Method for excitation-control-based doubly-fed induction generator fault ride-through assessment under condition of symmetrical faults

Abstract

The invention discloses a method for excitation-control-based doubly-fed induction generator fault ride-through assessment under a condition of symmetrical faults. The method includes: acquiring a simplified analytical expression between a minimum rotor fault current peak value of a doubly-fed induction generator and various factors such as generator parameters, pre-fault initial operating conditions and gird voltage drop depth; acquiring limit of an excitation control method under the condition of the symmetrical faults on the basis of the simplified analytical expression to further assess symmetrical fault ride-through capability of the doubly-fed induction generator on the basis of excitation control, wherein the simplified analytical expression can also be used for guiding the rotor-side converter capacity design of the doubly-fed induction generator. The assessment method is independent from the specific excitation control method and specific generator parameters and is high in universality; influences of various interference factors of reasonability of control parameters, accuracy of observation quantity and the like in simulation or experiments can be avoided, and the method is more suitable for assessment of theory limit of the excitation control method under generator hardware constraint; simplicity and convenience in calculation, easiness in implementation and high accuracy are realized.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and more specifically relates to a fault ride-through evaluation method for doubly-fed wind turbines based on excitation control under symmetrical faults. Background technique [0002] With the increasing penetration of wind power in the power grid, in order to maintain the safe and stable operation of the power system, countries have formulated grid-connected regulations for wind turbines, among which low-voltage ride-through requirements have attracted the most attention. Double-fed wind turbines have become the mainstream wind turbines in today's market because of their advantages such as wide speed range, variable speed and constant frequency, active and reactive power decoupling control, and small capacity of excitation converters. However, since the stator of the doubly-fed wind turbine is directly connected to the grid, it is very sensitive to the disturbance of the grid; whe...

AI Technical Summary

Problems solved by technology

The above conclusions are all obtained through simulation, so they are only applicable to the control method and unit parameters used, and their accuracy is also restricted by the control method used, that is, the control method used may not fully utilize the hardware conditions of the unit

Images