Voltage sensorless grid-forming power converters

Abstract

During the years, synchronization systems in power converter control has been mainly used for estimating the phase angle and the magnitude of the grid voltage, this estimated information is usually used for droop control strategies to ensure power sharing among power converters. Most of existing synchronization systems rely on the voltage measurements at the point of common coupling of the power converter, which may be distorted or unbalanced. This paper presents a voltage sensorless grid-forming structure for power converter in microgrids. By means of reading the voltage reference of the power converter, the system is able to synchronize with the grid. In addition, the virtual admittance compensation provides grid-forming capabilities to the power converter, which can emulate the inertia and damping of the synchronous machine in its synchronization structure, based on the power balance synchronization.