Design and Implementation of a Battery Charger for Different Input Power Sources

A battery charger for different input power sources (DIPS charger) is proposed in this thesis. This charger can be applied to various input sources, such as an AC source, a PV source, and a DC source, and can perform corresponding functions. For example, when connected with an AC power source, the proposed charger perform the power factor correction (PFC). While connecting with a PV panel, it can achieve the maximum power point tracking (MPPT) feature. Besides, it is also capable of connecting with a DC power source. The proposed charger also has the conventional charging control, constant current mode and constant voltage mode, to protect the Li-ion battery from excessive charging current or voltage. Moreover, the proposed charger can regulate the output voltage when its output load is not a battery but a resistor only. To realize these desired functions for the charger, this thesis proposes a different input power sources (DIPS) algorithm to achieve those corresponding functions. In this thesis, the control flow chart of the proposed DIPS algorithm for different input power sources is presented. On the other hand, a novel single-stage Buck-Boost-Zeta converter (BBZC), which is the fusion of a buck–boost converter and an isolated Zeta converter is proposed to carry out the proposed DIPS algorithm. The operating principle of the BBZC is explained, and its small signal transfer function is derived. Computer simulations and experimental results of a 65W BBZC as a battery charger are presented to verify the concept of the proposed DIPS charger.