Abstract:To address the problem that the traditional LLC resonant circuit still needs to convert AC to DC before DC conversion in the process of power conversion, this paper proposes a type of topology of LLC resonant converter based on AC-Link technology with corresponding control method. The topology can convert three-phase AC power to DC power by the control strategy of frequency conversion, and the input current has high power factor and low harmonic current, while the output voltage has excellent regulation ability. Finally, a Matlab/Simulink simulation model is established and a 1 kW experimental prototype with 380 V three-phase AC input and 500 V output is built for verification. The results show that the power factor of this topology can reach 0.99, the total harmonics distortion of the input current is 2.31%, and the output voltage error is less than 1%. Finally, the experimental prototype is constructed to test, and the experimental results prove the feasibility of the topology and control algorithm.