Experiment 4 - Part I: Boost Converter For the PV system shown below, the PV module produces a constant voltage of 12 V. The energy storage (ES) is made of lead-acid battery pack with a terminal voltage of 24 V. Design a DC-DC converter that converts the PV voltage to the ES bank voltage, i.e. from 12 V to 24 V. The maximum ripple in the converter's output voltage must be within ±0.5 V. ● ● DC/DC ES #70% ● DC/AC Grid Vin lin Vin L iL ip iin +s S ▷ Design a circuit that can meet these requirements. Show the simulation results for a few switching cycles for the current and voltage waveforms for all the components (switch, diode, inductor and capacitor). • At what duty cycle the converter must operate? If the PV voltage drops by 5%, 10%, 15% and 20%, explain how the converter would adjust its operation to meet the load requirement, i.e. 24 V output voltage. Support your answers with simulation results. D ic C iL Experiment 4 - Part II: Buck-Boost Converter In the previous system, another PV module is connected in series with the original one to increase the PV voltage. If the new PV voltage fluctuates by ± 50% throughout the day due to irradiance cloudy conditions variation throughout the day hours. Design a DC-DC converter that can operate under this wide input voltage window, i.e. 12 V-36 V. Show the simulation results for ± 10%, ±25% and ± 50% variation in the input voltage. The ripple in the output voltage must be within ±0.5 V. io K R iD

Fig: 1