Novel Approach for Power Management‐Based NPC STATCOM for Grid‐Connected Photovoltaic Battery System

ABSTRACT The development of power quality control systems and methods is a credible step for the modernization of the power grid. In this context, this paper presents novel approaches for the control of power quality and voltage of the power grid using power converters connected to photovoltaic battery systems. The photovoltaic system permits to generate the required power to adjust the grid voltage. Indeed, a three‐level neutral point clamped (NPC) converter, connecting the PV‐batteries to the power grid, plays the function of a static compensator (STATCOM) in the case of a fault causing power grid voltage variation. The NPC converter is controlled by a direct current vector control method based on a hysteresis controller. The amplitude and phase of the NPC converter reference currents are generated based on the irradiation value, the battery state of charge, and the grid voltage. In addition to the NPC converter, the proposed approach uses three DC–DC converters with the aim to extract the maximum power from the PV system and control the charge–discharge of the batteries. The bidirectional converter associated with the batteries and the four‐quadrant chopper connected to the NPC converter are controlled by proportional integral (PI) regulators in aim to maintain the voltage and state of charge of the batteries within the acceptable range. To coordinate the different scenarios, a power management system is proposed in this paper to generate adequate control signals for the control of the different power converters. PI closed‐loop controllers have been proposed to ensure the highest performance and stability of voltage regulation in the power grid. The different control methods have been implemented and verified in MATLAB‐Simulink environment. The results prove the effectiveness of the proposed approach to regulate the voltage and the grid power quality. The results demonstrate that the proposed system is capable of maintaining the grid voltage within ±10% of the nominal value, even under fault conditions, with a voltage regulation efficiency of 98%. Additionally, the power quality improvements are quantified, showing a reduction in total harmonic distortion (THD) of the grid current to below 3%, ensuring compliance with international power quality standards.