Small Signal Modeling and Controller Design of a Single-Phase Grid-Connected Inverter for Solid State Transformer

Abstract

A battery management system (BMS) is required for safety and efficiency of battery operations. The BMS can protect not only the operating battery but also other system components connected to the battery from electrical damage. This paper proposes the BMS design methodology considering the electrical characteristics of a rechargeable seawater battery. The BMS can accurately measure some significant parameters of battery status information including voltage, current, temperature, etc. Also, it can provide protection functionalities such as over-charge/discharge, over-voltage, over-current, and over-temperature protections. A seawater battery is one of rechargeable batteries such as a lithium-ion battery. Electrochemical operating mechanism of the seawater battery is as follows: first, rechargeable seawater battery uses seawater as the cathode material and second, sodium is harvested from seawater while charging the battery. Finally, the harvested sodium is discharged with oxygen dissolved in the seawater, functioning as oxidants to produce electricity. In this paper, the BMS design methodology will be proposed for suitable functionalities of the power converter consideringthe electrical characteristics of the seawater battery. The proposed design methodology will be verified with simulation results using PSIM software.