Title :
Control of circulating current for direct parallel grid-connected inverters in photovoltaic power generation
Author :
Ji, Suo ; Yong, Yang ; Chunqing, Qi
Author_Institution :
Dept. of Electron. Inf. Eng., Suzhou Vocational Univ., Suzhou, China
Abstract :
The generating mechanism of circulating currents for direct parallel photovoltaic grid-connected inverters is analyzed in detail at first. Then state average model of the parallel photovoltaic grid-connected inverters is constructed in dq rotating coordinates. Based on this model, interaction between the parallel photovoltaic grid-connected inverters is analyzed and the influence on circulating current when it is used zero vectors with space vector pulse width modulation (SVPWM) is also analyzed. The paper adopts a novel method based on which the circulating current can be effectively inhibited by controlling the operation time for different zero vectors in each PWM cycle. The simulated and experimental results show that the control strategy can effectively inhibit circulating current, so the feasibility and correctness.
Keywords :
electric current control; invertors; photovoltaic power systems; PWM cycle; circulating current control; direct parallel photovoltaic grid-connected inverters; dq rotating coordinates; photovoltaic power generation; space vector pulse width modulation; state average model; zero vectors; Automatic generation control; Automation; DC generators; Functional analysis; Photovoltaic systems; Power engineering and energy; Pulse inverters; Pulse width modulation inverters; Solar power generation; Space vector pulse width modulation; SVPWM; circulating currents; state average model; zero vectors;
Conference_Titel :
Mechatronics and Automation, 2009. ICMA 2009. International Conference on
Conference_Location :
Changchun
Print_ISBN :
978-1-4244-2692-8
Electronic_ISBN :
978-1-4244-2693-5
DOI :
10.1109/ICMA.2009.5246756
