Static and dynamic evaluation of different architectures for an actual HVDC link project

The employment of High-Voltage Direct Current (HVDC) transmission in modern power systems is mainly driven by requirements of increasing power transfer over high distances in a cost-efficient and controllable way. HVDC control can ensure fast and accurate power flow control to improve the whole system performance as well as increased flexibility to manage power flows from remote renewable generation to load centers, especially in a zonal market configuration. However, in the network planning phase the implications of a new HVDC connection, both on the steady-state and on the dynamic operation of a power system, must be carefully evaluated with particular reference to possible outage events, depending on the operating conditions and on the exploited control schemes. In this paper, a real HVDC project within the Italian transmission network is considered in both the Voltage Source Converter (VSC) and Line Commutated Converter (LCC) technologies. The study implies a methodology to analyze the impact on steady-state and dynamic performances in the presence of faults, with a focus on grid security and market efficiency aspects. The behavior of the interconnected Italian power system is simulated in a development planning viewpoint by means of software tools exploited by the System Operator.