Enhancing Renewable Energy Integration with Grid-Forming Converter-Based HVDC Systems: Modelling and Validation

Abstract

Pollution free renewable energy sources are key solutions for increasing power demand. Unpredictable nature of power electronic based renewable energy sources impacts negatively on grid voltage and frequency profile. Energy storage is one of the solutions to overcome fluctuating power generation from renewable energy sources. Shorter life span of energy storage makes it costly. Grid forming control is another solution to overcome fluctuating power generation from renewable energy sources. Grid forming converters can regulate voltage and frequency of existing grid by regulating output active and reactive power. Grid forming converter can also form the grid for the remote area where the loads are isolated from utility grid. To regulate output active power grid forming converter also require energy storage when utilized with renewable energy sources. High Voltage Direct Current (HVDC) with one of the converters operating under grid forming mode can supply large isolated load. Renewable energy sources which is operating under grid following mode can also be integrated with High Voltage Direct Current (HVDC) with one of the converters operating under grid forming mode. In this research work, capability of grid forming converter based HVDC in varying load condition has been verified. To understand the effect of integration of renewable energy with grid forming based HVDC, Doubly Fed Induction Generation (DFIG) based wind turbine has been integrated. To validate the capability of grid forming converter based HVDC modelling has been done in Simulink/MATLAB. Results show that Grid forming converter based HVDC system is capable to fulfil the load demand in varying load/generation condition.