Principle analysis and implementation of voltage control of hybrid excitation synchronous generator

A novel hybrid excitation synchronous generator (HESG) was developed to solve the problem that the output voltage is uncontrollable in permanent magnet generator. The magnetic flux distribution of both the permanent magnet section and the excitation section in the HESG were computed using finite element method. According to the demand for the output voltage, a control strategy for the excitation regulation system was made, and the operation process of this system was discussed. To verify the output voltage control capability of the HESG, a 2.5 kW generator and its regulation circuit were designed and produced, and then tested by experiment. The experimental results show that for no-load running, the output voltage of the HESG was equal to the resultant electric potential of the permanent magnet section and the excitation section; and that for load running, the HESG was able to vary the gap flux to maintain the constant terminal voltage (135 V) by adjusting the excitation current as the load increased.