## 6 Experimental Results
The second test evaluates the performance of the proposed converter during the charging mode under imposed changes in the load. The changing scenarios are shown in Fig. 14. The results during peak power loading: (a) Battery, SC, and PV currents and bus power; (b) Battery, SC, and output voltages and output current. Figure 13: Experimental results during peak power loading: (a) Battery, SC, and PV currents and bus power; (b) Battery, SC, and output voltages and output current. in Figure 14a. Initially, the load is consuming a constant power of 160 W, larger than the available PV power, and therefore, the battery discharges with a current of (\(\approx\)1 A). When the load power reduces to 100 W (t = 40 s), there is extra power available from the PV, and this causes the battery to charge with 4 A. As this current is below the assumed battery current limit of 5 A, the SC contributes with charging current only during short-term transients as expected from the low/high-frequency filter effects on the reference ESS power. The SC current then reduces to zero after battery power compensates for the excess PV power. When a significant reduction in the load power occurs (t = 63 s), the battery current reaches its specified limit, and hence the SC has to absorb current during the transient period as well as absorb the excess power remaining after PV/load/battery power exchanges. This results in a noticeable rise of the SC voltage, as seen in Figure 14b. If there is excess power when the SC reaches its maximum voltage (not shown here), the control of the PV should change and move away from MPPT by capturing only the power that is consumed by the load and possibly to be absorbed by the battery. The test confirms the capability of the proposed converter to maintain the output voltage Vo regulated and perform active power share control under different variations in the loads during the charging mode of the ESS. Figure 14: Experimental results during different loading scenarios with (**a**) battery, SC, and output voltages and output current; (**b**) Battery, SC and PV currents, and bus power. The last test evaluates the response of the converter system under the disturbances of the PV power, as shown in Figure 15. Initially, the load draws a constant power of 70 W, and the PV is supplying enough power to cover the load power and to charge the battery with 6 A. At t = 30 s, the PV source becomes unavailable; this is sensed by the control that orders the SC unit to act quickly and bridge the short-term power gap and orders the battery to start to discharge to supply the load until the PV power becomes available again at t = 85 s. As can be observed, due to the low power consumed by the load, the battery current remains below its limit (set at 10 A for this test); therefore, the SC supplies only the short-term component of the load (transient period). The test results confirm the capability of the proposed converter to maintain the regulation of the output voltage Vo under the disturbances caused by the presence/absence of the primary power source (PV) relaying on the active power share control of the ESS. A general observation that applies to all three transients is that the controller can maintain a constant output voltage with minimum disturbance (maximum of 8% of the set value).