Recently, the Guangzhou Power Supply Bureau's high-reliability intelligent low-carbon micro-grid project was put into operation in Nansha. This is the first batch of new energy micro-grid demonstration projects of the National Energy Administration selected by China Southern Power Grid.The project can ensure that the electricity users automatically leave the large power grid when the large power grid fails, and immediately access the micro power grid that can supply power for one week in less than 0.05 seconds, so as to achieve uninterrupted power supply to the electricity users.

Fast: 0.05 second switching power supply

Recently, the reporter came to the Nansha Training Base of the Technical Training Center of Guangzhou Power Supply Bureau, No. 225 West Huanshi Avenue, Nansha District. The high-reliability intelligent low-carbon microgrid project is piloted here.In the control room lobby, the Guangzhou Power Supply Bureau staff simulated the failure of the large power grid.In the flash, the power displayed on the monitor screen switches from "Grid-connected point (large grid)" to "Storage energy (micro-grid)"All electrical equipment throughout the process base operates as usual, but at this point the power to the pedestal is no longer from a large grid, but a smart microgrid.

“To ensure that power is not affected, the entire switching process must be as fast as 'seamless'.When the external large power grid fails, the microgrid system first intelligently detects the fault and disconnects the large power grid within 0.01 seconds, and then quickly starts the power storage device of the micro grid to supply power, the whole process is less than 0.05 seconds. "Li Tao, Planning Department of Guangzhou Power Supply Bureau introduced，“The main reason for this project to choose Nansha as a pilot is to consider the growing importance of electricity in Nansha, and the large power grid in Nansha is often attacked by natural disasters such as typhoons.”

Low carbon: photovoltaic power supply for microgrid

 The "storage energy" that reporters see on the monitor screen is actually the "big battery" of the microgrid.It is understood that charging this "big battery" is a photovoltaic power station in the base.Li Tao told reporters that in the case of normal power supply to the large power grid, the base photovoltaic power plant will also generate electricity at the same time, some of which are used for large power grids, and the other part is used to charge the microgrid and ensure sufficient storage capacity of the microgrid.  The smart microgrid with photovoltaic power generation as the main energy source has achieved a low carbon clean energy supply."After the success of the pilot, with the increasing popularity of photovoltaic power generation, this smart microgrid can be popularized.The National Development and Reform Commission and the National Energy Administration will have overall arrangements for this project. "

       According to Li Tao, at present, Nansha's photovoltaic power generation is in a leading position in the city. The total installed capacity of photovoltaic power generation in Guangzhou is 248,000 kilowatts, and only Nansha reaches 79,000 kilowatts, accounting for 31.8% of the city's installed capacity.The reporter learned from the Nansha Power Supply Bureau that as of May this year, the installed capacity of photovoltaic power generation in Nansha ranks first in the city. The largest photovoltaic power stations are the photovoltaic power station of Wanqing Shamei, the third production line of Guangqi Toyota, and the East. Electrical photovoltaic power station.

       Environmental protection: using decommissioned batteries for energy storage in the grid.

      "We use decommissioned electric vehicle power batteries for cascade utilization as energy storage devices for smart microgrids to improve resource utilization efficiency and also reduce environmental pollution caused by decommissioned batteries."The energy storage device that Li Tao said is the "big battery" of the smart microgrid, where photovoltaic power is stored.

        According to Li Tao, according to China's electric vehicle power battery technology standards, when the actual maximum charge is lower than the original maximum charge of 80%, the electric vehicle power battery will be forced to retire. Therefore, these increasingly electric vehicle power batteries have become smart micro The object favored by the power grid.“After all, these batteries have nearly 80% of the available capacity, and it is  needed to consider traffic safety of the car, but we can put these decommissioned batteries together for stepping configuration as our microgrid energy storage device.”

        It is understood that the Guangzhou Power Supply Bureau's high-reliability intelligent low-carbon micro-grid project is currently in good trial operation. The next step will be to optimize the system based on the data accumulated during the trial operation phase, and at the same time make further plans for user customization. In order to cope with future social needs.

           By: JUCRO Electric (Focus on Vacuum Interrupter, Vacuum circuit breaker, Vacuum contactor and Switchgear)

           October 2018