The feasibility study report of Diluo Hydropower Station, the fourth cascade hydropower station developed in the main stream of Xixi River, has recently passed the expert review organized by the Provincial Development and Reform Commission. Diluo Hydropower Station is located in Butuo County. The site is about 85 kilometers away from the county seat. It is a gate-dam diversion power station. The total storage capacity of the reservoir is 2.72 million cubic meters, and the total installed capacity is 95,000 kilowatts. The total construction period is 35 months. The total investment is 805 million. The development and construction of the power station will inject new vitality into Butuo to build a "power county".

The designed annual power generation of Diluo Hydropower Station is 446 million KWh. The unit wiring method of single unit, single transformer and single bus is adopted. The 220KV bus is connected in sections of the single bus. After the 220KV switch station is merged, the 550kv substation in Puti is merged into the Sichuan main network. 

According to Article 13.1.6 of "The National Energy Administration's Twenty-Five Key Requirements for Preventing Power Production Accidents" (Guo Neng Security [2014] No. 161), the Diluo Power Station of Xixi River Development of China Huadian Corporation stipulates: The connection between the density relay and the switchgear body should meet the requirement of not disassembling the verification density relay. At present, the SF6 circuit breaker density relay of the basin power station does not meet the connection method and inspection conditions required by the countermeasures. It is necessary to improve the online monitoring system of the SF6 density relay of the basin hydropower station, so as to realize the requirement of online detection and verification without dismantling the density relay.

In January 2016, Weavers and China Huadian Xixihe Hydropower Development Co., Ltd. successfully signed the project of "Sichuan Huadian Xixihe Hydropower Development Co., Ltd. Basin Power Station 220kV, 10kV SF6 Circuit Breaker Density Relay Online Monitoring System Transformation" project.
According to the transformation plan:
1. The SF6 density relay is equipped with a combined valve-controlled joint;
2. A new mechanical anti-mislock is installed on the installed combined valve control joint;
3. The installed combined valve-controlled joint is equipped with a rain cover;
4. Check the SF6 density relay.
 

The SF6 density relay transformation scheme, advanced equipment and services provided by Wevers for Diluo Power Station have strengthened the safety and reliability of SF6 electrical equipment and played a key role in the power supply optimization of Diluo Power Station.
 
Weavers' online verification system for SF6 density relay is based on not changing any original structure of the switch, through the SF6 density relay interface on the switch, and adding a combined valve with a breaking device. The valve is designed with The original SF6 density relay interface is equipped with the connector, the SF6 density relay connector, the breaking device and the connector connected with the special SF6 density relay calibrator. After the connection is made according to the design requirements, the on-off of the gas circuit of the SF6 density relay and the gas circuit of the switch body can be realized by rotating the breaking device. When the SF6 density relay needs to be calibrated, it is necessary to rotate the breaking device on the valve body to the closed state, and then connect the calibrator interface with the calibration interface reserved on the valve body to complete the connection, and then the SF6 density relay can be realized. This can greatly save the precious time of maintenance personnel, and can also greatly reduce the risk of SF6 leakage caused by regular calibration and disassembly.