CN111769577A - A kind of automatic power generation control method and device including wind and solar power system - Google Patents

Abstract

The invention discloses an automatic power generation control method and device of a wind-solar power system, which relate to the field of power system frequency modulation and comprise the following steps: (1) establishing a randomness model of control deviation of a region containing a wind-solar power system; (2) establishing an energy storage area control model, establishing an energy storage output model in an area interconnection system, and controlling the total active power difference of the power system; (3) and formulating an energy storage participation power grid AGC control strategy, partitioning energy storage output according to the average value of ACE, and further determining an energy storage control strategy. The energy storage AGC method of the wind-light-containing power system considering the random ACE can solve the negative influence of ACE uncertainty on the stability of the power system.

Description

A kind of automatic power generation control method and device including wind and solar power system

technical field

The present application belongs to the technical field of energy storage and frequency regulation, and in particular relates to an automatic power generation control method and device including a wind and solar power system.

Background technique

The power and frequency regulation of the tie line of the regional interconnected power grid is the main condition to maintain the stability of the system. Automatic generation control (AGC) is an important means to achieve the balance of power generation and load power, and to ensure the stability of grid frequency and tie line power. In recent years, with the vigorous development of renewable energy sources such as wind and solar, the frequency regulation of conventional units has been unable to meet the frequency regulation of the power system. As an auxiliary frequency regulation method, energy storage has a good application prospect in the AGC control of high-proportion wind and solar power systems.

Although the influence of wind power and photovoltaics on frequency is considered in the current research, the ACE model is still uncertain, which will negatively affect the frequency regulation of the power system and the auxiliary frequency regulation of energy storage, and even affect the stability of the power system. At the same time, the ACE model is uncertain, and the energy storage control strategy will change accordingly.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: in order to solve the problem that the uncertainty of the ACE model in the prior art has a negative impact on the frequency modulation of the power system and the auxiliary frequency modulation of the energy storage, and even affects the stability of the power system.

In order to solve the above technical problems, the present invention provides an automatic power generation control method and device for a wind and solar power system that considers randomness ACE. It can also cope with the situation where other loads are connected to the system.

The technical scheme adopted by the present invention to solve its technical problems is:

A first aspect of the present invention provides an automatic power generation control method including a wind and solar power system, including:

According to the calculated randomness area control deviation ACE, the energy storage output is divided into zones, namely dead zone, normal regulation zone, sub-emergency regulation zone and emergency regulation zone;

When 0≤|ACE|≤|ACE| _dead , it is determined that the value of ACE is in the dead zone range, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0, and |ACE| _dead represents the dead zone limit;

When |ACE| _dead <|ACE|≤|ACE| _regular , it is determined that the value of ACE is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio, and |ACE| _regular means normal Adjustment zone boundaries;

When |ACE| _regular <|ACE|≤|ACE| _emergency , it is determined that the value of ACE is within the range of the sub-emergency regulation area, and the traditional unit has been unable to meet the requirements of the system frequency regulation, and the energy storage performs frequency regulation with the maximum power, |ACE| _emergency means the boundary of the sub-emergency regulation area;

When |ACE|>|ACE| _emergency , it is determined that the value of ACE is within the range of the emergency regulation area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0.

A second aspect of the present invention provides an automatic power generation control device including a wind and solar power system, comprising:

The partition module is used to partition the energy storage output according to the calculated randomness area control deviation ACE, that is, the dead zone, the normal adjustment area, the sub-emergency adjustment area and the emergency adjustment area;

The first judgment module is used for when 0≤|ACE|≤|ACE| _dead , the value of ACE is in the dead zone range, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0, |ACE| _dead represents the dead zone limit;

The second judgment module is used for when |ACE| _dead <|ACE|≤|ACE| _regular , the value of ACE is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio. |ACE| _regular represents the boundary of the normal regulatory region;

The third judgment module is used for when |ACE| _regular <|ACE|≤|ACE| _emergency , the value of ACE is within the range of the sub-emergency regulation area, the traditional unit can no longer meet the requirements of the system frequency regulation, and the energy storage is at the maximum power Perform frequency modulation, |ACE| _emergency indicates the limit of the sub-emergency regulation area;

The fourth judgment module is used for when |ACE|>|ACE| _emergency , the value of ACE is within the range of the emergency adjustment area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0.

The beneficial effects of the present invention are: the technical solution of the present invention is feasible and effective, and the strategy of energy storage participating in the frequency regulation of the power grid provided by the present invention can not only cope with the scenario of random wind and solar access to the power system, but also cope with other load access systems Case.

Description of drawings

The technical solutions of the present application will be further described below with reference to the accompanying drawings and embodiments.

Fig. 1 is the method flow chart of the embodiment of the present application;

FIG. 2 is a schematic diagram of a partition of an energy storage output according to an embodiment of the present application.

Detailed ways

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

The technical solutions of the present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

Example 1

This embodiment provides an automatic power generation control method including a wind and solar power system, as shown in FIG. 1 , including:

S1: According to the calculated randomness area control deviation ACE, the energy storage output is divided into zones, namely dead zone, normal regulation zone, sub-emergency regulation zone and emergency regulation zone;

S2: When 0≤|ACE|≤|ACE| _dead , it is determined that the value of ACE is in the dead zone, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0, and |ACE| _dead indicates the dead zone limit;

S3: When |ACE| _dead <|ACE|≤|ACE| _regular , it is determined that the value of ACE is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio, |ACE| _regular Indicates the boundary of the normal regulation zone;

S4: When |ACE| _regular <|ACE|≤|ACE| _emergency , it is determined that the value of ACE is within the range of the sub-emergency regulation area, the traditional unit can no longer meet the requirements of the system frequency regulation, and the energy storage is used for frequency regulation with maximum power, | ACE| _emergency represents the boundary of the sub-emergency regulation area;

S5: When |ACE|>|ACE| _emergency , it is determined that the value of ACE is within the range of the emergency regulation area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0.

In this embodiment, by establishing a random model of the regional control deviation of the wind-solar power system, the random regional control deviation ACE is obtained by calculation, and according to the size of the calculated random regional control deviation ACE, the action interval of the energy storage is divided into dead zones. In the dead zone, 0≤|ACE|≤|ACE| _dead ; in the normal adjustment area, |ACE| _dead <| ACE|≤|ACE| _regular ; Secondary emergency adjustment area, |ACE| _regular <|ACE|≤|ACE| _emergency ; Emergency adjustment area, |ACE|>|ACE| _emergency .

Then, according to the interval in which the ACE is located, the energy storage output is controlled.

Optionally, the calculation method of the randomness area control deviation ACE in this embodiment is:

The wind speed and light intensity are simulated by Weibull distribution and beta distribution, and then the random output model of scenery is obtained;

A random model with regional control deviation of wind-solar power system is established, namely:

表示频率波动，

表示联络线功率波动，B为频率偏差系数。in,

represents the frequency fluctuation,

Indicates the power fluctuation of the tie line, and B is the frequency deviation coefficient.

In this embodiment, the wind speed and the light intensity are simulated by the Weibull distribution and the beta distribution, so as to obtain the random output of the scenery.

S11: Establishment of a stochastic model for wind power processing

According to the two-parameter Weibull distribution, the wind speed probability density function f(v) can be obtained:

And further get the wind speed probability distribution function F(v):

where v is the wind speed; k is the shape parameter; c is the scale parameter.

By calculating the average value and standard value of the actual wind speed, the values of the two parameters of the Weibull distribution can be obtained, and the random wind speed can be obtained:

Fan random output P _wind :

k₂＝-k₁v_ci；v_ci、v_co、v_r分别为风电机组的切入风速、切出风速和额定风速，m/s；P_wtr为风机额定功率，MW。where:

k ₂ =-k ₁ v _ci ; v _ci , v _co , and v _r are the cut-in wind speed, cut-out wind speed and rated wind speed of the wind turbine, m/s; P _wtr is the rated power of the wind turbine, MW.

S12: Establishment of stochastic model of photovoltaic output

The solar cell array is the core of the photovoltaic power generation system, and its output is directly related to the light irradiation intensity E, the total area S of the solar cell array and the photoelectric conversion efficiency η. The output model is:

P _p =ESn

Photovoltaic power generation uses beta distribution to simulate solar radiation intensity, and obtains the probability density function:

where E _m is the maximum value of E, α and β are the two shape parameters of beta distribution; by inverting the above probability density function f(E), the cumulative probability distribution function F(E) of E can be obtained:

Thereby, the random value of the light radiation intensity E is obtained:

E=E _M *F ^-1 (E)

S13: Establishment of stochastic model with regional control deviation (ACE) of wind-solar power system

如下：ACE is mainly determined by the frequency and the power of the tie line. In this embodiment, the random active power output changes of wind power and photovoltaics with frequency deviation Δf are considered.

as follows:

为风电出力功率；

为光伏出力功率。where:

output power for wind power;

output power for photovoltaics.

Under the premise of ignoring the load and other factors, the wind and light are added to the system as disturbances, and the influence of the system output and the moment of inertia M and damping coefficient D of the power system are also considered, and the change equation of frequency is obtained:

和联络线功率同步系数T_tie，联络线功率P_T的变化方程如下:In the formula: _ΔPG is the power adjustment amount. In the two-region interconnected system, consider the frequency fluctuation

and the tie line power synchronization coefficient T _tie , the change equation of the tie line power P _T is as follows:

为两个区域各自的频率波动。根据得到的频率和联络线功率波动方程，可得到随机性区域控制偏差(ACE)：In the formula: K _G is the unit adjustment power,

for the respective frequency fluctuations of the two regions. According to the obtained frequency and tie-line power fluctuation equations, the randomness area control deviation (ACE) can be obtained:

Among them, B is the frequency deviation coefficient.

Optionally, this embodiment further includes the step of establishing a random model of energy storage output, specifically:

In this embodiment, a battery energy storage system is used to control the random regional control deviation ACE, and a random model of energy storage output is established, as follows:

Due to the uncertainty of ACE, it is more difficult to adjust the frequency band of the power system, and conventional units can no longer meet the frequency regulation requirements. In this embodiment, the two-region interconnected system is used as an example. In the AGC, the energy storage is connected to perform auxiliary frequency regulation.

In a single-zone control system, before adding energy storage, the total active power change of the system can be obtained:

Under the action of the governor and the reheat steam turbine, the traditional thermal power unit can obtain the equivalent power output ΔP _G :

ΔP _R =∫K·ACEdt

In the formula: ΔP _R is the control power of ACE; K is the gain of the integral controller; R is the adjustment coefficient of the system; T _g and T _t are the time constants of the governor and the reheat steam turbine, respectively.

After the energy storage is added, the total active power change of the system changes as follows:

In the formula: ΔP _BESS is the energy storage output.

In this embodiment, the battery energy storage system is used to directly control the ACE, and the stochastic model of the energy storage output is as follows:

This embodiment formulates the energy storage to participate in the grid AGC control strategy as follows:

As shown in Figure 1, the present invention uses the ACE average value as a signal to guide the energy storage action, and divides the energy storage action interval into four parts: dead zone, normal adjustment zone, secondary emergency adjustment zone and emergency adjustment zone according to the magnitude of the absolute value of ACE. an adjustment interval.

When 0≤|ACE|≤|ACE| _dead , the value of ACE is within the range of the dead zone, the disturbance to the system is small at this time, and the energy storage does not act, that is, ΔP _BESS = 0;

When |ACE| _dead <|ACE|≤|ACE| _regular , the value of ACE is within the range of the normal regulation area. At this time, the energy storage allocates the frequency modulation signal demand to the energy storage according to a certain proportion, and the energy storage is mainly responsible for high The proportion of frequency components, at this time:

In the formula: k is the control coefficient, which can be taken from 0.3 to 0.4.

When |ACE| _regular <|ACE|≤|ACE| _emergency , the value of ACE is within the range of the sub-emergency regulation area, and the traditional unit can no longer meet the requirements of the system frequency regulation. At this time, the energy storage needs to be frequency-regulated with the maximum power;

When |ACE|>|ACE| _emergency , the value of ACE is in the range of the emergency regulation area. At this time, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0.

The invention can effectively describe the uncertainty description of the regional tie line power and frequency deviation caused by wind power and photovoltaic disturbances, and can realize the AGC control under the continuous random disturbance of the wind and the wind, which is more in line with the system reality than the traditional deterministic ACE. In addition, the AGC frequency regulation strategy of the invention It can achieve effective auxiliary frequency modulation effect.

Example 2

This embodiment provides an automatic power generation control device including a wind and solar power system, including:

The partition module is used to divide the action range of the energy storage into dead zone, normal regulation zone, sub-emergency regulation zone and emergency regulation zone according to the calculated randomness zone control deviation ACE;

The first judgment module is used for when 0≤|ACE|≤|ACE| _dead , the value of ACE is in the dead zone range, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0;

The second judgment module is used for when |ACE| _dead <|ACE|≤|ACE| _regular , the ACE value is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio;

The third judgment module is used for when |ACE| _regular <|ACE|≤|ACE| _emergency , the value of ACE is within the range of the sub-emergency regulation area, the traditional unit can no longer meet the requirements of the system frequency regulation, and the energy storage is at the maximum power frequency modulation;

The fourth judgment module is used for when |ACE|>|ACE| _emergency , the value of ACE is within the range of the emergency adjustment area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0.

Optionally, this embodiment further includes a random area control deviation ACE calculation module for:

The wind speed and light intensity are simulated by Weibull distribution and beta distribution, and then the random output model of scenery is obtained;

A random model with regional control deviation of wind-solar power system is established, namely:

表示频率波动，

表示联络线功率波动，B为频率偏差系数。in,

represents the frequency fluctuation,

Indicates the power fluctuation of the tie line, and B is the frequency deviation coefficient.

Optionally, this embodiment further includes an energy storage output model building module for:

The stochastic model of energy storage output is established as follows:

Among them, ΔP _BESS is the energy storage output, _TBESS is the energy storage output response time constant, and t is the time.

For the specific implementation of this embodiment, please refer to Embodiment 1.

Taking the above ideal embodiments according to the present application as inspiration, and through the above descriptions, relevant personnel can make various changes and modifications without departing from the technical idea of the present application. The technical scope of this application is not limited to the content in the description, and the technical scope must be determined according to the scope of the claims.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a 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, etc.) 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 present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

Claims (7)

1. an automatic power generation control method containing a wind-solar power system, is characterized in that, comprising: According to the calculated randomness area control deviation ACE, the energy storage output is divided into zones, namely dead zone, normal regulation zone, sub-emergency regulation zone and emergency regulation zone; When 0≤|ACE|≤|ACE| _dead , it is determined that the value of ACE is in the dead zone range, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0, and |ACE| _dead represents the dead zone limit; When |ACE| _dead <|ACE|≤|ACE| _regular , it is determined that the value of ACE is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio, and |ACE| _regular means normal Adjustment zone boundaries; When |ACE| _regular <|ACE|≤|ACE| _emergency , it is determined that the value of ACE is within the range of the sub-emergency regulation area, and the traditional unit has been unable to meet the requirements of the system frequency regulation, and the energy storage performs frequency regulation with the maximum power, |ACE| _emergency means the boundary of the sub-emergency regulation area; When |ACE|>|ACE| _emergency , it is determined that the value of ACE is within the range of the emergency regulation area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0. 2. the automatic power generation control method containing wind-solar power system according to claim 1, is characterized in that, the calculation method of randomness area control deviation ACE is: The wind speed and light intensity are simulated by Weibull distribution and beta distribution, and then the random output model of scenery is obtained; A random model with regional control deviation of wind-solar power system is established, namely:

in,

represents the frequency fluctuation,

Indicates the power fluctuation of the tie line, and B is the frequency deviation coefficient. 3. The automatic power generation control method according to claim 2, characterized in that, further comprising the step of establishing a random model of energy storage output, specifically:

Among them, ΔP _BESS is the energy storage output; T _BESS is the response time constant of the energy storage output, and t represents the time. 4. the automatic power generation control method containing the wind-solar power system according to claim 3, is characterized in that, when the value of ACE is in the scope of the normal regulation area, the energy storage output is as follows:

Among them, k is the control coefficient, the value is 0.3～0.4. 5. An automatic power generation control device containing a wind-solar power system, characterized in that, comprising: The partition module is used to partition the energy storage output according to the calculated randomness area control deviation ACE, that is, the dead zone, the normal adjustment area, the sub-emergency adjustment area and the emergency adjustment area; The first judgment module is used for when 0≤|ACE|≤|ACE| _dead , the value of ACE is in the dead zone range, the disturbance to the system is small, and the energy storage does not act, that is, the energy storage output is 0, |ACE| _dead represents the dead zone limit; The second judgment module is used for when |ACE| _dead <|ACE|≤|ACE| _regular , the value of ACE is within the range of the normal regulation area, and the energy storage allocates the frequency modulation signal demand to the energy storage according to the set ratio. |ACE| _regular represents the boundary of the normal regulatory region; The third judgment module is used for when |ACE| _regular <|ACE|≤|ACE| _emergency , the value of ACE is within the range of the sub-emergency regulation area, the traditional unit can no longer meet the requirements of the system frequency regulation, and the energy storage is at the maximum power Perform frequency modulation, |ACE| _emergency indicates the limit of the sub-emergency regulation area; The fourth judgment module is used for when |ACE|>|ACE| _emergency , the value of ACE is within the range of the emergency adjustment area, the energy storage and traditional units can no longer meet the frequency regulation requirements, and the energy storage output is 0. 6. The automatic power generation control device containing a wind-solar power system according to claim 5, further comprising a randomness area control deviation ACE calculation module for: The wind speed and light intensity are simulated by Weibull distribution and beta distribution, and then the random output model of scenery is obtained; A random model with regional control deviation of wind-solar power system is established, namely:

in,

represents the frequency fluctuation,

Indicates the power fluctuation of the tie line, and B is the frequency deviation coefficient. 7. The automatic power generation control device containing a wind-solar power system according to claim 5, further comprising an energy storage output model building module for: The stochastic model of energy storage output is established as follows:

Among them, ΔP _BESS is the energy storage output; T _BESS is the response time constant of the energy storage output; t represents the time.

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