Voltage Stabilization of Electric Vehicle Charger Using Fractional Order PID Controller

Abstract

In this study, a comprehensive analysis of the stability of Phase-Shifted Full Bridge DC-DC converter with zero voltage crossing is carried out by applying PID controller tuned using Ziegler Nichols tuning method, Cohen Coon method and Fractional Order PID controller using Genetic Algorithm optimization technique. First, the system specifications for the fast charging of electric vehicles were defined, from which converter parameters were then calculated. From the converter topology, the ac small signal mathematical model for the system was developed, and the transfer function was computed using the defined converter parameters. The three controllers were then designed and used to develop a closed-loop system. Eventually, system characteristics for stability, specifically the overshoot and speed of response of modelled converter were obtained and analyzed. From the obtained simulation results, the three different control strategies have certain levels of optimization in terms of overshoot and time adjustment, that is, rise time and settling time. Among the three controllers, the effect of PID controller tuned using Ziegler Nichols method was the least. The fractional Order PID controller using Genetic Algorithm provided the highest optimization and yielded satisfactory control performance that met the expected design optimization.