Compensated pulsed alternator（compulsator） is an especially designed synchronous alternator

which is commonly used in high-power pulsed lasers

fusion reactors

electromagnetic launchers

and electromagnetic aircraft launch. In general

external excitation is required in compulsator

which not only results in heavy and bulky components but also complicates and reduces the reliability of the system. To improve the reliability and the energy density of the machine

we propose a novel permanent magnets excited compulsator with high power density and relatively simple structure. Meanwhile

we introduce an analytic method to study the machine

and deduce no-load and short-circuit discharge models as simple formulas

which are in good agreement with the finite element method. The machine can be designed and analyzed easily by this analytic method. A scale-model prototype of an external rotor permanent magnetic（PM） compulsator is designed

fabricated

and tested. The actual performances show that the armature inductance of the machine is compensated significantly. The scaled prototype of the compulsator has the capability of exporting high pulsed current

and the pulse shape is consistent with the the oretical analysis.