Figure 4. Input and Output Current for FOSEPIC Converter
Figure 4 presents the input and output currents for the FOSEPIC
converter, with panel (a) depicting the currents during boost mode
operation and panel (b) showing the currents during buck mode operation.
It is evident that there are small, undesired ripples in the output
current, likely resulting from noise disturbances within the system.
Despite these ripples, the output voltage is consistently regulated at
48V in both operating modes. To maintain the load power amidst
variations in input voltage, adjustments to the input current are
necessary.
Performance Under Load Variations
The proposed control strategy’s performance was further evaluated under
load variations ranging from 50% to 70%. Figure 5 illustrates the
dynamic responses of the output voltage in response to abrupt changes in
load resistance, with a reference voltage (𝑉𝑟𝑒𝑓 ) set at 48V. The load
was switched from 50Ω to 33.33Ω and then back from 33.33Ω to 50Ω.
Figures 6 and 7 display the dynamic responses during these load changes
while the converter operates in both boost and buck modes,
respectively.Notably, the output voltage remains largely unaffected by
these load variations, demonstrating the controller’s capability to
regulate output voltage effectively. Although small overshoots and
undershoots occur during the transient periods, the output voltage
stabilizes quickly, confirming the robustness of the proposed control
strategy under varying load conditions.