本文選題：壓縮機(jī)變頻 + 魯棒控制��； 參考：《天津大學(xué)》2014年碩士論文

【摘要】：壓縮式制冷系統(tǒng)通常按照最大冷、熱負(fù)荷量進(jìn)行設(shè)計。實際運行時，制冷系統(tǒng)因外界環(huán)境影響，長期工作在非額定工況下，產(chǎn)生冷量大于實際所需冷量，，因而造成浪費。為了保證制冷系統(tǒng)能夠準(zhǔn)確的“按需供給”和“逐點優(yōu)化”，設(shè)計了基于內(nèi)模結(jié)構(gòu)的制冷系統(tǒng)控制策略，并通過仿真研究，驗證了該策略的有效性。 首先，根據(jù)實際制冷系統(tǒng)的實驗數(shù)據(jù)，分析了制冷系統(tǒng)的內(nèi)部特性，主要包括制冷系統(tǒng)主要參數(shù)變化的影響因素和變化趨勢，制冷系統(tǒng)組件輸入輸出變量間的耦合關(guān)系，以及部分輸出變量響應(yīng)滯后的現(xiàn)象及原因。此外，對本研究小組提出的制冷系統(tǒng)六階非線性模型進(jìn)行了特點分析，說明了該模型區(qū)別于以往模型的優(yōu)勢，能夠較為全面的體現(xiàn)制冷系統(tǒng)的主要特性，并為控制策略設(shè)計提供了依據(jù)。 其次，為消除制冷系統(tǒng)因耦合和滯后等特性給系統(tǒng)運行帶來的不良影響，設(shè)計出了制冷系統(tǒng)內(nèi)模解耦控制策略。在設(shè)計時，在線辨識了制冷系統(tǒng)帶時滯的二階線性數(shù)學(xué)模型，并分析了該模型是否為穩(wěn)態(tài)非奇異矩陣和模型逆是否存在復(fù)右半平面（RHP）極點的問題。利用分析結(jié)果，對制冷系統(tǒng)構(gòu)建了內(nèi)�？刂平Y(jié)構(gòu)，并將解耦控制納入了控制策略設(shè)計中。另外，采用最小穩(wěn)定過熱度曲線優(yōu)化了過熱度設(shè)定點，從而設(shè)計和完善了制冷系統(tǒng)內(nèi)模解耦控制策略。通過魯棒性分析，給出了該策略能夠保證制冷系統(tǒng)魯棒穩(wěn)定性的條件。在仿真實驗中，分時段加入了階躍輸入信號和階躍干擾信號，將該制冷系統(tǒng)內(nèi)模解耦控制策略與雙回路PID控制策略和帶Simth預(yù)估器的解耦控制策略的控制效果進(jìn)行對比，直觀的展示了該策略在解耦能力和抑制擾動方面的優(yōu)勢。在上述仿真實驗假設(shè)條件下，又加入了三種典型的不確定性條件，再次對比三種策略下的制冷系統(tǒng)輸出響應(yīng)曲線，驗證了該制冷系統(tǒng)內(nèi)模解耦控制策略在提高系統(tǒng)魯棒性方面優(yōu)于其他控制策略。 最后，由于該制冷系統(tǒng)內(nèi)模解耦控制策略所采用的線性模型不能完全真實地體現(xiàn)制冷系統(tǒng)的復(fù)雜性，因此提出了基于上述制冷系統(tǒng)六階非線性模型的非線性內(nèi)模控制策略。為了利于控制策略的設(shè)計，將上述模型簡化為仿射非線性形式，并采用反饋線性化方法將其變換為偽線性形式。針對變換后的偽線性系統(tǒng)構(gòu)建了內(nèi)�？刂平Y(jié)構(gòu)，從而完成了非線性內(nèi)�？刂撇呗缘脑O(shè)計。通過系統(tǒng)性能分析和魯棒性分析，從理論上證明了該策略的有效性，并給出了保證系統(tǒng)魯棒穩(wěn)定性的條件。同時，仿真結(jié)果驗證了該策略具有較強(qiáng)的解耦能力、抗擾性和魯棒性。
[Abstract]:Compression refrigeration systems are usually designed according to maximum cooling and heat loads. In the actual operation, the refrigeration system works under non-rated working conditions for a long time because of the influence of external environment, and the cooling rate is larger than the actual required cooling rate, thus causing waste. In order to ensure the accurate "on-demand" and "point-by-point optimization" of refrigeration system, the control strategy of refrigeration system based on internal model structure is designed, and the effectiveness of the strategy is verified by simulation. Firstly, according to the experimental data of the actual refrigeration system, the internal characteristics of the refrigeration system are analyzed, including the influencing factors and the changing trend of the main parameters of the refrigeration system, and the coupling relationship between the input and output variables of the refrigeration system components. And the phenomenon and reason of partial output variable response lag. In addition, the characteristics of the sixth-order nonlinear model of refrigeration system proposed by this research group are analyzed, which shows that the model is different from the previous model and can fully reflect the main characteristics of the refrigeration system. It also provides the basis for the design of control strategy. Secondly, the decoupling control strategy of internal model of refrigeration system is designed in order to eliminate the bad effect of coupling and hysteresis on the operation of refrigeration system. In the design, the second order linear mathematical model with time delay for refrigeration system is identified online, and the problem of whether the model is a steady state nonsingular matrix and whether there exists a complex right half plane (RHP) pole in the model inverse is analyzed. Based on the analysis results, the internal model control structure of the refrigeration system is constructed, and the decoupling control is incorporated into the design of the control strategy. In addition, the minimum stable superheat curve is used to optimize the setting point of superheat, so as to design and perfect the decoupling control strategy of internal model of refrigeration system. Through the robustness analysis, the condition that the strategy can guarantee the robust stability of the refrigeration system is given. In the simulation experiment, step input signal and step interference signal are added into the simulation experiment, and the control effect of the internal model decoupling control strategy of the refrigeration system is compared with that of the double loop pid control strategy and the decoupling control strategy with Simth predictor. The advantages of the strategy in decoupling ability and disturbance suppression are demonstrated intuitively. Under the assumption of the simulation experiment above, three kinds of typical uncertainty conditions are added, and the output response curves of the refrigeration system under the three strategies are compared again. It is verified that the decoupling control strategy of internal model of refrigeration system is superior to other control strategies in improving the robustness of the system. Finally, because the linear model used in the decoupling control strategy of the refrigeration system can not fully reflect the complexity of the refrigeration system, a nonlinear internal model control strategy based on the sixth-order nonlinear model of the refrigeration system is proposed. In order to facilitate the design of control strategy, the above model is simplified to affine nonlinear form, and the feedback linearization method is used to transform it into pseudo linear form. The internal model control structure is constructed for the transformed pseudo linear system, and the nonlinear internal model control strategy is designed. Through the system performance analysis and robustness analysis, the effectiveness of the strategy is proved theoretically, and the conditions to ensure the robust stability of the system are given. At the same time, the simulation results show that the strategy has strong decoupling ability, immunity and robustness.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TB657

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張又清;制冷系統(tǒng)中保持恒溫調(diào)定的新方法[J];家用電器;2001年12期

2 朱瑞琪,謝家澤,吳業(yè)正;制冷系統(tǒng)的綜合優(yōu)化控制模型[J];西安交通大學(xué)學(xué)報;2002年05期

3 田長青,竇春鵬,楊新江,石文星,彥啟森;制冷系統(tǒng)的穩(wěn)定性[J];流體機(jī)械;2002年04期

4 林新隊;R_(12)制冷系統(tǒng)改用R_(134a)的操作方法[J];咸寧師專學(xué)報;2002年03期

5 童蕾;基于綠色設(shè)計思想之冰箱制冷系統(tǒng)研發(fā)的探討[J];輕工機(jī)械;2005年02期

6 寧靜紅;;超市制冷系統(tǒng)與未來發(fā)展[J];家電科技;2006年02期

7 莊友明;王洪健;;泵供液制冷系統(tǒng)低溫管道保溫厚度的優(yōu)化[J];低溫工程;2007年06期

8 李兆堅;;某大型低溫環(huán)境室制冷系統(tǒng)設(shè)計[J];暖通空調(diào);2009年02期

9 席旺才;;丙烯制冷系統(tǒng)的改造[J];中氮肥;2011年02期

10 王東芳;吳玉庭;楊娟娟;劉績偉;馬重芳;;微型制冷系統(tǒng)性能試驗研究[J];工程熱物理學(xué)報;2011年05期

相關(guān)會議論文 前10條

1 寧靜紅;李惠宇;彭苗;;超市制冷系統(tǒng)的分析比較與未來發(fā)展[A];第3屆中國食品冷藏鏈新設(shè)備、新技術(shù)論壇論文集[C];2007年

2 田琦;楊凡;;太陽能噴射—壓縮二級制冷系統(tǒng)的

本文編號：2017342