Superconducting Magnetic Energy Storage Based DC Unified Power Quality Conditioner with Advanced Dual Control for DC-DFIG

Abstract

The development of DC custom power protection devices is still in infancy that confines the sensitive loads integrated into medium-voltage (MV) and low-voltage (LV) DC networks. Considering the DC doubly-fed induction generator (DC-DFIG) based wind energy conversion system (WECS), this paper proposes a dual active bridge (DAB) based DC unified power quality conditioner (DC-UPQC) with the integration of superconducting magnetic energy storage (SMES) to maintain the terminal voltage of DC-DFIG and regulate the current flow. The principle of the proposed DC-UPQC has three parts, i.e., parallel-side DAB (PDAB), series-side DAB (SDAB), and SMES, used for the voltage compensation, current and power regulation, and energy storage, respectively. The circuit principle of the PDAB and SDAB and the modeling of SMES are analyzed in this paper. A DC dual control strategy is also proposed to deal with the DC voltage oscillation generated by the AC-side asymmetrical fault. A case study of DC-DFIG interfaced with DC power grid is carried out, integrated with the proposed SMES-based DC-UPQC to verify the high-power applications of the proposed structure. Finally, an experiment is implemented, and the results demonstrate the correctness of the theoretical analysis and the feasibility of the proposed structure.

Design and control of DFIG with SMES storage under symmetrical grid fault

“…The DC DC converter is utilized to control power flow. The mode operating of the DC chopper [23], [24]: − Charging sequence: The DC converter stores excess power from DC link in the superconducting magnet. − Discharge sequence: The DC converter injects the power from superconducting magnet to DC link.…”

A new index for techno‐economical comparison of storage technologies considering effect of self‐discharge

“…It needs an AC/DC converter to provide the DC current; when this DC current passes through the superconducting coil, electrical energy is stored in the form of a magnetic field. Then, by discharging the coil, this magnetic field is converted into the network through an inverter [45].…”

Unified power quality conditioner-based solar EV charging station using the GBDT–JS technique

“…Due to the restricted cost and complex control of the UPQC, its utilization is limited in local distribution networks (Oubelaid et al, 2022a). In their studies, Yan and Wen (2021); Gao et al (2022); Yang et al (2022) introduced the DC-UPQC approach, incorporating a series-side distribution static synchronous compensator (DAB), a parallel-side DAB, and a superconducting magnetic energy storage (SMES) system. Their analysis focused on addressing DC voltage oscillations arising from AC-side asymmetrical faults.…”