A Modular Single-Stage PV Step-up Converter With Integrated Power Balancing Feature Using Inter-Coupled Active Voltage Quadruplers

Abstract

This paper presents a novel modular single-stage photovoltaic step-up converter with an integrated power balancing technique that features high frequency inter-connecting active voltage quadruplers (VQ). The input stage of each module consists of an integrated boost circuit with a CLL resonant circuit, allowing for both maximum power point tracking (MPPT) and soft-switching operation to be achieved. To achieve balanced output voltage for all the modules while providing MPPT, the output inductor of the resonant circuit in each module is coupled with the neighboring module with duty ratio control of the active VQ circuit is used to control the output voltage. The proposed technique allows the entire PV converter system to simultaneously achieve: (1) MPPT, (2) soft-switching operation for all modules, and (3) equal output voltage and power distribution without the use of additional circuitry. Descriptions of the proposed converter and the proposed power balancing technique are provided. Results on a 2kW, 3kV-output system is provided to highlight the features of the proposed converter configuration.