In case of operation of magnetically-saturated controllable reactor (MSCR)

AC and DC are excited together

and the magnetic field distribution of each part of the core is significantly different

which make the analysis and calcultion of the losses very difficult. In this paper

a three-dimensional finite element analysis model of field-circuit coupling is set up based on the prototype of single-phase separately excited magnetic saturation reactor. Firstly

the magnetic field distribution in the iron core is calculated

and the magnetic field distribution and variation characteristics in the typical areas are analyzed. On this basis

the core loss is simulated and calculaed

and the rule that the total loss of MSCR core changes with the load is concluded. The results show that the DC bias component of the magnetic valve increases obviously with increase of the load

and the alternating magnetic field component of the magnetic valve decreases with the increase of the load. Due to the influence of high DC magnetic bias component

the core loss density in the magnetic valve area is always significantly higher than that in other areas

particularly with sharp increase in case of load increase. At the same time

the loss density of the core column nearby also increases significantly

which easily leads to excessively high temperature of the valve column core.