An inertia response speed recovery control method based on wind power estimation

Abstract

The invention relates to an inertia response speed recovery control method based on wind power estimation, includes real-time detection and collection of basic parameters of wind turbine generator system, obtaining a rotational speed differential signal d omega g Omega / dt of the generator, calculating the wind power Paero captured by the fan according to the collected basic parameters of the windturbine and the rotational speed differential signal d omega g / dt of the generator, calculating the acceleration power DELTA PREC of the fan, and utilizing the formula Pe, ref=Pa-DELTA PREC calculation needs to switch to the normal MPPT control mode after the power set values Pe, ref and the fan speed are restored to near the optimal speed during the unit speed recovery period. The invention hasthe advantages that: the speed recovery is carried out according to the estimated wind power captured by the double-fed fan, and the sudden change during the speed recovery is avoided. The speed of the unit is restored by varying acceleration power, and the step curve is adopted to further ensure the speed smoothing and avoid the influence on the frequency of the power grid.

Description

technical field [0001] The invention relates to the field of wind turbine control, in particular to an inertia response speed recovery control method based on wind power estimation. Background technique [0002] The virtual inertia control of double-fed wind turbines can better provide inertia support for the power system and improve the system's ability to maintain frequency levels. Since the kinetic energy stored in the rotating elements of the doubly-fed fan is limited and the speed can only be changed within the safe operating range, the virtual inertia control capability of the fan is limited, generally only in a short period of time (a dozen seconds) after the system has an abnormal load change ) to provide frequency support, after which the wind turbine must resume normal operation, that is, the speed should be restored to the optimal speed corresponding to the maximum power tracking (MPPT) control, so it is difficult for the wind turbine to compensate for the large l...

AI Technical Summary

Problems solved by technology

Since the kinetic energy stored in the rotating components of the doubly-fed fan is limited and the speed can only be changed within the safe operating range, the virtual inertia control capability of the fan is limited, generally only in a short period of time (a dozen seconds) after an abnormal load change occurs in the system. ) to provide frequency support, after which the wind turbine must return to normal operation, that is, the speed should be restored to the optimal speed corresponding to the maximum power tracking (MPPT) control, so it is difficult for the wind turbine to compensate for the large load disturbance of the system (such as the synchronous generator exiting Active power unbalance caused by running or large load grid connection, etc.)

Moreover, even if the wind power virtual inertia control can fully compensate other total active power imbalances of the system, the support of the system frequency by the virtual inertia control can only last for a short period of time, and then the speed must be restored to return to the normal MPPT operating state

[0003] After the wind power virtual inertia control ends, the fan speed may drop sharply, resulting in a sharp drop in the captured wind power

In this way, in the process of restoring the speed of the wind turbine, the active power of the wind power must be greatly reduced (in order to restore the speed, the active power output by the wind power must be less than the captured wind power), which may have an extremely adverse impact on the system frequency

[0004] At present, it is difficult to select appropriate control parameters (k p,rec and k i,rec ): if k p,rec and k i,rec If the value is too small, the speed recovery cannot be performed or the speed recovery process is too slow; if k p,rec and k i,rec If the value is too large, the active power output of the fan will be greatly reduced, which will have an adverse effect on the system frequency

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