Flywheel energy storage two-stage power conversion system and control method

Abstract

The invention relates to the technical field of power electronics, in particular to a flywheel energy storage two-stage power conversion system and a control method. The system comprises a first end connected with a direct current power grid, a second end connected with a flywheel energy storage device, a first-stage power conversion unit and a second-stage power conversion unit. The system and the control method adopt two-stage power conversion to solve the problem of power conversion when the flywheel energy storage device is applied to the high-voltage direct current system, the system usestwo-stage power conversion without using a bidirectional converter with an isolation transformer to meet the requirements of the conventional flywheel energy storage power conversion system, such aslarge gap between DC voltage level and flywheel AC voltage level, large transmission power, which expands the application scope and adaptability of the system and improves the system efficiency.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a flywheel energy storage two-stage power conversion system and a control method. Background technique [0002] As a physical energy storage technology, flywheel energy storage has made great progress in recent years with the development of magnetic levitation technology and power electronic power conversion technology. Due to the advantages of high safety and reliability, high power density, 20-year service life, unlimited charge and discharge times, wide operating temperature range, low operation and maintenance costs, and green and pollution-free flywheel energy storage devices, they are being used in more and more field has been applied. [0003] In the application scenarios of the flywheel energy storage device, some application scenarios require the flywheel energy storage device to be connected to the DC system, such as: rail transit DC traction network, photovo...

AI Technical Summary

Problems solved by technology

For a DC system with a rated voltage of 1500V, the gap between the DC voltage level and the AC voltage level of the flywheel energy storage device is large, and the transmission power is required to be large. The conventional flywheel energy storage power conversion system is difficult to meet the requirements

If a bidirectional converter with an isolation transformer is used to achieve a wide range of DC 1500V boost, it will cause problems such as increased volume and reduced efficiency.

[0005] In the existing technology, one-stage DC / AC power conversion is generally used, and the DC side voltage is difficult to reach 1500V, and the application scenarios are limited.

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