Power Decoupling Control of Permanent Magnet Generating System

Permanent Magnet (PM) Machine based S/G system has huge advantages in terms of efficiency, power density, power-weight ratio, power quality and EMI. With the development in PM machine design and power electronics technology, PMS/G system is gaining more attention not only in low-power subsystems, but also in primary high-power systems. When the PM machine has salient pole rotor or the internal resistance is not negligible or both, there is obvious coupling between d-axis current and output power. However, in conventional control approach, the effect of d-axis current on output power is not compensated for in the q-axis current, which leads to unsatisfied control performance. This paper proposed a power decoupling control approach for PMS/G system in generating mode. The power coupling effect is mitigated which delivers improved control performance. Moreover, the output signal of voltage controller can always accurately reflect output power, which can be utilized for instantaneous power control and monitoring. The proposed approach is verified both by simulation and experiment.