Traditional fossil energy sources are increasingly exhausted, leading to the need for mankind to exploit alternative energy sources; and solar energy can be viewed as infinite. Solar photovoltaic and its applications are increasingly widely studied. However, due to its nonlinearity and unstable nature, high technology is required to achieve good conversion efficiency. One of the techniques to optimize solar cell efficiency is to use the Maximum Power Point Tracking algorithm (MPPT) and P&O is a relatively easy algorithm to implement. This article will present some problems about photovoltaic cells, power converters in solar power systems and using PSIM software to simulate an independent solar system with several harvesting solutions for solar power and compare the efficiency of them.

SARSCOV-2 virus and new strains have been spreading in most countries and regions around the world, the COVID-19 epidemic it causes has infected millions of people, the urgent need is to prevent their spread. On the market there are many types of hand wash equipment automatically spray disinfectant solution used with many different sensors and operating principles, but most are still using AC power. In this topic, we design automatic hand washing equipment by applying the transmitter and receiver principle of the moving infrared sensor circuit and delay relay circuit to detect someone appearing in the observation area, click activating the MP3 reader circuit plays the “5K” propaganda sound about Covid -19 disease prevention and the position sensor activates the mini-pump to spray the hand-washing gel within a certain detecting distance. We have conducted experiments and completed our projects with devices that use energy from solar cells, through charging circuits and storage batteries with the goal of using renewable energy, minimizing impact of the greenhouse effect.