The Equilibrium Points and Stability of Grid-Connected Synchronverters

Virtual synchronous machines are inverters with a control algorithm that causes them to behave towards the power grid like generators. A popular way realize such synchronverters. Their has evolved over time, but all different formulations in literature share same “basic algorithm”. We investigate equilibrium points and stability of synchronverter described by this basic algorithm, when connected an infinite bus. formulate fifth order model for grid-connected derive necessary sufficient condition existence points. show set positive field current is two-dimensional manifold can be parametrized corresponding pair $(P,Q)$ , where notation="LaTeX">$P$ active notation="LaTeX">$Q$ reactive power. This parametrization several surprizing geometric properties, instance, prime mover torque, angle seen directly as distances or angles plane. In addition, stable correspond subset certain angular sector Thus, we predict operating range from its parameters voltage frequency. Our result based on intrinsic two time scales property system, using tools singular perturbation theory. illustrate our theoretical results numerical examples.