Rotor Winding Design and Standalone Operation Research of High Natural Synchronous Speed Brushless Doubly-Fed Generator Based on Differential Modulation

Differential modulation brushless doubly-fed machine (DMBDFM) can achieve a smaller equivalent pole-pair number (PPN), which broadens the operating range and application of brushless doubly-fed machine (BDFM). However, the existing basic theory of BDFM cannot be directly applied to DMBDFM, and the design method of the modulated rotor with different combinations of PPNs is not complete. Therefore, to achieve the highest natural synchronous speed (
n
_s
) of BDFM at power system frequency, the rotor winding of 3/2 pole pairs is designed in this article. Then, the test prototype is developed with the designed rotor scheme and the relevant parameters are given. The validity of the rotor design scheme is verified by finite element simulation and test results.