Controllable short-term frequency supporting method for wind driven generator suitable for low-frequency disturbance

Abstract

The invention relates to the technical field of wind driven generator frequency control, in particular to a controllable short-term frequency supporting method for a wind driven generator suitable forlow-frequency disturbance. According to the method, droop control is added to fan rotor side control, and the active loss of a system is compensated by temporarily releasing the rotational kinetic energy stored in a fan; a self-defined droop parameter is calculated by considering the participation frequency modulation potential of the fan; rapid system frequency response is actively provided; thesystem frequency support control of a controllable wind turbine generator is realized under different fan operation conditions; that is to say, when the rotating speed of a fan rotor is high, rotating kinetic energy is fully released to compensate for active power loss and provide response time for a conventional generator set to participate in regulation, and when the rotating speed of the rotoris low, a proper amount of rotating kinetic energy is released to compensate for system active power loss, and the fan rotating speed instability problem and severe secondary frequency drop are not caused. A guarantee is provided for high-wind-power grid connection, and the use of an energy storage device for frequency modulation is reduced; and commercial development of the fan can be promoted.

Description

technical field [0001] The invention relates to the technical field of frequency control of wind power generators, in particular to a controllable short-term frequency support method for wind power generators suitable for low-frequency disturbances. Background technique [0002] Due to the use of advanced power electronic converter devices in doubly-fed wind turbines, advanced control functions such as maximum power tracking operation, decoupling control of active power and reactive power, etc. Grid frequency decoupling; this means that after a disturbance occurs, wind turbines cannot provide inertial response and primary frequency regulation capabilities like synchronous motors; especially with the increasing penetration of wind power, the lack of inertial response and primary frequency regulation has become increasingly prominent. This will lead to serious system frequency deviation, and may even trigger the underfrequency load shedding device. [0003] So far, the relati...

AI Technical Summary

Problems solved by technology

Li Yujun and other scholars pointed out that due to the large amount of noise in the grid frequency change rate, the active power increment cannot be accurately calculated when simulating the inertial response; researchers such as Jan Van De Vyver proposed that droop control can be used as an optional short-term frequency control technology; however, in When simulating droop control, due to the influence of the constant droop control coefficient, the fan cannot make full use of the rotational kinetic energy stored in the rotor, resulting in the limitation of the frequency support capability of the fan; in addition, in the scene of low fan rotor speed, excessive energy release is easy to cause The speed of the fan is reduced to the minimum speed, which will cause the instability of the fan speed and the serious drop of the secondary frequency

Images