Recently, the localization retrofit project for the main distributing valve of the turbine governor system at Huaneng Lancang River Xiaowan Hydropower Station successfully passed acceptance and entered stable operation. The key performance indicators of the upgraded equipment are better than national standards and comparable international products, marking an important achievement in the localization and independent control of key hydraulic components for high-head, large-capacity hydropower stations.
As one of the core hydraulic components in a hydro turbine governor system, the main distributing valve plays a critical role in converting electrical control signals into hydraulic execution signals. It directly affects unit speed stability, servomotor response, and power regulation performance. For a long time, this type of key component was mainly supplied by overseas brands, bringing challenges such as high procurement costs, long maintenance cycles, and limited adaptability to specific operating conditions.
To address these challenges, Huaneng Lancang River Hydropower Co., Ltd. worked with Nengshida Electric Co., Ltd. (“NSD Electric”) to establish a dedicated technical team. Based on the operating conditions of Xiaowan Hydropower Station’s 700 MW-class units, the team carried out systematic technical research, product adaptation, testing, and on-site retrofit work.
Drawing on successful experience from the localization retrofit of mechanical systems at the Three Gorges Hydropower Station, one of the world’s largest water conservancy projects, the NSD Electric project team developed a technical solution tailored to Xiaowan Hydropower Station’s high-head and large-flow operating characteristics.
The project adopted NSD’s independently developed WT-type main distributing valve. By optimizing the internal flow channel structure of the valve and building the control logic based on a domestically developed independent processor, the project achieved 100% localization of key components, including the main distributing valve.
After 72 hours of continuous trial operation, the retrofitted main distributing valve demonstrated strong performance. The neutral-position leakage was reduced by 95%, the servomotor dead time was shortened to within 0.19 seconds, and both control accuracy and operational stability reached an advanced level. At the same time, the overall equipment cost was reduced by more than 50% compared with imported alternatives.
The successful localization retrofit of the main distributing valve at Xiaowan Hydropower Station not only improves the independent supply capability of core components for 700 MW-class hydropower units, but also provides a replicable and scalable technical reference for the localization of key equipment in large-scale hydropower projects.
For existing hydropower plants, equipment localization and retrofit are becoming increasingly important for improving maintainability, reducing long-term operating costs, shortening spare parts delivery cycles, and enhancing equipment adaptability. This project demonstrates how targeted engineering innovation can support the long-term safe, stable, and efficient operation of hydropower units.
NSD Electric will continue to promote the application of localized and independently controllable hydropower control equipment across major river basin power stations. By advancing technology transformation and engineering application, NSD aims to support the upgrading of China’s hydropower equipment industry and contribute to the construction of a new energy system with stronger technical foundations.
Learn more about NSD hydropower control solutions or contact us to discuss your retrofit, spare parts, or technical service requirements.
