Impedance type multi-module series photovoltaic DC boost converter

Abstract

The present invention provides an impedance-type multi-module series photovoltaic DC boost converter, including a quasi-Z source impedance network and a full-bridge DC-DC converter; wherein, the quasi-Z source impedance network and the full-bridge DC-DC conversion The impedance-type power conversion units are formed by cascading the impedance-type power conversion units; the input ends of the impedance-type power conversion units are used to connect to the photovoltaic array, and the output ends are connected in series to obtain DC high voltage; the number of the impedance-type power conversion units is multiple. It also includes a single-bipolar conversion DC converter; the output ends of multiple impedance DC-DC converters are connected in series to the input circuit of the single-bipolar conversion DC converter. The invention has good expandability, and has potential engineering application value for the development and construction of large-scale DC photovoltaic power stations and power generation bases in my country in the future.

Description

technical field [0001] The invention relates to circuit topology and operation control of an impedance type converter, in particular to an impedance type multi-module series photovoltaic DC boost converter. Background technique [0002] Photovoltaic power generation is one of the most important forms of new energy power generation at present, and it is the main force for my country to realize the replacement of renewable energy in the future. The distribution of light resources in my country and the pattern of the power system determine that large-scale construction and centralized grid connection will become an important form of photovoltaic development and utilization in the future. [0003] Photovoltaic power generation has the inherent characteristics of low power density, low export voltage, and large random fluctuations. It must be boosted and converged by the collection system to achieve grid-connected conditions. The traditional photovoltaic power station adopts the...

AI Technical Summary

Problems solved by technology

[0004] 1. The stability problem of multi-inverter parallel connection under the support of weak synchronization is prominent, and the voltage exceeds the limit and the wide frequency domain oscillation occurs frequently;

[0005] 2. The loss of the exchange and collection lines in the station and between stations is large, and the overall efficiency of the system is low

The DC-DC device selected in this document is a non-isolated DC-DC converter. The range of voltage gain that can be achieved by this converter is small. Modules cannot achieve maximum power point tracking of photovoltaics

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