Kehua's Solution Refreshes the Altitude Record of Energy Storage


In the Ali networking project, which is the world's ultra-high-altitude and extremely difficult power transmission and transformation projects, power lines are erected at the place closest to the sky, so that 380,000 herdsmen along the project can use stable and reliable large-scale grid power. On the snowy plateau, the light lit up and changed the world. This historic leap is due to the commissioning of the six substations of the Ali Networking Project.

Kehua participated in the energy storage projects of two 220kV substations in Saga and Zhongba in the Ali networking project. The substations reach 4,688 meters and 4,576 meters above sea level respectively. The average temperature is 0-5°C, the temperature difference between day and night exceeds 25°C, and the air oxygen content is only 50-60% of that in the plain area. Even machinery fails due to "altitude sickness". Not only are builders challenging the limits, but energy storage technology, equipment safety, and reliability are also facing severe tests.

Relying on nuclear-class quality equipment and a comprehensive service system, Kehua has provided advanced technology, stable performance, safe and reliable, high-altitude, low-temperature-resistant energy storage conversion and energy management solutions for project design. The world's rare super-difficult power transmission and transformation projects are escorted.




Project: Energy Storage Project For 220kV Substations In Saga And Zhongba

Location: Saga County/Zhongba County, Shigatse City, Tibet Autonomous Region

Installation: 1MW/6.32MWh

Grid connection time: November 2020

For Saga and Zhongba 220kV substation energy storage projects, each substation is equipped with a 500kW/3.16MWh emergency power storage system, with a total project capacity of 6.32MWh. Kehua design without derating at an altitude of 4000 meters above sea level. The system fully considers the parallel current sharing design of multiple clusters of batteries, especially the application problem of matching a single PCS with an AC switch cabinet and a DC combiner cabinet. The PCS adopts a built-in isolation transformer solution, which saves on-site installation and wiring time, and solves the engineering application problems of energy storage in the snowy plateau area.

In order to ensure the reliability of power supply, Kehua has configured a considerable-scale energy storage battery system for each substation. The system includes 5 battery clusters, which are fed into 500kW PCS through 2 sets of 3-to-1 DC combiner cabinets. The PCS outgoing wires are connected to the station power system through a 400V isolation transformer. The 400V output side of the isolation transformer is equipped with an AC cabinet. The cabinet meets the output of two independent circuits, which are respectively connected to the emergency power bus for the station.

As a backup emergency power supply for substations, Kehua Energy Storage System uses lead-carbon batteries to replace traditional lead-acid batteries, which improves system reliability and has a longer life. When the station electricity is in normal operation, the station electricity is given priority to independently supply power to the load. When the power grid fails, the energy storage system switches to the off-grid operation mode, and the energy storage system supplies power to the substation load.

The Saga and Zhongba 200kV substations are currently the highest 220kV substations in the world. With the implementation of the project, the altitude record of the world's ultra-high voltage power grid energy storage construction field was refreshed by Kehua Digital Energy, and it also brought a breakthrough demonstration significance for the energy storage business in the field of high altitude, low temperature and strong wind resistance. 

Read More >