# Analysis of Non-Minimum Phase System for AC/DC Battery
## 6 Simulation Results  
The feasibility and performance of the proposal will be evaluated by means of simulation using PSIM software. The simulated schematic, which consists of the power stage explained in Figure 1 and the control circuit presented in Figure 16, is combined with the parameters of Table 2. To make the simulation more realistic, ESR are being added to the inductance and capacitance, the switches are Level-2 model and the diodes also include their parasitic effects. The load is a sink current source. The input is a sinusoidal input voltage, which is being rectified by a passive H-bridge. Figure 17 shows the steady state waveforms of the inductor current \(i_{L1}(t)\) at boost and buck operation modes at full load after using the RC Snubber. These two waveforms can be compared with the previous Figures 8 and 9. In both operation modes, the current waveform of the inductor \(L_{1}\) follows the reference and reshapes the current to a rectified sinusoidal waveform. Figure 18 shows the steady state waveforms of input voltage \(v_{g}(t)\), input current \(i_{g}(t)\), output voltage \(v_{o}(t)\) and the output current \(i_{o}(t)\) at two different output currents. The output voltage is 200 V and the peak input voltage is 300 V, which operates the converter in buck mode. Figure 18a shows the waveforms when the converter operates at the full load absorbing 8 A. This figure depicts how the input current waveforms perfectly follow the current reference and it is in phase with the input voltage with low distortion factor, wherein the PF is measured to be 0.99. The output voltage ripple can be controlled by the value of the output capacitance according to the application requirement, here the output capacitor is 800 \(\mathrm{\SIUnitSymbolMicro F}/450\) V. The output voltage ripple is 25 V, which is 12.5% of the averaged value. Figure 18b shows the waveforms when the converter operates at the half load absorbing 4 A. This figure depicts how the input current waveforms perfectly follow the current reference and it is in phase with the input voltage with low distortion factor, wherein the PF is measured to be 0.99. The output voltage ripple is 18 V which is 9% of the averaged value. Figure 16: Controller circuit schematic diagram. Figure 17: Waveforms of inductor current \(i_{L1}(t)\) in: (**a**) Boost mode. (**b**) Buck mode. Figure 19 shows the steady state waveforms of input voltage \(v_{g}(t)\), input current \(i_{g}(t)\), output voltage \(v_{o}(t)\) and the output current \(i_{o}(t)\) at two different output currents. The output voltage is 400 V and the peak input voltage is 300 V which means the converter operates in boost mode. Figure 19a shows the steady state waveforms at full load where the current source absorbs 8 A. This figure represents how the input current waveforms perfectly follow the current reference and it is in phase with the input voltage with low distortion factor, wherein the PF is measured to be 0.99. The output voltage ripple is 30 V, which is 7.5% of the averaged value. Figure 19b shows the waveforms when the converter operates in the half load where the current source absorbs 4 A. This figure depicts how the input current waveforms perfectly follow the current reference and it is in phase with the input voltage with low distortion factor, wherein the PF is measured to be 0.99. The output voltage ripple is 20 V which is 5% of the averaged value. To show the dynamics of the converter controller after developing to be minimum phase system, output current transient is tested to check for this purpose. There are two mode of transient that tested for this converter by allowing the current source to step down from the high current (full power) to the low current (half power), and vice versa from the low current to the high current. Then, checking the other waveforms till they arrived in steady state point. This test is done for both converter modes boost and buck wherein, the input voltage is fixed 300 V and the output voltage changes from 200 V for buck mode to 400 V for the boost mode.