T10.7 - Direct Digital Control and Capacitor Current Compensation to Improve Grid-Current Distortion for Three-Phase Three-Wire LCL Grid-Connected Inverter Under Distorted Grid Voltages

Wednesday, March 22, 2023

11:00 AM – 11:20 AM ET

Location: W102

Authors: Tsai-Fu Wu, Yun-Hsiang Chang, Jui-Yang Chiu, Chien-Chih Hung, Tzu-Hsien Chuang

Technical Lecture Presenter(s)

Tsai-Fu Wu, PhD

Professor
National Tsing Hua University, Taiwan (Republic of China)

PDF Handouts

This paper presents the grid-current improvement with direct digital control (DDC) and capacitor current compensation (CCC) for 3Φ3W LCL grid-connected inverter under distorted grid voltages. With a repetitive control, the capacitor voltages feedforward and then take the derivative to yield the capacitor current which is used to improve grid currents. The virtual impedance method is adopted to confirm the stability when the filter inductances drop and capacitor voltages feedforward. Experimental results from 12 kW are used to verify the theoretical analyses and discussions.