A Grid-Supporting Rectifier with Frequency and Voltage Regulation Capabilities

In recent years, with the increasing number of grid-interfaced converters on both the supply side and the demand side, the reduction of conventional synchronous machines in the energy share has caused a significant loss of the total system inertia, which can make the power system less stable and more susceptible to variations. This paper proposed a grid-interfaced three-phase rectifier featuring grid-supporting capabilities. It can alleviate the grid side frequency and voltage variations by adjusting the active power and reactive power drawn from the grid side. To realize the power balance synchronization under system dynamics, an additional battery energy storage system (BESS) was connected to the rectifier DC side to handle the excess or shortage of energy during frequency variations, while maintaining the DC-link voltage. The proposed rectifier’s grid-support capabilities are verified by MATLAB-Simulink simulation results. The stability enhancement merit of the proposed rectifier compared to the conventional grid-tracking rectifier is shown by stability assessments based on the general Nyquist criterion (GNC).