Control of power electronics-based synchronous generator for the integration of renewable energies into the power grid

Abstract

This paper addresses a single synchronous controller (SSC) for interfaced converters with high penetration of renewable energy resources (RERs) into a low inertia power grid. The SSC is modelled based on a comprehensive dependence between each operative feature of a synchronous generator (SG) and a power electronics converter. This can properly improve the performance of the power grid in such scenarios in which large-scale penetration of RERs are detected. The main contribution of this paper is representing an exhaustive relation between active components of the proposed SSC and SG features which enables the proposed SSC-based interfaced converter to more accurately mimic the behaviour of SGs during active power generating along with providing controllable inertia. Due to containing sufficient decoupling, both components of the proposed SSC have no impact on each other, also the proposed SSC has a superior operational flexibility within a wide range of inertia from very low to high values. Thus, two closed-loop control systems are considered to separately analyse the characteristic effects of SGs in active and reactive power sharing apart from the power grid stability challenges. In addition, the impacts of active power variations on reactive power are subsequently evaluated. To further analyse the operation of the system, the effects of the virtual mechanical power (VMP) error embedded in the SSC are considered as an alternative option for assessing the power grid stability. Also, the variations of the virtual angular frequency (VAF) error are carefully deliberated for more considerations associated with the active and reactive power performance of the SSC. Simulation results are presented to demonstrate the high performance of the SSC in the control of the power electronics-based SG when high-penetration renewable energy sources are integrated into the low inertia power grid.