Fault-tolerant control method and system for back-to-back converters of wind power generation system

Abstract

The invention discloses a fault-tolerant control method and system for a back-to-back converter of a wind power generation system. The method reconstructs the remaining five healthy bridge arms after determining the faulty bridge arm among the six bridge arms of the back-to-back converter It is a five-leg converter, using bidirectional thyristors to connect the corresponding phases of the original faulty bridge arm to the healthy bridge arm, which is defined as the common bridge arm; in order to avoid the overcurrent of the common bridge arm under fault-tolerant control, the common bridge arm If the current of the common bridge arm is greater than the current warning value, adjust the generator speed to control the phase difference between the generator side and the grid side on the common bridge arm at 120 。 —240 。 In order to realize the normal operation of the wind power grid-connected system. The fault-tolerant control method involved in the invention can realize the uninterrupted fault-tolerant operation of the system under the fault of the converter, and at the same time can keep the common bridge arm from flowing, and has good robustness.

Description

technical field [0001] The invention belongs to the field of new energy power generation, and relates to a fault-tolerant control method and system in a fault state of a converter of a wind power generation system. Background technique [0002] Since the 1870s, countries that use coal and oil as their main fuels have faced severe environmental pollution. Coupled with the deepening of the dual crisis of limited fossil fuels and reduced reserves, the development and utilization of new energy has become an important part of the world's energy sustainable development strategy. It is an integral part, and wind energy is one of the most potential energy sources in new energy sources. Under the situation of continuous energy shortage, many countries in the world, especially developed countries, are looking for a sustainable new energy source that can replace conventional energy sources and is non-polluting to the environment. The large-scale development and utilization of new ener...

AI Technical Summary

Problems solved by technology

[0003] Since the wind power generation system is a high-order, multi-variable, time-varying non-linear system, and has been in a complex and changeable working environment such as coastal plateaus for a long time, the converter is very prone to failure due to continuous operation with high power and high load. link, the failure of the converter will cause the production process to stop, and may even cause a serious disaster

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