外文翻譯---電動汽車dc-dc電源轉(zhuǎn)換器的原理、建模和控制-汽車設(shè)計(jì)-在線瀏覽
2024-07-24 09:05本頁面
【正文】 er supply into the lowvoltage DC power 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 DCDC convertors of EV are introduced. The method of the systemresponse to a unit stepfunction input and the frequencyresponse method are applied to researching the convertor’s mat hematics model and control characteristic. Experiments show that the designed DCDC convertor’ s output voltage precision is high , the antijamming ability is strong and the adjustable performance is fast and smooth. Key words: EV 。 DCDC convertors 。 mathematics model 。 ② The setting value of the chip SG3525 adopts the middling value Ui0 to make the width of an impulse be about T 。 ④ The output waveform of Uo ( = Uo 0 + d Uo ) is shown in Fig. 6. As shown in Fig. 6 when f 1 = 400 Hz , period T = ms (5 grills) , the time for the maximum voltage value is about grills. d Uo’ s stable voltage amplitude is grills. Peak overshoot is 1 grill. Every grill in the vertical direction represents 5 V. By this way the data of systemresponse to a unit stepfunction input can be obtained as follows : peak time tp = ms 。 output and input’ s incremental ratio K0 = d Uo/ d Ui = 10/ 1 = 10. The measuring block diagram of the openloop system Fig. 6 The systemresponse to a unit stepfunction input Determining the OpenLoop Transfer Function According to Ref s. [2,3 ] , we have the damping ratio ξ , undamped natural frequency ω n and transfer function of controlled object Gp ( s) as follows : In order to ensure that when the output voltage Uo =24 V the feedback voltage to pin1 of the SG3525 is V to balance the input voltage Ui = V, we take the feedback and measuring factor as Kb = Ub/ Uo = 15/ 4 = 01104. ( 4 ) Design of the PID Regulator 2. The Principle Scheme and Transfer Function of the PID Regulator To resist the disturbance of the power supply voltage and load current to the DCDC convertor so as to improve control precision , an integral pensator is adopted. The principle scheme of the integral pensator is shown in Fig. 7. Fig. 7 The principle scheme of the integral pensator It s transfer function is Gc ( s) = Ki/ s = 1/ ( RCs). ( 5 ) In Fig. 7 and Eq. (5), R = 10 kΩ , C = F , Ki = 1/ ( RC) = 1/ (10 103 011 10 6)= 1 000. 2. The Bode Drawing of the System OpenLoop Transfer Function The system openloop transfer function is the product of the controlled object’ s , feedback and measuring circuit’ s and integral pensator’ s transfer functions. We have G( s) = Gc ( s) Gp ( s) Gb ( s) = The system Bode drawing is shown in Fig. 8 from Eq. (6). The curves ① and ④ are respectively the logarithmic gainfrequ
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