A comparison between fuzzy logic, and PID controllers to guidance their application in a DC-DC boost converter system with PV source

Abstract

There is a need to integrate alternative sources of energy due to the expected lack of conventional sources, in addition to this energy consumption is expected to grow. Solar photovoltaic (PV) energy has emerged as a highly abundant source, and its use has increased in recent years, but it is important to consider that, as this source produces direct DC power, the voltage regulation is a crucial part in PV systems. To achieve this task PID control is a widely used control technique, however intelligent control strategies have been developed in recent years, among these strategies, Fuzzy Logic Control (FLC) use has been increasing, as it aims to be a simpler control technique. PID and FLC have both been used to control the voltage in PV systems, each of these techniques being capable of regulating the output voltage in DC-DC converters, but both controllers behave differently, and each have their own tuning mechanism, so, in order to prove the performance of both control methodologies, a comparison to differentiate the main features that these controllers can bring in PV systems is required. In this work it is developed a DC-DC boost converter model in MATLAB/SIMULINK, and with the application of optimization algorithms, such as particleswarm, patternsearch, simulannealbnd and genetic algorithms it is tuned the PID gains, and it is developed a PID controller tuned by each algorithm and are compared with fuzzy controllers whose membership functions are tuned with the information obtained by the PID controllers performance. In total 8 different controllers are compared, even though the PID controllers presented lower error values, the FLC’s presented advantages in rise time and settling time reduction, overshoot minimization and ripple limitation in the response. In addition, a robustness analysis of both controller methodologies is carried out, changing the temperature and irradiance from the PV source, and a sensitivity analysis of the controllers changing the voltage reference.