[1] These devices lack the intrinsic behaviors (like the inertial response of a synchronous generator) and their features are almost entirely defined by the control algorithms, presenting specific challenges to system stability as their penetration increases,[1] for example, a single software fault can affect all devices of a certain type in a contingency (cf.
[5] The GFL devices cannot contribute to the grid strength, dampen active power oscillations, or provide inertia.
Unlike a conventional generator, the GFM device has no overcurrent capacity and thus will react very differently in the short-circuit situation.
[1] Adding the GFM capability to a GFL device is not expensive in terms of components, but affects the revenues: in order to support the grid stability by providing extra power when needed, the power semiconductors need to be oversized and energy storage added.
Incidences of disconnections during contingency events where the fault ride through was expected, and poor damping of subsynchronous oscillations in weak grids were reported.