Research on a permanent magnet passively compensated pulsed alternator with ultra low mutual inductance research on a permanent magnet passively compensated pulsed alternator with ultra low mutual inductance
In this investigation, a permanent magnet passively compensated pulsed alternator (PMPCPA) with ultra low mutual inductance has been designed to provide an electrical pulse with the large power for the load in the shorter period. The electric excitation is replaced by the permanent magnet excitation, the passively compensated mode is adopted, and two-phase symmetrical windings with an electric angle difference of 90 degrees are respectively placed in the stator slots with both deep and shallow specifications to reduce the mutual inductance between the windings. On the basis of design scheme, the inductance of armature winding of alternator is calculated. Both noumenon and short circuit discharge models for the PMPCPA are established to perform the simulation, and the mutual inductance of PMPCPA is measured. The simulated and experimental results show that the present alternator can meet the design requirements, and the effectiveness of method for reducing the mutual inductance is verified.
Simulation research of CPA powered railgun system
The railgun, as a novel kinetic energy weapon, is being taken seriously by each country military. The pulse power source and railgun barrel, directly related to the performance of the total system, are important parts of the railgun system. The compensation pulse alternator, with its high energy storage density and power density, becomes one of the most potential pulse powers. The simulation of the pulse generator powered railgun system is researched in this paper. In order to accurately simulate the characteristic of the railgun system, the time-varying characteristic of the parameters and the kinetic resistance are taken into account in the process of building the raigun model. The railgun model is completed through the Matlab/simulink. The generator model is set up in FLUX. The coupling module between the two softwares is utilized to realize the co-simulation of the railgun system. The simulation results show that the optimum length (the displacement of the projectile exiting the muzzle while the current exactly reduces to zero) of the barrel has the relation with trigger moment of alternator. The velocity of the projectile will decrease when the trigger moment is delayed or the distance between the breech and the armature becomes further.
Experimental study of solid armatures for EML applications
Capacitor-driven railgun test facilities of 150 kJ and 500 kJ with a 15-mm round bore were used to study the behavior of solid armatures. The parameters investigated include projectile design and material testing. It was found that the appropriate projectile design and material choice makes it possible to inject the current at the front side of the projectile and to distribute the current over the whole armature. The electrical resistance of the solid armature can be as low as a few tens of mu Omega , and the rail erosion is significantly lowered compared to the plasma armature tests. The authors also present an acceleration calculation based on current measurements; for a current of 600 kA the acceleration value is about 2*10/sup 6/ m/s/sup 2/. >