Losses Calculation And Temperature Field Research Of Air Core Reactor

The reactor is important equipment in electric power system, which is applied to compensate the reactive capacity and limit the short-circuit current. Compared with iron core reactor, air core reactor has some advantages. So it is widely used in power systems. In this thesis the calculation of losses and the research on magnetic filed and temperature filed of air core reactor are studied.The scheme of losses separation calculation is proposed according to the calculation of 2D and 3D magnetic field. Firstly, a field-circuit coupled FEM model is established to calculate 2D magnetic field and winding currents. According to the winding currents, the resistance losses which include circulating current losses have been calculated. The eddy current losses in winding had been calculated base on the magnetic flux density distribution in the winding. Finally the calculated winding currents have been taken as excitation to analyze 3D magnetic field of reactor. The 3-D magnetic field and eddy current losses in spider arms can be computed.The heat sources and the cooling conditions of the air core reactor had been analyzed. Taking all losses as thermal sources, the temperature field of reactor has been analyzed and discussed. Air core reactor dissipate its heat mainly through heat conduction inside the reactor,and radiation and convection on surface of the reactor. Two methods have been used to simulate the convection heat transfer on the surface of the reactor. (1)A 3D FEM model is established to calculate 3D temperature field. The convection coefficient of each surface has been computed through iterative calculation. Taking the convection coefficient and emissivity as boundary conditions, the temperature distribution of the reactor has been analyzed using the finite element method. (2) The 2D and 3D fluid-temperature field coupled FEM model have been established to predict the temperature of air core reactor. The fluid field around the reactor and the temperature field in the reactor have been analyzed together to simulate the convection heat transfer on the surface of the reactor. Taking the radiation on the surface of the reactor as consideration, the temperature field of air core reactor has been analyzed.