外文資料翻譯---開關(guān)模式中功率半導(dǎo)體的應(yīng)用-資料下載頁
2025-05-12 04:47本頁面
【導(dǎo)讀】從譯文看，文章翻譯語句通順，語言表達清楚，較好反映。原文內(nèi)容，符合本次畢業(yè)設(shè)計外文翻譯要求。電能通常不會用在其生產(chǎn)或分布的形式。幾乎所有的電子系統(tǒng)需要某種形式的。通過電路把電能從一個特定源轉(zhuǎn)移到一個特定負載所用的設(shè)備稱作為電。這種裝置被稱為開關(guān)電源。關(guān)閉時，它會阻止電壓和電流的流動，在兩種狀態(tài)中均比較低。尺寸較小，重量較輕，從而減少了無源元件的尺寸，降低了熱量的產(chǎn)生。源的設(shè)計采用了安森美半導(dǎo)體元件，因此直接的稱之為開關(guān)電源或SMPS。線性電源包含一個電源變壓器和耗散系列穩(wěn)壓器。兩者都是嚴重的缺陷。30％的典型效率是線性的標準關(guān)系。效率，目前可使用開關(guān)電源設(shè)計。能量的電路結(jié)構(gòu)被稱為開關(guān)電源拓撲結(jié)構(gòu)，這是設(shè)計過程中極其重要的組成部分。壓，進而使得線性穩(wěn)壓器得以運行。這種余量虧損導(dǎo)致線性穩(wěn)壓器只有百分之三十。開關(guān)穩(wěn)壓器作用于電源設(shè)備整版和截止的。這會造成線路系統(tǒng)中電壓過度下降，三相。傳遞系統(tǒng)中的不平衡問題。
【正文】 additional output voltages to the switching power supply. The panies building their own power systems are leaning toward transformer isolation in as many power supplies as possible since it prevents a domino effect during failure conditions. The remainder of the factors involves how much stress the power semiconductors are being subjected to. The differences between the various topologies used within switching power supplies. The transformerisolated topologies are typically used within the power industry at various power and voltage levels. At reduced DC input voltages and at higher powers, the peak currents that must be sustained by the power switch grow higher which then affects the stress they must endure. The various areas show which topology best fits within that range of input voltage and output power that exhibits the least amount of stress on the power semiconductors. The present day power supplies use a capacitive input filter when powered from the AC power line. A resulting shorting is that the AC line is rectified which results in high peak currents at the crests of the AC voltage. These peak currents are typically three to five times higher than the average current drawn by the power supply. This causes excessive voltage drop in the wiring and imbalance problems in the three phase delivery system. Also the full energy potential of the AC line is not utilized. The task is to increase the conduction angle of the AC rectifiers and to make the resulting current waveform look as sinusoidal and in phase with the voltage waveform as possible. In this way, the power drawn by the power supply from the line is maximized for real power. A popular method of acplishing this is by using a boost converter prior to the actual power supply. Boostmode supplies exhibit the largest input dynamic range of all the switching power supply topologies. Input voltages down to 30 volts can be boosted to 370 volts on its output (higher than the highest expected peak operating AC crest voltage). The bulk input filter capacitor is now placed on the output of the boost converter. The input capacitor, just following the 50/60 Hz rectifier bridge is now less than 1 uF. This produces an input voltage waveform to the PFC circuit that has a high level of ripple voltage and the boost converter draws its power directly from the line. The semiconductors within a power factor correction stage have some special requirements. First, the 50/60 Hz rectifiers now have to be ultrafast rectifiers, since fast current pulses are being drawn through them. The boost output rectifier will have to be ultrafast if the boost converter is operating in the continuousmode. The power switch has to clear the diode’s reverse recovery charge. In the discontinuousmode (Pin 200 watts), the output rectifier need not be ultrafast since there is no current flowing through the diode prior to the power switch turning on
畢業(yè)設(shè)計相關(guān)推薦
鄂ICP備17016276號-1