Saudi Diesel Equipment Co has signed a contract to supply diesel generators (DGs) to Yanbu power station, which is on the Red Sea coast of Saudi Arabia and is the nerve center of the Kingdom’s petrochemicals industry.
Entrusted with the task, Saudi Diesel opted for alternators from Nidec Leroy-Somer, its trusted supplier.
The power station caters to the region’s total electricity demand. In case of any unexpected shutdown, the GTGs are restarted by DG sets designed specifically for Black Start applications.
One of Yanbu’s critical installations is the power station, which has several Gas Turbine Generators (GTGs) with a total capacity of 524.6MW.
The GTGs are equipped with DOL starter motors of 600kW, a 4.16kV rating, and the starting current is very high, which means there is a huge inrush current experienced by the alternator.
The DG set first acts as a Black Start and is primarily responsible to start the turbines that are down or under planned maintenance shutdown.
The DG set is also used to feed auxiliary loads in case the need arises – emergency loads other than the turbine load – before or after the Black Start, till such time the turbines take over the full load.
Nidec Leroy-Somer also used the latest D550 digital AVR, which is ideal for parallel genset operation. The AVR also has a wide range of functionalities including online monitoring with manual and remote controls.
The two alternators were designed and manufactured after a thorough calculation of all electrical parameters following detailed discussions with the client before finalizing the design.
Once assembled, the alternators were tested and approved by Saudi Diesel along with third party inspectors, a prerequisite for any machine exported to Saudi Arabia.
Commenting on the development, Nawar Shubber, Regional Sales Manager at Nidec Leroy-Somer, said, “Any application that involves a power plant is very critical, because in case of a shutdown, the unit has to restart and come online as fast as possible, and these are very heavy turbines, each of 50MW.
He said, also they must run to a synchronous speed before energizing the equipment and connecting to the grid. That is the critical part – getting the GTGs into a synchronous speed before connecting to the grid.
Echoing similar sentiments, Kathim Alrifai, Project Manager at Saudi Diesel Equipment Company said, “Enclosures for the entire generator set, fabricated locally, contain UL-motorized louvers for totally enclosed operation during shut-down. The package is designed as a gas-tight enclosure while the fire alarm and suppression systems in these units are tested in accordance with NFPA 2001 and BS EN 15004-1.