Open AccessSwitching strategy for improving the lifetime of dc‐link capacitor in a fault‐tolerant active power decoupling topology
Author(s) -
Pradeep Kumar Vetcham V.S.,
Fernandes Baylon G.
Publication year - 2018
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2017.0202
Subject(s) - decoupling (probability) , network topology , capacitor , electrolytic capacitor , decoupling capacitor , topology (electrical circuits) , computer science , engineering , reliability (semiconductor) , electronic engineering , electrical engineering , power (physics) , voltage , control engineering , computer network , physics , quantum mechanics
Reliability is an important requirement for a grid‐connected photovoltaic (PV) system in remote military‐secured areas, which are difficult to access for system maintenance. However, the reliability of the PV system is reduced by the use of electrolytic capacitors in inverters. Active power decoupling (APD) topologies eliminate the need for these capacitors by using an additional decoupling circuit. However, the vulnerability of switching devices to failure is another reason for reduced reliability of inverters, which is not addressed in these topologies. Several fault‐tolerant topologies are proposed in literature to address this limitation. However, these topologies use electrolytic capacitors in dc‐link, which affects the overall reliability of inverter. To address these limitations, a fault‐tolerant strategy is proposed in this study. In the proposed strategy, a conventional APD topology is used along with an electrolytic capacitor in the dc‐link. The lifetime of the capacitor is improved using the decoupling circuit of the APD topology. In this regard, a switching strategy is proposed, using which the current flowing through dc‐link capacitor is reduced. Furthermore, in the event of a device fault, the topology continues to function like the conventional H‐bridge inverter. The operation of proposed strategy is validated through simulation and experimental studies.