電源選型推薦
整個DTU系統(tǒng)的電源解決方案，主要考慮到不間斷供電的問題，所以需要雙電源供電的一個供電形式，主流的供電方式一般是有兩部分組成，一部分是大功率300W或者500W的AC/DC充電電源，這個電源一般兩路輸出，一路給后級的板卡進(jìn)行供電，一方面給后級的蓄電池或者是超級電容進(jìn)行充電；另外的一部分就是蓄電池或者超級電容，這個主要是在市電斷電的情況下，保證整個系統(tǒng)的正常運(yùn)行。另外，電網(wǎng)對于EMC方面的要求比較苛刻，特別是浪涌方面，需要完全滿足4級的要求。主電源和蓄電池都掉電時，系統(tǒng)掉電保持時間500mS以上。
根據(jù)上面的應(yīng)用描述，我們推薦選用金升陽MBP500-2A54D54的接線式電源，它具備電池充電功能，可對48V 鉛酸電池充電；工業(yè)級工作溫度：-40℃～+70℃；2500VAC 高隔離電壓；大瞬時過功率達(dá)540W；優(yōu)越的EMC性能；接線式安裝。
另外，如果鉛酸電池的電壓值為24V，還可以選用金升陽公司的MBP300-2A27D27的接線式電源，可對24V的鉛酸電池充電，穩(wěn)態(tài)功率達(dá)到351W。
電源是各種電子設(shè)備必不可缺的組成部分,其性能優(yōu)劣直接關(guān)系到電子設(shè)備的技術(shù)指標(biāo)及能否安全可靠地工作。目前常用的直流穩(wěn)壓電源按功率管的工作方式分為線性電源和開關(guān)電源兩大類。線性穩(wěn)壓電源亦稱串聯(lián)調(diào)整式穩(wěn)壓電源,電路技術(shù)比較成熟。具有低紋波、高穩(wěn)壓性能等優(yōu)點(diǎn)。但由于必須使用工頻變壓器,且調(diào)整管工作在線性放大區(qū),因而體積大和重量大、效率低。開關(guān)電源調(diào)整管工作在高頻開關(guān)狀態(tài),功率損耗小,且使用小體積的高頻變壓器替代笨重的工頻變壓器來實(shí)現(xiàn)電壓變換和電網(wǎng)隔離。
為解決傳統(tǒng)的PWM型變換器的上述問題,可采用諧振、準(zhǔn)諧振、多諧振以及具軟開關(guān)的PWM型變換器。這些變換器吸收、利用了PWM型變換器中的寄生參數(shù)或外加電感、電容作為諧振參數(shù),使變換器中的功率開關(guān)在零電壓或零電流下開通和關(guān)斷,開關(guān)兩端的電壓或經(jīng)過開關(guān)的電流是正弦或半正弦波形。因此大大減少開關(guān)的瞬問損耗和開關(guān)應(yīng)力以及電磁干擾和射頻干擾.使其工作頻率可進(jìn)一步提高到1Mhz以上，效率達(dá)90%以上。再加上小型片狀電子元器件,包括磁性材科,例如:平板型變壓器等以及表面安裝技術(shù)以及散熱方式的改進(jìn)，就使電源系列、標(biāo)準(zhǔn)化、模塊化成為現(xiàn)實(shí)。
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