An isolated three-port bidirectional DC-DC converter for photovoltaic systems with energy storage

Abstract

Abstract-This paper proposes a new isolated, three-port, bidirectional, DC-DC converter for simultaneous power management of multiple energy sources. The proposed converter has the advantage of using the least number of switches and soft switching for the main switch, which is realized by using a LCL-resonant circuit. The converter is capable of interfacing sources of different voltage-current characteristics with a load and/or a DC microgrid. The proposed converter is constructed for simultaneous power management of a photovoltaic (PV) panel, a rechargeable battery, and a load. Simulation and experimental results show that the proposed converter is capable of maximum power point tracking control for the PV panel when there is solar radiation and controlling the charge and discharge of the battery when there is surplus energy and power deficiency with respect to the load, respectively.

An isolated multiport bidirectional DC-DC converter for PV-battery-DC microgrid applications

“…This paper extends the work in [9] by adding two extra controllable switches on the secondary side of the transformer. The proposed BDC not only is capable of maximum power point tracking (MPPT) control for the PV system when solar energy is available, but also can charge the battery from the PV system and the DC microgrid.…”

“…However, the battery in [7] and [8] had to be charged and discharged within a switching period, i.e., the battery had to be charged and discharged with a high frequency, which is not desired from the perspective of the battery life. Recently, a new isolated three-port BDC was proposed for a PV-battery system [9]. That BDC used the least number of switches among all existing three-port BDCs, i.e., three switches for three ports, to realize the power management for the PV-battery system.…”

“…A number of multiport converters have been proposed for renewable energy systems [2]- [9]. The multiport converter topologies can be classified into two categories: nonisolated topologies and isolated topologies.…”

Modeling and control of a three-port DC-DC converter for PV-battery systems

“…Recently, a new multiport bidirectional DC-DC converter with the least number of switches has been proposed [11]. In that converter, the battery was charged and discharged at a low frequency and the main switch could be turned off under the zero-current switching (ZCS) condition using a resonant circuit.…”

“…In this paper, an isolated three-port DC-DC converter (TPC) is proposed. Compared with the TPC in [11], the proposed TPC has the same number of the switch and all the switches can be turned on under the zero-voltage switching (ZVS) condition. Since a multiport converter is a multi-input multi-output (MIMO) system, a decoupling technique is desired to control different state variables of the system independently [6].…”