A Novel Variable-Level ANPC Inverter with Capacitor Voltage Reconfiguration Method for 2 kV Photovoltaic Applications

The 2 kV photovoltaic (PV) system is widely regarded as the next evolution for megawatt (MW)-scale PV systems, enabling higher rated power. This article proposes a novel variable-level (VL) active neutral-point clamped (ANPC) inverter, capable of operating in both 3-level and 4-level modes by incorporating a simple bypass switch, K. To meet the 2 kV voltage grade requirement, the principle of device selection is thoroughly deduced, identifying the hybrid adoption of 1200 V and 1700 V devices as an optimal solution in terms of cost and efficiency. Additionally, to maximize overall efficiency across the full maximum power point tracking voltage range of PV arrays, a capacitor voltage reconfiguration strategy and a unified adaptive-level PWM method are proposed. These approaches optimize the switching voltage stress distribution between 1200 V and 1700 V devices, significantly enhancing the efficiency of the proposed VL ANPC inverter. Simulation and experimental results validate that the proposed inverter, along with its modulation and control methods, offers a competitive and viable solution for 2 kV PV applications.