Development of a Geometrically Summing Voltage Inverter Circuit for Water Pumps Operating in Photoelectric Systems
Abstract
Conventional single-stage PV inverters typically require ≥ 10.8 V and drop out under poor irradiance, interrupting the 220 V supply. We propose a low-voltage architecture based on two series-connected inverter modules and a specialized controller that performs geometric (vector) voltage addition with dynamic phase coordination. Each module can operate from ≥ 6 V, and the controller synchronizes amplitude and phase to synthesize a stable 220 V output across wide irradiance variations. The control stack integrates low-voltage MPPT, PLL synchronization, adaptive amplitude regulation, and seamless mode transitions with built-in protections. Across representative overcast conditions, the architecture increases delivered AC energy by ≈6–15% (median ≈10–12%) versus a single inverter with a 10.8 V cutoff, by harvesting low-irradiance windows; low-voltage conversion efficiency improves by ≈5–7 percentage points at 0.2–0.4 p.u. input while remaining within ±1 pp of the baseline at nominal irradiance. The concept is applicable to distributed PV/ESS and retrofit scenarios where maintaining 220 V under sub-nominal DC conditions is critical, extending the operating envelope of PV inverters toward lower input voltages.