COMBINING PERMANENT MAGNET AND ELECTROMAGNET IN MOMENTUM REMOVAL METHOD FOR EARTH-POINTING SATELLITE

A new approach for optimal designing for removing the momentum of reaction wheels system for satellite is presented in this paper. In this approach designing of electromagnets(EMs) and permanent magnets(PMs) are considered together. In order to model the effect of PM, the geomagnetic field estimated by a new method. In this method to reduce the required momentum of wheels to a desired value, we can determine the PM and EM values by simple calculations. Altogether comparing with a system which does not contain PMs, this method reduces needed sum of the magnetic moment, the sum of the capacity of wheels, volume and weight of magnetic coils control system, and consuming electric energy, very much. At the end of the article the two methods are compared and the simulation results, shows the advantages of the suggested method.