POWER FREQUENCY MAGNETIC-FIELD MANAGEMENT USING A COMBINATION OF ACTIVE AND PASSIVE SHIELDING TECHNOLOGY

Power frequency magnetic fields are difficult and expensive to shield, particularly when the fields originate from sources with complicated field patterns. A method is discussed and test data presented which su ggests that carefully combining active and passive shielding technique s can produce results which are importantly superior to either techniq ue when used alone. The results are generally consistent with an analy sis which considers sources as a superposition of elementary source fi elds with different order terms.