In recent years, dry-type air core bridge arm reactor is widely used in VSC-HVDC transmission projects. It is easy to cause local overheating due to improper design and unreasonable material selection, which will lead to insulation damage, turn to turn short circuit, and even burnout. Therefore, it is necessary to calculate the temperature field of body winding and metal accessories on bridge arm reactor to check whether they meet the requirements of equipment specification. Based on the thermal field analysis theory, this paper establishes the two-dimensional calculation model of bridge arm reactor body and the three-dimensional calculation model based on metal accessories, and calculates the temperature field distribution of bridge arm reactor body and metal accessories under four working conditions: rated working condition, 50Hz temperature rise current working condition, 100Hz AC load current working condition and 1.2 times rated working condition. In addition, the temperature field of body winding under DC temperature rise current condition is calculated. The calculation results show that the hot spot temperature rise of the body winding is not more than 85K, and the hot spot temperature rise of the metal accessories is not more than 100K, which meets the requirements of the equipment specification. Except for 1.2 times rated working condition, the hot spot temperature rise margin of the body winding is more than 20%, and the hot spot temperature rise margin of the metal accessories is more than 25.2%. At the same time, the temperature rise tests of bridge arm reactor under DC temperature rise current condition, 50Hz temperature rise current condition and 100Hz AC load current condition are carried out, and the temperature rise results of body winding and metal accessories meet the requirements of equipment specification with the margin at least more than 20%.This result shows that the bridge arm reactor body and metal structure accessories do not have the risk of overheating caused by improper design and material selection, which lays a good foundation for the safe and reliable operation of bridge arm reactor.

 

bridge arm reactor, body winding, metal accessories, temperature field, hot spot temperature rise