PSO-based LQR gain selection for the stand-alone PV system. This paper uses DC-to-DC and DC-to-AC converters, including a boost converter and a PWM single-phase full bridge inverter. The purpose of these power converters is to fulfill the desired results acquired from the PV, a source. The voltages generated by the PV are regulated using a boost converter that steps the voltages up to the desired level. These DC voltages are converted to AC voltages by passing them through a DC-to-AC converter to supply the load with power, also known as an inverter. Similarly, the battery, as another source in parallel to the PV system, is used to keep the hold on the charges/ energy. A switching topology deals with all modes of conditions into which this system is driven. The power is supplied to and from the PV to the load, to the battery, and vice versa. Furthermore, an algorithm and a controller are used to overcome the fluctuations caused by the voltages. Particle Swarm Optimization (PSO) and Linear Quadratic Regulator (LQR). PSO helps the LQR set the gain to supply the load with constant and desired voltages by providing the best values. Eventually, an impedance model of this entire project is designed to make comparisons and to get fruitful results.