Three-Phase Grid-Connected Inverter

A three-phase grid-connected inverter is an electrical power conversion device primarily designed to convert direct current (DC) electrical energy into alternating current (AC) electrical energy. The system implements dual-loop control architecture comprising voltage and current regulation loops, enabling precise management of output voltage and current characteristics. From an implementation perspective, the voltage loop typically maintains DC-link stability using PI controllers, while the current loop employs techniques like PR (Proportional Resonant) controllers or advanced PWM modulation strategies to achieve accurate grid current tracking. Crucially, the current loop reference values are dynamically generated through power control algorithms - commonly implemented via dq-axis decoupling control or direct power control methods - allowing the inverter to autonomously adjust its output power according to varying load demands. The control logic often incorporates Clarke/Park transformations for three-phase coordinate system conversion and maximum power point tracking (MPPT) integration for renewable energy applications. Overall, the three-phase grid-connected inverter serves as a vital component in modern power systems, finding extensive applications in solar power generation, wind energy systems, and other distributed generation scenarios where efficient DC-AC conversion and grid synchronization are required.