看是否把 LED 燈的陰陽極接反。 （ 3）．軟件測試：寫一個功能小程序，來具體單個的功能硬件電路是否有問題，如果有問題再具體看是硬件的問題還是軟件的問題，若沒有問題，則可以進行下一個功能電路的測試。 調(diào)試步驟 （ 1） .元件安裝前的測量 :在元件沒有在萬能板上進行焊接的時候我們是不能直接拿過來就進行使用的，必須經(jīng)過檢測，像 LED 燈可以用萬用表測試一下看其是否會發(fā)光，測試三級 管的好壞，器件的檢測工作都要在焊接之前做好。 電路檢測 上電后觀察電路工作性能，如不能正常工作，按原理圖分模塊進行電路檢測，是否有虛焊或漏焊現(xiàn)象；如焊接正常，在按信號傳遞的方向逐級檢測，找 出出問題的一級，并向該級的上級進行檢測，直到將故障排除。軟件編程中，首先編寫單元模塊程序，并且解決在硬件上調(diào)試成功問題，即可以做系統(tǒng)整體程序調(diào)試。經(jīng)過初步分析設計之后