Non-linear load current compensation control method and device based on flywheel energy storage

Abstract

The invention discloses a non-linear load current compensation control method and device based on flywheel energy storage. According to the control method, conversion between electric energy and mechanical energy is achieved through the charging and discharging processes of a flywheel energy storage device; in the energy conversion process, PWM is used for driving and controlling a main circuit switching tube, the current of the device is controlled, the harmonic current is compensated, and a fundamental wave active current with a certain amplitude is injected into or absorbed into a power grid; the compensated current is the sinusoidal current with the same phase as the load fundamental wave active current, and the amplitude of the compensated current is smaller than or larger than that of the load fundamental wave active current. The real-time and dynamic compensation of the non-linear load current is realized, each harmonic can be dynamically eliminated, and the current waveform is improved; moreover, the method has a wide voltage and power application range, avoids the frequent switching of a main circuit between an inverter and a rectifier, and solves problems of high limitation of harmonic compensation capability, small voltage and power application range, and short overall service life of a main circuit switching tube in an existing method.

Description

technical field [0001] The invention relates to a non-linear load current compensation control method and device based on flywheel energy storage, and belongs to the technical field of energy storage technology application. Background technique [0002] There are a large number of non-linear loads in industrial and commercial users, such as rolling mills, electric welding machines, elevators, and electric locomotives. Such loads generate a large number of harmonics during operation, which will pollute the power grid, increase power loss, and reduce power supply reliability. Normal and safe operation of power grid and equipment. [0003] The existing harmonic suppression methods mostly use LC filter or active power filter (APF) to realize. The LC filter can suppress harmonics and compensate reactive power, but its compensation characteristics are easily affected by the impedance of the grid and the operating state, and it is easy to generate parallel resonance with the syste...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a non-linear load current compensation control method and device based on flywheel energy storage, which can realize real-time and dynamic compensation of non-linear load current, can dynamically eliminate each harmonic, and improve the current waveform; And it has a wide range of voltage and power adaptability, and avoids frequent switching of the main circuit between the inverter and the rectifier, which solves the problem that the existing method has strong limitations in harmonic compensation capability, and the adaptability of voltage and power is small. low lifespan problem

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