外文翻譯---電動(dòng)汽車dc-dc電源轉(zhuǎn)換器的原理、建模和控制

1、<p><b>　　外文原文</b></p><p>　　Principle, Modeling and Control of DC-DC Convertors for EV</p><p>　　ZHAN G Cheng-ning , 　SUN Feng-chun , 　ZHAN G Wang</p><p>　　(School of

2、 Vehicle and Transportation Engineering , Beijing Institute of Technology , Beijing 100081)</p><p>　　Abstract : DC-DC convertors can convert the EV’s high-voltage DC power supply into the lowvoltage DC power

3、 supply. In order to design an excellent convertor one must be guided by theory of automatic control. The principle and the method of design, modeling and control for DC-DC convertors of EV are introduced. The method of

4、the system-response to a unit step-function input and the frequency-response method are applied to researching the convertor’s mat- hematics model and control characteristic</p><p>　　Key words: EV ; DC-DC c

5、onvertors ; automatic control ; mathematics model ; Bode drawing</p><p>　　CLC number : U 469-72 　　　Document code : A</p><p>　　Generally there are two power supplies in EV. One is the DC high-vol

6、tage power supply that is used by high power devices such as traction motors and air conditioners etc. The other is the DC low-voltage power supply that is usually used in some control circuit and low-voltage electrical

7、devices such as the inst- rument and lighting. It s rating voltage is 24 V or 12 V. The low-voltage power supply can be gained from the high-voltage power supply by a DC-DC conver-</p><p><b>　　tor.<

8、/b></p><p>　　In this paper, the main performance of the designed convertor is that the input voltage range is from DC 250 V to DC 450 V , the output voltage is DC 24 V , the maximum output current is DC 2

9、0 A , and the output precision is 1 %.</p><p>　　1 　Principle of the Convertor</p><p>　　1.1 　The Block Diagram of the DC-DC Convertor</p><p>　　The block diagram of the DC-DC converto

10、r is showed in Fig. 1. The battery series provide the DC high-voltage input Us. The low-voltage output of the con-</p><p>　　vertor is Uo. The setting value Ui of the convertor is equal to or is in proportion

11、 to the demanded output voltage Uo. The convertor is a closed-loop negative feedback-system with voltage feedback.</p><p>　　1.2 　Power Switch Circuit</p><p>　　The power switch circuit with semi-

12、bridge mode is showed in Fig. 2. L1 and C1 constitute an input filter to avoid high-frequency impulses flowing bac- kwards. Capacitors C2and C3 constitute the partial-voltage circuit while resist-</p><p>　　a

13、nces R1 and R2do so. IGBT1 and IGBT2 are semiconductor switch devices. C6 is a separation DC capacitor. T1 is a transformer that reduces the voltage. L2 and C7 constitute an output filter. RL is the load resistance. When

14、 the PWM signals</p><p>　　in the reverse semi-waves are inputted onto IGBT1 and IGBT2’s control poles , the corresponding DC voltage can be yielded from the convertor.</p><p>　　Fig. 2 　Principle

15、 circuit of power switch with semi-bridge mode</p><p>　　1.3 　Control Circuit</p><p>　　The chip SG3525 is used in the PWM control circuit showed in Fig. 3. V cc is the power voltage applied to th

16、e chip, it is 12.0 V. A base-voltage of 5.1 V is yielded on pin16 of the chip that is partially used as parameter voltage input Ui. The chip includes a sawtooth-wave generator. Rt and Ct are the external resis-</p>

17、<p>　　tance and capacity that determine the sawtooth-wave’s frequency.Pin2 of the chip is a positive-phase input port. Voltage input Ui is putted to the port, here Ui =2. 5 V. Pin1 of the chip is the negative-phas

18、e input port where the feedback voltage is inputted.Pin9 of the chip is the output end of the inside amplifier of the chip. The proper resistance and capacitor are connected between the pin1 and pin9 to realize compensat

19、ion of the DC-DC convertor.C8 is the integral capacitor. The integral com</p><p>　　Fig. 3 　The connection circuit for the PWM control chip SG3525</p><p>　　1.4 　Drive Circuit</p><p>

20、　　The drive circuit of IGBT usually adopts a pulse-transformer or an opto-</p><p>　　coupler to isolate the power circuit from the control circuit. An individual power supply is needed if an opto-coupler is u

21、sed, which increases the complexity of the system. So the isolation-circuit adopt s a pulse-transformer showed in Fig. 4. Transistors BG1 and BG2 in Fig. 4 compose a complementation power amplification circuit. T2 is the

22、 pulse-transformer that isolates the power circuit from the control circuit. R5 and C8 compose the acceleration circuit. The diode D6 eliminates negative imp</p><p>　　Fig. 4 Principle circuit for IGBT drive

23、</p><p>　　2　Modeling and Control</p><p>　　2.1 　Modeling</p><p>　　The DC-DC convertor is a voltage negative feedback-system. Aiming to obtain the better dynamic and static characteri

24、stic we must model and analyse it in theory. According to Ref. [ 1 ] ,DC-DC convertors are the approximate second-order systems. In order to obtain accurate parameters , the method of the system-response to a unit step-f

25、unction input is adopted in this paper.</p><p>　　2.1.1 　Measuring the Open-Loop System’s Response to a Unit Step-Function Input</p><p>　　The block diagram for measuring is shown in Fig. 5. The c

26、oncrete method is described as follows : ① The voltage feedback signal is cut off ; ② The setting value of the chip SG3525 adopts the middling value Ui0 to make the width of an impulse be about 0.5 T ; ③ Ui0 is superimpo

27、sed with d Ui that is composed by positive and negative rectangle wave impulses. The amplitude of d Ui is taken to be equal to 0.2Ui0. It should make d Uo be easy to be observed to select the rectangle wave frequency , a

28、dop</p><p>　　peak time tp = 0.1 ms ; peak overshoot σp = 1/ 2 = 50 %;</p><p>　　output and input’s incremental ratio K0 = d Uo/ d Ui = 10/ 1 = 10.</p><p>　　Fig.5 The measuring block

29、 diagram of the open-loop system</p><p>　　Fig. 6 　The system-response to a unit step-function input</p><p>　　2.1.2 　Determining the Open-Loop Transfer Function</p><p>　　According to

30、 Ref s. [2,3 ] , we have the damping ratio ξ, undamped natural frequency ωn and transfer function of controlled object Gp ( s) as follows :</p><p>　　In order to ensure that when the output voltage Uo =24 V t

31、he feedback voltage to pin1 of the SG3525 is 2.5 V to balance the input voltage Ui = 2.5 V, we take the feedback and measuring factor as</p><p>　　Kb = Ub/ Uo = -15/ -4 = 01104. ( 4 )</p>&l

32、t;p>　　2.2　Design of the PID Regulator</p><p>　　2. 2.1　The Principle Scheme and Transfer Function of the PID Regulator</p><p>　　To resist the disturbance of the power supply voltage and load c

33、urrent to the DC-DC convertor so as to improve control precision , an integral compensator is adopted. The principle scheme of the integral compensator is shown in Fig. 7.</p><p>　　Fig. 7 The principle sche

34、me of the integral compensator</p><p>　　It s transfer function is</p><p>　　Gc ( s) = Ki/ s = 1/ ( RCs). ( 5 )</p><p>　　In Fig. 7 and Eq. (5), R = 10 kΩ, C = 0.1μF , Ki

35、= 1/ ( RC) = 1/ (10 ×103 ×011 ×10 - 6)= 1 000.</p><p>　　2. 2.2 　The Bode Drawing of the System Open-Loop Transfer Function</p><p>　　The system open-loop transfer function is the p

36、roduct of the controlled object’s , feedback and measuring circuit’s and integral compensator’s transfer functions. We have</p><p>　　G( s) = Gc ( s) Gp ( s) Gb ( s) =</p><p>　　The system Bode dr

37、awing is shown in Fig. 8 from Eq. (6). The curves ①and ④are respectively the logarithmic gain-frequency characteristic ,logarithmic phase-frequency characteristic of controlled object Gp ( s). The curves ② and ⑤ are resp

38、ectively the logarithmic gain-frequency characteristic , logarithmic phase-frequency characteristic of the feedback and measuring circuit joint the integral compensator. The curves ③ and ⑥ are respectively the logarithmi

39、c gain-frequency characteristic and logari</p><p>　　Fig. 8 　The Bode drawing of the system open2loop transfer function</p><p>　　3 　The Result and Conclusion of Experiment</p><p>　　W

40、hen the load resistance RL = 1.2Ω , the experiment data of Us , I s , Uo , Io , η(ηis efficiency of the convertor) are shown in Tab. 1. When the load resistance RL = 2.4Ω , the experiment data of Us , I s , Uo , Io , ηar

41、e shown in Tab.2.</p><p>　　4 　Conclusions</p><p>　?、貰ecause the integral compensator is adopted , the output voltage Uo of the convertor has quite high precision even if the input power voltage

42、and the load changes.</p><p>　?、赥he width of the impulses is adjusted automatically in the convertor to realize constant output voltage value. With the increase of the input voltage the width of the impulses

43、 turn narrow , the convertor’s efficiency drops. In the process of designing a DC-DC convertor, we must diminish the adjustable range of the impulse width and make the impulse width wider when the convertor operates.<

44、/p><p>　?、?The reasonable value of the resistance and capacitor in the feedback circuit must be selected so that the feedback-system has enough gain margin and phase margin that can guarantee the control-system

45、 to be adjusted smoothly.</p><p>　　References:</p><p>　　[1 ] 　Cai Xuansan , Gong Shaowen. High-frequency electronics (in Chinese) [ M].Beijing : Science Press , 1994. 232 - 246.</p><p

46、>　　[2] 　Zhang Wang , Wang Shiliu. Automatic control principle (in Chinese)[M]. Beijing: Beijing Institute of Technology Publishing House , 1994. 71 - 72.</p><p>　　[3 ] 　D’Azzo J J. Linear control system a

47、nalysis and design [M]. San Francisco: McGraw-Hill Book Company,1981. 83 - 92.</p><p>　　電動(dòng)汽車DC-DC電源轉(zhuǎn)換器的原理、建模和控制</p><p>　　張承寧, 　孫逢春, 　張　旺</p><p>　　(北京理工大學(xué)車輛與交通工程學(xué)院, 北京　100081)</p&

48、gt;<p>　　摘要：為了設(shè)計(jì)出在電動(dòng)汽車上把高壓直流電源變換成低壓直流電源的高品質(zhì)DC-DC 變換器,采用自動(dòng)控制理論進(jìn)行指導(dǎo). 介紹電動(dòng)汽車DC-DC 變換器原理和設(shè)計(jì),建模與控制方法. 應(yīng)用階躍響應(yīng)法、頻率法研究其數(shù)學(xué)模型和控制特性,并且進(jìn)行分析和計(jì)算. 實(shí)驗(yàn)結(jié)果表明,用這種方法所研制的電動(dòng)汽車DC-DC 變換器輸出電壓精度高,抗干擾能力強(qiáng),調(diào)節(jié)特性快速、平穩(wěn).</p><p>　　關(guān)鍵詞：

49、 電動(dòng)汽車; DC-DC 變換器; 自動(dòng)控制; 數(shù)學(xué)模型; Bode 圖</p><p>　　中圖分類號(hào)U 469172 文獻(xiàn)標(biāo)識(shí)碼A</p><p>　　通常有兩種電源電動(dòng)汽車。一個(gè)是直流高壓電源采用高功率設(shè)備,如牽引電機(jī)和空調(diào)等。另一個(gè)是低壓直流電源,通常被用在一些控制電路和低壓電器設(shè)備,如儀表和照明。它的額定電壓24 V或12 V低壓供電,可由高電壓供電直流-直流變換器得到在本文中

50、,主要性能設(shè)計(jì)的是輸入電壓轉(zhuǎn)換器,范圍從直流250 V到直流450 V,輸出直流電壓24 V、最大輸出電流是直流20 A,輸出精度為1%。</p><p><b>　　1變換器原理</b></p><p>　　1·1直流-直流變換器的原理框圖</p><p>　　直流-直流轉(zhuǎn)換器的原理框圖如圖1所示，電池組提供直流高壓輸入U(xiǎn)s，低壓變

51、頻器的輸出是Uo。變頻器的調(diào)定值Ui等于或者是按比例到要求的輸出電壓Uo。這個(gè)轉(zhuǎn)換器是一個(gè)負(fù)電壓反饋閉環(huán)系統(tǒng)。</p><p><b>　　1·2功率開關(guān)電路</b></p><p>　　圖2所示電路的電源開關(guān)半橋接模式，L1和C1構(gòu)成一個(gè)輸入濾波器來避免高頻脈沖反流，C2和C3電容器與電阻R1和R2分別構(gòu)成部分電壓回路，T1和T2是半導(dǎo)體開關(guān)，C6是一個(gè)分

52、離直流電容器，T1是一個(gè)減少電壓的變壓器，L2和C7構(gòu)成一個(gè)輸出過濾器，RL是負(fù)載電阻。當(dāng)逆向半波上的PWM信號(hào)均在T1和T2的控制限時(shí)，相應(yīng)的直流電壓可以從自己的變換器中產(chǎn)生。</p><p>　　圖2電路的電源開關(guān)半橋接模式</p><p><b>　　1·3控制電路</b></p><p>　　用于PWM控制電路的SG3525芯

53、片如圖3所示，Vcc是芯片的電源電壓，它是12V，在芯片腳16上5.1V的基極電壓部分作為參數(shù)輸入界面電壓Ui，芯片包含一個(gè)鋸齒波發(fā)生器，Rt和Ct是確定的鋸齒波頻率的外部電阻和電容，芯片的腳2是正的輸入端口，輸入電壓Ui是針對(duì)端口，Ui=2.5V，芯片的腳1是輸入反饋電壓的負(fù)輸入端，芯片的腳9是芯片內(nèi)部放大器輸出結(jié)果。連接在腳1和腳9之間適當(dāng)?shù)碾娮韬碗娙輰?shí)現(xiàn)直流—直流變換器的補(bǔ)償。C8是積分電容，采用整體補(bǔ)償系統(tǒng)的補(bǔ)償制度，PWM脈沖

54、從腳11和腳4產(chǎn)生，當(dāng)PWM控制電路正常運(yùn)行時(shí)，腳2上的Ui和腳1上的Ub應(yīng)該平衡，當(dāng)Ui不等于Ub時(shí)，PWM技術(shù)寬度可自動(dòng)調(diào)節(jié)PWM控制電路使Ui等于Ub，通過這種方法我們可以控制變壓器的輸出電壓。</p><p>　　圖3用于PWM控制電路的SG3525芯片</p><p><b>　　1·4驅(qū)動(dòng)電路</b></p><p>　　

55、IGBT驅(qū)動(dòng)電路通常采用脈沖變壓器或光耦合器通過控制電路隔離電源電路，如果光耦合器需要使用個(gè)人電源，就會(huì)增加系統(tǒng)的復(fù)雜度，所以隔離電路采用脈沖變壓器如圖4所示，如圖4中晶體管BG1和BG2組成一個(gè)互補(bǔ)的功率放大電路，T2是控制電路中的脈沖變壓器隔離電路，R5和C8組成加速電路，二極管D6消除負(fù)脈沖，二極管D7和晶體管BG3在IGBT的控制下組成快速放電電路分布電容。</p><p>　　圖41GBT驅(qū)動(dòng)電路原理&

56、lt;/p><p><b>　　2建模和控制</b></p><p><b>　　2·1建模</b></p><p>　　直流—直流轉(zhuǎn)換器是一個(gè)電壓負(fù)反饋系統(tǒng)，以獲得良好的動(dòng)態(tài)和靜態(tài)特性，我們必須理論上模型和分析，根據(jù)參考【1】，直流—直流轉(zhuǎn)換器是近似二階系統(tǒng)，為了獲得正確的參數(shù)，本文采用對(duì)單位階躍函數(shù)輸入系統(tǒng)響應(yīng)的

57、方法。</p><p>　　2·1·1對(duì)單位階躍函數(shù)輸入的開環(huán)系統(tǒng)響應(yīng)測(cè)量</p><p>　　測(cè)量原理框圖如圖５所示，基本方法是描述如下：①電壓反饋信號(hào)被切斷②調(diào)定值上的芯片SG3525采用中等價(jià)值Uio是每個(gè)脈沖密度達(dá)到大約0.5特，③Uio與Ui疊加產(chǎn)生正負(fù)矩形脈沖，使Ui振幅等于0.2倍Uio，它將會(huì)使Uo容易被觀察去選擇矩形波的頻率，采用f1=400赫茲，④U

58、o的輸出波形如圖6所示，當(dāng)f1=400赫茲時(shí)，周期T=2.5毫秒（5格），最大電壓值的時(shí)間約為0.1毫秒，Uo為穩(wěn)定電壓幅值時(shí)為1ms,峰值超調(diào)為1格，每格在垂直方向代表5V，通過這種方法，系統(tǒng)響應(yīng)的數(shù)據(jù)輸入到一個(gè)單位階躍函數(shù)可以得到如下：峰值時(shí)間tp=0.1ms 峰值超調(diào)σp = 1/ 2 = 50 %;</p><p>　　輸出和輸入的增量的比Ko=dUo/ dUi=10/ 1=10.</p>

59、<p>　　圖5開環(huán)系統(tǒng)測(cè)量原理框圖</p><p>　　圖6對(duì)單位階躍函數(shù)輸入系統(tǒng)響應(yīng)</p><p>　　2·1·2開環(huán)傳遞函數(shù)的確定</p><p>　　根據(jù)參考【2、3】，我們有阻尼比ξ、被控制對(duì)象Gp ( s)、固有頻率ωn無阻尼自由振動(dòng)微分方程：</p><p>　　為了確保輸出電壓Uo=2.4V電

60、壓反饋給SG3525腳1的為2.5V，來平衡輸出電壓Ui=2.5V時(shí)，我們采用反饋和測(cè)量的參數(shù)</p><p>　　Kb = Ub/ Uo = 2.5/ 24 = 0.104. ( 4 )</p><p>　　2·2 PID調(diào)節(jié)器的設(shè)計(jì)</p><p>　　2·2·1 PID調(diào)節(jié)器的原理方案及傳遞函

61、數(shù)</p><p>　　直流—直流轉(zhuǎn)換器的抗擾動(dòng)電源電壓和負(fù)載電流，以提高控制精度采用整體補(bǔ)償、積分補(bǔ)償器的原理如圖7</p><p><b>　　圖7整體補(bǔ)償原則</b></p><p><b>　　它的傳遞函數(shù)</b></p><p>　　Gc(s)=Ki/s=1/(RCs)

62、 ( 5 )</p><p>　　由圖7和公式5 , R = 10 kΩ , C = 0.1μF , Ki = 1/ ( RC) = 1/ (10×0.1 ×0.001)= 1 000</p><p>　　2·2·2開環(huán)傳遞函數(shù)的繪制</p><p>　　該系統(tǒng)開環(huán)傳遞函數(shù)是被控制對(duì)象的產(chǎn)品，反饋和檢測(cè)

63、電路和整體補(bǔ)償器的傳遞函數(shù)，我們有</p><p>　　G( s) = Gc ( s) Gp ( s) Gb ( s)</p><p>　　=104/s＊10/(s*s/32150*32150+2*0.2154*s*s/32150+1) ( 6 )</p><p>　　由公式6該系統(tǒng)圖如圖8所示，曲線①和④分別獲得對(duì)數(shù)頻率特性，對(duì)數(shù)相頻特性的控制對(duì)象Gp

64、( s)，曲線②和⑤對(duì)數(shù)頻率特性分別獲得對(duì)數(shù)相頻特性的反饋和測(cè)量電路的整體補(bǔ)償關(guān)節(jié)。曲線③和⑥分別獲得頻率特性和對(duì)數(shù)相頻特性的開環(huán)系統(tǒng)的補(bǔ)償。由圖8我們知道系統(tǒng)是自我模型系統(tǒng)，當(dāng)輸入不改變，沒有穩(wěn)態(tài)誤差。它的初始階段ωc = 1 016 rad/ s，相位邊緣γ= 89.21°,所以可以調(diào)節(jié)系統(tǒng)性能的快捷順暢。</p><p>　　圖8系統(tǒng)開環(huán)傳遞函數(shù)圖</p><p><

65、b>　　3 實(shí)驗(yàn)結(jié)果和結(jié)論</b></p><p>　　當(dāng)負(fù)載電阻RL = 1.2Ω時(shí)，表一顯示實(shí)驗(yàn)數(shù)據(jù)Us , I s , Uo , Io , η（效率的摸），當(dāng)負(fù)載電阻RL = 2.4Ω時(shí), 表二顯示實(shí)驗(yàn)數(shù)據(jù)Us , I s , Uo , Io , η。</p><p>　　表一當(dāng)負(fù)載電阻RL = 1.2Ω時(shí)</p><p>　　表二當(dāng)負(fù)載電阻

66、RL = 2.4</p><p><b>　　4總結(jié)</b></p><p>　?、儆捎诓捎玫恼w補(bǔ)償法，即使輸入電壓和負(fù)載變化，轉(zhuǎn)換器的輸出電壓Uo有很高的精度；</p><p>　?、诿}沖的寬度自動(dòng)調(diào)整來實(shí)現(xiàn)變頻器輸出電壓不變，隨輸入電壓的增加脈沖的寬度將縮小，轉(zhuǎn)換器的效率下降，在設(shè)計(jì)DC-DC轉(zhuǎn)換器的過程中，當(dāng)轉(zhuǎn)換器運(yùn)作時(shí)我們必須減少脈沖

67、寬度的可調(diào)范圍和是脈沖寬度更寬；</p><p>　?、鄯答侂娐分须娮韬碗娙萜骱侠淼膬r(jià)值必須選擇為能夠使反饋系統(tǒng)有足夠的增益和極限來保證控制系統(tǒng)可以順利進(jìn)行調(diào)整</p><p><b>　　5參考文獻(xiàn)</b></p><p>　　[ 1 ] 　Cai Xuansan , Gong Shaowen. High2frequency electron

68、ics ( in Chinese) [ M] . Beijing : Science Press , 1994. 232 - 246.</p><p>　　[ 2 ] 　Zhang Wang , Wang Shiliu. Automatic control principle (in Chinese) [M] . Beijing : Beijing Insti2 tute of Technology Publis