隨著科技進步，各種通信系統除強化各式功能外，在網路管理能力，更不斷增進，以期能以最少之工程人員即能使通信設備達到極致效能。網路管理是系統規劃之重要環節，藉其涵蓋能力，可提升系統維護及偵錯能力，更可降低人力成本。中華電信將為其多年來所佈建之戶外交接箱，加裝網路管理功能控制板，期減少線路維護之人力成本。因應網管功能控制板須有饋電系統需求，本文主要在呈現戶外交接箱饋電系統之研製過程，饋電系統在市場應用層面，有極大商機，值得投入人力及時間加以研製。在評估可行的饋電架構後，需兩顆模組各置於局端及交接箱內，便以較容易降低切換損失之準諧振返馳式（QR Flyback）架構，來實現功率瓦數需求較高之局端饋電模組，另以成本較低廉之傳統返馳式（Flyback）架構，來實現功率瓦數需求較低之戶外交接箱電源模組。準諧振返馳式轉換器之基本觀念是利用電路的雜散元件，核心部份為變壓器初級側電感和開關元件汲極端等效雜散電容所形成之諧振槽，藉由適當控制器使轉換器操作於臨界導通模式，促使開關元件確切在諧振槽之適當波谷位置進行切換動作，以達所謂峰谷電壓切換操作，進而降低開關元件之切換損失。在電路設計過程，則分別以QR控制器及定頻PWM控制器設計兩端模組電路，並選取適當鐵芯繞製變壓器。硬體電路板實作及性能測試驗證了整體設計過程，最後以系統整合方式確認饋電架構在有限距離內是可行的。

As the development of new technologies, not only various new applications and functions for telecom equipment are presented, but also the network management functions are improved a lot to enhance the added value of operating engineers and increase the network reliability. Network management is an important technology for system architecture. It is able to enhance the capabilities of maintenance, troubleshooting and save manpower to operate a complicated telecom system. For the purpose to reduce manpower cost in subscriber’s loop maintenance and increase the network reliability, Chunghwa Telecom plans to install a control board inside the outdoor distribution cabinet with network management functions. Based on this new requirement, the power feeding system is required at both central office side and outdoor distribution cabinet for the new added control boards. This thesis presents the design process of the power feeding systems. It is valuable to take design efforts owing to the future potential market. Two converters are adopted after careful evaluation. The first one is located in the central office side. Due to the higher power requirement, it will be implemented with a quasi-resonant (QR) flyback to reduce switching losses. The other one is located in outdoor distribution cabinet, which will be implemented with a conventional flyback to reduce cost and meet lower power requirement. The basic concept of a QR flyback is to integrate the parasitics of circuit elements with transformer’s primary inductance to form a resonant tank. By choosing a proper controller operated in critical conduction mode, it will force the main switch turn on at the valley position of the drain-to-source voltage, to achieve the operation of valley-voltage-switching and reduce turn-on losses on main switch. A QR controller and a fixed-frequency PWM controller will be selected and used for the power supplies at central office side and outdoor distribution cabinet, respectively. Proper ferrite cores for transformers are also selected for both applications. Prototypes have been realized to verify the design process. System integration test is used to verify the operations of power feeding systems, which is proved to be effective within a limited loop distance.

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