Development Of Dry-type Air-core Reactor Used For Power Distribution Networks

Dry-type air-core reactor has many advantages such as simple construction,high mechanical strength,good linearity,and convenient maintenance.There is a huge variety of dry-type air-core reactors that are used in many fields.Especially,it has been widely applied in electric power system.Air-core reactor used for power distribution networks mainly has several types including current-limiting reactor,series reactor and filter reactor which have effects on limiting short circuit current,restricting switching inrush current of capacitor and filtering power harmonics.Nowadays,these kinds of reactors used expose some problems in design and quality.For the purpose of developing air-core reactor with excellent design and reliable performance,this paper presents the computing method of design of air-core reactor.The inductance,turns and current are calculated and the mathematical model of calculating essential parameters such as losses and temperature rise are discussed.Based on the analysis of the design and quality problems of air-core reactor used for distribution networks,the frame open-type winding structure is introduced.According to the advantages of its structural performance,the frame open-type winding reactor with large current small inductance is proposed in order to solve a range of issues such as encapsulated insulation cracking and aging,noise increasing,and high temperature rise in the closed structure.A improvement method is discussed for the closed structure and applied to the prototype manufacturing.The prototypes of the reactors with open-type and closed structure are respectively designed on the basis of engineering examples.The design parameters of winding structure and calculation method and data of inductance value of the prototype are provided.The process flow and key processes of the two kinds of structural reactors are introduced.The experiment methods,data conversion and analysis are discussed in detail in terms of the parameters paid more attention such as temperature rise,losses and noise.The accuracy of computing method and the feasibility of improvement measures is verified by the data of prototype experiments.Finally,the prototype is put into operation and the operation data is tested to achieve design requirements.This paper proves that the design and calculation methods proposed are reliable and have practical engineering value.