An innovative risk control strategy in power systems involving advanced HVDC networks

In the context of power system operation, probabilistic techniques not only can provide a deeper insight into security aspects, by quantitatively considering power system uncertainties and contingency impact, but they can also be helpful to identify and suggest operators the most adequate control actions to reduce operational risk. This paper proposes an innovative risk-based strategy to control the operational risk of High-Voltage Alternating Current (HVAC) power systems connected to Multi-Terminal High-Voltage Direct Current (MT HVDC) networks like those envisaged for the integration of future, large off-shore wind farms. The proposed method minimizes the operational risk by minimizing the overall costs to re-dispatch both conventional generation and power injections from MT HVDC network, also taking into account the operating limits of the HVDC network (in particular, cable current limits). Results of the methodology applied to an IEEE test system and on a realistic power system are presented and discussed, and some conclusions are drawn.