Control of grid-connected power converters based on a virtual admittance control loop

Abstract

The connection of electronic power converters to the electrical network is increasing mainly due to\ud massive integration of renewable energy systems. However, the electrical dynamic performance of\ud these converters does not match the behavior of the network, which is mainly formed by generation\ud facilities based on big synchronous generation systems. Depending on the desired electrical operation\ud mode different control structures can be implemented in the converters in order to get adapted with the\ud grid conditions. However, changing between different control structures and operation is not an\ud optimal solution, as the resulting system results complex and is not highly robust. As an alternative,\ud this paper presents a new control technique for grid connected power converters based on the concept\ud of virtual admittance. The proposed control permits to emulate the electrical performance of\ud generation facilities based on classical synchronous generators with a power converter, with no need\ud of implementing different control structures, giving rise to a system that provides a friendly and robust\ud operation with the network.Peer ReviewedPostprint (published version

Multi‐terminal HVDC grids with inertia mimicry capability

“…The admittance block is more feasible for the realistic implementation compared with the impedance block due to the absence of derivative term that is contained in the impedance block [27] and the simplicity in configuring the converter to be a current source rather than a voltage source. The resistance and inductance of the virtual admittance can be either set according to the predefined values or secondary control layer commands.…”

Synchronous Power Controller With Flexible Droop Characteristics for Renewable Power Generation Systems

“…The overall control scheme of synchronous power controller the virtual admittance structure emulates the output impedance without leading to the difficulties in implementation. The main advantages lay on the effectiveness for the complete range of harmonic frequencies and the simplicity in the inner loop implementation [18].…”

“…According to (18), the virtual reactance for each converter is set to the same per-unit value for a proportional load sharing.…”

“…The virtual admittance structure adopted in [13], [18] is selected as the structure of the inner control loops, which is shown in Fig. 2.…”

Analysis of derivative control based virtual inertia in multi‐area high‐voltage direct current interconnected power systems

“…In most of these applications, the matter of inertia and different control methodologies for providing inertia is missing. Recently, several efforts have been carried out to perform virtual inertia with different control methodologies [22][23][24][25]. This virtual inertia is emulated by advanced control of power converters considering a short-term energy storage [25] which gave rise to the possibility of having a huge amount of converter-based components without comprising the system stability.…”