Operation control method of double-fed wind generator participating in electric power system frequency modulation

Abstract

The invention relates to an operation control method of a double-fed wind generator participating in electric power system frequency modulation. The operation control method is characterized in that a deloading operation curve which has a power up-regulation capacity is set and a deloading control strategy in which variable speed and variable pitch are used for coordination control is designed according to an operation physical constraint condition of a Double-Fed Induction Generator (DFIG) which is common in a variable speed constant frequency generator, and the maximum deloading amplitude capability of the wind generator under each operation condition is quantitatively analyzed according to the operation physical constraint condition of the wind generator at different wind speeds. Through adjustment and control of a dropping frequency, the support effect of the wind generator to the system frequency under a deloading operation mode is verified. Through the simulation analysis, it is verified that in the deloading frequency modulation control scheme, when the system frequency fluctuates, the variable speed and variable pitch wind generator can effectively release kinetic energy, and the frequency support is provided for the system.

Description

technical field [0001] The invention relates to the technical field of wind power generation, and relates to an operation control method of a doubly-fed wind generator set participating in power system frequency regulation. Background technique [0002] The grid frequency is an important indicator to measure the power quality of the power system. The unbalanced power supply and demand of the power system leads to large fluctuations in the system frequency. The large fluctuations in wind power power or the power loss of generator sets can easily induce the system frequency to exceed the limit, which has a serious impact on the stable operation of the power system. Different from the synchronous generator set, the double-fed induction wind turbine is controlled by the four-quadrant converter and operates in the Maximum Power Point Tracking (MPPT) mode, which realizes the decoupling of the system frequency and the rotor speed, and does not contribute to the system inertia itself...

AI Technical Summary

Problems solved by technology

[0002] The grid frequency is an important indicator to measure the power quality of the power system. The unbalanced power supply and demand of the power system leads to large fluctuations in the system frequency. The large fluctuations in wind power power or the power loss of generator sets can easily induce the system frequency to exceed the limit, which has a serious impact on the stable operation of the power system. Different from the synchronous generator set, the double-fed induction wind turbine is controlled by the four-quadrant converter and operates in the Maximum Power Point Tracking (MPPT) mode, which realizes the decoupling of the system frequency and the rotor speed, and does not contribute to the system inertia itself. Unable to adjust power upwards, and does not have the ability to respond to system frequency changes, so the problem of frequency regulation in power grids with high wind power penetration is becoming more and more prominent

[0003] To meet the needs of wind turbines to participate in system frequency regulation, wind turbine load shedding (DeloadingPowerPointTracking, DPPT) frequency regulation control strategy is usually used, that is, to give up the maximum wind power tracking in exchange for long-term power support, but the load shedding control of coordinated control of variable speed and pitch is commonly used The strategy does not specify the specific maximum load shedding capacity of wind turbines at different wind speeds, that is, it fails to specify the reserve capacity that wind turbines can reserve under different wind speeds, resulting in the inability to obtain optimal results when wind turbines are required to participate in frequency regulation

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