A wind farm-oriented subsynchronous oscillation damping control method

Abstract

A wind farm-oriented subsynchronous oscillation damping control method includes constructing a model for calculating an oscillation damping signal, calculating the damping signal in real time according to the oscillation condition, for suppressing the oscillation, calculating the optimized control parameters of A, B and C three-phase, and optimizing the control parameters when the subsynchronous component in the voltage signal is high, to improve the suppression effect. The method considers the design of the subsynchronous oscillation controller parameters of different voltage and current power systems, meets the needs of most application scenarios, and overcomes the difficulty that the current for suppressing the subsynchronous oscillation cannot be optimal when the oscillation component in the current or voltage changes by optimizing the control parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system stability control, in particular to a wind farm-oriented subsynchronous oscillation damping control method. BACKGROUND

[0002] In order to improve the transmission capacity of high-voltage lines and save the power transmission corridor, series compensation capacitors are generally added to high-voltage transmission lines or high-voltage direct current transmission methods are used. However, these devices often cause unstable subsynchronous oscillation in the power system, which seriously affects the stable operation of the power grid. At present, the subsynchronous damping controller based on power electronic converters can be added to the power grid to suppress subsynchronous oscillation. The power electronic converter takes the control output signal calculated by the subsynchronous controller as the reference signal and sends out the current for suppressing subsynchronous oscillation. However, when the oscillation component in the current or voltage changes, the current for suppressing subsynchronous oscillation often cannot achieve the optimal, therefore, a method for designing an optimal subsynchronous oscillation suppression current signal is needed. SUMMARY

[0003] In view of the above problems, the present application designs a wind farm-oriented subsynchronous oscillation damping control method, which can improve the stability of the power system to improve the output capability of the power electronic converter and improve the subsynchronous oscillation suppression capability.

[0004] A wind farm-oriented subsynchronous oscillation damping control method, the method comprises calculating a damping signal in real time according to the oscillation condition for suppressing oscillation; and optimizing the control parameters when the subsynchronous component in the voltage signal is high to improve the suppression effect.

[0005] The specific method for calculating the oscillation damping signal is as follows:

[0006]

[0007] Wherein, i A-OUT (s), i B-OUT (s), i C-OUT (s) are the oscillation damping signals of three-phase A, B and C, respectively, i A-IN (s), i B-IN (s), i C-IN (s) are three-phase current signals input by the wind farm line, u A-IN (s), u B-IN (s), u C-IN (s) are three-phase voltage signals input by the wind farm line, the current signal input by the wind farm line and the voltage signal input by the wind farm line are multiplied by the transfer function to obtain G i (s) and G u (s), respectively, and s is the frequency domain.

[0008] in, K i For current signal gain; K u For voltage signal gain;

[0009] G F (s) is the transfer function of the bandpass filter. ω F Let ξ be the center angular frequency, ξ be the damping coefficient, and F be the bandpass filter.

[0010] G com,i (s) is the proportional phase-shift transfer function of the current signal. T ai These are the phase shift parameters for the current signal;

[0011] G com,u (s) is the voltage signal proportional phase-shift transfer function. T au These are phase-shifting parameters for the voltage signal;

[0012] H A-IN (s), H B-IN (s), H C-IN (s) represent the optimized control parameters for phases A, B, and C, respectively, wherein the optimized phase A control parameter H... A-IN The specific method for calculating (s) is as follows:

[0013] If u A-IN (s)≤i A-IN (s), then H A-IN (s) = 1;

[0014] If u A-IN (s)>i A-IN (s), then

[0015] The optimized B-phase control parameter H B-IN The specific method for calculating (s) is as follows:

[0016] If u B-IN (s)≤i B-IN (s), then H B-IN (s) = 1;

[0017] If u B-IN (s)>i B-IN (s), then

[0018] The optimized C-phase control parameter H C-IN The specific method for calculating (s) is as follows:

[0019] If u C-IN (s)≤i C-IN(s), then H C-IN (s) = 1;

[0020] If u C-IN (s) > i C-IN (s), then By calculating the control parameters, the output oscillation damping signal is optimized, and the damping oscillation is effectively suppressed.

[0021] Preferably, the current collector and the voltage collector are used to collect the input current signal i A-IN (s), i B-IN (s), i C-IN (s) and the input voltage signal u A-IN (s), u B-IN (s), u C-IN (s).

[0022] Preferably, the damping coefficient ξ is 0.5.

[0023] The application provides a wind farm-oriented subsynchronous oscillation damping control method, which considers the design of different voltage and current power system subsynchronous oscillation controller parameters, meets the needs of most application scenarios, and overcomes the difficulty that the current cannot reach the optimal subsynchronous oscillation suppression when the oscillation component in the current or voltage changes. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application provides a wind farm-oriented subsynchronous oscillation damping control method. Figure 1 is a schematic diagram of the wind farm-oriented subsynchronous oscillation damping control method. DETAILED DESCRIPTION

[0025] In order to make the technical scheme of the application easier to understand, the application discloses a wind farm-oriented subsynchronous oscillation damping control method, which is described clearly and completely in combination with specific embodiments.

[0026] Step 100: constructing an oscillation damping signal calculation model

[0027]

[0028] Preferably, the current collector and the voltage collector are used to collect the input current signal i A-IN (s), i B-IN (s), i C-IN (s) and the input voltage signal u A-IN (s), u B-IN (s), u C-IN (s)

[0029] Step 110: Perform transfer function multiplication on the current signal and voltage signal input to the wind farm line to obtain G. i (s) and G u (s), where s is in the frequency domain:

[0030] K i For current signal gain, 0 <K i <100; K u For voltage signal gain, 0 <K u <100;

[0031] G F (s) is the transfer function of the bandpass filter. ω F The center angular frequency, 0 < ω F <314, ξ is the damping coefficient, F is the bandpass filter, and generally, the value of ξ is 0.5;

[0032] G com,i (s) is the proportional phase-shift transfer function of the current signal. T ai For current signal phase shift parameters, 0 <T ai <1;

[0033] G com,u (s) is the voltage signal proportional phase-shift transfer function. T au For voltage signal phase shift parameters, 0 <T au <1.

[0034] Step 120: Calculate the optimal control parameters H for phases A, B, and C. A-IN (s), H B-IN (s), H C-IN (s):

[0035] The optimized A-phase control parameter H A-IN The specific method for calculating (s) is as follows:

[0036] If u A-IN (s)≤i A-IN (s), then H A-IN (s) = 1;

[0037] If u A-IN (s)>i A-IN (s), then

[0038] The optimized B-phase control parameter H B-IN The specific method for calculating (s) is as follows:

[0039] If uB-IN (s)≤i B-IN (s), then H B-IN (s) = 1;

[0040] If u B-IN (s)>i B-IN (s), then

[0041] The optimization C phase control parameter H C-IN (s) is calculated as follows:

[0042] If u C-IN (s)≤i C-IN (s), then H C-IN (s) = 1;

[0043] If u C-IN (s)>i C-IN (s), then

[0044] It should be noted that for those skilled in the art, without departing from the principles and spirit of the present application, a number of improvements, substitutions, modifications and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A wind farm oriented subsynchronous oscillation damping control method, characterized by, The specific method for calculating the subsynchronous oscillation damping signal is: wherein, i A-OUT (s), i B-OUT (s), i C-OUT (s) are the oscillation damping signals of three phases A, B, C respectively, and the i A-IN (s), i B-IN (s), i C-IN (s) are three-phase current signals inputted by the wind farm line, u A-IN (s), u B-IN (s), u C-IN (s) are three-phase voltage signals inputted by the wind farm line, and the current signals inputted by the wind farm line and the voltage signals inputted by the wind farm line are multiplied by transfer functions respectively to obtain G i (s) and G u (s), and s is a frequency domain. wherein, K i is the current signal gain; K u is the voltage signal gain; G F (s) is a bandpass filter transfer function, ω F is the center angular frequency, ξ is the damping coefficient, and F is the bandpass filter; G com,i (s) is a current signal proportional phase shift transfer function, T ai is a current signal phase shift parameter; G com,u (s) is a voltage signal proportional phase shift transfer function, T au is a voltage signal phase shift parameter; H A-IN (s), H B-IN (s), H C-IN (s) are the optimized control parameters of the three phases A, B and C respectively, and the calculation method of the optimized control parameter H A-IN (s) is specifically as follows: If u A-IN (s)≤i A-IN (s), then H A-IN (s) = 1; If u A-IN (s) > i A-IN (s), then The optimization B phase control parameter H B-IN The calculation method of (s) is specifically: If u B-IN (s)≤i B-IN (s), then H B-IN (s) = 1; If u B-IN (s) > i B-IN (s), then The optimized C-phase control parameter H C-IN The calculation method of (s) is specifically: If u C-IN (s)≤i C-IN (s), then H C-IN (s) = 1; If u C-IN (s) > i C-IN (s), then 2. The wind farm oriented subsynchronous oscillation damping control method according to claim 1, characterized in that, The current signal i inputted by the wind farm line is collected in real time by the current collector and the voltage collector respectively A-IN (s), i B-IN (s), i C-IN (s) and the voltage signal u inputted by the wind farm line A-IN (s), u B-IN (s), u C-IN (s).

3. The wind farm oriented subsynchronous oscillation damping control method of claim 1, wherein, The damping coefficient ξ is 0.5.

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