Analysis and Grid-Tied Implementation of Seventeen Level Utility-Scale SPV Configuration Considering Real-Time Geographical Irradiance

Abstract

A new configuration for integration of large-scale solar photovoltaic plant with a medium voltage (MV) grid (typically 11 kV) is presented. This modular multilevel converter topology uses four cells with 1:3 (trinary) PV voltages in each phase to have seventeen levels in pole voltage. Each module has two PV arrays with six switches to have five levels (0, +V _pv , +2V _pv , +3V _pv , and +4V _pv ). The presented configuration has a lower total standing voltage for higher level switching states. The converter uses new modules to effectively control power in a closed loop and with improved power quality (meeting the IEEE grid code 519). Control for maximum power, inverter-independent power control, and switching control are detailed. A round function-based evaluation is done to switch using the nearest level switching scheme. The converter is tested with a change in the real-weather solar profile. The obtained results manifest that large-scale power is transferred to MV grid perfectly with real-time geographical analysis of Bhadla Solar Park (Latitude: 27.5176° N, Longitude: 71.9304° E). Indices such as global average irradiance test case, direct average irradiance test case, and diffuse average irradiance are used as test cases. Moreover, investigation with European efficiency analysis validates the practicability of large-scale solar PV system.