【導讀】裝置比設(shè)計主要開關(guān)電源電路技術(shù)知識，采用二次逆變。最后經(jīng)過LC工頻濾波及相應的輸入輸出保護電路后，輸出穩(wěn)定的。準正弦波，供負載使用。過熱保護電路．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．39. 致謝詞．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．43. 附錄一外文翻譯．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．46. 電器產(chǎn)品使用，是一種較方便的車用電源轉(zhuǎn)換設(shè)備。

　　

【正文】 應電流。該感生電流經(jīng)過整流濾波之后通過分壓電阻 R20 轉(zhuǎn)化為電壓信號，然后將該電壓信號輸入到電壓比較器 U2A 的反向端，通過與正向端的基準電壓比較來輸出相應的電平信號，該電平信號輸入驅(qū)動芯片 IR2110 的控制端 SD 實現(xiàn)對電路的保護功能 [17]。 圖 輸出過流保護電路圖 此處設(shè)定輸出最大電流為 ,電 流互感器的原副邊匝數(shù)比為 1：，在副邊會感生出 10mA 的電流，經(jīng)過整流橋和濾波電容的整流濾波之后轉(zhuǎn)換為穩(wěn)定的直流電流，經(jīng)過可變電阻 R20 后在運放的反向端輸入一個電壓，取 R20 為 1K,則反向端電壓為 5V。調(diào)整 R19，使得正向端的電壓也為 5V,則當電流大于 時，運放輸出低電平，則 Q10 集電 的 SD 腳輸出高電平，逆變器停止工作，從而實現(xiàn)過流保護。 輔助電源設(shè)計 在本系統(tǒng)中，我們需要對脈寬調(diào)制芯片 SG3525A、 MOS 開關(guān)管驅(qū)動芯片IR21正弦波發(fā)生器 ICL8038 等提供 +15V 的電源，現(xiàn)設(shè)計一個 輔助電源，來對這三個芯片等進行供電。 在本輔助電源設(shè)計電路中，我們通過在交流輸出端接入一個雙路輸出的反饋變壓器 T2。我們通過逆變電源輸出的交流 220V 的電壓作為本輔助電源的輸入，通過變壓器變壓后變成交流低壓，經(jīng)過全橋整流電路 D25 后變成約 20V 的直流電壓，再通過 LM7815 的穩(wěn)壓，穩(wěn)定的輸出 15V 直流電壓，作為各個芯片的電源。 圖 輔助電源設(shè)6 總結(jié) 本文設(shè)計了一款高性能的車載逆變電源。該電源采用的是比較經(jīng)典的兩級變換的方式，即第一級是運用直流 /直流的變換方式，第二級是運用直流 /交流的變換方 式。在該高性能車載逆變器中采用中間直流環(huán)節(jié)的高頻變壓器式逆變電源系統(tǒng)結(jié)構(gòu)，它由高頻變壓器升壓、整流濾波、高頻 SPWM 逆變和高頻濾波輸出組成。因它工作在高頻情況下，可使變壓器、濾波電容、電容的體積及重量減小，噪聲降低，反應速度提高。其中的高頻 SPWM 由集成芯片構(gòu)成的純硬件電路來產(chǎn)生，避免了使用單片機而需要大量計算和編程的麻煩。該逆變器的主要功能是把汽車上的蓄電瓶提供的 12V 直流電壓變換成電器所需要的 220V/50Hz 的交流電，來對我們車上的一些用電設(shè)備進行供電，方便我們的出行。 本設(shè)計具有靈活方便、適用范圍廣 的特點，基本能夠滿足實踐需求。而且本設(shè)計采用高頻逆變方式，具有噪聲降低、反應速度提高以及電路調(diào)整靈活的優(yōu)點。設(shè)計符合逆變電源小型化、輕量化、高頻化以及高可靠性、低噪聲的發(fā)展趨勢。 致 謝 感謝 P W Kalgren。 M J Roemer。 D W Brown .Electronic Prognostics a Case Study Using Switched Mode Power Supplies SMPS . 2021附錄 1 外文翻譯 外文資料 Switchedmode power supply A switchedmode power supply also switchingmode power supply, SMPS, or simply switcher is an electronic power supply unit PSU that incorporates a switching regulator. While a linear regulator maintains the desired output voltage by dissipating excess power in a pass power transistor, the switchedmode power supply switches a power transistor between saturation full on and cutoff pletely off with a variable duty cycle whose average is the desired output voltage. It switches at a muchhigher frequency tens to hundreds of kHz than that of the AC line mains , which means that the transformer that it feeds can be much smaller than one connected directly to the line/mains. Switching creates a rectangular waveform that typically goes to the primary of the transformer。 typically several secondaries feed rectifiers, series inductors, and filter capacitors to provide various DC outputs with low ripple. The main advantage of this method is greater efficiency because the switching transistor dissipates little power in the saturated state and the off state pared to the semiconducting state active region . Other advantages include smaller size and lighter weight from the elimination of low frequency transformers which have a high weight and lower heat generation due to higher efficiency. Disadvantages include greater plexity, the generation of high amplitude, high frequency energy that the lowpass filter must block to avoid electromagic interference EMI , and a ripple voltage at the switching frequency and the harmonic frequencies thereof. A note about terminology Although the term power supply has been in use since radios were first powered from the line/mains, that does not mean that it is a source of power, in the sense that a battery provides power. It is simply a device that usually accepts mercial AC power and provides one or more DC outputs. It would be more correctly referred to as a power converter, but long usage has established the term. Classification SMPS can be classified into four types according to the input and output waveforms: AC in, DC out: rectifier, offline converter input stage DC in, DC out: voltage converter, or current converter, or DC to DC converter. AC in, AC out: frequency changer, cycloconverter, transformer DC in, AC out: inverter Input rectifier stage If the SMPS has an AC input, then the first stage is to convert the input to DC. This is called rectification. The rectifier circuit can be configured as a voltage doubler by the addition of a switch operated either manually or automatically. This is a feature of larger supplies to permit operation from nominally 120 volt or 240 volt supplies. The rectifier produces an unregulated DC voltage which is then sent to a large filter capacitor. The current drawn from the mains supply by this rectifier circuit occurs in short pulses around the AC voltage peaks. These pulses have significant high frequency energy which reduces the power factor. Special control techniques can be employed by the following SMPS to force the average input current to follow the sinusoidal shape of the AC input voltage thus the designer should try correcting the power factor. An SMPS with a DC input does not require this stage. An SMPS designed for AC input can often be run from a DC supply for 230V AC this would be 330V DC , as the DC passes through the rectifier stage unchanged. It39。s however advisable to consult the manual before trying this, though most supplies are quite capable of such operation even though nothing is mentioned in the documentation. However, this type of use may be harmful to the rectifier stage as it will only utilize half of diodes in the rectifier for the full load. This may result in overheating of these ponents, and cause them to fail prematurely. If an input range switch is used, the rectifier stage is usually configured to operate as a voltage doubler when operating on the low voltage ~120 VAC range and as a straight rectifier when operating on the high voltage ~240 VAC range. If an input range switch is not used, then a fullwave rectifier is usually used and the downstream inverter stage is simply designed to be flexible enough to accept the wide range of dc voltages that will be produced by the rectifier stage. In higherpower SMPSs, some form of automatic range switching may be used. Inverter stage The inverter stage converts DC, whether directly from the input or from the rectifier stage described above, to AC by running it through a power oscillator, whose out