Quzhou, Zhejiang: Ensuring Winter Power Grid Safety—Precision Inspections Build a Robust Regulation and Control Network for Distributed Photovoltaics

"No abnormalities were detected in the temperature and humidity of the equipment room. Attention should be paid to standardizing the labeling of communication optical fibers." On January 6, following the completion of the inspection at Yanqian Photovoltaic Power Station, State Grid Quzhou Power Supply Company successfully finished the patrol inspection and on-site technical services for 24 distributed photovoltaic power stations operating at 10 kV. The company conducted on-site verification and re-testing of the functions of key dispatching network equipment in the stations. This effort consolidated the ability of distributed photovoltaic systems to participate in grid regulation and laid a solid foundation for the safe and reliable power supply during winter and subsequent holidays such as the Spring Festival.

A bird's-eye view of Yougekou Photovoltaic Power Station, Xinchang Township, Quzhou, Zhejiang Province

[Photo by Dong Ruiheng]

With the large-scale coverage of distributed photovoltaics (PV) featuring the so-called "Four Feasibilities"—observability, controllability, measurability and adjustability, the reliability and stability of the regulation capacity of new energy sources have become a critical factor for the safe operation of power grids. Focusing on this key point, State Grid Quzhou Power Supply Company has identified the maintenance and enhancement of distributed PV regulation capacity as its priority work in the near term. During this on-site inspection, technical personnel conducted a comprehensive inspection of key equipment of the PV power stations, including automated communication systems, regulation and control systems, and reactive power compensation devices.

During the inspection, the staff of State Grid Quzhou Power Supply Company conducted in-depth exchanges with the person-in-charge of each power station, and specially emphasized the importance of communication link maintenance. "Most photovoltaic power stations are located in remote or open-field areas, so the physical safety of communication optical fibers cannot be ignored. Effective measures must be taken to prevent interruptions caused by gnawing from wild animals." Meanwhile, in response to the low-temperature and humid environment in winter, the staff urged the relevant personnel to implement proper anti-condensation measures for the equipment, so as to avoid loss of equipment control caused by insulation degradation, component failure or device crash, which would otherwise jeopardize the operational safety of the power grid.

"Having established the 'Four Feasibilities' capacity, it is even more crucial to make full use of it — this is also the key to our recent work," said a representative from the System Planning Department of State Grid Quzhou Power Supply Company. "Prior to New Year's Day, due to a malfunction in network security equipment at the Yougekou Photovoltaic Power Station located on the hills of Xinchang Township, the Automatic Generation Control (AGC) device lost its connection to the dispatching master station, rendering it unable to receive remote regulation commands. In response to this incident, we immediately dispatched technical personnel to provide on-site services and guidance. Working in collaboration with the power station's operation and maintenance team, we analyzed the root cause of the problem and formulated a targeted solution."

This special on-site inspection and technical service initiative is a concrete manifestation of the Company’s implementation of lean management and the proactive shifting of risk prevention and control forward. Through proactive risk identification and on-site guidance, the initiative has not only timely eliminated equipment risks and improved the coordinated regulation level of distributed power sources, but also further strengthened the communication and collaboration mechanism between the power grid and power sources. Moving forward, State Grid Quzhou Power Supply Company will continue to deepen the grid-connection services and operation management of distributed photovoltaics, and continuously consolidate the "protective barrier" for power grid security. With a more reliable power supply, the Company will safeguard the thousands of lights during the Spring Festival holiday and contribute to the high-quality development of the local economy and society.

(Authors: Zhu Tao, Sun Lin)