DC Link Voltage Enhancement in DC Microgrid Using PV Based High Gain Converter with Cascaded Fuzzy Logic Controller

Abstract

Renewable-based sources can be interconnected through power electronic converters and connected with local loads and energy storage devices to form a microgrid. Nowadays, DC microgrids are gaining more popularity due to their higher efficiency and reliability as compared to AC microgrid systems. The DC Microgrid has power electronics converters between the DC loads and renewable-based energy sources. The power converters controlled with an efficient control algorithm for maintaining stable DC bus voltage in DC microgrids under various operating modes is a challenging task for researchers. With an aim to address the above-mentioned issues, this study focuses on the DC link voltage enhancement of a DC Microgrid system consisting of PV, DFIG-based wind energy conversion system (WECS), and battery Energy Storage System (ESS). To elevate PV output voltage and minimize the oscillations in DC link voltage, a high-gain Luo converter with Cascaded Fuzzy Logic Controller (CFLC) is proposed. Droop control with virtual inertia and damping control is proposed for DFIG-based WECS to provide inertia support. Artificial Neural Network (ANN) based droop control is utilised to regulate the ESS’s State of Charge (SOC). The effectiveness of the proposed converter and its control algorithms for maintaining stable DC bus link voltage has been analysed using MATLAB/Simulink and experimentally validated using a prototype model and FPGA Spartan 6E controllers.

Anti-Interference Control Method of Buck–Boost Converter Based on High-Order Nonlinear Disturbance Observer

“…The PID control method is simple in design and easy to implement in practical applications, but when there are disturbances in the system, it will affect the robustness of the system. Fuzzy control has a strong nonlinear adaptive ability [10], which can overcome the shortcomings of the traditional PID controller, but cannot overcome the influence of load uncertainty in the Buck-Boost converter. Sliding mode control [11] can solve the problem of model uncertainty, but it will lead to the chattering of output voltage [12], and variable switching frequency will lead to electromagnetic interference [13], so the system has a steady-state error.…”