This article proposes a novel solid-state transformer (SST) having a low-frequency medium-voltage ac (LF-MVac) port distinctively, which can be the key equipment for smart distribution networks based on LF-MVac interconnection. The proposed SST has four ports of power-frequency medium-voltage ac (MVac), LF-MVac, low-voltage dc (LVdc), and low-voltage ac (LVac). In addition to the two-level low-voltage dc/ac converter, the proposed SST is mainly composed of an isolated modular multilevel matrix converter (I-M3C), which can achieve single-stage three-port power conversion. First, the topology of the I-M3C is introduced. Then, a simple modulation scheme is provided to achieve single-stage three-port power conversion, and the operating principles of the I-M3C are given in detail. In addition, a control strategy based on dual- dq coordinate system is designed, which can achieve stable operation without the complex multistage coordinated control and voltage-balancing control strategies. Finally, the effectiveness of the proposed control strategy is verified through a 10-kV/2-MW full-power simulation platform, and a 100-V/1-kW scaled-down experimental prototype is built to further demonstrate the correctness of the proposed I-M3C.     «

This article proposes a novel solid-state transformer (SST) having a low-frequency medium-voltage ac (LF-MVac) port distinctively, which can be the key equipment for smart distribution networks based on LF-MVac interconnection. The proposed SST has four ports of power-frequency medium-voltage ac (MVac), LF-MVac, low-voltage dc (LVdc), and low-voltage ac (LVac). In addition to the two-level low-voltage dc/ac converter, the proposed SST is mainly composed of an isolated modular multilevel matrix c...     »

Modulation, Medium voltage, Low voltage, Frequency conversion, Distribution networks, Transformers, Topology, Solid-state Transformer, Modularity Matrix, Ac Port, Medium Voltage Ac, Modular Multilevel Matrix Converter, Control Strategy, Distribution Network, Power Conversion, Modulation Scheme, Simulation Platform, Experimental Prototype, Multilevel Converter, Modular Multilevel Converter, Two-level Converter, Key Equipment, Modulation Of Signaling, Sudden Changes, Power Grid, Transmission Power, Load Changes, DC Transmission, Unit Conversion, Microgrid, Power Stage, Load Resistance, Port-a-cath, Modulation Ratio, DC Bias, Front Stage, Winding Loss, Isolated modular multilevel matrix converter (I-M3C), low-frequency medium-voltage ac (LF-MVac), single-stage three-port power conversion, solid-state transformer (SST)     «

Modulation, Medium voltage, Low voltage, Frequency conversion, Distribution networks, Transformers, Topology, Solid-state Transformer, Modularity Matrix, Ac Port, Medium Voltage Ac, Modular Multilevel Matrix Converter, Control Strategy, Distribution Network, Power Conversion, Modulation Scheme, Simulation Platform, Experimental Prototype, Multilevel Converter, Modular Multilevel Converter, Two-level Converter, Key Equipment, Modulation Of Signaling, Sudden Changes, Power Grid, Transmission Power...     »