Complex dual-tree wavelet transform and unified power management based control architecture for hybrid wind power system

Abstract

This study proposes a complex dual-tree wavelet transform (CDTWT) based control technique for a combined sensitive load, battery, and hybrid wind power system (HWPS) to improve the power quality (PQ). To make the system hybrid both DC-grid and AC-grid are connected through two parallel inverters and to circumvent the sudden power demand, it is connected to the main grid. The CDTWT based control technique easily decomposes the non-linear load current into different frequency levels and extracts the fundamental line frequency component for the computation of the actual active current component. In addition to that, to improve the power reliability (PR) and generate the desired current signals, a novel centralized control and power management (CCPM) approach is proposed. The generated reference current is used to coordinate both of the parallel inverters for offering synchronize power flow, regulate the voltage and frequency and offer regardless of switching operation, at both grid supporting and islanding conditions. The MATLAB/Simulink software is used to develop and test the proposed HWPS at different working modes as the failure of one inverter and the sudden addition of two wind turbines at grid-supporting mode and to show battery functionalities at islanding modes of operation. To justify the necessity of the proposed controller, the total harmonic distortion (THD), stability, and advancement of CDTWT results are also presented at different operating modes. From the test results, it is found that with the presence of 20.06% non-linear load current, the overall improvement percentage of inverter and grid current is 96%-97% and 99% respectively. In addition to that, the proposed technique takes only 0.04 s-0.05 s transition time. The above percentages are well within the prescribed limit of IEEE-1541 and IEEE 1547–2018 and are suggested for real-time complex microgrid operation.