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-汽車設(shè)計(jì)(編輯修改稿)
2025-06-26 09:05 本頁面
【文章內(nèi)容簡介】 mposed with d Ui that is posed by positive and negative rectangle wave impulses. The amplitude of d Ui is taken to be equal to . It should make d Uo be easy to be observed to select the rectangle wave frequency , adopting f 1 = 400 Hz 。 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 。 peak overshoot σ p = 1/ 2 = 50 %。 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 gainfrequency characteristic ,logarithmic phasefrequency characteristic of controlled object Gp ( s). The curves ② and ⑤ are respectively the logarithmic gainfrequency characteristic , logarithmic phasefrequency characteristic of the feedback and measuring circuit joint the integral pensator. The curves ③ and ⑥ are respectively the logarithmic gainfrequency characteristic and logarithmic phasefrequency characteristic of the pensated openloop system. By Fig. 8 we know that the system is Imodel system. When the inp
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