A Novel DC Capacitor Deficit Power Balancing Mechanism for Innate Maximum Power Tracking With Eliminated Regulators in PV-Inverters

In grid-connected inverters, dc capacitors maintain the dc bus voltage to feed the grid's regulated power. Nevertheless, the dc bus voltage influences the solar panel power extraction characteristics in a single-stage inverter configuration. Therefore, controlling the dc capacitor charge arbitrates solar energy extraction and simultaneous injection into the grid. At the initial start of the inverter, the dc capacitor is charged to the open circuit voltage of the solar farm, where the incoming power is zero but exhibits the maximum natural force for grid power injection. Allowing the grid power injection due to natural force alters the incoming solar power through an adaptive capacitor charge balance. By analyzing the natural phenomena of the exhibited forces on the dc capacitor during energy exchange, this work proposes a novel deficit power balancing model to derive the inverter modulation. The proposed power balancing mechanism eliminates the conventional power tracking algorithms, voltage, and current regulators while deriving inverter modulation. The derived inverter modulation through the proposed model naturally alters the inverter's operational equilibrium point to the maximum power point. Thus, regardless of irradiance, the system is stable at the solar farm's maximum power point. The efficacy of the proposed mechanism is verified on hardware.