Modularized photovoltaic direct current collection converter with automatic voltage balancing capability

Abstract

The invention discloses a modularized photovoltaic direct-current collection converter with automatic voltage balancing capability, and belongs to the technical field of power generation, power transformation or power distribution. The converter comprises a resonance voltage-sharing bus and a middle-high voltage direct current power grid bus, wherein the resonance voltage-sharing bus is composed of N full-bridge quadruple voltage rectifying sub-modules and N LC resonance type power self-balancing branches. Aiming at an application occasion that a photovoltaic direct current boost with an IIOS structure is merged into a middle-high voltage direct current power grid, a secondary side switch tube of the converter is in complementary conduction at a duty ratio of 50%, photovoltaic MPPT is realized by controlling a phase shift angle of a sub-module, and the control is simple; by optimizing the LC resonance type power equalization branch, the processing power of the equalization branch is reduced, and the efficiency of the system is improved; and when the power of the photovoltaic array is mismatched, the output voltage of each module is balanced, so that the overvoltage damage of the device is avoided, and the effective operation of MPPT is ensured.

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