A Hysteresis Current Controller for the Interleaving Operation of the Paralleled Buck Converters Without Interconnecting Lines

Paralleled buck converters have garnered significant attention for fulfilling the increasing demands of power supplies in modern applications. They have the advantages of increased current capacity and reduced current ripple. Under this architecture, applying distributed control brings the benefits of reliability and scalability. However, the interconnecting lines between the converters are required for achieving the interleaving operation, which reduces the reliability and scalability. To eliminate the interconnecting lines, this paper proposed a hysteresis current controller to achieve the symmetric interleaving operation. First, the parallel structure with a common output filter was proposed to provide the hardware basis for the proposed control method. Then, the hysteresis current controller was constructed based on the inductor voltage of each buck module to achieve the interleaving operation. The experiment of the three-module-paralleled buck converter was conducted. The experimental results show that the symmetric interleaving was achieved with a maximum phase shift error of 4.1%; the output of the parallel system can recover within 2.60 ms after the load transitions from 50% to 100%; and the parallel system can recover within 1.96 ms after one module removal. The simulation results of the six-module-paralleled buck converter show that the parallel system can recover within 1.00 ms after one module addition, which illustrates the scalability of the proposed method.