A Closed-Loop Virtual Synchronous Generator for Enhanced Stability in Islanded Solar Power Systems: Advancing Sustainable Energy Transition

Traditional thermal power plants operate with high inertia with the rotating synchronous machines and seamlessly manage real time disturbances such as load and generation variation, electrical faults etc. Solar integrated isolated power networks, however suffer from low inertia in addition to weather dependent unpredictable intermittent generation. The traditional way of improving inertia includes physical deployment of DC motor and Synchronous generator set which is less efficient and costly. This paper revisits an alternative approach to solve this problem using Virtual Synchronous Generators (VSGs) to promote a sustainable renewable energy (Solar) based transition of power system networks. The work presents real time integration of solar operated power network with VSG to demonstrate improvement of transient stability and thus inertia virtually and efficiently. The work also shows that the virtual DC motor part of hardware in loop (HIL) system of VSG can be effectively used to regulate the performance of the real power network more efficiently by a closed loop VSG supported by a Proportional plus Integral plus Derivate (PID) controller. The whole work has been conducted in MATLAB SIMULINK primarily with encouraging results, motivating towards its hardware implementation.