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In remote areas, the distribution networks are usually underdeveloped; thus, three-phase medium-voltage grids may provide a low-cost power supply solution for residential buildings. A new centralized approach topology of three-port power hub converter, which consists of a V/V transformer, a back-to-back inverter, and a static volt-ampere reactive (VAR) compensator with adaptive impedance, is proposed for remote area power supply. The proposed three-port converter interfaces two bidirectional power ports connecting three-phase ac grid and dc grid, respectively, and one unidirectional power port connects ac loads. The functions of the proposed converter are the bidirectional power flow control between three-phase ac grid and dc grid and power quality compensation to the three-phase ac grid. Finally, to verify the validity of the proposed three-port converter and its control performance, different simulation and experimental cases are implemented under different operation conditions. [ABSTRACT FROM AUTHOR]

The respective advantages of ac and dc microgrids lead to the blooming development of the hybrid ac/dc microgrid, which consists of ac and dc microgrid tied by an interlinking converter. A new structure of hybrid coupled interlinking converter (HCIC), which composed of a converter in series with a static VAR compensator (SVC), is proposed for hybrid ac and low voltage dc (LVdc) microgrids. Moreover, a new droop control method is correspondingly developed for the proposed HCIC. Its fundamental active and reactive power flow in the hybrid ac/dc microgrid is controlled by P-δ and Q-P-V droop control for converter part of the HCIC, and P-Q-α droop control is proposed for SVC part of the HCIC. Furthermore, a fast harmonic control is given based on a decoupled control strategy to improve the filtering characteristics of SVC part of the HCIC, suppress the harmonic power, and/or inject active power. Finally, simulation and experimental results are provided to verify that the proposed HCIC for hybrid ac/LVdc microgrids has the ability of good power flow control and power quality compensation, which not only meets the power flow requirements with low rating system, but also greatly promotes the development of more robust hybrid ac/dc microgrids. [ABSTRACT FROM AUTHOR]

Based on cascaded ac–ac converter with controllable phase and amplitude (ACCPA), a novel π model ACCPA was proposed for power flow control, whose output voltage phase and amplitude can be regulated, respectively, and simultaneously with respect to the input voltage. Single-phase π model ACCPA comprises a buck-type ac unit, a third harmonic trap and a boost-type ac converter. Compared with single-phase cascaded ACCPA, it has a more simplified structure by dispensing with the LC output filter of the buck-type ac converter, and can adopt the same two-stage duty-cycle modulation. The buck-type ac unit regulates the phase of output voltage and the boost-type ac converter does the amplitude. By utilizing impedance compensation with capacitance in single-phase π model ACCPA, it is effective to counteract or reduce the lag effect which is put on fundamental voltage by line impedance of third harmonic trap and inductance. Three-phase π model ACCPA comprises three buck-type ac units and a three-phase boost-type ac converter, it not only dispenses with three LC output filters, but also does three third harmonic traps, so it has simple structure. Experimental results verified the feasibility of π model ACCPA and the correctness of its theory. [ABSTRACT FROM PUBLISHER]

In this paper, a new modeling and parameter design method for the thyristor-controlled LC-coupled hybrid active power filter (TCLC-HAPF) is proposed, which includes the analysis of the inner flowed three-phase unbalanced power during unbalanced condition. Different from the conventional method which ignores the inner flowed three-phase unbalanced power, the proposed design method can achieve better performance during unbalanced compensation. To verify the validity and advantages of the proposed modeling and parameter design method of TCLC-HAPF, the mathematical analysis, representative simulation and experimental results for compensating different unbalanced loading situation are presented in comparison with the conventional design method. [ABSTRACT FROM PUBLISHER]