Photovoltaic Burp Charge System on Energy-Saving Configuration by Smart Charge Management

Abstract

To achieve pulse charge using direct photovoltaic (PV) energy, it is necessary to keep the energy supply from PV module continuous and optimum, especially to prevent energy supply from interrupting during the pulse break period. To perform the mentioned idea, a PV burp charge system (PV-BCS) proposed is to make PV energy pump continuous with optimum maximum power point tracking (MPPT), which increases the PV utilization, and to dispatch the remaining PV energy for further storage in the pulse break period. A smart charging management (CM) presents three kinds of charge statuses, a burp pulse (BP) charge and two pulse charges, which charges three batteries, Bm, B1, and B2 concurrently and individually. The two pulse charges provided are for accompanying the BP charge in order to keep the PV energy supply continuous and cherish the remaining energy for further storage. The BP charge for Bm is composed of a positive pulse (PP) charge in a positive burp pulse (PBP) period and negative pulse (NP) charge in non-PBP period. The other two batteries B1 and B2 are always with PP charge in the non-PBP period, in which B1 charges the remaining PV energy to keep the PV energy supply continuous, realizing the energy treasuring concept; B2 charges the discharge amount from Bm by intensely discharging, which indeed is equivalent to the NP charge, achieving the energy recovery concept. A laboratory prototype, 250-W PV-BCS, with elaborated simulation and experiment demonstrates the proposed concurrent charging idea, which is feasible for conceiving an energy-saving concept, especially applicable in a large-scale energy management for such as battery exchange station to electric vehicle service. In addition, the PV-BCS can be further as a hybrid charger for renewable energy application if additional renewable energy is mixed with the PV energy, such as wind energy.