Droop vs. virtual inertia: Comparison from the perspective of converter operation mode

Abstract

This is a repository copy of Droop vs. virtual inertia: Comparison from the perspective of converter operation mode.

LQR-Based Adaptive Virtual Synchronous Machine for Power Systems With High Inverter Penetration

“…Furthermore, we incorporate the impact of grid-forming converters, as they are the only type of PE-interfaced units providing frequency support [3], [15]. A particular focus is set on droop and VSM-based control schemes, as two of the currently most prevalent emulation techniques in the literature [5], which in fact have equivalent properties in the forming mode of operation [16]. Hence, the set of grid-forming converters providing either droop…”

“…with f n denoting the nominal frequency and γ mimicking the traditional composite frequency response characteristic (β) of synchronous generators in a low-inertia system; P l0 and D l are the load power at nominal frequency and its sensitivity to frequency changes, whereas R ci = D −1 ci is the respective droop equivalent of a VSM-based controller [16]. The traditional generators are omitted from the computation of γ due to high time constants and a significantly slower frequency regulation compared to VSCs.…”

“…The complete mathematical model consists of 13 states and is implemented in per unit. More details on the overall converter control structure and employed parametrization can be found in [15], [16], [20].…”

Interval-Based Adaptive Inertia and Damping Control of a Virtual Synchronous Machine

“…impact of grid-forming converters, as they are the only type of PE-interfaced units providing frequency support [2], [14]. A particular focus is set on droop (j ∈ N d ) and VSMbased (k ∈ N v ) control schemes, as these are two of the currently most prevalent emulation techniques in the literature [15], which in fact have equivalent properties in the forming mode of operation [16]. Here, T cm are the time constants of the converters, R cj and K cj are the respective droop and mechanical power gain factors, whereas M c k and D c k denote the normalized virtual inertia and damping constants of VSM converters.…”

Fast Frequency Control Scheme through Adaptive Virtual Inertia Emulation

“…∆M max = 0.5M 0 . The employed controller model is obtained from the following equivalence between an emulated virtual inertia and a standard droop control [12]:…”