Improvement of Integrated-Induction-Based Hybrid Excitation Brushless DC Generator by Employing Novel Consequent-Pole Rotor

In order to achieve both the brushless excitation and flexible regulation of output voltage, the integrated-induction-based hybrid excitation brushless dc generator (II-HEBDCG) combining the main generator part with the induced excitation part is presented in this article. Moreover, the novel consequent-pole rotor featuring the pole sequence of iron-S-iron-iron-N-iron (I-S-I-I-N-I) is proposed to enhance the flux regulation capability because each coil of the main field winding (MFW) can regulate the flux of two iron poles simultaneously, where the flux paths of permanent magnet and MFW exhibit in parallel. The selection rules of pole and slot combination are summarized theoretically, and the principle of flux regulation is revealed based on the equivalent magnetic circuit, which are confirmed by finite element analysis. Then, the influences of key parameters on the performance are discussed. Furthermore, the electromagnetic performance of the proposed II-HEBDCG with the pole sequence of I-S-I-I-N-I, including the no-load flux density distribution, no-load voltage regulation, output characteristics, loss and efficiency, are comprehensively investigated and compared with that of the II-HEBDCG with conventional pole sequence of N-iron-iron-iron. It is demonstrated that the proposed II-HEBDCG obtains not only better flux (or voltage) regulation capability but also higher output power, and hence, obtains higher efficiency than the conventional one. Finally, a prototype is built and tested to verify the analyses.