Harmonic suppression method of bidirectional converter of energy accumulation unit in wind and light accumulation system

Abstract

The invention discloses a harmonic suppression method of a bidirectional converter of an energy accumulation unit in a wind and light accumulation system. The harmonic suppression method comprises the steps of: extracting a quintic harmonic voltage and a septic harmonic voltage and a current of a power grid; then figuring out corresponding voltage compensation quantities of v alpha 5th, v beta 5th, v alpha 7th and v beta 7th; adding voltage quantities v alpha and v beta obtained through decoupling control with a current of an inner ring to obtain output reference quantities V alpha and V beta; and carrying out SVPWM (Space Vector Pulse Width Modulation) on the output reference quantities V alpha and V beta to obtain switching signals of switching on and switching of a controllable switch tube of a three-phase bridge arm of a bidirectional converter. Because the quintic harmonic and the septic harmonic are taken into account in control quantities, the problem of pollution of high-order harmonics due to nonlinear factors of the bidirectional converter is eliminated. The harmonic suppression method is suitable for a harmonic suppression process of the bidirectional converter used by the energy accumulation unit in renewable energy source systems such as the wind and light accumulation system, and can achieve better harmonic suppression effect under the condition of no need of additional hardware input.

Description

technical field [0001] The invention belongs to the technical field of power grid connection in the electric power industry, and more specifically relates to a method for suppressing harmonics caused by nonlinear factors of bidirectional converters of energy storage units in a wind-solar-storage system. Background technique [0002] On the one hand, the wind-solar-storage system uses the complementary characteristics of wind energy and solar energy to generate wind-solar complementary power generation, which reduces the adverse effects of wind energy and solar energy intermittent and random on single energy power generation; on the other hand, combined with energy storage technology, through the energy storage unit Charge and discharge control can suppress power fluctuations to a greater extent and improve the power quality of power generation. [0003] The application of energy storage technology provides a solution for smoothing the output power of distributed generation, ...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a harmonic suppression method for the bidirectional converter of the energy storage unit in the wind-solar-storage system, so as to suppress the high-order harmonic pollution problem caused by the nonlinear factors of the bidirectional converter

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