A hybrid harmonic mitigation strategy for smart grid integration of solar PV systems in developing power networks

The world shift to renewable energy has drastically changed the power system models due to climate concerns and decarbonization efforts. Solar PV has emerged as one of the renewable technologies because of its cost that is falling steadily, scale, and negligible environmental impact. Nonetheless, the consideration of solar PV in ageing grid systems, especially in developing countries presents technical issues, the most prominent of which, the harmonic distortion by power electronic converters in full interaction with the nonlinear loads. This causes instability of voltages, decreases equipment longevity and system performance. However, smart grid technologies provide advanced control and sensing capabilities, however, the implementation of smart grids in resource-constrained environments is minimal at the moment. This paper puts forward a hybrid harmonic mitigation approach which is weak grid specific and involves a combination of optimized Maximum Power Point Tracking (MPPT), Proportional-Integral (PI) control as well as a two-stage passive-active filtering system. It has been proven with simulations in MATLAB/Simulink that inverter synchronization, dynamic response and uniform Total Harmonic Distortion (THD) reduction to 5% or below, require better inverter synchronization, better inverter operation and constant simulation results, as indicated by Fast Fourier Transform (FFT) analysis under different load conditions and all of these are within the standards of IEEE 519. This contributes to the reason why the proposed system is a cost-effective and scalable solution to the utilities in the emerging economies, especially due to its modular nature that enables its implementation to happen in phases. The publication adds a viable platform to improve the level of power and stability during the shift toward cleaner and smarter energy systems.