This report presents the performance of the Wallgrove grid-forming battery when responding to grid disturbances and modelling studies using synthetic inertia provided by VMM (Tesla’s virtual machine mode).
Report extract
The outcomes of this report show that while the Wallgrove is capable of providing an inertial response, it is not a like-to-like response of that of synchronous generators.
VMM tuning is limited by the GPS requirements, resulting in a trade-off with the battery performance in providing synthetic inertia. Modelling was performed to understand if it is possible to achieve the same response of synchronous machines by increasing the tuning parameters (beyond what is possible to meet the GPS requirements), as well as the effect of the battery size and location. The results have shown that although it is possible to obtain an inertial response as fast as that with synchronous generators, it results in the battery not being able to appropriately ride through faults, resulting in instability.
The conclusion is that although the VMM cannot mimic synchronous generators, it provides a faster response to frequency disturbances. More studies with different technologies and under different conditions are necessary to fully understand the potential of grid forming inverters in providing frequency management services.
