First Sentence

"The use of permanent magnets (PMs) in construction of electrical machines brings the following benefits: no electrical energy is absorbed by the field excitation system and thus there are no excitation losses which means substantial increase in the efficiency, higher torque and/or output power per volume than when using electromagnetic excitation, better dynamic performance than motors with electromagnetic excitation (higher magnetic flux density in the air gap), simplification of construction and maintenance, reduction of prices for some types of machines."