Design of 20 kW audio power supply for single-phase/three-phase applications

In this paper, a design method is proposed for a 20 (kW) audio amplifier power supply that can be used for both single-phase and three-phase applications. The proposed circuit is a boost converter + LLC resonant converter structure with additional rectifier diodes added to the single-phase PFC converter. It has the advantages of a high power density and a high output power. A power factor of 0.9 or more can be satisfied without control. In addition, an unregulated LLC converter is adopted for the isolated DC/DC stage to improve power density and efficiency since LLC converters have excellent dynamic characteristics. For the design of the proposed circuit, an appropriate design method is presented that considers the audio load. The performance of the proposed circuit has been verified on a 20 (kW) [input voltage 220/380 (V-ac), output voltage 450 (V)] prototype designed with the design method.