阅读说明：本技术 一种双馈风电机组转子控制方法及装置 (Rotor control method and device for doubly-fed wind turbine generator ) 是由 田新首 李琰 迟永宁 汤海雁 刘超 苏媛媛 于 2020-03-30 设计创作，主要内容包括：本发明涉及一种双馈风电机组转子控制方法及装置,包括：获取上一调频时段双馈风电机组的动能变化量和风能捕获量；根据上一调频时段双馈风电机组的动能变化量和风能捕获量确定上一调频时段双馈风电机组的调频能量变化量；基于上一调频时段双馈风电机组的调频能量变化量控制当前调频时段双馈风电机组的转子转速；本发明将双馈风电机组的调频能量变化量作为双馈风电机组转子控制时的影响因素,提高了控制双馈风电机组转子转速的精度以及机组的运行稳定性。(The invention relates to a method and a device for controlling a rotor of a doubly-fed wind turbine generator, which comprise the following steps: acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period; determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period; controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period; according to the invention, the variable quantity of the frequency modulation energy of the double-fed wind turbine generator is used as an influence factor when the rotor of the double-fed wind turbine generator is controlled, so that the precision of controlling the rotating speed of the rotor of the double-fed wind turbine generator and the operation stability of the double-fed wind turbine generator are improved.)

1. A rotor control method for a doubly-fed wind turbine generator is characterized by comprising the following steps:

acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period;

determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

2. The method of claim 1, wherein the obtaining of the kinetic energy variation and wind energy capture of the doubly-fed wind turbine generator during the last frequency modulation period comprises:

the method comprises the steps of obtaining the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period, and determining the kinetic energy variation of the double-fed wind turbine generator at the last frequency modulation period according to the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period;

and determining the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period according to the active power of the double-fed wind turbine generator set in the last frequency modulation period.

3. The method according to claim 2, wherein the rotor speed ω of the doubly-fed wind turbine at the initial time of the last frequency modulation period is obtained as follows:

when P is present₀≤P_minWhen ω is ω ═ ω_min；

When P is present_min＜P₀＜P_maxThen, ω is equal to the actual sample value;

when P is present₀≥P_maxWhen ω is ω ═ ω_max；

Wherein, P₀The active power, omega, of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxIs the upper limit value, P, of the rotor speed of the doubly-fed wind turbine_minIs the active power lower limit value, P, of the doubly-fed wind turbine generator_maxThe active power upper limit value of the doubly-fed wind turbine generator is obtained.

4. The method of claim 2, wherein the determining the kinetic energy variation of the doubly-fed wind turbine generator set in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine generator set at the initial moment in the last frequency modulation period comprises:

determining the kinetic energy variation delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_D：

In the formula, P_DIs the number of pole pairs, J, of the doubly-fed wind turbine_DOmega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, and omega ∈ [ omega ] is the total rotational inertia of the doubly-fed wind turbine generator_min,ω_max]，ω_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxThe upper limit value of the rotor rotating speed of the doubly-fed wind turbine generator is shown.

5. The method of claim 2, wherein the determining the wind energy capture amount of the doubly-fed wind turbine generator in the last frequency modulation period according to the active power of the doubly-fed wind turbine generator in the last frequency modulation period comprises:

determining the wind energy capture quantity delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_P：

In the formula, P_W(t) is the active power of the doubly-fed wind turbine generator at the frequency modulation time t in the last frequency modulation period, P₀The active power t of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_onFor the initial time of the last frequency-modulated period, t_offAt the end of the last FM period, t ∈ [ t ]_on,t_off]。

6. The method of claim 1, wherein the determining the variation of the frequency modulation energy of the doubly-fed wind turbine generator in the last frequency modulation period according to the variation of the kinetic energy and the wind energy capture of the doubly-fed wind turbine generator in the last frequency modulation period comprises:

determining the frequency modulation energy variation delta E of the double-fed wind turbine generator in the last frequency modulation period according to the following formula:

ΔE＝ΔE_D+ΔE_P+M

in the formula,. DELTA.E_DThe kinetic energy variation, delta E, of the double-fed wind turbine generator set in the last frequency modulation period_PThe wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period is M, and the energy loss of the double-fed wind turbine generator in the last frequency modulation period is M.

7. The method of claim 1, wherein the controlling the rotor speed of the current frequency modulation period doubly-fed wind turbine generator based on the frequency modulation energy variation of the last frequency modulation period doubly-fed wind turbine generator comprises:

determining the active power target value P of the doubly-fed wind turbine generator set according to the following formula_ref：

P_ref＝P′_ref+ΔPΔE

Of formula (II) to (III)'_refThe active power reference value of the double-fed wind turbine generator is obtained, delta P is the active power variation of the double-fed wind turbine generator, and delta E is the frequency modulation energy variation of the double-fed wind turbine generator in the last frequency modulation period;

and taking the active power target value of the doubly-fed wind turbine generator as the input of a rotor variable frequency controller, and controlling the rotor rotating speed of the doubly-fed wind turbine generator at the current frequency modulation time period by using a control signal generated by the rotor variable frequency controller.

8. The method of claim 7, wherein the active power reference value P 'of the doubly-fed wind turbine generator set is determined according to'_ref：

In the formula, ω_refThe rotor speed reference value is the rotor speed reference value of the doubly-fed wind turbine generator, omega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, K is the proportional coefficient of the rotating speed controller, and T is the integral time constant of the rotating speed controller.

9. The method of claim 7, wherein the active power variation Δ P of the doubly-fed wind turbine is determined according to the following formula:

in the formula, K_fIs the differential coefficient and f is the grid frequency.

10. A double-fed wind turbine generator rotor control device is characterized in that the device comprises:

the acquiring unit is used for acquiring the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period;

the determining unit is used for determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and the control unit is used for controlling the rotor rotating speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

Technical Field

The invention relates to the technical field of new energy control, in particular to a method and a device for controlling a rotor of a doubly-fed wind turbine generator.

Background

With the rapid development of global wind power generation and the rapid increase of installed capacity of fans, the construction of a large-scale grid-connected wind power plant becomes an effective way for efficiently utilizing wind energy. However, wind power has the characteristics of intermittency, volatility, inverse peak load regulation and the like, and large-scale wind power integration enables the power balance and frequency modulation difficulty of a system to be increased continuously, so that challenges are provided for the aspects of operation control, protection, scheduling and the like of the system.

The double-fed wind turbine generator can utilize the self-rotation kinetic energy of the generator to participate in system frequency modulation, the inertia of the generator is not reduced when the generator operates based on maximum power tracking control, and the inertia effect of the generator can be expressed through additional frequency control. The frequency control of the doubly-fed wind turbine generator is simultaneously influenced by the disturbance type of a power grid and the operation condition of the generator, but at present, the research on the frequency control of the doubly-fed wind turbine generator mainly focuses on realizing the frequency change of a response system, a frequency controller lacks the consideration on the operation characteristics of the doubly-fed wind turbine generator, the precision of a rotor of the doubly-fed wind turbine generator is controlled to be low, and the operation stability of the doubly-fed wind turbine generator is poor.

Therefore, when the rotor of the doubly-fed wind turbine generator is controlled, how to fully apply the operating characteristics of the doubly-fed wind turbine generator so as to improve the precision of controlling the rotating speed of the rotor of the doubly-fed wind turbine generator is a problem to be solved in the field.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method and a device for controlling a rotor of a doubly-fed wind turbine generator, which take the operating characteristics of the rotor of the doubly-fed wind turbine generator in a frequency modulation period into consideration when the rotor of the doubly-fed wind turbine generator is controlled, so as to improve the precision of controlling the rotating speed of the rotor of the doubly-fed wind turbine generator and the operating stability of the doubly-fed wind turbine generator.

The purpose of the invention is realized by adopting the following technical scheme:

the invention provides a rotor control method of a doubly-fed wind turbine generator, which is improved in that the method comprises the following steps:

acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period;

determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

Preferably, the acquiring the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period includes:

the method comprises the steps of obtaining the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period, and determining the kinetic energy variation of the double-fed wind turbine generator at the last frequency modulation period according to the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period;

and determining the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period according to the active power of the double-fed wind turbine generator set in the last frequency modulation period.

Further, the rotor speed ω of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period is obtained according to the following method:

when P is present₀≤P_minWhen ω is ω ═ ω_min；

When P is present_min≤P₀≤P_maxThen, ω is equal to the actual sample value;

when P is present₀≥P_maxWhen ω is ω ═ ω_max；

Wherein, P₀The active power, omega, of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxIs the upper limit value, P, of the rotor speed of the doubly-fed wind turbine_minIs the active power lower limit value, P, of the doubly-fed wind turbine generator_maxThe active power upper limit value of the doubly-fed wind turbine generator is obtained.

Further, the kinetic energy variation of the last frequency modulation period double-fed wind turbine generator set is determined according to the rotor speed of the last frequency modulation period initial moment double-fed wind turbine generator set, and the method comprises the following steps:

determining the kinetic energy variation delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_D：

In the formula, P_DIs the number of pole pairs, J, of the doubly-fed wind turbine_DOmega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, and omega ∈ [ omega ] is the total rotational inertia of the doubly-fed wind turbine generator_min,ω_max]，ω_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxThe upper limit value of the rotor rotating speed of the doubly-fed wind turbine generator is shown.

Further, the determining the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period according to the active power of the double-fed wind turbine generator set in the last frequency modulation period includes:

determining the wind energy capture quantity delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_P：

In the formula, P_W(t) is the active power of the doubly-fed wind turbine generator at the frequency modulation time t in the last frequency modulation period, P₀The active power t of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_onFor the initial time of the last frequency-modulated period, t_offAt the end of the last FM period, t ∈ [ t ]_on,t_off]。

Preferably, the determining the frequency modulation energy variation of the double-fed wind turbine generator set in the previous frequency modulation period according to the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator set in the previous frequency modulation period includes:

determining the frequency modulation energy variation delta E of the double-fed wind turbine generator in the last frequency modulation period according to the following formula:

ΔE＝ΔE_D+ΔE_P+M

in the formula,. DELTA.E_DThe kinetic energy variation, delta, of the double-fed wind turbine generator set in the last frequency modulation periodE_PThe wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period is M, and the energy loss of the double-fed wind turbine generator in the last frequency modulation period is M.

Preferably, the control of the rotor speed of the current frequency modulation period double-fed wind turbine generator based on the frequency modulation energy variation of the last frequency modulation period double-fed wind turbine generator comprises:

determining the active power target value P of the doubly-fed wind turbine generator set according to the following formula_ref：

P_ref＝P′_ref+ΔPΔE

Of formula (II) to (III)'_refThe active power reference value of the double-fed wind turbine generator is obtained, delta P is the active power variation of the double-fed wind turbine generator, and delta E is the frequency modulation energy variation of the double-fed wind turbine generator in the last frequency modulation period;

and taking the active power target value of the doubly-fed wind turbine generator as the input of a rotor variable frequency controller, and controlling the rotor rotating speed of the doubly-fed wind turbine generator at the current frequency modulation time period by using a control signal generated by the rotor variable frequency controller.

Further, determining an active power reference value P 'of the doubly-fed wind turbine generator set according to the following formula'_ref：

In the formula, ω_refThe rotor speed reference value is the rotor speed reference value of the doubly-fed wind turbine generator, omega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, K is the proportional coefficient of the rotating speed controller, and T is the integral time constant of the rotating speed controller.

Further, the active power variation delta P of the doubly-fed wind turbine generator is determined according to the following formula:

in the formula, K_fIs the differential coefficient and f is the grid frequency.

Based on the same invention concept, the invention also provides a double-fed wind turbine generator rotor control device, and the improvement is that the device comprises:

the acquiring unit is used for acquiring the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period;

the determining unit is used for determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and the control unit is used for controlling the rotor rotating speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

Compared with the closest prior art, the invention has the following beneficial effects:

the invention provides a method and a device for controlling a rotor of a doubly-fed wind turbine generator, which comprise the following steps: acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period; determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period; controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period; according to the invention, the variable quantity of the frequency modulation energy of the double-fed wind turbine generator is used as an influence factor when the rotor of the double-fed wind turbine generator is controlled, so that the precision of controlling the rotating speed of the rotor of the double-fed wind turbine generator is improved, the running stability of the generator in the speed regulation process is improved, and the frequency modulation requirement of a power grid can be met to the maximum extent; when the variable quantity of the frequency modulation energy of the double-fed wind turbine generator is obtained, the rotor speed, the active power and the frequency modulation loss of the generator are fully considered, and a foundation is laid for improving the operation stability of the generator.

Drawings

FIG. 1 is a flow chart of a rotor control method of a doubly-fed wind turbine generator according to the invention;

FIG. 2 is a schematic diagram of a rotor control device of a doubly-fed wind turbine generator set.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a rotor control method of a doubly-fed wind turbine generator, which comprises the following steps of:

acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period;

determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

In order to more clearly illustrate the objects of the present invention, the following embodiments are further explained.

In the embodiment of the present invention, the acquiring the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator in the previous frequency modulation period includes:

the method comprises the steps of obtaining the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period, and determining the kinetic energy variation of the double-fed wind turbine generator at the last frequency modulation period according to the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period;

and determining the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period according to the active power of the double-fed wind turbine generator set in the last frequency modulation period.

The rotor rotating speed omega of the double-fed wind turbine generator at the initial moment of the last frequency modulation period is obtained according to the following method:

when P is present₀≤P_minWhen ω is ω ═ ω_min；

When P is present_min≤P₀≤P_maxThen, ω is equal to the actual sample value;

when P is present₀≥P_maxWhen ω is ω ═ ω_max；

Wherein, P₀The active power, omega, of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxIs the upper limit value, P, of the rotor speed of the doubly-fed wind turbine_minIs the active power lower limit value, P, of the doubly-fed wind turbine generator_maxIs the active power upper limit value, omega, of the double-fed wind turbine generator_max＝1.2pu，ω_min＝0.7pu，P_minA value of 0.7pu, P_maxIs 1.2 pu.

Specifically, the above-mentioned kinetic energy variation amount that confirms last frequency modulation period double-fed wind turbine generator system according to the rotor speed of last frequency modulation period initial moment double-fed wind turbine generator system includes:

determining the kinetic energy variation delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_D：

In the formula, P_DIs the number of pole pairs, J, of the doubly-fed wind turbine_DOmega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, and omega ∈ [ omega ] is the total rotational inertia of the doubly-fed wind turbine generator_min,ω_max]，ω_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxThe upper limit value of the rotor rotating speed of the doubly-fed wind turbine generator is shown. Wherein, ω is_max＝1.2pu，ω_min＝0.7pu。

Specifically, the determining the wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period according to the active power of the double-fed wind turbine generator in the last frequency modulation period includes:

determining the wind energy capture quantity delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_P：

In the formula, P_W(t) is the active power of the doubly-fed wind turbine generator at the frequency modulation time t in the last frequency modulation period, P₀The active power t of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_onFor the initial time of the last frequency-modulated period, t_offAt the end of the last FM period, t ∈ [ t ]_on,t_off]。

In an embodiment of the present invention, the determining the variation of the frequency modulation energy of the double-fed wind turbine generator in the previous frequency modulation period according to the variation of the kinetic energy and the wind energy capture amount of the double-fed wind turbine generator in the previous frequency modulation period includes:

determining the frequency modulation energy variation delta E of the double-fed wind turbine generator in the last frequency modulation period according to the following formula:

ΔE＝ΔE_D+ΔE_P+M

in the formula,. DELTA.E_DThe kinetic energy variation, delta E, of the double-fed wind turbine generator set in the last frequency modulation period_PThe wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period is M, and the energy loss of the double-fed wind turbine generator in the last frequency modulation period is M.

In an embodiment of the present invention, the controlling the rotor speed of the current frequency modulation period based on the frequency modulation energy variation of the last frequency modulation period double-fed wind turbine generator includes:

determining the active power target value P of the doubly-fed wind turbine generator set according to the following formula_ref：

P_ref＝P′_ref+ΔPΔE

Of formula (II) to (III)'_refThe active power reference value of the double-fed wind turbine generator is obtained, delta P is the active power variation of the double-fed wind turbine generator, and delta E is the frequency modulation energy variation of the double-fed wind turbine generator in the last frequency modulation period;

and taking the active power target value of the doubly-fed wind turbine generator as the input of a rotor variable frequency controller, and controlling the rotor rotating speed of the doubly-fed wind turbine generator at the current frequency modulation time period by using a control signal generated by the rotor variable frequency controller.

Specifically, the active power of the doubly-fed wind turbine generator is determined according to the following formulaReference value P'_ref：

In the formula, ω_refThe rotor speed reference value is the rotor speed reference value of the doubly-fed wind turbine generator, omega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, K is the proportional coefficient of the rotating speed controller, and T is the integral time constant of the rotating speed controller.

Specifically, the active power variation Δ P of the doubly-fed wind turbine generator is determined according to the following formula:

in the formula, K_fIs the differential coefficient and f is the grid frequency.

In the embodiment of the present invention, the active power target value of the doubly-fed wind turbine generator is used as an input of the rotor variable frequency controller, and the control signal generated by the rotor variable frequency controller is used to control the rotor speed of the doubly-fed wind turbine generator in the current frequency modulation period, specifically, the active power target value of the doubly-fed wind turbine generator obtained by the present invention is used as the active power target value P in the document "interaction principle between the doubly-fed wind turbine generator and the static var generator and system oscillation characteristic research" published in volume 41 and 2 of 2017, month 2 in the power grid technology_refAnd the control on the rotor rotating speed of the current frequency modulation time period double-fed wind turbine generator is realized.

Based on the same inventive concept, the invention also provides a rotor control device of the doubly-fed wind turbine, as shown in fig. 2, the device comprises:

the acquiring unit is used for acquiring the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period;

the determining unit is used for determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period;

and the control unit is used for controlling the rotor rotating speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period.

In the embodiment of the present invention, the acquiring the kinetic energy variation and the wind energy capture amount of the double-fed wind turbine generator in the previous frequency modulation period includes:

the method comprises the steps of obtaining the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period, and determining the kinetic energy variation of the double-fed wind turbine generator at the last frequency modulation period according to the rotor rotating speed of the double-fed wind turbine generator at the initial moment of the last frequency modulation period;

and determining the wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period according to the active power of the double-fed wind turbine generator set in the last frequency modulation period.

The rotor rotating speed omega of the double-fed wind turbine generator at the initial moment of the last frequency modulation period is obtained according to the following method:

when P is present₀≤P_minWhen ω is ω ═ ω_min；

When P is present_min≤P₀≤P_maxThen, ω is equal to the actual sample value;

when P is present₀≥P_maxWhen ω is ω ═ ω_max；

Wherein, P₀The active power, omega, of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxIs the upper limit value, P, of the rotor speed of the doubly-fed wind turbine_minIs the active power lower limit value, P, of the doubly-fed wind turbine generator_maxIs the active power upper limit value, omega, of the double-fed wind turbine generator_max＝1.2pu，ω_min＝0.7puP_minA value of 0.7pu, P_maxIs 1.2 pu.

Specifically, the above-mentioned kinetic energy variation amount that confirms last frequency modulation period double-fed wind turbine generator system according to the rotor speed of last frequency modulation period initial moment double-fed wind turbine generator system includes:

determining the kinetic energy variation delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_D：

In the formula, P_DIs the number of pole pairs, J, of the doubly-fed wind turbine_DOmega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, and omega ∈ [ omega ] is the total rotational inertia of the doubly-fed wind turbine generator_min,ω_max]，ω_minIs the lower limit value, omega, of the rotor speed of the doubly-fed wind turbine_maxThe upper limit value of the rotor rotating speed of the doubly-fed wind turbine generator is shown.

Specifically, the determining the wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period according to the active power of the double-fed wind turbine generator in the last frequency modulation period includes:

determining the wind energy capture quantity delta E of the double-fed wind turbine generator set in the last frequency modulation period according to the following formula_P：

In the formula, P_W(t) is the active power of the doubly-fed wind turbine generator at the frequency modulation time t in the last frequency modulation period, P₀The active power t of the double-fed wind turbine generator at the initial moment of the last frequency modulation period_onFor the initial time of the last frequency-modulated period, t_offAt the end of the last FM period, t ∈ [ t ]_on,t_off]。

In an embodiment of the present invention, the determining the variation of the frequency modulation energy of the double-fed wind turbine generator in the previous frequency modulation period according to the variation of the kinetic energy and the wind energy capture amount of the double-fed wind turbine generator in the previous frequency modulation period includes:

determining the frequency modulation energy variation delta E of the double-fed wind turbine generator in the last frequency modulation period according to the following formula:

ΔE＝ΔE_D+ΔE_P+M

in the formula,. DELTA.E_DThe kinetic energy variation, delta E, of the double-fed wind turbine generator set in the last frequency modulation period_PThe wind energy capture amount of the double-fed wind turbine generator in the last frequency modulation period is M, and the energy loss of the double-fed wind turbine generator in the last frequency modulation period is M.

In an embodiment of the present invention, the controlling the rotor speed of the current frequency modulation period based on the frequency modulation energy variation of the last frequency modulation period double-fed wind turbine generator includes:

determining the active power target value P of the doubly-fed wind turbine generator set according to the following formula_ref：

P_ref＝P′_ref+ΔPΔE

Of formula (II) to (III)'_refThe active power reference value of the double-fed wind turbine generator is obtained, delta P is the active power variation of the double-fed wind turbine generator, and delta E is the frequency modulation energy variation of the double-fed wind turbine generator in the last frequency modulation period;

and taking the active power target value of the doubly-fed wind turbine generator as the input of a rotor variable frequency controller, and controlling the rotor rotating speed of the doubly-fed wind turbine generator at the current frequency modulation time period by using a control signal generated by the rotor variable frequency controller.

Specifically, determining an active power reference value P 'of the doubly-fed wind turbine generator set according to the following formula'_ref：

In the formula, ω_refThe rotor speed reference value is the rotor speed reference value of the doubly-fed wind turbine generator, omega is the rotor speed of the doubly-fed wind turbine generator at the initial moment of the last frequency modulation period, K is the proportional coefficient of the rotating speed controller, and T is the integral time constant of the rotating speed controller.

Specifically, the active power variation Δ P of the doubly-fed wind turbine generator is determined according to the following formula:

in the formula, K_fIs the differential coefficient and f is the grid frequency.

In summary, the method and device for controlling the rotor of the doubly-fed wind turbine generator provided by the invention comprise the following steps: acquiring kinetic energy variation and wind energy capture quantity of the double-fed wind turbine generator in the last frequency modulation period; determining the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period according to the kinetic energy variation and wind energy capture amount of the double-fed wind turbine generator set in the last frequency modulation period; controlling the rotor speed of the double-fed wind turbine generator set in the current frequency modulation period based on the frequency modulation energy variation of the double-fed wind turbine generator set in the last frequency modulation period; according to the invention, the variable quantity of the frequency modulation energy of the double-fed wind turbine generator is used as an influence factor when the rotor of the double-fed wind turbine generator is controlled, so that the precision of controlling the rotating speed of the rotor of the double-fed wind turbine generator is improved, the running stability of the generator in the speed regulation process is improved, and the frequency modulation requirement of a power grid can be met to the maximum extent; when the variable quantity of the frequency modulation energy of the double-fed wind turbine generator is obtained, the rotor speed, the active power and the frequency modulation loss of the generator are fully considered, and a foundation is laid for improving the operation stability of the generator.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.