Transient-state reconstruction system for improving fault ride-through capability of DFIG (Double-Fed Induction Generator) and control method

Abstract

The invention relates to a transient-state reconstruction system for improving fault ride-through capability of a DFIG (Double-Fed Induction Generator) and a control method. Firstly, a fault ride-through transient-state reconstruction topological structure of an energy storage DFIG is built by taking a traditional DFIG as foundation so as to achieve switching of an energy storage DFIG structure under a normal running state and a power grid voltage fault state; secondly, a stator voltage compensation mechanism and power flow thereof of the energy storage DFIG under the transient-state reconstruction topological structure when the power grid voltage is suddenly reduced and risen are analyzed; and finally, a control method of the transient-state reconstruction topological structure of the energy storage DFIG is acquired, and fault ride-through control of the DFIG under a power grid voltage fault is achieved. By the system, smooth control on an output power of a wind power plant under a normal running condition of a power grid can be achieved, meanwhile, the fault ride-through control of the DFIC can helped to achieve when the power grid voltage is suddenly reduced or risen, and the application value and the economic benefit of an energy storage device in a double-fed wind power generation system are improved.

Description

technical field [0001] The invention relates to the field of operation, analysis and scheduling of power systems, in particular to a transient reconfiguration system and a control method for improving the fault ride-through capability of a double-fed fan. Background technique [0002] With the rapid development of wind power in recent years, the penetration rate of wind power in the power grid has been increasing, and it is responsible for a part of the power balance of the power system. Network accidents pose a great threat to the stable operation of the power system. Among them, as one of the mainstream models, the doubly-fed fan (DFIG) is particularly sensitive to grid voltage faults because the stator side is directly connected to the grid, and is prone to off-grid accidents caused by grid voltage drops or sudden rises, which seriously restricts Grid-connected operation of DFIG. [0003] In order to ensure that the doubly-fed wind turbines can continue to operate witho...

AI Technical Summary

Problems solved by technology

Improving control strategies, such as de-excitation control, introducing PI-R controller as a supplement to PI controller, etc., can improve the fault ride-through capability of DFIG, but it is still difficult to meet the increasingly stringent grid-connection requirements of wind turbines in the grid-connected code

Adding hardware-assisted methods, such as installing a dynamic voltage restorer (DVR) and a series coupling compensation device (SCC) on the stator side, can effectively compensate the stator terminal voltage to a normal level and improve the fault ride-through capability of DFIG, but it will obviously increase significantly System hardware cost

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