A System Adaptive Control Method Considering Action Threshold

Abstract

The invention discloses a system adaptive control method with an action threshold considered. The method comprises the following steps: 1, the control method continuously detects and controls the frequency and the voltage deviation of the system, and when the deviation is smaller than a DFIG (Doubly-Fed Induction Generator) action threshold, the DFIG cluster does not participate in the adjustment of the system; and the DFIG adopts a power control mode, a fuzzy adaptive controller does not act, and a STATCOM / BESS (Battery energy storage system) adjusts the voltage and the frequency of the system through fuzzy adaptive control; 2, when the system voltage or the frequency deviation is further expanded, the DFIG turns to a voltage and frequency control mode from the original power control mode, and the control sensitivity of the DFIG is smaller than that of the STATCOM / BESS; and 3, when the system deviation is increased continuously and is larger than a coordination action threshold, the STATCOM and the DFIG act at the same time, and the voltage and frequency control mode is adopted. The sensitive adjustment mode is adopted, and the stability of the system is greatly increased.

Description

technical field [0001] The invention relates to a system adaptive control method, in particular to a system adaptive control method considering an action threshold. Background technique [0002] In recent years, due to the intermittence, randomness, and volatility of wind power, large-scale wind power grid integration still has many challenges. Distributed wind power generation can restore island power supply when a power outage occurs, and has become an indispensable and important supplement to centralized power supply. In order to better realize the distributed power generation of wind turbines, it is necessary to study the control method of wind turbines in island operation. [0003] Nowadays, the Doubly-Fed Induction Generator (DFIG) has become the mainstream model selected by wind farms. Because the wind turbine adopts the flexible connection method of the stator and rotor, the anti-interference ability is poor. The energy storage device is installed on the DC capacit...

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Problems solved by technology

During the start-up process of the wind turbine group, the cost of large-scale energy storage system investment is large, which cannot meet the economic requirements of the power grid. Start the remaining wind turbines with the assistance of

[0004] However, in the process of coordinated operation of wind turbines and reactive power compensation devices, new problems arise in the stability of the system: on the one hand, when the frequency and voltage of the system deviate, DFIG and STATCOM / BESS act at the same time, which increases the system control At the same time, it prolongs the stable time of the system; on the other hand, because the control of the two is mainly the traditional PI control, and the adjustment between the PI controllers will affect each other, the parameter design of the PI controller may cause the system to be unstable. Stablize

Usually, the PI controller parameter is the only value for global tuning. When facing a multivariable, nonlinear, and strongly coupled system at the time of self-starting of a wind farm, a single tuning value cannot satisfy various aspects of startup and subsequent motion control. situation, and cannot fundamentally solve the contradiction between dynamic and static, tracking set value and anti-interference ability

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