發(fā)布時間：2018-06-30 20:41

  本文選題：恒能量脈沖 + 調頻　； 參考：《昆明理工大學》2015年碩士論文

【摘要】：當今的電力電子技木,主要通過PWM (Pulse Width Modulation)即脈沖寬度調制方式來完成功率主電路的變流,而存在以下幾個不足：①功率開關器件在開通關斷過程中由于電壓和電流的不同步而導致主開關器件要承受瞬時功率很高的開關損耗,且隨著變流功率的增大和斬波頻率的提高,這種損耗也隨之增加,從而使得PWM方式的最高斬波頻率受到限制；②PWM變流主電路的能量傳輸方式為電壓傳輸特性,因此,需要在變流主回路中設置過流速斷保護來解決輸出過負載和輸出短路的問題,由于過流速斷保護電路在關斷的瞬間,電路中的di/dt的值很大,該di/dt值與導線的分布電感相互作用而在電路中產生極高的尖峰電壓,該尖峰電壓與電源電壓正向串聯(lián)后極易將功率開關器件擊穿；③若輸出要求為恒功率特性(即不管負載的阻值如何變化而輸出功率不變),則現(xiàn)有的技術只能通過電壓和電流的雙閉環(huán)負反饋控制來實現(xiàn),這種的雙閉環(huán)負反饋控制方法過于繁瑣,增加了控制電路實施的困難。本項目為企業(yè)委托開發(fā)項目,經查詢,國內目前沒有滿足要求的產品。因此,只能通過自行研發(fā)來解決,技術要求高且難度大,而本論文為項目完成過程的部分成果之一。論文的主要創(chuàng)新點在于：①依據(jù)電子電路的功率特性傳輸原理和項目的目標要求,提出了一種單通道調頻式恒能量脈沖功率合成變流新方法,使所構建的應用系統(tǒng)在開環(huán)條件下即可實現(xiàn)恒功率特性輸出,同時又能保證輸出不失真條件下有效提高電路斬波頻率,減小整個電路的體積；②為克服DSP運行速度的限制,采用模擬方式對功率主回路實施控制；③為克服傳統(tǒng)的電壓-頻率轉換電路線性區(qū)不夠寬的問題,提出了一種全新結構的對稱式高速高精度的電壓-頻率轉換電路；④完成了全系統(tǒng)的控制電路和主回路的原理圖及PCB板的設計和焊接,調試及波形指標的檢測,最終達到了項目的要求。本文對電力電子技術的現(xiàn)狀和存在問題作了簡單論述,并對論文所涉及的知識進行了簡要的介紹,在此基礎上,對高速高精度電壓-頻率轉換電路的原理進行了論述,同時對恒能量斬波式功率合成電路的系統(tǒng)原理及電路的設計進行了較為詳細的分析。
[Abstract]:Nowadays, power electronics technology, mainly through PWM (Pulse width Modulation), that is, pulse width modulation to complete the main power circuit converter, However, there are the following shortcomings: 1 power switch devices in the turn-off process, because the voltage and current are not synchronized, leading to the main switch device has to bear a very high switching loss of instantaneous power. With the increase of converter power and chopper frequency, the loss increases, so the maximum chopping frequency of PWM mode is limited. The energy transmission mode of PWM converter is voltage transmission characteristic. In order to solve the problem of output overload and output short circuit, it is necessary to install overvelocity protection in the converter main circuit. Because the value of di/dt in the circuit is very large when the circuit is turned off, The di/dt value interacts with the distributed inductance of the conductor to produce a very high peak voltage in the circuit. The peak voltage in series with the supply voltage is easy to break down the power switch device. (3) if the output is required to be constant power (that is, no matter how the resistance of the load changes and the output power is constant), the existing technology can only be realized by double closed loop negative feedback control of voltage and current. This double closed loop negative feedback control method is too complicated and makes it difficult to implement the control circuit. This project is commissioned by the enterprise development project, after inquiry, domestic products have not met the requirements. Therefore, it can only be solved by R & D, the technical requirements are high and difficult, and this paper is one of the achievements of the project completion process. The main innovation of this paper is that according to the transmission principle of the power characteristic of the electronic circuit and the target requirement of the project, a new method of single channel frequency modulation constant energy pulse power synthesis converter is proposed. In order to overcome the limitation of DSP speed, the constructed application system can realize the constant power characteristic output under open loop condition, at the same time, it can effectively increase the chopping frequency of the circuit under the condition that the output is not distorted, and reduce the volume of the whole circuit. In order to overcome the problem that the linear range of the traditional voltage-frequency conversion circuit is not wide enough, a novel symmetrical high speed and high precision voltage-frequency conversion circuit is proposed in this paper. (4) the schematic diagram of the control circuit and the main circuit of the whole system, the design and welding of PCB board, the debugging and the testing of the waveform index are completed. Finally, the requirements of the project are met. In this paper, the current situation and existing problems of power electronics technology are briefly discussed, and the knowledge involved in this paper is briefly introduced. On the basis of this, the principle of high speed and high precision voltage-frequency conversion circuit is discussed. At the same time, the system principle and circuit design of constant energy chopped power combiner are analyzed in detail.
【學位授予單位】：昆明理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN73

【參考文獻】

中國期刊全文數(shù)據(jù)庫 前1條

1 徐德鴻;21世紀電力電子技術的機遇與挑戰(zhàn)[J];電工技術雜志;2002年10期

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本文編號：2086790