Current sharing method and device for interleaved parallel LLC resonant converter

Abstract

The invention provides a novel current sharing method and a novel current sharing device for an interleaved parallel LLC resonant converter, aiming at overcoming the defects of the existing current sharing technology. The multi-phase interleaving LLC resonant converter device comprises a multi-phase interleaving LLC resonant converter composed of N half-bridge LLC resonant converter modules, N * (N-1) / 2 active impedance balancing units and a controller, N is equal to 2 or 3, each active impedance balancing unit is connected in series between every two phases of LLC resonant converter modules, and the controller is connected in series between the half-bridge LLC resonant converter modules. And the first end and the second end of the active impedance balance unit, the resonant capacitor of the connected two-phase LLC resonant converter module and the primary side ground form a loop. By changing the equivalent impedance of the active impedance balancing unit connected in series between the LLC resonant converter modules of each phase, the output current of the LLC resonant converter modules of each phase is not influenced by the parameter deviation of the resonant element, and the output current sharing of the multi-phase interleaved parallel LLC resonant converter can be realized.

Description

technical field [0001] The invention belongs to the switching power supply technology in the technical field of power electronics, and relates to a novel current sharing method and device of a multiphase interleaved parallel LLC resonant converter. Background technique [0002] LLC resonant converters have been widely used in applications with high requirements for converter efficiency and power density due to their high efficiency, low EMI, and high power density. In high-power and high-current applications, the converters are required to have larger capacity, higher power density, and lower losses. Obviously, single-phase LLC resonant converters can no longer meet the requirements. Therefore, multi-phase interleaved parallel LLC resonant converters are usually used to reduce the output current ripple and improve the output power. [0003] However, since the voltage gain of the LLC resonant converter is closely related to the parameters of the resonant device, in the pract...

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Problems solved by technology

[0003] However, since the voltage gain of the LLC resonant converter is closely related to the parameters of the resonant device, in a practical multi-phase parallel system, due to the deviation of the manufacturing process and the parameter changes caused by environmental changes, there will inevitably be differences among the resonant components. In turn, there will be a large deviation in the voltage gain between the parallel phases, resulting in different load currents output by each phase resonant converter, which will seriously affect the efficiency, reliability and service life of the entire system

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