Energy-saving type cascade multilevel photovoltaic grid-connected generating control system

Abstract

The invention discloses an energy-saving type cascade multilevel photovoltaic grid-connected generating control system comprising an energy-saving cascade multilevel photovoltaic generating inverter, a controller and a power grid, wherein the multilevel inverter consists of 3n energy-saving type photovoltaic generating modules, wherein n modules are connected in series into one phase of a three-phase inverter; and the single-stage power of each module is converted to realize the buck-boost, the inverting and energy saving and adapt to the wide-range change of the battery voltage with high reliability. 3n photovoltaic cells and energy-saving cells are distributed on 3n modules; the generation of each module is independently controlled, thereby realizing the distributed maximum power track,collecting solar energy to the maximum extent, realizing high efficiency and avoiding the problems of power loss and hot spot caused by the local shade generated when the photovoltaic cells are connected in series; and the invention can flexibly control the stable power of a feeder grid of the multilevel inverter and achieve the functions of reactive power consumption, the power pitch peak control and the like, has the advantage of multilevel inversion and low output harmonic voltage and is suitable for high-voltage, high-power and transformer-free grid connection.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation, in particular to an energy storage type cascaded multi-level photovoltaic grid-connected power generation control system. Background technique [0002] As one of new energy power generation, photovoltaic power generation has the following characteristics: 1) Utilizing sufficient solar energy resources, it will not be exhausted; 2) No pollution, no noise, safe and reliable; 3) Not subject to geographical restrictions, it is easy to integrate with buildings and utilize Building walls and roofs, converting solar energy into electricity, etc. Therefore, as energy and environmental protection attract much attention today, photovoltaic power generation is attracting more and more attention. At present, there are two main types of photovoltaic power generation systems: independent power generation systems and grid-connected power generation systems. Independent power generation s...

AI Technical Summary

Problems solved by technology

However, the existing schemes are based on the above three types of photovoltaic power generation system structures, using traditional single-stage or two-stage power converters, which have their own shortcomings; in order to effectively manage the charging and discharging of energy storage batteries, an additional bidirectional DC / DC conversion is introduced controller, which increases the hardware cost and control complexity, and the efficiency will be reduced

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