Objective: For this project, a buck converter is to be designed that will convert 42 V input to an output voltage based on your group number: Output voltage: (N+5) volts dc where N is the last digit of your ZID. The following steps should be accomplished in the design: A) For this project the controller shown in fig. 3 can be approximated by the equivalent circuit of fig. 4. Calculate the gain Kp required so that the steady state error of the system for a step input is less than 1%. Although the system is a nonlinear system its average behavior for a given operating point can be approximated with a linear transfer function. See Appendix A for the development of this transfer function. Assume the triangle wave peak, Vp, has a value of 5 V for your calculations. V ref. V Vp Ov out Kp M Page 3 of 6 To Voltage- Controlled Voltage-Source/nB) Calculate values for Lf and Cf in fig. 1 to keep the capacitor voltage ripple less than 0.01v. Calculations should be based on a 50 kHz switching frequency. The rated output current is to be 2 A. The linearization theory used for the control is based on assuming the bandwidth of the closed loop system is considerably smaller than the switching frequency, that is @ << 2πfs. The choice of Lf and Cf should therefore ensure the system bandwidth is small enough. See Appendix A for information on the system bandwidth. C) Simulate the buck converter using a SPICE based software at rated load current. Show your design meets the design requirements. For the report, follow the outline given in Appendix B. The report should just contain a summary of the method and not a formal report. References [1] D. W. Hart, Power Electronics, McGraw Hill, 2010, pp. 302 - 325. [2] N. Mohan, Power Electronics: A First Course, Wiley, 2023, pp. 99 - 105; Appendix 4B.

Fig: 1

Fig: 2