Solar Energy has been the most popular sources of renewable energy for residential and semi commercial applications. Fluctuations of solar energy harvested due to atmospheric conditions can be mitigated through energy storage systems. Solar energy can also be used to charge electric vehicle batteries to reduce the dependency on the grid. One of the requirements for a converter for such applications is to have a reduced number of conversion stages and provide isolation. Z-source inverter (ZSI) topology is able to remove multiple stages and achieve voltage boost and DC-AC power conversion in a single stage. The use of passive components also presents an opportunity to integrate energy storage systems (ESS) into them. This paper presents modeling, design and operation of a modified Z-source inverter (MZSI) integrated with a split primary isolated battery charger for DC charging of electric vehicles (EV) batteries. Simulation and experimental results have been presented for the proof of concept of the operation of the proposed converter.
- Active filter
- Energy storage
- Photovoltaic (PV) power generation
- Quasi-Zsource inverter (qZSI)
- Single-phase systems
- Transportation electrification
- Solar energy
- Distributed power generation
Fig. 1. Simplified Block Diagram of the System
EXPECTED SIMULATION RESULTS
Fig. 2. Simulation Waveform of the grid current,Ig, DC link voltage,VPN, Capacitor Voltage,VC1, and Battery current,ib for the power balance between the Photovoltaic input power, the AC Grid side and the battery power.
Fig. 3. Simulation Waveform for the power balance between the Photovoltaic input power, the AC Grid side and the battery power.
A modified ZSI topology has been proposed in this paper is an attractive solution for photovoltaic grid connected charging systems. It consist of a single stage photovoltaic grid (PV-Grid) connection and an integrated charger for PV-Grid connected charging or energy storage. This topology can be applied to centralized configuration for charging in semi-commercial locations such as a parking lot of a shopping mall. For residential applications, this idea can be extended to string inverters with the charger side of the string inverter configurations connected in series or parallel for current sharing. The paper proposes a an energy storage topology using Z source converter through symmetrical operation of its impedance network.
 D. Aggeler, F. Canales, H. Zelaya, D. L. Parra, A. Coccia N. Butcher, and O. Apeldoorn, “Ultra-fast dc-charge infrastructures for ev-mobility and future smart grids,” in Proc. of IEEE PES Innovative Smart Grid Technologies Conference Europe, pp. 1–8, Oct. 2010.
 G. Carli and S. S. Williamson, “Technical considerations on power conversion for electric and plug-in hybrid electric vehicle battery charging in photovoltaic installations,” IEEE Trans. on Ind. Electron., vol. 28, no. 12, pp. 5784–5792, 2013.
 J. G. Ingersoll and C. A. Perkins, “The 2.1 kw photovoltaic electric vehicle charging station in the city of santa monica, california,” in Proc. of the Twenty Fifth IEEE Photovoltaic Specialists Conference, pp. 1509– 1512, May. 1996.
 S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “A review of single-phase grid-connected inverters for photovoltaic modules,” IEEE Trans. on Ind. Appl., vol. 41, no. 5, pp. 1292–1306, Sep. 2005.
 N. A. Ninad, L. A. C. Lopes, and I. S. Member, “Operation of Single-phase Grid-Connected Inverters with Large DC Bus Voltage Ripple,” Proc. of the IEEE Canada Electrical Power Conference, 2007.