更變開關 的英文怎麼說
中文拼音 [gēngbiànkāiguān]
更變開關
英文
sense switch-
Second, the starting and stopping behaviors under disturbed condition are analyzed and calculated by using the dynamic concentrative parameter model, which gives some advice to better prescribe refrigeration system and set theoretic foundation for carrying out automatic control of refrigeration system. third, the normal running process is analyzed and calculated by means of rational matching theory, which gives some advice on how to better understand the parameter change under steady state and the affection of inlet - parameter on evaporator. fourth, the simulation software with dynamic characteristic is designed, which can be applied to calculate thernio - parameter of cryogen, air humidity and frost thickness under different initial and boundary conditions, and to carry out dynamic simulation under conditions of dryness, wetness and frostiness, at the same time, to achieve detection and simulation at any stage from starting to stopping
本文的主要內容如下: 1 )對翅片管蒸發器結構特點進行分析,選取適當的微元控制體,就干、濕和霜工況下對每個微元分別進行傳熱傳質分析,基於經驗關系式確定霜的有關參數,對于霜工況下的霜生長建立模型,經適當假設,運用質量守恆、能量守恆和動量守恆方程建立適合動態模擬的蒸發器數學模型,為系統模擬奠定基礎; 2 )對蒸發在大擾動下的開、停機過程,運用動態集中參數模型進行分析和計算,為更好地描述製冷系統運行的全過程奠定基礎,同時也為製冷系統實現自動控制提供一定的理論基礎; 3 )對蒸發器正常運行過程,運用動態分佈參數和參數間定量耦合的觀點來分析和計算,為更好地了解穩態工況下各點參數的變化情況及各入口參數對蒸發器動態特性的影響即蒸發器性能對各參數變化的敏感性; 4 )編寫翅片管蒸發器動態特性模擬計算程序,可以計算不同邊界條件和初始條件下的製冷劑熱力參數、空氣溫濕度和霜厚度分佈場,實現對翅片管蒸發器在干、濕和霜工況下的動態模擬。Variable voltage and variable frequency ( vvvf ) inverter control technology applied by ford passenger lift extends the utilization from the elevators drive system to the door machine system, plus its matching none link lever synchronous belt type door machine structure, it results in the more smooth sensitive and secure door open and shut. the passengers feel the doubled warmth in entering into and exiting the elevators
福德乘客電梯所應用的變壓變頻( vvvf )逆變器控制技術,從電梯驅動系統延伸運用到了門機系統中,加上與之相匹配的無連桿同步帶式門機結構,使電梯門的開啟和關閉更加平穩、靈敏和安全,令進出電梯的乘客倍感親切。With the best modulation strategy which was found on condition that it must have largest energy transfer ratio, smallest current ripple of the inductor, and realizing zvs of each switches, the converter overcomes the drawbacks presented by the conventional zvs fb converter, such as high voltage stress of each switches, large current ripple of the inductor, and severe parasitic ringing on the rectifier diodes, so it can get higher efficiency, faster respond speed, and wider application area. the operation principle of the proposed converter is analyzed and verified by a 3kw, 50khz experimental prototype. experiments and research results show that the scheme of the tl topology derivation is reasonable, adjusted modulation strategy makes some other severe problems in conventional topologies easy to solve or makes the converter more competitive
研究結果表明,本文提出的三電平拓撲變換方案合理,針對各種三電平拓撲尋找到的控制策略可以解決變換器存在的某些問題或使變換器表現出更突出的優勢:例如針對單管直流變換器三電平拓撲的控制策略可以減小電感的設計值,針對推挽直流變換器三電平拓撲的控制策略可以實現開關管的軟開關、解決變壓器偏磁問題等,針對全橋直流變換器三電平拓撲的控制策略可以減小電感的設計值、實現開關管的軟開關等。This paper demonstrates how to generate variable pwm waveform based on standard cpld device, the proposed circuit is incorporated with mcu to provide simple and effective solution for high - performance pwm converters. in the brushless model, the igbt ( isolated gate bipolar transistor ) switch state period table is gained by mc33035 which analyzes the signal of position feed - back
這部分功能在cpld器件中用vhdl語言開發實現,其isp (在系統編程)方式使得設計與維護都比傳統方法方便靈活,由於逆變器開關元件的觸發信號是由硬體來產生的,因此更容易實現準確的高速實時控制。Because direct torque control requires very high performance of real - time, the popular microcomputer core dsp is used as controller in the design of hardware. its high speed of running is suitable for the experiment. in the main circuit, there is a highly integrated power element : ipm as inverter, which includes seven igbt, has high switch frequency and fault diagnosis function
在本控制系統的具體實現上,由於直接轉矩控制對實時性要求很高,因此在硬體方面,採用了目前比較流行的數字信號處理器( dsp )作為系統的控制器,其處理速度高的特點正好符合本實驗的需要:在主電路中,本系統使用了集成度高的功率器件:智能功率模塊( ipm ) ,作為逆變環節,其集成了七個igbt ,實現了高開關頻率逆變以及故障診斷的功能,從而使控制系統的體積大大縮小、控制更加靈活。Due to the direct torque control requires very high performance of real - time, the popular microcomputer core dsp is used as controller in the design of hardware. its high speed of running is suitable to the experiment. in the main circuit, there is a highly integrated power element : ipm as inverter, which includes seven igbt, has high switch frequency and fault diagnosis function
在本控制系統的具體實現上,由於直接轉矩控制對實時性要求很高,因此在硬體方面,本課題採用了目前比較流行的數字信號處理器( dsp )作為本實驗的控制器,其處理速度高的特點正好符合本實驗的需要;在主電路中,本系統使用了集成度高的功率器件:智能功率模塊( ipm ) ,作為逆變環節,其集成了七個igbt ,實現了高開關頻率逆變以及故障診斷的功能,從而使控制系統的體積大大縮小、控制更加靈活。A novel resonant pole zvt three - phase pwm inverter circuit for three - phase ac motor driving is presented. the proposed circuit has the feature of being more flexible with three inverter arms in zvt process. using only one resonant inductance, the inverter can not only reduce the power loss of inductance but also avoid possibility of unbalance in motor ' s three stator windings
提出了一種針對三相交流電機驅動的新型諧振極零電壓過渡三相pwm逆變器電路,該電路中三個逆變橋臂的零電壓過渡更具有靈活性,僅使用一個諧振電感,既減少了電感損耗又防止了電機三相定子繞組可能存在的不平衡問題,並且諧振電感中殘余能量能夠回饋給電源;新型逆變器的輔助開關均工作在零電流開關條件下,並且控制邏輯簡單。The shift capacity also has been improved continually and the shift ways are more perfect with days. my subject study is the vaccum tap switch of the load voltage regulation with the dry transformer, which has features of safety, reliability and convenience for maintain
開關的切換容量不斷提高。滅弧方式更加完善。本課題研究的是配合乾式變壓器有載調壓的真空分接開關。It can be seen in the future, power electronics converter will get higher efficiency and power density
可以預見軟開關技術的應用可使電力電子變換器具有更高的效率和更高的功率密度。The exact design methods of switched - current filters are summarized, such as the director synthesis of z - plane, euler mapping, state variable analysis, matrix decomposition, and signal - flow - graph simulation of the lc and switched capacitor prototypes. at the same time, a modified left decomposition matrix method is proposed to overcome the usual problems of large silicon area, high sensitivity and component spreads by minimizing the input circuits. examples of switched - current low - pass, high - pass and band - pass filters are given to verify the feasibility of these methods
總結分析了實現高精度開關電流濾波器設計的各種實用方法,包括z域綜合法、歐拉映射法、模擬無源lc網路和開關電容網路的狀態變量法、矩陣分解法和信號流圖轉置法,並對左分解法加以整理改進,提出一種更為簡潔的設計結構,通過減化輸入電路克服一般電路中存在的佔用矽片面積大、靈敏度高等問題。Many practical factors, such as effects of line fuses protection, disconnected switches, scheduled maintenance, spare electrical source, spare transformers in distribution system, are considered in the assessment arithmetic. in the assessment, it is more practical that low - voltage power system is equivalent to an element on the lateral section of mid - voltage system. especially, the minimal cut - sets are divided into direct cuts and indirect cuts, which makes the effects of elements in cuts on system more legible and exact
演算法考慮了分支線熔斷器保護、隔離開關、計劃檢修、備用電源、有無備用變壓器的影響,將低壓系統等效為中壓系統分支饋線上的一個等效元件進行評估,使得該方法更符合實際,特別是,將最小割集分為直接割集和間接割集,使割集元件的影響更加清晰準確,並以c + +語言編制了計算軟體。The acquisition by group ormazabal in 2004 has further increased the company ' s product variety with primary switchgear and compact substations, and strengthened its position in the china market
2004年,歐瑪嘉寶集團的並購,使得公司的產品更加多樣化,可以生產用於一級配電網路的開關櫃及箱式變電站,也意味著歐瑪嘉寶集團在中國市場的力量得到了更大的充實。In face of competition and challenge brought by foreign financial institutions after entering wto in 2006, the commercial banks should focus on management on capital at risk, change the way of development, enrich the capital, and reach the 8 % capital adequacy which < basle accord > ordered
面對2006年銀行業全面開放后外資金融機構進入中國市場所帶來的競爭和挑戰,商業銀行更應該關注經濟資本管理,轉變業務增長模式,充實資本金,使之達到《巴塞爾協議》規定的8 %的資本充足率。Although dm can also solve the modulation time error, but the output waveforms can ’ t reach the industrial standard ( total harmonic distortion thd ). considering this, a new control strategy called current optimal control ( coc ) is presented in paper. coc is that system samples the output value real time, comparing with expected value, considering all switching actions available then draw a concluding to decide which way would be fastest and best way to render system smooth
針對這一缺點,本文提出了一種更好的控制策略,電流最優delta調制,它是在電流滯環控制的基礎上,根據電路的輸出信號來分析,考慮所有可能的逆變器動作來決定選用哪一種開關轉換方式能最快最平穩地達到預期值,採用的是一種電流預測控制手段,從而使輸出波形的紋波最小。A topology of asymmetrical half bridge soft switching is researched in this thesis, which has inherent zero voltage switching ( zvs ) capability and thus potentially higher efficiency by its resonating of the leakage of power transformer with the parasitic capacitances of the power mosft switches, whereas it does n ' t raise the expense of the converter these studies in the thesis have been done as follows : ( 1 ) the topology of asymmetrical half bridge is introduced, and its principle and the relation of duty cycle and input voltage and output voltage discussed, the method of eliminating the deflection magnetism is also brought forward
雖然,軟開關技術能夠實現功率變換器的小型化、模塊化等,但是,電路變得更加復雜,使得中小功率的變換器的成本增加,往往不利於商業競爭。本文研究了一種零電壓的不對稱半橋拓撲結構,它可以在不增加電路成本的基礎上,利用電路自身的特點,實現軟開關。本文所做的主要工作如下: ( 1 )對不對稱半橋主電路工作原理進行分析,給出了占空比與輸出電壓、輸入電壓的關系以及消除變壓器偏磁的方法。Closed - ended ( yes or no, this or that ) questions are preferred ; open - ended questions can get long and involved, reducing their overall relevancy and the likelihood that you ' ll get the response you desire
封閉式(是或否,這或那)問題當然更好,開放式問題會讓郵件變得很長很混亂,減少了總體的相關性,並且你可能會得到並非你期望的答復。The other way is to use a single - stage power processor to correct power factor and regulate voltage simultaneously. however, the technology has only been applied in low power of single - phase ac input and has no use in high power of three - phase. so, the three - phase high power supply as the main emi equipment is becoming one of the hot points in international research
目前,這僅在輸入電源為單相的變換器中實現,而且不是軟開關,仍存在emi ;對于污染問題更嚴重的輸入電源為三相三線的較大功率的變換器,則未見報道,同時,三相大功率的電磁污染治理問題也成為國際研究的熱點之一。Controlling the sequence and working time of the switching status of every invert cell is an easy way to avoid unbalanced power distribution among invert cells, so that the whole system can work more stably in general
通過控制各逆變單元開關的導通順序和導通時間改善各逆變單元間應力分配不均衡,使整個逆變器工作更穩定。With the vast amount of using of the vaccum load tap switch, the steps that enlarge the applying scope will be quickened and it will be advantageous to the renewal and transform of the traditional style of the electric power system
隨著真空有載分接開關的大量推廣使用,將使乾式變壓器擴大使用范圍的步伐加快,並有利於電力系統傳統模式的更新、改造。The teacher organizes the teaching by creating the real situation for teaching and learning. third, the teaching order of the class reconstruct, the student becomes the agent of the classroom. the pleasurable teaching atmosphere is constructed by the equal teacher - student relationship and the implied and skillful class administration
本文主要從以下幾個方面建構理論:首先,課堂學習方式被改變,探究與合作成為師生教學活動的主題;其次,課堂被賦予更為開放的意義,現代教育技術進入課堂,營造課堂情境成為教師組織教學的重要手段;第三,課堂的教學秩序被重建,學生成為課堂的主體,平等的師生關系、更加隱蔽和技巧性的管理行為營造了愉快的教學氛圍。分享友人