Grid-Connected Inverter PI Double Closed-Loop Control Design

This document presents a grid-connected inverter design incorporating PI double closed-loop control system with LCL filter. The primary objective of this design is to achieve voltage and current decoupling through dq-coordinate transformation, implementing PI dual-loop control to obtain superior voltage and current waveform characteristics. The control algorithm typically involves Park/Clarke transformations for coordinate conversion and separate PI controllers for d-axis and q-axis current regulation. Key implementation aspects include: - LCL filter parameter design for harmonic suppression - DC-link voltage outer loop and current inner loop control structure - PWM modulation techniques for switching signal generation - Phase-locked loop (PLL) implementation for grid synchronization Notable features and advantages of this design comprise high efficiency, reliability, and robust performance under grid disturbances. The control system can be implemented using digital signal processors with sampled three-phase voltage/current measurements processed through coordinate transformation algorithms. If you're interested in this design methodology, we welcome technical discussions regarding specific implementation details, practical application performance, and potential application scenarios. We can explore aspects like controller tuning methods, stability analysis, and real-time code implementation strategies for various microprocessor platforms.