High efficiency bridgeless AC/DC power supply with single step conversion for the data centers powered from the three-phase network

This paper analyzes a new architecture of the AC/DC type power supply for data centers. The source cumulates the following functions: three-phase current rectification, transformation of voltage parameters and DC voltage stabilization. The source ensures the reactive power compensation and does not distort the currents in the power three-phase network. The transfer of power from the alternating current network to the DC circuit is done at high frequency (over 100 kHz). The switching of semiconductor device is done in soft switching mode using Triangular Current Mode. The proposed algorithm for controlling semiconductor devices is performed at variable frequency in PWM mode. This leads to the reduction of loss in the switch regime of transistors. As a result, it is possible to increase the efficiency of the source to approximately 98%. The optimization of the switching mode of the semiconductor devices of the source with the power of about 0.5 kW does not require the use of radiators to ensure the thermal regime of the transistors. This leads, to the miniaturization of power supplies and the reduction of manufacturing costs. In the proposed source, the capacity of the direct current bus — the smoothing filter decreases a few times. At the same time it ensures the reduction pollution of the three-phase power supply circuit with superior harmonics. Verification of the proposed solution was done by mathematical simulations and by testing of a laboratory prototype of 2 kW. The AC supply voltage is 0.4 kV and the DC output voltage is 24 volts. The following mass indexes of the converter were obtained: the specific power 4 kW / kg.