Grid-connected converters with virtual electromechanical characteristics: experimental verification

Abstract

Abstract-Grid-connected power converters, which are frequently used to link renewable generation plants with the grid, are required to provide a better functionality for large scale integration of renewables. They are expected to be gridfriendly, or even grid-supportive, instead of simply grid-feeding or grid-demanding. This paper designs a synchronous power controller for grid-connected converters in detail, emulating the electromechanical characteristics of synchronous machines and improving even its actual performance, as it is based on a virtual approach. Based on this design, the grid-interfacing units are capable of showing inertia, damping, and droop characteristics as synchronous machines and presenting thus a grid-supporting behavior. The detailed control design and experimental validation on a 10 kW laboratory setup acts as the main contribution of this paper, compared with the existing studies on generator emulation controls.

Virtual Oscillator Control of Equivalent Voltage-Sourced and Current-Controlled Power Converters

“…The idea of virtual admittance is not new in converter controls [21][22][23][24][25][26]. It has been studied for DC systems to create droop phenomena and enforce power sharing in DC [23,27,28] and AC [24,[29][30][31] microgrids, and similarly in battery management systems [22]. Another application is to regulate harmonic voltages in current-controlled inverters [29,32].…”

Artificial Intelligence-Based Control Design for Reliable Virtual Synchronous Generators

“…To increase grid inertia and provide frequency support in the future power electronics based power system, the virtual synchronous generator (VSG) technology has been proposed by mimicking the essential characteristics of the SGs so that the rotating inertia can be emulated in power electronics interface converters [4], [5]. There are various implementations of VSGs in literature, like virtual synchronous machine [6], virtual synchronous generator (VSG) [7]- [9], synchronverter [10], synchronous power controller [11], etc. The inertia characteristics emulated by VSGs can contribute to the total inertia of the grid and enhance the transient frequency stability.…”

“…There are several works discussing the parameter design of the VSG. In [8], [11], the closed-loop characteristic equation of the VSG power loop is derived and a relationship between dynamic performance and deisgn parameters (inertia constant and damping coefficient) is developed. In [12], the coupling effect between active power loop and reactive power loop is analyzed and the inertia coefficient is designed based on the small signal model from the perspective of system stability.…”

An optimal modal coordination strategy based on modal superposition theory to mitigate low frequency oscillation in FCWG penetrated power systems

“…OWER system low frequency oscillation (LFO) stability could be significantly impacted by the increasing penetration level of wind power generation [1][2][3][4][5]. Full converter-based wind power generation (FCWG, i.e., permanent magnet synchronous generator (PMSG)) is very promising to replace other types of wind power generation (such as doubly-fed induction generator (DFIG)) in the future market owing to the rapid development of power electronics [6][7][8]. Due to the completely different physical structure of the wind power generators from the conventional thermal power synchronous generators (CSGs), the high penetration of FCWG, especially the replacement of CSGs with FCWG, may lead to inertia and damping reduction of the multi-machine power system (MMPS).…”