DC modularized PVmodules serialconnected system based on Boost/Buck
CHEN Yuzha1, LI Yuling2, WANG Guanjian2
(1.Hangzhou Silan microelectronics incorporated company, Hangzhou 310013, China;
2.College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)
 

Abstract: Aiming at the problems that the maximum power point tracking was defeated and output current of DC bus was limited in DC modularized photovoltaic (PV)modules serialconnected system under mismatching power of PV modules condition,a Boost/Buck converter was proposed to be applied in the DC modularized PV modules serialconnected system. Work principle of Boost/Buck circuit and influence of parameters on the system performance were investigated. Then a carrierwave overlap modulation strategy was introduced to the system to control the switches, and carrierwave overlap range was designed reasonably.Consequently, the presented Boost/Buck modularized PV modules can work in Boost, Buck and Boost/Buck mode, and can transfer automatically with different work condition of the PV modules input side. The results indicate that the system can achieve wide range maximum power point tracking with this converter, and system can track the maximum power point even in severe imbalanced condition,and each PV module in serialconnected system does not affect each other.
Key words: Boost/Buck;carrierwave overlap; maximum power point track; DC modularized PV system