Frequency response characterisation and enhancement The traditional large synchronous machines are phasing out in Denmark, and the main components of the system are offshore/onshore wind farms, solar PV farms, synchronous condensers, HVDC and cable transmission systems. The studies will develop algorithms to quantify the frequency response properties, and design frequency controller at a system level to ensure the security of energy supply. The work will use real time digital simulator as the main tool to perform modelling and simulation. Assessment of short-circuit power/protection system and enhancement The short-circuit power level of future Danish system are evaluated. The impacts from renewable systems, especially large wind farms and HVDC lines, on the prevalent protection systems, including distance relay, differential relay, and overcurrent relay, will be analyzed. The work will use real time digital simulator as the main tool to perform modelling and simulation. Optimal SC properties in a renewable-based system The task develops a systematic method for the best design and tuning of the SC control system to obtain optimal characteristics of the SC for system voltage support against different operating points. The dynamic performances of different types of excitation systems are investigated and compared. The work uses hardware-in-the-loop test by real time digital simulator. Optimal characteristics of synchronous condensers This task focuses on identifying the optimal synchronous condenser characteristics with respect to electromagnetic and mechanical properties and losses and the cost of ownership. |