Engine network side combination control algorithm based on energy of doubly-fed induction wind power generation system

Abstract

The invention provides an engine network side combination control algorithm based on energy of a doubly-fed induction wind power system, belonging to the technical field of wind power generation control. The invention divides the whole system into four subsystems in accordance with energy flow of the wind power system; a variable of each subsystem port is designed so as to determine the interconnection structure among the subsystems; the whole system ports are controlled by a Hamilton model in accordance with the internal structure of the subsystems and feedback interconnection among the subsystems; the expected equilibrium point of the system is set; control energy is determined by the deviation between expected energy of the system at the equilibrium point and the present energy; an energy matching equation is listed so as to solve the control variable and then the engine network side combination controller based on energy is achieved. The invention has clear physical significance, strong robustness and coordination control for the engine side power and the network side power of a converter. The invention not only realizes the respective control goal at engine side and network side preferably, but also improves dynamic control performance of direct voltage so as to reduce the demand to capacitance in the converter, saving the system cost and strengthening the reliability of the whole system.

Description

(1) Technical field [0001] The invention belongs to the technical field of wind power generation control, and specifically relates to a non-linear algorithm for realizing the unit-side and grid-side joint control of a doubly-fed induction wind power generation system from an energy-based viewpoint. (2) Background technology [0002] At present, with the large-scale development of grid-connected wind turbines, doubly-fed induction wind power generation systems have become the mainstream of mainframes due to their small excitation inverter capacity, large speed range, and independent adjustment of active and reactive power. At the same time, as a typical variable-speed constant-frequency power generation system, the machine-side control target of the doubly-fed induction wind power generation system changes with the wind speed. That is, below the rated wind speed, it is required to maintain the best tip speed ratio to achieve maximum wind energy capture; near the rated wind speed t...

AI Technical Summary

Problems solved by technology

[0004] In view of the existing algorithm in the control application of the doubly-fed induction wind power generation system, the independent control of the machine side and the grid side is generally used to cut off the physical connection between the two, so that there is a large difference in the instantaneous energy of the two parts, and a large capacitor has to be used To avoid DC voltage fluctuations, resulting in increased system cost, increased volume and weight, and increased failure rate, the present invention proposes a nonlinear algorithm for combined control of doubly-fed induction wind turbine generator side and grid side based on the energy point of view

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