An ultra efficient composite modular power delivery architecture for solar farm and data center

This paper presents an ultra-efficient composite modular power delivery architecture (COMPDA) that is able to be used for DC-DC, DC-AC, AC-DC, and AC-AC applications. The proposed architecture has very good module structure, the devices in each module have the same voltage and current stress. When it is used for high conversion ratio dc-dc applications, the device voltage stress is the same with the low voltage side, and the device current stress is the same with the low current side. Compared with the buck, flying capacitor multilevel or modular multilevel dc-dc converters, the proposed architecture has much lower total device power or current stress, which means a significant semiconductor chip area reduction. During the operation, the modules are connected in-series to sustain the high voltage and connected in-parallel to pump the high current. By properly design the resonant tank in the COMPDA, all the switching devices could achieve zero current switching or zero voltage switching. A partial power regulator could be integrated in the proposed architecture, where only a minimum amount of power needs to be processed in order to achieve the output voltage fine regulation. By properly control the operation of modules, the COMPDA can also be used as a high boost ratio DC-AC inverter or high step-down ratio AC-DC rectifier while keeping the soft-switching features, which are specially suitable for solar farm and data-center application. When apply the COMPDA to single-phase DC-AC or AC-DC applications, only a minimum amount dc-link capacitor is needed since the needs of energy storage is minimized, and there is no high voltage dc-link requirement anymore. In order to show the benefits of the COMPDA, one special unregulated case derived from the proposed architecture has been used for 48 V–8 V DC-DC data center application, which is also named switched-tank converter. Finally, a GaN based prototype is built and tested to verify the theoretical analysis. The proposed converter can achieve the peak efficiency at 98.55% under switching frequency 253 kHz and power density is ∼750W/inch3.