CEM’s MOP 1.4 billion Pac On Substation – its third Guangdong-Macao Interconnection – will come into operation tomorrow, giving the city’s power grid a substantial boost.
Pac On, which is now CEM’s largest local substation, was jointly constructed by CEM and China Southern Power Grid.
The new facility is CEM’s first 220kV substation and the first to adopt the one-and-half breaker connection mode, which significantly enhances the reliability of the power supply and the flexibility of operation and dispatch. For every enclosed circuit, three breakers are connected to two busbars – electrical conductors that carry a large current – and two feeders, with each feeder provided with two breakers.
Most importantly, faulty bus bars can be quickly isolated or a failed breaker can be suspended without causing any outgoing line outage, ensuring a reliable supply for consumers.
River Leng Sio Ho, senior manager of CEM’s Primary Substation Construction Unit of the Transmission and Distribution Department, said that after the energisation with the one-and-half breaker connection mode, the power supply capacity of the whole power grid in Macao will be increased by 55 per cent, enabling the local power grid to be stronger and more reliable.
Leng added that the Pac On Substation, which is connected with Yandun Substation in Hengqin, is a key project under the Guangdong-Macao Cooperation Framework Agreement and an important infrastructure linking the Guangdong-Hong Kong-Macao Greater Bay Area. It is connected to 13 sets of high-voltage cables, with a total length of 71 kilometres of indoor low-voltage cables.
Evan Liu Xiaoju, director of CEM’s Power and Networks Dispatch Department, said that in retrospect Typhoon Hato in 2017 had a “certain impact” on Macao’s power supply. However, he pointed out that thanks to the Pac On Substation, if one interconnection fails due to extreme weather conditions, the other two interconnections can now also meet Macao’s basic power needs,The Macau Post Daily reported.
Leng pointed out that nowadays 90 per cent of the electricity consumed in Macao comes from mainland China, while about 10 per cent is being generated by CEM as backup and, therefore, “in the case of electricity failure from across the border, our generators can come into action very quickly to provide power to our system, probably covering about 10 per cent of the local electricity capacity.”
