Application of a HVDC link to promote stability by sharing dynamic reserve power after generation deficiencies

The Gulf Cooperation Council Interconnection Authority (GCCIA) is installing an HVDC converter station as part of an interconnection of the transmission systems of Kuwait, Saudi Arabia, Bahrain and Qatar. Planning studies indicated a 53% load increase over a 7 year period, hence the need for interconnection of the independent transmission systems to provide mutual support in the event of loss of generation in one network. Since Saudi Arabia operates at 60Hz and the other countries operate at 50Hz, only an asynchronous interconnection is possible. Specific control functionalities have been developed to ensure that the HVDC system can assist in achieving dynamic stability. Nominal power transfer ratings of the link is achieved using two identical 600MW HVDC back-to-back converters, which is an optimum FACTS solution to achieve dynamic stability. However, under (N-l) operating conditions, 1200MW should be quickly available from the HVDC interconnector and therefore three 600 MW poles are installed Innovative control strategies are implemented for automatic reserve sharing, making use of both network voltage control, frequency control and rapid power reversal to ensure reliable operation of the networks. The paper presents the design and simulation work carried out in the development of dynamic reserve power sharing (DRPS) and economic power dispatch (EPD) modes of operation.