Along with the prolonged operation of dry type of reactor, insulation problem is exposed gradually, and the faults occur successively, which causes the certain influence on safe and stable operation of power system.

The dry-type smoothing reactor is one of the most important equipments for the ±800kV UHVDC transmission project, and its fault will result in the outage of one pole immediately because two 150mH smoothing reactors are installed at the neutral bu.

Dry hollow reactor is an inductive device of the electrical power system, which has important roles in many respects such as current limiter, regulator, reactive compensation, and so on Dry Hollow Reactor is one of the new type reactors which was developed in recent years.

Development and application of design software of dry-type air-core reactor;

Analysis on tree discharge on the surface of dry-type air-core reactors is made through a series of characteristic tests on breakdown of epoxy resin compound insulation, surface discharge test on reactor model, electric field calculation Of insulation structure and study on monitoring and prevention of surface discharge on reactors.

With the parameters of a real dry-type air-core reactor, the emulation analysis verifies that the impulse-voltage method is suitable to test its turn-to-turn insulation.

On the basis of comparison of three methods analytic method,numerical method and mixed method,the detailed analysis and calculation of the eddy losses of the dry type air cored reactor is provided using the mixed calculating method.