Robustness analysis of PID controller Bidirectional SEPIC/Zeta for Energy Management in DC Nanogrid Isolated System

Abstract

Renewable energy is needed to reduce sources of electrical energy utilization derived from coal and fossil fuel. Photovoltaic is a component of renewable energy that used sunlight to produce electrical energy. The problem that occurs in photovoltaic is the output power that changes depending of light intensity. That problem causes the output power in the Photovoltaic to supply the load to be unstable due to changes in sunlight The solution of the problem is using the bidirectional converters. The bidirectional converter are currently widely used to store excess power in energy storage system and keep output voltage of the system on stable condition. Therefore this problem requires a good control to be applied to the bidirectional converter. The PID controller can be applied to the bidirectional converter to keep the voltage on the DC bus steady at the set point. Therefore, this paper proposed the performance of bidirectional SEPIC/Zeta converters using PID controller to solve that problem. The experiment result shows the PID controller can keep the DC bus voltage in stable condition. Average time speed to reach set point when charging mode is 1,024 ms with average error is 0,08%. On the other side average time speed to reach set point when discharging is 1,288 ms with average error is 0,6012%.