Two-Stage Modulation Study for DAB Converter

Abstract

The dual active bridge (DAB) is a dc/dc converter frequently employed in multiple applications due to its advantages of isolation, power flexibility, and input and output voltage defined by design. Different multi-phase modulations have been reported to increase DAB efficiency and reduce components stress but, certainly, the control and implementation complexity increases with every displacement angle added because of the multiple variable measurements. This paper presents two-stage modulations based on the single phase-shift (SPS), which allows maintaining simplicity while improving the efficiency of the DAB converter depending on the design conditions. The paper also gives a direction for selecting the proper modulation to achieve the best efficiency for each situation. The different two-stage modulations are described, analyzed, and experimentally tested.

Design and Implementation of Single-Phase Grid-Connected Low-Voltage Battery Inverter for Residential Applications

“…The steady-state grid current waveform remains nearly sinusoidal. However, the steady-state waveform of i p (t) indicates that the DAB DC-DC converter operates in the boost mode, where N s /N p V B > V D [19]. At this operating point, the battery voltage was 54.3 V, causing N s /N p V B = 424 V.…”

“…The steady-state grid current waveform remains nearly sinusoidal. However, the steady-state waveform of 𝑖 𝑡 indicates that the DAB DC-DC converter operates in the boost mode, where 𝑁 𝑁 ⁄ 𝑉 𝑉 [19].…”

“…This method can attenuate the dynamic and static DC offset components [18]. For simplicity, the dynamic DC offset compensation can be embedded into the modulation scheme, where the phase angle of each leg of the DAB DC-DC converter is independently controlled [19,20]. These dynamic DC offset compensation methods require only delay elements.…”