This Paper presents a space vector modulation(SVM)-based switching strategy for a three-level neutral point clamped (NPC) converter that is adapted as a STATCOM.
標(biāo)簽： STATCOM 三電平 變換器 空間矢量
上傳時(shí)間： 2013-10-20
上傳用戶(hù)：zyt
設(shè)計(jì)了水聲信號(hào)發(fā)生系統(tǒng)中的功率放大電路，可將前級(jí)電路產(chǎn)生的方波信號(hào)轉(zhuǎn)換為正弦信號(hào)，同時(shí)進(jìn)行濾波、功率放大，使其滿足換能器對(duì)輸入信號(hào)的要求。該電路以單片機(jī)AT89C52，集成6階巴特沃思低通濾波芯片MF6以及大功率運(yùn)算放大器LM12為核心，通過(guò)標(biāo)準(zhǔn)RS232接口與PC進(jìn)行通信，實(shí)現(xiàn)信號(hào)增益的程控調(diào)節(jié)，對(duì)干擾信號(hào)具有良好的抑制作用。經(jīng)調(diào)試該電路工作穩(wěn)定正常，輸出波形無(wú)失真，在輸出功率以及放大增益、波紋系數(shù)等方面均滿足設(shè)計(jì)要求。 This Paper presented a design and implementation of underwater acoustic power amplifer. This circuit converted the rectangle signal generated by frontend circuit into the sine signal， then filtered and power amplification， it meets the requirements of the transducer.Included AT89C52， 6th order Butterworth filter MF6， hipower amplififier LM12.Communication with PC through the RS232 port. The signal gain is adjustable and could be remote controlled. It has a good inhibitory effect on the interference signal. After debugged， this circuit works stable， the output waveform has no distortion， it meets the design requirement in outprt power， amplifier gain and ripple factor.
上傳時(shí)間： 2013-11-20
上傳用戶(hù)：qwe1234
1.什么是CTP? CTP包括幾種含義: 脫機(jī)直接制版(Computer-to-plate) 在機(jī)直接制版(Computer-to-press) 直接印刷(Computer-to-Paper/print) 數(shù)字打樣(Computer-to-proof) 普通PS版直接制版技術(shù),即CTcP(Computer-to-conventional plate) 這里所論述的CTP系統(tǒng)是脫機(jī)直接制版(Computer-to-plate)。CTP就是計(jì)算機(jī)直接到印版，是一種數(shù)字化印版成像過(guò)程。CTP直接制版機(jī)與照排機(jī)結(jié)構(gòu)原理相仿。起制版設(shè)備均是用計(jì)算機(jī)直接控制，用激光掃描成像，再通過(guò)顯影、定影生成直接可上機(jī)印刷的印版。計(jì)算機(jī)直接制版是采用數(shù)字化工作流程，直接將文字、圖象轉(zhuǎn)變?yōu)閿?shù)字，直接生成印版，省去了膠片這一材料、人工拼版的過(guò)程、半自動(dòng)或全自動(dòng)曬版工序。
標(biāo)簽： CTP
上傳時(shí)間： 2013-10-27
上傳用戶(hù)：baiom
In this Paper, two types of MMIC voltage controlled oscillators have been successfully demonstrated. The first chip with single tuning diode shows the excellent tuning linearity. The second chip with two tuning diodes can improve the tuning bandwidth.
上傳時(shí)間： 2013-10-17
上傳用戶(hù)：xjz632
為了改變目前電網(wǎng)現(xiàn)場(chǎng)作業(yè)管理的變電巡檢、變電檢修試驗(yàn)、輸電線路巡檢檢修等管理系統(tǒng)各自獨(dú)立運(yùn)行，信息不能共享，功能、效率受限，建設(shè)和維護(hù)成本高的現(xiàn)狀，提出了采用B/S+C/S構(gòu)架模式，將各現(xiàn)場(chǎng)作業(yè)管理模塊和生產(chǎn)MIS（管理系統(tǒng)）集成為一體的現(xiàn)場(chǎng)作業(yè)管理系統(tǒng)的設(shè)計(jì)方案，做到各子系統(tǒng)和生產(chǎn)MIS軟硬資源共享，做到同一數(shù)據(jù)唯一入口、一處錄入多處使用。各子系統(tǒng)設(shè)備人員等基礎(chǔ)信息來(lái)源于生產(chǎn)管理系統(tǒng)，各子系統(tǒng)又是生產(chǎn)管理系統(tǒng)的作業(yè)數(shù)據(jù)、缺陷信息的重要來(lái)源。經(jīng)過(guò)研究試用成功和推廣應(yīng)用，目前該系統(tǒng)已在江西電網(wǎng)220 kV及以上變電站全面應(yīng)用。 Abstract: In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This Paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
標(biāo)簽： 電網(wǎng) 信息化 管理系統(tǒng)
上傳時(shí)間： 2013-11-15
上傳用戶(hù)：han_zh
光伏發(fā)電是未來(lái)新能源發(fā)電重要方向之一，而光伏變流器是光伏發(fā)電系統(tǒng)的核心。介紹一種基于微網(wǎng)理念的光伏變流器設(shè)計(jì)。以該變流器為核心的光伏發(fā)電系統(tǒng)可以看做一個(gè)小型的微網(wǎng)系統(tǒng)。該系統(tǒng)能根據(jù)外部電網(wǎng)情況，工作于并網(wǎng)模式和離網(wǎng)模式。介紹了該系統(tǒng)的各個(gè)組成部件的設(shè)計(jì)以及變流器主電路部分器件的選型。最后，由實(shí)驗(yàn)樣機(jī)進(jìn)行測(cè)試。試驗(yàn)結(jié)果驗(yàn)證了電路拓?fù)浣Y(jié)構(gòu)及控制方案的可行性，也說(shuō)明了系統(tǒng)參數(shù)設(shè)計(jì)方法的正確性。 Abstract: Solar Photovoltaic generation is an important direction of new energy power generation in the future，while photovoltaic converter is the core of photovoltaic generation system. This Paper deals with a study on photovoltaic inverter based on the concept of microgrid. This Paper describes a system whose core component is the photovoltaic inverter，can work on grid-connected mode or run independently according to the external situation. The Paper simply describes the main components of the system. At last，the prototype was produced and tested. Test result has proved feasibility of circuit topology structure and controlling scheme and shown correctness of system parameters.Key words: PV inverter； microgrid； off-grid； storage battery
標(biāo)簽： 光伏 變流器 系統(tǒng)設(shè)計(jì)
上傳時(shí)間： 2014-12-24
上傳用戶(hù)：Shaikh
This white Paper raises some fundamental issues the design engineer should address before deciding upon a communication approach for a wireless network. As no universal wireless network solution exists, it should be custom tailored to suit the application demands. Defining your application communication characteristics is the key to ensure optimal communication reliability and resistance to interfering noise sources.
標(biāo)簽： 無(wú)線通信網(wǎng)絡(luò) 基本概念
上傳時(shí)間： 2013-11-23
上傳用戶(hù)：zhichenglu
為了提高PCB板制作的效率，改變傳統(tǒng)的化學(xué)腐蝕制板工藝，使用機(jī)械仿形銑制作電路板的方法，設(shè)計(jì)了以ATMEGA16單片機(jī)為核心部件的PCB板雕刻機(jī)控制系統(tǒng)。其中包括PCB雕刻機(jī)的基本功能、主要硬件電路設(shè)計(jì)和軟件的實(shí)現(xiàn)流程，并給出了相關(guān)設(shè)計(jì)電路。重點(diǎn)分析了雕刻機(jī)步進(jìn)電機(jī)的驅(qū)動(dòng)電路以及主軸電機(jī)的驅(qū)動(dòng)電路，該雕刻機(jī)經(jīng)實(shí)際運(yùn)行，系統(tǒng)工作良好，可有效提高PCB板的制作效率。 Abstract: In order to improve the efficiency of production of PCB board and change the traditional chemical etching plates， using of mechanical copying milling method makes circuit boards，this Paper introduces the PCB engraving machine control system used ATMEGA16 microcomputer as the core components. It includes basic function， the hardware circuit design and software realization process， and gives the corresponding circuit design.It analyses the drive circuit of engrawing machine stepper motor and spindle motor in detail. This engraving machine by practical operation， the system works well， which can effectively improve the production efficiency of PCB board.
上傳時(shí)間： 2013-10-17
上傳用戶(hù)：liangliang123
數(shù)字控制的交流調(diào)速系統(tǒng)所選用的微處理器、功率器件及產(chǎn)生PWM波的方法是影響交流調(diào)速系統(tǒng)性能好壞的直接因素。在介紹了正弦脈寬調(diào)制(SPWM)技術(shù)的基礎(chǔ)上，設(shè)計(jì)了一種以8098單片機(jī)作為控制器，以智能功率模塊IPM為開(kāi)關(guān)器件的變頻調(diào)速系統(tǒng)。通過(guò)軟件編程，產(chǎn)生正弦脈沖寬度調(diào)制波形來(lái)控制絕緣柵雙極晶體管的導(dǎo)通和關(guān)斷，從而達(dá)到控制異步電動(dòng)機(jī)轉(zhuǎn)速的目的。實(shí)驗(yàn)結(jié)果表明，該系統(tǒng)可調(diào)頻率調(diào)電壓，穩(wěn)定度高，調(diào)速范圍寬，具有較強(qiáng)的實(shí)用價(jià)值 Abstract: AC variable speed with digital control systems used microprocessors， power devices and generate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of introducing the sinusoidal pulse width modulation (SPWM) technology，this Paper designed variable speed system which used 8098 as a controller， intelligent power module IPM as switching device. Through software programming， resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off， so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage， high stability， wide speed range， has a strong practical value.
標(biāo)簽： 8098 SPWM 單片機(jī) 變頻調(diào)速系統(tǒng)
上傳時(shí)間： 2013-11-14
上傳用戶(hù)：ynwbosss
在理論分析循環(huán)碼編碼和譯碼基本原理的基礎(chǔ)上，提出了基于單片機(jī)系統(tǒng)的(24，16)循環(huán)碼軟件實(shí)現(xiàn)編碼、譯碼的方案。仿真結(jié)果表明(24，16)循環(huán)碼能有效地克服來(lái)自通訊信道的干擾，保證數(shù)據(jù)通信的可靠及系統(tǒng)的穩(wěn)定，使誤碼率大幅度降低。本論文對(duì)(24，16)循環(huán)碼的研究結(jié)果表明，可以有效地降低錯(cuò)誤概率和提高系統(tǒng)的吞吐量，實(shí)現(xiàn)糾錯(cuò)僅需要在接收端增加有限的存儲(chǔ)空間和計(jì)算復(fù)雜度，具有一定的實(shí)用價(jià)值。 Abstract: Based on analyzing the theory of encoding and decoding of cyclic code， this Paper showed the schemes of encoding and decoding of(24，16)cyclic code by the software and based on microcontroller. Simulation results show that using (24，16) cyclic codes can effectively overcome the interference from communication channel， ensure the reliability and stability of data communication systems， and reduce the bit error rate greatly. The results of this Paper show that by using the (24，16) cyclic code， the error rate can be reduced and the system throughput can be improved. Meanwhile， the system only needs to enlarge limited storage space and computation the complexity at the receiving end to realize error correction. Thus the (24，16) cyclic code has a practical value.
標(biāo)簽： 24 16 單片機(jī)系統(tǒng) 循環(huán)碼
上傳時(shí)間： 2013-11-09
上傳用戶(hù)：gaoliangncepu
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