Stabilizing Power of Grid-connected Power Systems

Inhalt:
This paper proposes a generalized method to quantify the power response (stabilizing power) of grid-connected power systems using instantaneous time-domain power definitions. The changing structure of today’s electric power grids requires this generalization, because of an increasing share of power-electronic converters (PEC). At a relevant PEC-based power contribution, they have to assist synchronous generators (SG) to provide the required stabilizing power in case of disturbances. Due to different properties of SG and PEC such as system time constants as well as current, energy and power limitations, the power response of PEC-interfaced power systems cannot be quantified adequately by the well-known concept of SG, often referred to as inertia response. Therefore, this paper proposes an instantaneous method, which is independent of time constants, applies to arbitrary power systems and reveals their non-linearities. As a special feature, this method can distinguish the stabilizing power regarding the use of energy or power reserves of a power system. This supports the specification of grid-forming and grid-supporting properties in grid-planning applications. The proposed definitions can be applied to simulations and real systems. A simulative study verifies the definitions and illustrates their implications.