At the macroscopic level of system layout, the most important issue is path loss. In the older mobile radio systems that are limited by receiver noise, path loss determines SNR and the maximum coverage area. In cellular systems, where the limiting factor is cochannel interference, path loss determines the degree to which transmitters in different cells interfere with each other, and therefore the minimum separation before channels can be reused.
標簽： Characteristics Channel Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
Intensive development of digital technologies coincided in time with the beginning of the new era in telecommunications. It made possible to formalize many proce- dures of data exchange and to atomize some operations which made providing of serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew telecommunication technologies were born out of the necessity for use of specific configurations of network elements and networks, as well as for a possibility of providing maximum characteristics of efficiency combined with high requirements to the stability of operation, the overcoming of different catastrophic situations and deadlockconditions,such as failuresand ”pending”of the networkandthe like. The thresholdbetweeninformationsystems andtelecommunicationsystems has become practically invisible. It resulted in such a new term as ”infocommunication”
上傳時間： 2020-06-01
上傳用戶：shancjb
基于TMS320F2812 光伏并網發電模擬裝置PROTEL設計原理圖+PCB+軟件源碼+WORD論文文檔,硬件采用2層板設計，PROTEL99SE 設計的工程文件，包括完整的原理圖和PCB文件，可以做為你的學習設計參考。 摘要：本文實現了一個基于TMS320F2812 DSP芯片的光伏并網發電模擬裝置，采用直流穩壓源和滑動變阻器來模擬光伏電池。通過TMS320F2812 DSP芯片ADC模塊實時采樣模擬電網電壓的正弦參考信號、光伏電池輸出電壓、負載電壓電流反饋信號等。經過數據處理后，用PWM模塊產生實時的SPWM 波，控制MOSFET逆變全橋輸出正弦波。本文用PI控制算法實現了輸出信號對給定模擬電網電壓的正弦參考信號的頻率和相位跟蹤，用恒定電壓法實現了光伏電池最大功率點跟蹤（MPPT），從而達到模擬并網的效果。另外本裝置還實現了光伏電池輸出欠壓、負載過流保護功能以及光伏電池輸出欠壓、過流保護自恢復功能、聲光報警功能、孤島效應的檢測、保護與自恢復功能。系統測試結果表明本設計完全滿定設計要求。關鍵詞：光伏并網，MPPT，DSP Photovoltaic Grid-connected generation simulator Zhangyuxin，Tantiancheng，Xiewuyang(College of Electrical Engineering, Chongqing University)Abstract: This paper presents a photovoltaic grid-connected generation simulator which is based on TMS320F2812 DSP, with a DC voltage source and a variable resistor to simulate the characteristic of photovoltaic cells. We use the internal AD converter to real-time sampling the referenced grid voltage signal, outputting voltage of photovoltaic, feedback outputting voltage and current signal. The PWM module generates SVPWM according to the calculation of the real-time sampling data, to control the full MOSFET inverter bridge output sine wave. We realized that the output voltage of the simulator can track the frequency and phase of the referenced grid voltage with PI regulation, and the maximum photovoltaic power tracking with constant voltage regulation, thereby achieved the purpose of grid-connected simulation. Additionally, this device has the over-voltage and over-current protection, audible and visual alarm, islanding detecting and protection, and it can recover automatically. The testing shows that our design is feasible.Keywords: Photovoltaic Grid-connected，MPPT，DSP 目錄引言 11. 方案論證 11.1. 總體介紹 11.2. 光伏電池模擬裝置 11.3. DC-AC逆變橋 11.4. MOSFET驅動電路方案 21.5. 逆變電路的變頻控制方案 22. 理論分析與計算 22.1. SPWM產生 22.1.1. 規則采樣法 22.1.2. SPWM 脈沖的計算公式 32.1.3. SPWM 脈沖計算公式中的參數計算 32.1.4. TMS320F2812 DSP控制器的事件管理單元 42.1.5. 軟件設計方法 62.2. MPPT的控制方法與參數計算 72.3. 同頻、同相的控制方法和參數計算 8
標簽： tms320f2812 光伏 并網發電 模擬 protel pcb
上傳時間： 2021-11-02
上傳用戶：
ICN6201/02 is a bridge chip which receives MIPI? DSI inputs and sends LVDS outputs. MIPI? DSI supports up to 4 lanes and each lane operates at 1Gbps maximum; the totally maximum input bandwidth is 4Gbps; and the MIPI defined ULPS(ultra-low-power state) is also supported. ICN6201 decodes MIPI? DSI 18bepp RGB666 and 24bpp RGB888 packets.The LVDS output 18 or 24 bits pixel with 25MHz to 154MHz, by VESA or JEIDA format.ICN6201/02 support video resolution up to FHD (1920x1080) and WUXGA (1920x1200).ICN6201 adopts QFN48 package and ICN6202 adopts QFN40 package
標簽： icn6202
上傳時間： 2022-06-10
上傳用戶：kingwide
The information disclosed to you hereunder (the Materials ) is provided solely for the selection and use of Xilinx products. To the maximum extent permitted by applicable law: (1) Materials are made available"AS IS"and with all faults, Xilinx hereby DISCLAIMS ALL WARRANTIES AND CONDITIONS, EXPRESS, IMPLIED, OR ST ATUTORY, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY NON-INFRINGEMENT, OR FITNESS FOR ANY PARTICULAR PURPOSE; and (2) Xilinx shall not be liable (whether in contract or tort. includina nealigence. or under anv other theorv of liabilitv) for any loss or damage of any kind or nature related to, arising under, or in connection with, the Materials (including vour use of the Materials), including for any direct, indirect, special, incidental, or consequential loss or damage (including loss of data, profits, qoodwill, or any type of loss or damage suffered as a result of anv action brought by a third party)
上傳時間： 2022-06-18
上傳用戶：
在光伏發電系統中，光伏電池的利用率除了與光伏電池的內部特性有關外，還受使用環境如輻照度、負載和溫度等因素的影響。在不同的外界條件下，光伏電池可運行在不同且惟一的最大功率點（Maximum Power Point，MPP）上，因此，對于光伏發電系統來說，應該尋求光伏電池的最優工作狀態，以最大限度地將光能轉化為電能，即需要采用最大功率點跟蹤（Maximum Power Point Tracking，MPPT）技術.本文根據光伏電池最大輸出功率與光照度的關系，建立了基于Boost電路的MPPT仿真模型，采用擾動觀測法，通過調整DC-DC電路的占空比實現了最大功率點追蹤。使用Matlab/Simulink 工具，在輻照度恒定和階躍變化的情況下，對MPPT進行了仿真分析。1光伏電池的特性光伏電池實際上就是一個大面積平面二極管，其工作可以圖1的單二極管等效電路來描述1，光伏電池的特性方程如式（1）所示。
上傳時間： 2022-06-21
上傳用戶：
化石能源日趨枯竭，核能發展受限，能源問題愈來愈成為全人類所不可避免的一個嚴峻挑戰。光伏發電技術是太陽能利用的主要形式。基于提高太陽能轉換效率的最大功率點跟蹤（Maximum power point tracking，簡稱MPPT）的提出與應用為光伏發電系統的優化利用提供了堅實的基礎。本文針對MPPT技術開展了細致的工作計劃，完成了以MPPT控制器為核心的光伏發電系統設計和仿真，較好地解決了能量轉換低下的問題。首先，總體介紹了光伏發電系統。其次，闡述了光伏發電系統基本原理。然后就MPPT控制器的實現部分-DCDC變換電路，闡述了電路CCM工作模式，利用兩種方法對Buck和Boost電路進行了建模和仿真分析.Boost電路設計簡便、可升壓，且能夠保證一直工作于CCM下，具有更實用的特點，更進一步地，說明了傳統MPPT算法的實現原理和控制流程，仿真研究表明改進型變步長擾動觀察法在光強變化時具有較好的跟蹤控制性能，但是溫度變化時跟蹤效果差。針對傳統算改進型擾動觀察發法不能很好地響應環境的變化同時存在嚴重振蕩，偏差較大的情況，提出一種人工智能控制方法--模糊控制法，進行系統分析，模糊控制規則確定以及FIS編輯器參數設置等，完成了系統的設計。最后搭建出光伏發電MPPT人工智能控制系統的仿真模型，設置相關參數。通過仿真結果的比較和分析驗證了模糊控制法的有效性和可行性。
上傳時間： 2022-06-21
上傳用戶：
The following table covers the main features offered by the MT7628KN and MT7628AN. Overall, the MT7628KN supports the requirements of an entry level AP/router, while the more advanced MT7628AN supports a number of interfaces together with a large maximum RAM capacity.Features· Embedded MIPS24KEc (575/580 MHz) with 64KBl-Cache and 32KB D-Cache·2T2R 2.4GHz with 300 Mbps PHY data rate· Legacy 802.11b/g and HT 802.11n modes·20/40 MHz channel bandwidth· Reverse Data Grant(RDG)· Maximal Ratio Combining(MRC)· Space Time Block Coding(STBC)· MCM 8 Mbytes DDR1 KGD(MT7628KN)·16-bit DDR1/2 up to 128/256 Mbytes(MT7628AN/KN)· SPI/SD-XC/eMMC·x1 USB 2.0 Host,x1 Ple Root Complex·5-port 10/100 FE PHY
標簽： mt7628
上傳時間： 2022-07-25
上傳用戶：
此強而有力的工具將會增加網站聯機速度。它最佳化了操作系統的設定及連結。Amplify修改了MTU(Maximum Transmission Unit)、RWIN(Receive Window)，TTL(Time to Live)、PMTU's(Path Maximum Transmission Unit)。這些改改將的減少數據處理的分割次數，可以將資料快速的呈現在使用者面前。
標簽：
上傳時間： 2013-06-29
上傳用戶：eeworm
