Power-Loop-Free Virtual DC Machine Control With Differential Compensation

Conventional virtual dc machine (VDCM) control incorporates the mechanical characteristics of dc machines to emulate necessary system inertia. Utilizing already-existing proportional-integral control loops in the conventional VDCM control, this article eliminates the requirement of calculating torques using power measurements, i.e., power-loop-free VDCM, which greatly simplifies the conventional VDCM and reduces required resources for implementation. Theoretical analysis of the proposed power-loop-free VDCM shows that the controlled steady-state and dynamic characteristics are not aligned and sometimes even conflicting. This work further incorporates a differential compensation in the proposed power-loop-free VDCM to enhance the dynamic performance without affecting its steady-state characteristics. The proposed power-loop-free VDCM control is validated by both numerical simulations and hardware-in-the-loop experiments, and the results of both validations are consistent with the theoretical analysis, which justifies the effectiveness of the proposed VDCM control.