Enhanced Power Multiexcitation Brushless DC Generator Using Parallel Magnetic Circuits

This article proposes a brushless multiexcitation generator (MEG) using parallel magnetic circuits for dc power system with enhanced output power capability. The multiexcitation sources include permanent magnets (PMs), dc excitation, and ac excitation. The key is that an appropriate ac excitation field is constructed and combined with the PM and dc excitation fields, thus realizing field enhancement, armature reaction compensation, and output power improvement. Additionally, the ac excitation power is extracted from the PM field of the MEG by utilizing the decoupled parallel magnetic circuits, realizing self ac excitation. The dc excitation winding and the diode rectifier are retained, ensuring good generator system reliability. In this article, the operation mechanism of the proposed multiexcitation scheme is deduced and revealed. To evaluate the power enhancement of the proposed method, the MEG is compared with an existing dual-excitation generator. At last, experiment results verify the proposed method.