Research on Magnetic Energy Recovery of Pulsed Alternator in Separate Excitation Mode

Pulsed alternator is widely concerned in the field of pulse power supply, and the heat generation of the field coil is an important reason for the temperature rise of the rotor, which is unfavorable to the thermal management of the pulsed alternator. Therefore, a parallel excitation and serial recovery magnetic energy recovery topology for the separate excitation pulsed alternator is proposed in this article. In contrast with the conventional (no recovery) topology, there are two changes in this topology. One is that the diode is replaced by a thyristor in freewheeling circuit, which can realize the switching of the field current from the freewheeling state to the recovery state. The other is that serial recovery topology is used, which can realize the rapid recovery of magnetic energy. First, the analytical expressions of the field current and the pulse capacitor voltage are derived under the three states of parallel excitation, freewheeling, and serial recovery. Second, four performance parameters for evaluating topology are derived based on the obtained analytical expressions. Third, the influence of the number of serial modules $n$ on the four performance parameters is analyzed. Finally, the maximum value of $n$ is solved, and the simulation models under different $n$ values are built. The simulation results verify the correctness of the analytical model and the benefits and losses of the magnetic energy recovery topology are discussed.