The State Grid Zhejiang Power Supply Company recently installed a series-connected grid-level voltage regulation device on the low-voltage line of the village public transformer in Shencun village, Yunhe county, Zhejiang province, to stabilize the voltage for end-users in small-scale substations. This marks a milestone for the company in enhancing the quality of electric energy for users.

With the widespread access of new sources and loads such as distributed photovoltaics and electric vehicle charging facilities, the issue of "bidirectional overvoltage" in small substations is becoming increasingly common.

Taking Shencun village as an example, the substation there has distributed photovoltaic access and a large number of new energy charging piles for homes. During the midday peak period of distributed photovoltaic power generation, the voltage on the local area network lines in Shencun village can reach up to 245 volts, while in the evenings when a large number of home charging piles are in use, the user voltage can drop to as low as 180 V.

To meet the rapid development needs of new energy sources, the State Grid Zhejiang Power Supply Company has conducted in-depth data analysis and pilot practices, developed series-connected infinite regulation devices to address the issue of bidirectional overvoltage caused by distributed photovoltaic access and concentrated end loads. At the same time, this device can assist in the comprehensive management of reactive power compensation, harmonics and three-phase imbalances, to further enhance the stability of the mountainous power grid operation.

In the future, the State Grid Zhejiang Power Supply Company said it will focus on the adoption of intelligent tools, comprehensively consolidate and improve the quality of electric energy for users and take new steps to provide high-quality electricity services.