| Abstract |
An autonomous DC microgrid system that uses a triple-active bridge (TAB) converter as a three-way power routing unit is proposed. In this system, various renewable energies, batteries, and local consumer appliances could be integrated by the three-way power routers with different operating DC voltages, such as 400 V DC bus voltages, 110 V battery systems, and 48 V ICT equipment. Accordingly, the three-way power router has to control the power flow independently among each output port with different operating DC bus voltages. Furthermore, it has to achieve constant current (CC) control or constant voltage (CV) control to satisfy different electrical applications. In this paper, a decoupling power flow control with a voltage difference between each port of the TAB converter is proposed. A prototype of the TAB converter rated at 400 V/400 V/48 V, 10 kW, and 20 kHz operating frequency was implemented to demonstrate the feasibility. In addition, two output ports have a voltage difference and different control targets where port 2 operated in 400 V output voltage and CC control, and port 3 operated in 48 V output voltage and CV control, respectively. The validity of the system was experimentally demonstrated by measuring the step response of the TAB converter. The experimental waveforms of the prototype with a voltage difference show that the CC control and CV control operate normally. Moreover, since the interference between each port was not observed, the control system was proved to be effective when the TAB converter had a voltage difference between each port. |
