Cascaded dual fuzzy logic controller for stable microgrid operation mitigating effects of natural uncertainty in solar and wind energy sources

Abstract

In a microgrid system, the perturbations due to variable solar irradiance, fluctuating wind speed, and even the sudden fluctuation in load lead to the deviation in system voltage, frequency, DC-Link voltage, etc., causing instability. Thus, this paper proposes a robust and adaptive energy management system using the cascaded dual-fuzzy logic-based control approach to mitigate such issues. Besides, the system considers the auto-tuned PI-based voltage regulator with the reference voltage 415 V for inverter control and nine controllable/non-controllable system parameters for the proposed cascaded control approach. The proposed algorithm can control the battery operation, mode of microgrid, and load management to improve stability. It is analyzed for experimental conditions like reduced renewable output, microgrid transition, and unhealthy grid/microgrid conditions. In addition, the proposed method has been compared with the existing control topologies by assessing load voltage, frequency, and DC-Link voltage. The proposed approach has been validated for stable microgrid operation using MATLAB-Software. As per observations, it maintains the limits of 0.25% frequency deviation, 0.57% voltage deviation, and 0.877% DC link voltage deviation, which are acceptable as per IEEE 1547 standard, IEEE 2030 standard, and Indian standard CERC 2011 for the concerned system parameters.

Keywords

• Microgrid
• Renewable power sources
• Fuzzy logic approach
• Energy management system
• Stable operation