State Grid Corporation of China (SGCC), the country's largest power supplier, said Sunday it has put to trial operation a cross-border electricity transmission project in northeastern Heilongjiang province to supply Chinese with Russia's electric power exports.

The electric power SGCC purchased from Russia began reaching Chinese customers late Saturday night after the completion of the direct-current back-to-back networking substation, or called "the trans-Amur project" by Russians, SGCC said in a statement on its website.

The trial operation will last 168 hours, SGCC said in the statement.

With a transmission capacity of 750 mega-watts, the electricity transmission project is China's biggest cross-border power line, according to SGCC.

"The implementation of the project will gain experience for the expansion of Sino-Russian energy cooperation and help promote the economic development for both countries," SGCC said.

The project is also part of the Sino-Russian energy and trade cooperation.

Russian Deputy Energy Minister Andrei Shishkin said in June 2011 that the transmission project would increase Russia's power supply to five or six billion kilowatt hours of electricity to China and Russia intended to increase its electricity supply to China in the coming years.

Russian companies plan export 60 billion kwh of electricity to China by 2020. Power plants will be built along its border with China to reduce power transmission losses and reduce transportation costs.

Also on Sunday, an oil pipeline linking Russia's far east and northeast China witnessed its one year anniversary of operation, as operators announced an accumulated 15 million tonnes of oil had been transported into China in 2011.