The application of renewable energy is stimulating since the environmental pollution and the increase in demand for global energy consumption have become the main concerns of humanity. However, the intermittent nature of renewable sources could seriously affect the frequency stability of the system which needs to be solved. In this paper, the Virtual Synchronous Generator (VSG) based on battery/supercapacitor Hybrid Energy Storage System (HESS) is proposed to handle the stochastic power output of Photovoltaic (PV). First, the power allocation methods for HESS and its comparison are illustrated. Second, the comparison of the frequency deviation suppression strategies is presented. Moreover, as the adjustable parameters of VSG (J, D) is a key superior to the conventional synchronous generator; hence, a part of this paper will be introduced a new evolutionary algorithm called Backtracking Search Optimize Algorithm (BSA) to tune the parameters of the VSG in real time. To investigate the control performance, the standalone microgrid is modeled in the MATLAB/Simulink environment. Several case studies are conducted, and the results prove the improvement of the system frequency by attenuating the maximum overshoot of frequency deviation from 50.18 Hz to 50.03 Hz.

A rapid growth in electric vehicles has led to a massive number of retired batteries in the transportation sector after 8–10 years of use. However, retired batteries retain over 60% of their original capacity and can be employed in less demanding electric vehicles or stationary energy storage systems. As a result, the management of end-of-life electric vehicles has received increased attention globally over the last decade due to their environmental and economic benefits. This work presents knowledge and technology for retired electric vehicle batteries that are applicable to the Thai context, with a particular focus on a case study of a retired lithium-ion battery from the Nissan X-Trail Hybrid car. The disassembled battery modules are designed for remanufacturing in small electric vehicles and repurposing in energy storage systems. The retired batteries were tested in a laboratory under high C-rate conditions (10C, 20C, and 30C) to examine the limitations of the batteries’ ability to deliver high current to electric vehicles during the driving operation. In addition, the electric motorcycle conversion has also been studied by converting the gasoline engine to an electric battery system. Finally, the prototypes were tested both in the laboratory and in real-world use. The findings of this study will serve as a guideline for the sorting and assessment of retired lithium-ion batteries from electric vehicles, as well as demonstrate the technical feasibility of reusing retired batteries in Thailand.