外文翻譯--高頻開關電源電路原理.doc

High-frequency switching powerSupply circuit of high frequency switching power supply from the following components : first. a main circuit from the exchange network input, DC output of the entire process, including : an import filter : its role is to network the clutter filtration, but also hindered the plane of the clutter feedback to the public grid. 2, rectifier and filter : direct AC power rectifier for smoother DC, for under a transformation. 3, the inverter : Rectifier the high frequency alternating current into direct current, high-frequency switching power supply is the core component of the higher frequency, size, weight and output ratio smaller. 4, and the rectifier output filter : Under load the need to provide stable and reliable DC power supply. Second, the control circuit while output from the sample, with the set standards, then controlled inverter, change its frequency or pulse width output achieve stability, on the other hand, according to test data provided by the circuit by circuit protection identification, Control circuit for the unit for various protection measures. Third, in addition to providing detection circuit protection circuit is running various parameters, but also provide information display instruments. Fourth, the auxiliary power supply circuit for the single power supply to the different requirements.Switching regulator control principleSwitching Control Switching Regulators K principle to a certain time interval repeatedly connected and disconnected, connected to the switch K, Input voltage E and K through switching circuit filter to load RL, the entire switch connected, Power E to provide energy load; When K disconnect switch, the input power is interrupted E. energy delivery. This shows that the importation of power to provide energy load is intermittent, for the load can be provided for the energy, Switching power supply must be a set of storage devices, the switches will be connected to a part of the energy stored in the switch disconnected. Load to the release. Map from the inductance L, capacitance diode D and C2 components of the circuit, it is such a function. Inductor L for energy storage in switch disconnected, stored in the inductor L of energy release through diodes D to load, so that load is continuous and stable energy, diode D enable continuous load current, known as the continued flow diode. AB in the average voltage EAB can be given by : EAB=TON/T*E where TON connected to the switch each time, T-off switch for the cycle (that is, access time TON switch and turn-off time and TOFFs). - We can see from the change switch connected to the work cycle time and the ratio of the voltage between the AB average change also, therefore, With the load and input supply voltage changes and automatically adjust TON T ratio, it will cause the output voltage V0 unchanged. Change the access time and cycle TON percentage change is the pulse duty cycle. This method, known as time ratio control (Time Ratio Control, for the initials TRC). TRC under control principle, there are three ways : 1. Pulse width modulation (Pulse Width Modulation, acronym for PWM) switching constant cycle by changing the pulse width to change the duty cycle approaches. 2, pulse frequency modulation (Pulse Frequency Modulation, acronym for the PFM) conduction pulse width constant by changing the switching frequency to change the duty cycle approaches. 3, mixed conduction modulation and pulse width switching frequency not fixed are, they change the way It is more than two hybrid models. SMPS developments and trends in the United States in 1955 Roje (GH.Roger) invention of the self-excited oscillation push redeem transistor single transformer DC converters, high-frequency conversion is the beginning of control circuit, 1957 United States investigation tournament (Jen Sen) since the invention of the push-pull double Flyback transformers, 1964 American scientists proposes to abolish the frequency transformer series switching power supply scenario, This power to the right size and weight of the decline was a fundamental way. To the 1969 high-power silicon transistor because the pressure increase diode reverse recovery time shortened, and other components improve, and finally turned into a 25 kHz switching power supply. Currently, switching power supply to small, Light volume and the characteristics of high efficiency has been widely used in electronic computer-driven variety of terminal equipment, Communications equipment almost all electronic equipment, the electronic information industry indispensable to the rapid development of a power mode. Currently the market for sale in the switching power supply using bipolar transistors made of 100kHz. use made of 500kHz MOS power, though practical, but its frequency to be further enhanced. To improve the switching frequency, it is necessary to reduce the switching loss, and to reduce the switching loss, you need to have high-speed switching devices. However, the switching speed, will be affected by the circuit inductance and capacitance diode or stored charge arising from the impact of the surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Among them, with the switch to prevent Kai-closed by the voltage surge, it is R-C or L-C Composite bumpers, and the storage charge by the diode current surge caused by the use made of amorphous cores such as magnetic bumper. However, the high frequency of 1 MHz and above, using resonant circuit, Switch to enable the voltage or current through the switch was a sine, which could reduce the switching loss, This can also control the surge occurred. Switches such as resonant mode switching. Currently such SMPS of very active, because this means no significant increase switching speed can theoretically put switching loss fall to zero. and the noise is small, is expected to become high-frequency switching power supply of one of the main ways. At present, many countries in the world are working on several trillion Hz converter practical research.高頻開關電源電路原理高頻開關電源由以下幾個部分組成：一、 主電路從交流電網(wǎng)輸入、直流輸出的全過程，包括：1、輸入濾波器：其作用是將電網(wǎng)存在的雜波過濾，同時也阻礙本機產(chǎn)生的雜波反饋到公共電網(wǎng)。2、整流與濾波：將電網(wǎng)交流電源直接整流為較平滑的直流電，以供下一級變換。3、逆變：將整流后的直流電變?yōu)楦哳l交流電，這是高頻開關電源的核心部分，頻率越高，體積、重量與輸出功率之比越小。4、輸出整流與濾波：根據(jù)負載需要，提供穩(wěn)定可靠的直流電源。二、控制電路 一方面從輸出端取樣，經(jīng)與設定標準進行比較，然后去控制逆變器，改變其頻率或脈寬，達到輸出穩(wěn)定，另一方面，根據(jù)測試電路提供的資料，經(jīng)保護電路鑒別，提供控制電路對整機進行各種保護措施。三、除了提供保護電路中正在運行中各種參數(shù)外，還提供各種顯示儀表資料。四、輔助電源提供所有單一電路的不同要求電源。開關控制穩(wěn)壓原理 開關K以一定的時間間隔重復地接通和斷開，在開關K接通時，輸入電源E通過開關K和濾波電路提供給負載RL，在整個開關接通期間，電源E向負載提供能量；當開關K斷開時，輸入電源E便中斷了能量的提供。可見，輸入電源向負載提供能量是斷續(xù)的，為使負載能得到連續(xù)的能量提供，開關穩(wěn)壓電源必須要有一套儲能裝置，在開關接通時將一部份能量儲存起來，在開關斷開時，向負載釋放。圖中，由電感L、電容C2和二極管D組成的電路，就具有這種功能。電感L用以儲存能量，在開關斷開時，儲存在電感L中的能量通過二極管D釋放給負載，使負載得到連續(xù)而穩(wěn)定的能量，因二極管D使負載電流連續(xù)不斷，所以稱為續(xù)流二極管。在AB間的電壓平均值EAB可用下式表示：EAB=TON/T*E 式中TON為開關每次接通的時間，T為開關通斷的工作周期（即開關接通時間TON和關斷時間TOFF之和）。由式可知，改變開關接通時間和工作周期的比例，AB間電壓的平均值也隨之改變，因此，隨著負載及輸入電源電壓的變化自動調(diào)整TON和T的比例便能使輸出電壓V0維持不變。改變接通時間TON和工作周期比例亦即改變脈沖的占空比，這種方法稱為“時間比率控制”（Time Ratio Control,縮寫為TRC）。按TRC控制原理，有三種方式：一、脈沖寬度調(diào)制（Pulse Width Modulation,縮寫為PWM） 開關周期恒定，通過改變脈沖寬度來改變占空比的方式。二、脈沖頻率調(diào)制（Pulse Frequency Modulation,縮寫為PFM） 導通脈沖寬度恒定，通過改變開關工作頻率來改變占空比的方式。 三