The paper proposes a novel battery charger through use of
two serially-connected LLC resonant converters. The first
stage utilises a capacitor-diode clamped LLC resonant
converter which allows operation in both constant voltage
(CV) and constant current (CC) modes, as found in most
battery chargers, to be realised, whilst the second stage
provides the necessary gain and line and load regulation. A
design example is included that demonstrates the resulting
converter topology operating under the full battery charging
conditions and its inherent current-limiting capability.
Experimental results are used to validate the underlying
approach
