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  本文選題：模型　切入點(diǎn)：計(jì)算機(jī)仿真　出處：《農(nóng)業(yè)工程學(xué)報(bào)》2017年07期 　論文類型：期刊論文

【摘要】：混流式水輪機(jī)綜合特性曲線反映了水輪機(jī)高效率區(qū)域的特性,但不滿足水輪機(jī)大范圍內(nèi)過渡過程仿真需求,在仿真前需要對水輪機(jī)低效率及負(fù)效率區(qū)域的特性進(jìn)行拓展。目前常用的拓展方法其原理均是根據(jù)水輪機(jī)綜合特性曲線中各參數(shù)的變化趨勢并結(jié)合飛逸特性曲線等約束進(jìn)行的拓展,沒能充分考慮水輪機(jī)內(nèi)在規(guī)律,拓展結(jié)果過度依賴個人經(jīng)驗(yàn),具有較大的隨意性。該文通過分析水輪機(jī)各部件的能量損失建立了水輪機(jī)能量平衡關(guān)系式,結(jié)合流量調(diào)節(jié)方程對水輪機(jī)內(nèi)特性模型進(jìn)行了改進(jìn)。針對改進(jìn)后的內(nèi)特性模型特點(diǎn)設(shè)計(jì)了一種遺傳算法與最小二乘法相結(jié)合的參數(shù)辨識方法,采用水輪機(jī)綜合特性曲線及飛逸特性曲線對模型參數(shù)進(jìn)行了辨識,采用辨識后的水輪機(jī)模型繪制了較大范圍的水輪機(jī)特性曲線并與實(shí)測特性曲線進(jìn)行了比對,并結(jié)合實(shí)測結(jié)果對誤差來源及誤差對過渡過程影響進(jìn)行了分析。結(jié)果表明改進(jìn)后的混流式水輪機(jī)內(nèi)特性模型能夠正確描述水輪機(jī)特性,采用最小二乘法與遺傳算法相結(jié)合的方法能夠辨識模型中的參數(shù),將該模型應(yīng)用在水輪機(jī)外特性曲線拓展及過渡過程仿真中,機(jī)組過渡過程中最大轉(zhuǎn)速上升率相對誤差從2.11%降低到0.54%,最大壓力上升率相對誤差從10.70%降低到9.52%,說明該模型能夠減小仿真誤差、減小傳統(tǒng)方法中對個人經(jīng)驗(yàn)的依賴,對過渡過程計(jì)算提供了參考。
[Abstract]:The comprehensive characteristic curve of Francis turbine reflects the characteristics of the high efficiency region of the turbine, but it does not meet the needs of the transient process simulation in a wide range of hydraulic turbines. It is necessary to extend the characteristics of the low efficiency and negative efficiency region of the turbine before simulation. At present, the principle of the expansion methods is based on the variation trend of the parameters in the comprehensive characteristic curve of the turbine and combined with the flight escape characteristic curve. The expansion of equal constraints, The inherent law of the turbine was not fully considered, and the expansion result was excessively dependent on personal experience, which was arbitrary. By analyzing the energy loss of the various components of the turbine, the energy balance relationship of the turbine was established in this paper. According to the characteristics of the improved internal characteristic model, a parameter identification method combining genetic algorithm and least square method is designed. The model parameters are identified by the comprehensive characteristic curve and the flight characteristic curve of the turbine, and a large range of characteristic curves of the turbine are drawn by using the identified model and compared with the measured characteristic curve. The results show that the improved internal characteristic model of Francis turbine can accurately describe the characteristics of the turbine. The parameters of the model can be identified by combining the least square method and genetic algorithm. The model is applied to the expansion of the outer characteristic curve of the turbine and the simulation of the transition process. The relative error of the maximum speed rise rate decreases from 2.11% to 0.54, the relative error of the maximum pressure rise rate decreases from 10.70% to 9.52, which shows that the model can reduce the simulation error and reduce the dependence on personal experience in the traditional methods. It provides a reference for the calculation of transition process.
【作者單位】： 西安理工大學(xué)水利水電學(xué)院;
【基金】：國家自然科學(xué)基金資助項(xiàng)目(51479166);國家自然科學(xué)基金資助項(xiàng)目(51339005)
【分類號】：TK733.1

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本文編號：1601175