48V25A直流高頻開關(guān)電源設(shè)計(jì)

電子機(jī)電論文編號(hào):JD310       論文字?jǐn)?shù):18839,頁數(shù):41

目  錄
摘  要 I
Abstract II
目  錄 III
第一章  引 言 1
1.1開關(guān)通信電源系統(tǒng)的介紹 1
1.1.1通信設(shè)備對(duì)開關(guān)通信電源的要求 1
1.1.2通信電源系統(tǒng)的組成 2
1.2通信直流開關(guān)電源的發(fā)展現(xiàn)狀和發(fā)展方向 2
1.2.1開關(guān)電源的發(fā)展和趨勢 2
1.2.2軟開關(guān)技術(shù)的發(fā)展 3
1.3本文的主要工作 4
第二章  高頻開關(guān)電源主電路的設(shè)計(jì)與實(shí)現(xiàn) 6
2.1高頻開關(guān)電源的技術(shù)指標(biāo) 6
2.2高頻開關(guān)電源主電路的硬件設(shè)計(jì) 6
2.2.1輸入整流電路的設(shè)計(jì) 6
2.2.2直流變換器的設(shè)計(jì) 7
2.2.3輸出整流電路的設(shè)計(jì) 8
2.3移相全橋諧振軟開關(guān)電路[2][3][7] 9
2.3.1移相全橋零電壓PWM軟開關(guān)電路的工作原理 9
2.3.2移相零電壓軟開關(guān)電路存在問題的解決 11
2.3.3 ZVS的實(shí)現(xiàn)及副邊占空比丟失 12
2.3.4 結(jié)論 13
2.4主電路元件參數(shù)的選擇 14
2.4.1 輸入電路參數(shù)的選擇[8] 14
2.4.2高頻變壓器的設(shè)計(jì)[1] 15
2.4.3輸出濾波電感的設(shè)計(jì) 17
2.4.4輸出濾波電容的選擇 17
2.4.5 吸收電路器件的選擇 18
2.4.6功率器件的選擇 19
2.5本章小結(jié) 19
第三章  高頻開關(guān)電源控制電路的硬件設(shè)計(jì)與實(shí)現(xiàn) 21
3.1移相控制芯片UC3875的概述 21
3.3.1 UC3875電氣特性 21
3.1.2 UC3875外圍電路的設(shè)計(jì) 22
3.1.3 UC3875輸出波形的分析 25
3.1.4 光電耦合器 26
3.2保護(hù)電路的設(shè)計(jì) 26
3.2.1電壓與電流的保護(hù) 27
3.2.2過熱保護(hù)電路 28
3.3 輔助電源設(shè)計(jì) 28
3.4 本章小結(jié) 29
第四章  電路的仿真及分析 30
結(jié)  論 34
參考文獻(xiàn) 35
致  謝 36
附  錄 37

摘  要
目前開關(guān)電源向著高頻、高可靠性、低功耗、低噪聲、抗干擾和模塊化方向發(fā)展，本論文設(shè)計(jì)了一種通信系統(tǒng)常采用的48V/25A直流高頻開關(guān)電源。
本論文首先對(duì)高頻開關(guān)電源的主電路進(jìn)行了設(shè)計(jì)，分析了零電壓軟開關(guān)技術(shù)在移相全橋電路中的應(yīng)用，開關(guān)電源的軟開關(guān)技術(shù)采用移相PWM控制，通過相移芯片UC3875產(chǎn)生具有一定相序的脈沖去觸發(fā)MOSFET管。在主電路設(shè)計(jì)中，進(jìn)行了高頻變壓器的設(shè)計(jì)，并對(duì)輸出整流電路進(jìn)行了分析、研究與設(shè)計(jì)。
其次，對(duì)開關(guān)通信電源的控制電路進(jìn)行了設(shè)計(jì)。控制電路以UC3875芯片為控制核心，采用閉環(huán)控制模式，實(shí)現(xiàn)系統(tǒng)的穩(wěn)壓和限流。另外，對(duì)控制系統(tǒng)的過電流保護(hù)、過壓保護(hù)、過熱保護(hù)電路等保護(hù)電路進(jìn)行了設(shè)計(jì)。
最后，用SABER仿真軟件對(duì)電路進(jìn)行了系統(tǒng)仿真與驗(yàn)證，仿真結(jié)果表明了設(shè)計(jì)的正確性。

關(guān)鍵詞：  軟開關(guān)，  UC3875，  移相控制

Abstract
At present, the switching power supply developed high frequency, high reliability, low energy consumption, low noise, interference and modular direction. That is to develop the inverter power source controlled by microcomputer which adopts soft-switches .
This researching task is put forward on the base of discussing the characteristics and virtues of the welding inverter. The phase-shift chip UC3875 is adopted phase-shift pulse width modulate. The design about high frequency transformer is given .The amplified circuit and the commuted circuit are designed. The paper mostly researches and designs the soft-switch control system.
Secondly, the control circuit, the protect circuit of the power supply are analyzed and designed. Its control circuit is centered on UC3875, uses a control that based regulation to realize the function is composed of analog of voltage-stabilization and current-limited.
In addition, the safeguard circuit that mainly consists of over current, over heat, over voltage and circuit are studied and designed in the paper.
And the circuit is simulated by the SABER, Simulation results show that the design is correct.

Key words: soft-switch,  UC3875,  phase-shift