Auxiliary frequency modulation method and device based on new energy frequency modulation flexible polymer

Abstract

The invention provides an auxiliary frequency modulation method and device based on a new energy frequency modulation flexible polymer, and belongs to the field of power system frequency modulation. The method determines the corresponding target frequency modulation device for auxiliary frequency modulation based on the difference value between the power system frequency and the rated frequency, improves the flexibility of power system frequency modulation, obtains the droop control curve of the target frequency modulation device based on the preset expected frequency modulation speed information, and enables the droop control curve of the target frequency modulation device to be adjusted according to different operation and requirements. The adaptive adjustment control strategy improves the adaptability and stability of the system, thereby improving the frequency stability and response speed of the power system, and achieving the accurate control of the system frequency.

Description

Technical Field

[0001] The present invention relates to the field of power system frequency regulation, and in particular to an auxiliary frequency regulation method based on a new energy frequency regulation flexible polymer. Background Art

[0002] With the massive access of distributed renewable energy, the frequency regulation requirements of the power system have also changed. On the one hand, the randomness and volatility of renewable energy have brought challenges to the frequency stability of the power system; on the other hand, the access of renewable energy has also increased the complexity and uncertainty of the power system. Power system frequency regulation is an important part of ensuring the stable operation of the power grid. Therefore, how to effectively use distributed renewable energy for auxiliary frequency regulation has become an important issue facing the power system.

[0003] However, the droop control strategy of traditional frequency modulation methods based on renewable energy is often linear, and the droop control parameters are constant, which easily affects the stability and power quality of the power system and cannot achieve accurate control of the system frequency. Summary of the invention

[0004] The embodiment of the present invention provides an auxiliary frequency modulation method and device based on a new energy frequency modulation flexible polymer to solve the problem of being unable to achieve accurate control of the system frequency.

[0005] In a first aspect, an embodiment of the present invention provides an auxiliary frequency modulation method based on a new energy frequency modulation flexible polymer, comprising:

[0006] Obtaining the power system frequency, and determining whether the power system frequency is within the frequency modulation action range;

[0007] If the power system frequency is within the frequency modulation action interval, the target frequency modulation device in the new energy frequency modulation flexible aggregate is determined according to the difference between the power system frequency and the rated frequency; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate;

[0008] Based on the preset expected frequency modulation speed information, a droop control curve of the target frequency modulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the power system frequency, and the expected frequency modulation speed information is used to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device;

[0009] Based on the droop control curve, the output power of the target frequency regulation device is adjusted to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0010] In a possible implementation, obtaining the droop control curve of the target frequency modulation device based on preset expected frequency modulation speed information includes:

[0011] Obtaining the frequency interval in which the droop control curve acts;

[0012] Based on the expected frequency modulation speed information, determining the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval;

[0013] Obtaining a preset curve expression; wherein the preset curve expression includes parameters to be solved;

[0014] According to the power output values ​​of the target frequency regulation device at the boundary points and the median points of the frequency interval, the values ​​of the parameters to be solved in the preset curve expression are determined, and based on the values ​​of the parameters to be solved, the droop control curve of the target frequency regulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation device within the frequency interval and the frequency of the power system.

[0015] In a possible implementation, determining a target frequency regulation device in a new energy frequency regulation flexible aggregate according to a difference between the power system frequency and the rated frequency includes:

[0016] If the difference is a positive number, it is determined that the target frequency modulation device includes a photovoltaic inverter and an energy storage converter, and the working state of the energy storage converter is controlled to be a charging state;

[0017] If the difference is a negative number, it is determined that the target frequency modulation device includes a charging pile and an energy storage converter, and the working state of the energy storage converter is controlled to be a discharging state.

[0018] In a possible implementation, the frequency modulation action interval includes a first interval and a second interval;

[0019] The obtaining of the frequency interval of the droop control curve comprises:

[0020] If the target frequency modulation device includes a photovoltaic inverter and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the first interval; wherein the sum of the rated frequency of the power system and the first preset threshold is the first boundary point of the first interval, and the sum of the rated frequency and the second preset threshold is the second boundary point of the first interval; and the second preset threshold is greater than the first preset threshold;

[0021] If the target frequency modulation equipment includes a charging pile and an energy storage inverter, the frequency interval in which the droop control curve acts is determined to be the second interval; wherein the difference between the rated frequency and the second preset threshold is the first boundary point of the second interval, and the difference between the rated frequency and the first preset threshold is the second boundary point of the second interval.

[0022] In a possible implementation, the preset curve expression is a quadratic polynomial curve, and the parameters to be solved include quadratic term coefficients, linear term coefficients, and a constant term;

[0023] The step of determining the value of the parameter to be solved in the preset curve expression according to the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval, and obtaining the droop control curve of the target frequency modulation device based on the value of the parameter to be solved includes:

[0024] Solving the preset curve expression according to the power output values ​​of the target frequency modulation device at the first boundary point, the second boundary point and the median point of the frequency interval to determine the value of the quadratic term coefficient, the value of the linear term coefficient and the value of the constant term in the preset curve expression;

[0025] According to the values ​​of the quadratic term coefficient, the linear term coefficient and the constant term in the preset curve expression, the droop control curve of the target frequency modulation device is obtained.

[0026] In a possible implementation, after adjusting the output power of the target frequency regulation device based on the droop control curve to assist the thermal power unit in regulating the frequency of the power system, the method further includes:

[0027] Monitoring of power system frequency;

[0028] If the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is determined that the power system frequency is in a stable state, and the output power of the target frequency modulation device is controlled to be restored to the output power before the frequency modulation.

[0029] In a possible implementation manner, after determining that the power system frequency is in a stable state, the method further includes:

[0030] according to Calculate and obtain the evaluation index of joint frequency modulation;

[0031] Among them, Q f is the evaluation index, T is the time interval, t over is the time when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value during the time period T, Nis the rated frequency, Δf over is the deviation of the absolute value of the difference between the power system frequency and the rated frequency exceeding the first preset threshold, f over is the frequency value when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value, Δf is the first preset threshold;

[0032] Based on the evaluation index, the expected frequency modulation speed information is adjusted.

[0033] In a possible implementation, after acquiring the power system frequency and determining whether the power system frequency is within the frequency modulation action interval, the method further includes:

[0034] If the power system frequency is not in the frequency regulation action interval, determining the absolute value of the difference between the power system frequency and the rated frequency;

[0035] If the absolute value of the difference is less than a first preset threshold, the new energy frequency modulation flexible polymer is instructed to maintain the current working state;

[0036] If the absolute value of the difference is greater than a second preset threshold, it is determined that a fault occurs in the power system, and a fault prompt message is output.

[0037] In a second aspect, an embodiment of the present invention provides an auxiliary frequency modulation device based on a new energy frequency modulation flexible polymer, comprising:

[0038] An acquisition unit, used to acquire the power system frequency and determine whether the power system frequency is within the frequency modulation action range;

[0039] The first processing unit is used to determine the target frequency modulation device in the new energy frequency modulation flexible aggregate according to the difference between the power system frequency and the rated frequency if the power system frequency is within the frequency modulation action interval; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate;

[0040] A second processing unit is used to obtain a droop control curve of the target frequency modulation device based on preset expected frequency modulation speed information; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the power system frequency, and the expected frequency modulation speed information is used to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device;

[0041] The third processing unit is used to adjust the output power of the target frequency regulation device based on the droop control curve to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0042] In a possible implementation manner, the second processing unit is specifically configured to:

[0043] Obtaining the frequency interval in which the droop control curve acts;

[0044] Based on the expected frequency modulation speed information, determining the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval;

[0045] Obtaining a preset curve expression; wherein the preset curve expression includes parameters to be solved;

[0046] According to the power output values ​​of the target frequency regulation device at the boundary points and the median points of the frequency interval, the values ​​of the parameters to be solved in the preset curve expression are determined, and based on the values ​​of the parameters to be solved, the droop control curve of the target frequency regulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation device within the frequency interval and the frequency of the power system.

[0047] The embodiment of the present invention provides an auxiliary frequency modulation method and device based on a new energy frequency modulation flexible polymer. When the power system frequency is within the frequency modulation action range, the target frequency modulation device in the new energy frequency modulation flexible polymer is determined according to the difference between the power system frequency and the rated frequency; wherein the new energy frequency modulation flexible polymer includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible polymer; further, based on the preset expected frequency modulation speed information, a droop control curve of the target frequency modulation device is obtained; finally, based on the droop control curve, the output power of the target frequency modulation device is adjusted to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system. The method determines the corresponding target frequency modulation device for auxiliary frequency modulation based on the difference between the power system frequency and the rated frequency, thereby improving the flexibility of the power system frequency modulation, and based on the preset expected frequency modulation speed information, the droop control curve of the target frequency modulation device is obtained, so that the control strategy can be adaptively adjusted according to different operations and needs, and the adaptability and stability of the system are improved, thereby improving the frequency stability and response speed of the power system, and accurate regulation of the system frequency can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a flow chart for implementing the auxiliary frequency modulation method based on the new energy frequency modulation flexible polymer provided by an embodiment of the present invention;

[0050] Figure 2 It is a flow chart for realizing another auxiliary frequency modulation method based on a new energy frequency modulation flexible polymer provided by an embodiment of the present invention;

[0051] Figure 3 is a schematic diagram of a droop control curve corresponding to a photovoltaic inverter provided in an embodiment of the present invention;

[0052] Figure 4 is a schematic diagram of a droop control curve corresponding to an energy storage converter provided in an embodiment of the present invention;

[0053] Figure 5 is a schematic diagram of a droop control curve corresponding to a charging pile provided in an embodiment of the present invention;

[0054] Figure 6 is a schematic diagram of power recovery of a photovoltaic inverter provided by an embodiment of the present invention;

[0055] Figure 7 It is a structural schematic diagram of an auxiliary frequency modulation device based on a new energy frequency modulation flexible polymer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention. SUMMARY OF THE INVENTION

[0058] With the increasing attention paid to environmental protection and sustainable development around the world, energy transformation has become an irreversible trend. Traditional fossil energy is gradually being replaced by new energy due to its limited nature and environmental pollution problems. Distributed new energy, such as wind energy and solar energy, has become an important direction for the development of new energy due to its clean, renewable and widely distributed characteristics. These distributed new energy sources are usually connected to medium and low voltage distribution network systems, providing a rich source of energy for the power system. With the large-scale access of distributed new energy, the frequency regulation requirements of the power system have also changed. On the one hand, the randomness and volatility of new energy have brought challenges to the frequency stability of the power system; on the other hand, the access of new energy has also increased the complexity and uncertainty of the power system. Power system frequency regulation is an important link to ensure the stable operation of the power grid. Therefore, how to effectively use distributed new energy for auxiliary frequency regulation has become an important issue facing the power system.

[0059] After research, the inventors found that traditional droop control is implemented based on the power output characteristics of the synchronous generator, and a completely autonomous control system is formed by controlling the output voltage and frequency of the micro-source. However, in the process of achieving system power balance, droop control will cause voltage drop. In other words, power balance is achieved at the expense of voltage drop. This voltage reduction may affect the stability and power quality of the power system. In addition, the selection of the droop coefficient is also very critical. It is not only related to the effect of power distribution, but also related to the deviation of frequency and voltage. In practical applications, the droop coefficient cannot meet the adaptability problems in different scenarios or complex situations. At the same time, constant control parameters cannot achieve accurate control of the system frequency. Therefore, in the prior art, there are problems of stability and accuracy in the droop control of the power system.

[0060] With the idea of ​​improving the frequency stability of the power system and achieving accurate control of the system frequency of the power system, in an embodiment of the present invention, the frequency of the power system is monitored, and based on the difference between the power system frequency and the rated frequency, the corresponding target frequency regulation equipment is determined for auxiliary frequency regulation, thereby improving the flexibility of the power system frequency regulation, and based on the preset expected frequency regulation speed information, the droop control curve of the target frequency regulation equipment is obtained, and the control strategy can be adaptively adjusted according to the different operating conditions and requirements of the power system, thereby improving the adaptability and stability of the system, thereby improving the frequency stability of the power system and the response speed of the frequency regulation, and achieving accurate control of the system frequency.

[0061] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0062] Figure 1 The implementation flow chart of the auxiliary frequency modulation method based on the new energy frequency modulation flexible polymer provided in the embodiment of the present invention is described in detail as follows:

[0063] Step 101, obtaining the power system frequency, and determining whether the power system frequency is within the frequency modulation action range.

[0064] Exemplarily, this embodiment monitors and acquires the power system frequency value in real time, and determines whether the power system frequency is within the frequency modulation action range based on preset conditions.

[0065] Among them, the frequency regulation action range refers to the frequency range in which power generation equipment or energy storage systems perform power regulation in order to maintain system frequency stability when the power system frequency exceeds the frequency dead zone.

[0066] Frequency dead zone refers to a small range of system frequency near the rated frequency during the power system frequency regulation process. In this range, the power generation equipment does not perform frequency regulation. This is because the power system frequency will fluctuate slightly during normal operation. In order to avoid frequent power regulation of power generation equipment, which will cause unnecessary equipment wear and energy loss, a frequency dead zone is set.

[0067] The rated frequency of the power system refers to the standard frequency of the alternating current in the power system under normal operating conditions.

[0068] Step 102, if the power system frequency is within the frequency modulation action range, determine the target frequency modulation device in the new energy frequency modulation flexible aggregate according to the difference between the power system frequency and the rated frequency; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate.

[0069] Exemplarily, if the determination result is that the power system frequency is within the frequency regulation action range, this embodiment determines the devices in one or more new energy frequency regulation flexible aggregates as target frequency regulation devices based on the difference between the power system frequency and the rated frequency.

[0070] For example, if the difference between the power system frequency and the rated frequency is a positive value, it means that the current power system energy is in a surplus state, and the target frequency regulation equipment needs to absorb energy. Then, it is determined that the target frequency regulation equipment includes a photovoltaic inverter and an energy storage converter, and the working state of the energy storage converter is controlled to be a charging state.

[0071] In a feasible implementation manner, when the difference between the power system frequency and the rated frequency is a positive value, this embodiment may also use a photovoltaic inverter or a charging energy storage converter as a target frequency regulation device.

[0072] On the contrary, if the difference is a negative number, it means that the current power system energy is insufficient and the target frequency regulation equipment needs to release energy. The target frequency regulation equipment is determined to include a charging pile and an energy storage inverter, and the working state of the energy storage inverter is controlled to be a discharge state.

[0073] In a feasible implementation manner, when the difference is a negative number, this embodiment can also use the charging pile or the energy storage converter in the discharge state as the target frequency modulation device.

[0074] Step 103, based on the preset expected frequency modulation speed information, obtain a droop control curve of the target frequency modulation device; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the power system frequency, and the expected frequency modulation speed information is used to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device.

[0075] Exemplarily, this embodiment may predefine expected frequency modulation speed information to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device. Therefore, after determining the target frequency modulation device, this embodiment obtains preset expected frequency modulation speed information, and determines the droop control curve corresponding to one or more target frequency modulation devices based on the expected frequency modulation speed information.

[0076] The expected frequency modulation speed information is set according to the auxiliary frequency modulation capability of the light-storage-load flexible polymer and the expected frequency modulation speed. In this embodiment, the new energy frequency modulation flexible polymer can be a light-storage-load flexible polymer, including a photovoltaic inverter, an energy storage converter and a charging pile.

[0077] Step 104, based on the droop control curve, adjust the output power of the target frequency regulation equipment to assist the thermal power units in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0078] Exemplarily, this embodiment adjusts the output power of the corresponding target frequency regulation equipment based on the obtained droop control curve, so that it releases energy or absorbs system energy to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0079] In summary, the embodiment of the present invention determines the corresponding target frequency regulation equipment for auxiliary frequency regulation based on the difference between the power system frequency and the rated frequency, thereby improving the flexibility of the power system frequency regulation, and based on the preset expected frequency regulation speed information, obtains the droop control curve of the target frequency regulation equipment, so that the control strategy can be adaptively adjusted according to different operations and requirements, thereby improving the adaptability and stability of the system, thereby improving the frequency stability and response speed of the power system, and realizing accurate control of the system frequency.

[0080] This embodiment specifically determines the corresponding target frequency modulation equipment according to the difference between the power system frequency and the rated frequency, and controls the target frequency modulation equipment to be in the corresponding working state, so as to facilitate auxiliary frequency modulation; in addition, this embodiment determines the power output value of the target frequency modulation equipment at the boundary point and the median point of the frequency interval based on the expected frequency modulation speed information, and then solves the quadratic polynomial curve based on the power output value of the target frequency modulation equipment at the boundary point and the median point of the frequency interval to obtain the corresponding droop curve, thereby realizing fast and accurate solution of the droop curve, thereby improving the response speed of frequency modulation; in addition, this embodiment constructs an evaluation index for frequency modulation, and based on the evaluation index, adjusts the expected frequency modulation speed information, which can optimize the frequency modulation control strategy, further improve the frequency stability and response speed of the power system, and realize accurate control of the system frequency.

[0081] Figure 2 Another implementation flow chart of an auxiliary frequency modulation method based on a new energy frequency modulation flexible polymer provided in an embodiment of the present invention is described in detail as follows:

[0082] Step 201, obtaining the power system frequency, and determining whether the power system frequency is within the frequency modulation action range.

[0083] In a feasible implementation, if the power system frequency is not in the frequency regulation action range, the absolute value of the difference between the power system frequency and the rated frequency is determined; if the absolute value of the difference is less than a first preset threshold, the new energy frequency regulation flexible aggregate is instructed to maintain the current working state; if the absolute value of the difference is greater than a second preset threshold, it is determined that a fault has occurred in the power system, and a fault prompt message is output.

[0084] Exemplarily, the first preset threshold may be a frequency dead zone. The sum of the second preset threshold and the rated frequency is the maximum value of the frequency modulation action interval, and the rated frequency minus the second preset threshold is the minimum value of the frequency modulation action interval. That is, if the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is considered that the power system frequency is within a normal fluctuation range and no frequency modulation is required. If the absolute value of the difference between the power system frequency and the rated frequency is greater than the second preset threshold, it is considered that a power system failure has occurred and emergency measures need to be taken.

[0085] In one example, this embodiment is based on the rated frequency f N , frequency dead zone f de , minimum value of frequency modulation action interval f min , maximum value of frequency modulation action interval f max , determine the frequency modulation action interval [fmin,(f N -fde)]、[(f N +fde),fmax]; that is, when the power system frequency (f N -fde ) <f<(f N +f de ), it is determined that the power system frequency is within the normal fluctuation range, the power system is stable, and no frequency modulation is required; when the power system frequency f <f min or f>f max , it is determined that the power system frequency is abnormal, and other emergency measures such as load reduction and machine cutting should be taken when a power system failure occurs.

[0086] In a feasible implementation manner, this embodiment calculates the deviation between the power grid system frequency and the rated frequency according to the current load dynamic situation, and determines whether the power system frequency is within the frequency regulation action range.

[0087] Step 202, if the power system frequency is within the frequency modulation action range, the target frequency modulation device in the new energy frequency modulation flexible aggregate is determined according to the difference between the power system frequency and the rated frequency; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate.

[0088] In one example, step 202 includes the following steps:

[0089] If the difference is a positive number, it is determined that the target frequency modulation equipment includes a photovoltaic inverter and an energy storage converter, and the working state of the energy storage converter is controlled to be a charging state.

[0090] If the difference is a negative number, it is determined that the target frequency modulation equipment includes a charging pile and an energy storage converter, and the working state of the energy storage converter is controlled to be a discharge state.

[0091] For example, this embodiment refers to step 102 and will not be described in detail.

[0092] Step 203, obtaining the frequency interval in which the droop control curve acts.

[0093] In one example, the frequency modulation action interval includes a first interval and a second interval; step 203 includes the following steps:

[0094] If the target frequency regulation equipment includes a photovoltaic inverter and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the first interval; wherein the sum of the rated frequency of the power system and the first preset threshold is the first boundary point of the first interval, and the sum of the rated frequency and the second preset threshold is the second boundary point of the first interval; and the second preset threshold is greater than the first preset threshold.

[0095] If the target frequency modulation equipment includes a charging pile and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the second interval; wherein the difference between the rated frequency and the second preset threshold is the first boundary point of the second interval, and the difference between the rated frequency and the first preset threshold is the second boundary point of the second interval.

[0096] Exemplarily, the frequency modulation action interval consists of two parts, including a first interval and a second interval, that is, [f min ,(f N -f de )]、[(f N +f de ),f max ]. Among them, [(f N +f de ),f max ] is the first interval, [f min ,(f N -f de )] is the second interval.

[0097] Step 204: determine the power output values ​​of the target frequency modulation device at the boundary points and the median points of the frequency interval based on the expected frequency modulation speed information; wherein the expected frequency modulation speed information is used to indicate the slope of the droop control curve corresponding to the target frequency modulation device.

[0098] Exemplarily, the desired frequency modulation speed information is set according to the auxiliary frequency modulation capability of the light-storage-load flexible polymer and the desired frequency modulation speed. In this embodiment, the new energy frequency modulation flexible polymer can be a light-storage-load flexible polymer, including a photovoltaic inverter, an energy storage converter and a charging pile.

[0099] In one example, the expected frequency modulation speed information may define the value of the midpoint of the frequency modulation interval in the droop curve corresponding to the target frequency modulation device, so as to indicate the power of the droop curve.

[0100] In a feasible implementation, in the light-storage-load flexible polymer, the coordinates of the upper boundary value point, the middle value point and the lower boundary value point of the frequency modulation interval corresponding to the photovoltaic inverter can be respectively (f N +f de ,1), and (f max ,0); where the horizontal axis represents the power system frequency at the current moment, and the vertical axis represents the photovoltaic inverter power value corresponding to the power system frequency at the current moment.

[0101] In the light-storage-charge flexible polymer, the coordinates of the lower boundary value point, the middle value point and the upper boundary value point of the charging pile frequency modulation interval can be respectively (f min ,0), and (f N -f de,1); where the horizontal axis represents the power system frequency at the current moment, and the vertical axis represents the charging pile power value corresponding to the power system frequency at the current moment.

[0102] In the light-storage-charge flexible polymer, the coordinates of the upper boundary value point, the middle value point and the lower boundary value point of the frequency modulation interval of the energy storage converter in the discharge stage are (f min ,1), and (f N -f de ,0); the charging stages can be (f N +f de ,0), and (f max ,-1); where the horizontal axis represents the power system frequency at the current moment, and the vertical axis represents the energy storage converter power value corresponding to the power system frequency at the current moment. The power in the energy storage discharge phase is defined as a positive value, and the power in the charging phase is a negative value.

[0103] In this embodiment, the power of the target frequency modulation device adopts a per unit value, and the power reference value is the rated power of each target frequency modulation device.

[0104] Step 205, obtain a preset curve expression, and determine the value of the parameter to be solved in the preset curve expression according to the power output value of the target frequency regulation device at the boundary point and the median point of the frequency interval, and obtain the droop control curve of the target frequency regulation device based on the value of the parameter to be solved; wherein the preset curve expression includes the parameter to be solved, and the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation device within the frequency interval and the frequency of the power system.

[0105] In a feasible implementation manner, the preset curve expression is a quadratic polynomial curve, and the parameters to be solved include quadratic term coefficients, linear term coefficients, and a constant term; step 205 includes:

[0106] According to the power output values ​​of the target frequency modulation device at the first boundary point, the second boundary point and the median point of the frequency interval, the preset curve expression is solved to determine the values ​​of the quadratic term coefficient, the linear term coefficient and the constant term in the preset curve expression.

[0107] According to the values ​​of the quadratic term coefficient, the linear term coefficient and the constant term in the preset curve expression, the droop control curve of the target frequency modulation device is obtained.

[0108] Exemplarily, this embodiment is based on the characteristics of the photovoltaic inverter in the light-storage-load flexible polymer participating in the grid frequency regulation, and determines that the quadratic polynomial curve expression function corresponding to the photovoltaic inverter is P1=a1f 2 +b1f+c1,(f N +f de)≤f≤f max ; Where P1 is the output power of the photovoltaic inverter, f is the current power system frequency, a1, b1, c1 are the coefficients of the function expression, and the rated frequency is f N , the frequency dead zone is f de , the maximum value of the frequency modulation action interval is f max .

[0109] According to the characteristics of the charging pile participating in the grid frequency regulation in the light-storage-charge flexible polymer, the quadratic polynomial curve expression function corresponding to the charging pile is determined as P2=a2f 2 +b2f+c2,f min ≤f≤(f N -f de ); where P2 is the output power of the charging pile, f is the current power system frequency, a2, b2, c2 are the function expression coefficients, and the rated frequency is f N , the frequency dead zone is f de , the minimum value of the frequency modulation action interval is f min .

[0110] According to the characteristics of the energy storage converter in the photovoltaic-storage-load flexible polymer participating in the grid frequency regulation, the quadratic polynomial curve expression function corresponding to the energy storage converter is determined as follows:

[0111]

[0112] Among them, P3 is the output power of the energy storage converter, f is the power system frequency at the current moment, and the rated frequency is f N , the frequency dead zone is f de , the minimum value of the frequency modulation action interval is f min , the maximum value of the frequency modulation action interval is f max , when f min ≤f≤(f N -f de ), the energy storage system is in the discharge state, when (f N +f de )≤f≤f max When , the energy storage system is in a charging state, a3, b3, c3, a4, b4, and c4 are the coefficients of the function expression respectively.

[0113] This embodiment solves the parameters to be solved corresponding to the photovoltaic inverter, charging pile and energy storage converter in the light-storage-load flexible aggregate by substituting the coordinate values ​​of the corresponding upper boundary value point, middle point and lower boundary value point of the frequency modulation interval into the quadratic polynomial curve expression, so that the power system can be accurately assisted in frequency modulation based on the accurately calculated parameters to be solved.

[0114] Substitute the coordinates of the upper boundary point, the middle point and the lower boundary point of the frequency modulation interval into the quadratic polynomial curve expression to solve the coefficients of the droop control curve function expression of the photovoltaic inverter in the light-storage-load flexible polymer. The solutions are a1, b1, c1.

[0115] Substitute the coordinates of the upper boundary point, the middle point and the lower boundary point of the frequency modulation interval into the quadratic polynomial curve expression to solve the coefficients of the droop control curve function expression of the charging pile in the light-storage-charge flexible polymer. The solution is a2, b2, c2.

[0116] Substitute the coordinates of the upper boundary point, the middle point and the lower boundary point of the frequency modulation interval into the quadratic polynomial curve expression to solve the coefficients of the droop control curve function expression of the energy storage converter in the light-storage-load flexible polymer. Solve to get a3, b3, c3, a4, b4, c4.

[0117] In one example, this embodiment obtains the droop control curves corresponding to the photovoltaic inverter, energy storage converter and charging pile as follows: Figures 3 to 5 As shown in the figure, the horizontal axis of the curve is the frequency, in Hertz (Hz); the vertical axis is the power corresponding to the device, in kilowatts (kW). Figure 3 As shown in the figure, the droop control curve corresponding to the photovoltaic inverter increases with the increase of output power. max , C) to (f2, B) and then to (f1, A), the slope of the curve decreases gradually. Figure 5 In (f min , D) to (f3, E) and then to (f4, F), the slope of the curve gradually decreases. Figure 3 and Figure 5 As shown in the figure, the droop control curve presents an S shape, that is, as the output power increases, the rate of change of the frequency and amplitude of the output voltage gradually decreases. This S-shaped characteristic helps to reduce the fluctuations of frequency and voltage. At the same time, compared with the traditional droop control algorithm, through the flexible control of the light-storage-load flexible polymer, it can assist frequency regulation and realize joint frequency regulation with thermal power units, thereby improving the frequency stability and response speed of the power system.

[0118] In addition, the droop control divides the droop control curve into multiple intervals, each interval corresponds to different control parameters and slopes, so that the control strategy can automatically adjust the control parameters according to different operations and needs, improve the adaptability and stability of the system, and in each segmented interval, the droop control curve presents an S shape, ensuring the precise control of the light-storage-load flexible polymer, thereby improving the frequency stability and response speed of the power system. Figure 4 , Figure 4 Medium (f min, A), (f3, B), (f4, A) divide the left droop control curve into multiple intervals, each interval corresponds to different control parameters and slopes; Figure 4 (f1, D), (f2, E), (f max ,F), the right droop control curve is divided into multiple intervals, each interval corresponds to different control parameters and slopes.

[0119] Step 206, based on the droop control curve, adjust the output power of the target frequency regulation device to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0120] For example, when the frequency drops, the target frequency regulation equipment increases power output to supplement the system power shortage, reduce the regulation burden of the thermal power units, and help the thermal power units have enough time to adjust their output power so that the system frequency returns to the normal range. Similarly, when the frequency rises, the target frequency regulation equipment reduces power output and maintains the system frequency stability together with the thermal power units.

[0121] Step 207, monitor the power system frequency. If the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is determined that the power system frequency is in a stable state, and the output power of the target frequency modulation device is controlled to be restored to the output power before the frequency modulation.

[0122] Exemplarily, after adjusting the output power of the target frequency regulation device based on the droop control curve to assist the thermal power units in regulating the frequency of the power system, this embodiment monitors the power system frequency in real time. If the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is determined that the power system frequency is in a stable state. Alternatively, if the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold within a time period greater than or equal to the preset time length, it is determined that the power system frequency is in a stable state. After determining that the power system frequency is in a stable state, this embodiment controls the output power of the target frequency regulation device to return to the output power before the frequency regulation.

[0123] Figure 6 is a schematic diagram of power recovery of an inverter device provided by an embodiment of the present invention; Figure 6 As shown, it is assumed that the power value of the inverter equipment during frequency modulation changes from P t1 Change to P t2 , the timing starts when the power system frequency is in a stable state, and the inverter equipment power starts to recover after 15s, and recovers linearly to P according to the Pt expression within 2s. t1 .

[0124] The expression of Pt is:

[0125]

[0126] Where P is the power value of the inverter equipment, t is the time after the power of the photovoltaic inverter or charging pile changes, P t1 is the power value before the inverter is activated, P t2 It is the power value after the inverter is activated.

[0127] In a feasible implementation manner, after determining that the power system frequency is in a stable state, the present embodiment performs the following operations according to The evaluation index of joint frequency modulation is calculated; Q f The smaller the value, the better the FM effect. f is the evaluation index, T is the time interval, t over is the time when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value during the period T, f N is the rated frequency, Δf over The absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold, f over is the frequency value when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value, Δf is a first preset threshold.

[0128] Based on the evaluation index, adjust the expected frequency modulation speed information. For example, if the evaluation index Q f The larger the value, the higher the desired frequency modulation speed can be adjusted.

[0129] In summary, the auxiliary frequency modulation method based on the new energy frequency modulation flexible polymer provided in this embodiment has more flexible and precise control than the traditional droop control. When the system is externally disturbed, resulting in a deviation in the grid frequency, the new energy auxiliary frequency modulation method provided by the present invention can fully integrate the light-storage-load flexible polymer composed of photovoltaics, energy storage, charging piles, etc., and analyze and study the group characteristics and effects of the light-storage-load flexible polymer, so that it has the ability to participate in the grid frequency modulation, can quickly respond to the frequency changes of the system, quickly provide active output, and effectively improve the inertia / frequency stability level of the new power system.

[0130] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0131] The following is an embodiment of the device of the present invention. For details not described in detail, reference may be made to the corresponding method embodiments described above.

[0132] Figure 7The structure diagram of the auxiliary frequency modulation device based on the frequency modulation flexible polymer of new energy provided by the embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0133] like Figure 7 As shown, the auxiliary frequency modulation device 7 based on the new energy frequency modulation flexible polymer includes:

[0134] The acquisition unit 71 is used to acquire the power system frequency and determine whether the power system frequency is within the frequency modulation action range.

[0135] The first processing unit 72 is used to determine the target frequency modulation device in the new energy frequency modulation flexible aggregate according to the difference between the power system frequency and the rated frequency if the power system frequency is within the frequency modulation action range; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate.

[0136] The second processing unit 73 is used to obtain a droop control curve of the target frequency modulation device based on preset expected frequency modulation speed information; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the power system frequency, and the expected frequency modulation speed information is used to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device.

[0137] The third processing unit 74 is used to adjust the output power of the target frequency regulation device based on the droop control curve to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

[0138] In a possible implementation manner, the second processing unit 73 is specifically configured to:

[0139] Get the frequency range in which the droop control curve acts.

[0140] Based on the expected frequency modulation speed information, the power output values ​​of the target frequency modulation device at the boundary points and the median points of the frequency interval are determined.

[0141] Obtain a preset curve expression; wherein the preset curve expression includes parameters to be solved.

[0142] According to the power output values ​​of the target frequency regulation equipment at the boundary points and the median points of the frequency interval, the values ​​of the parameters to be solved in the preset curve expression are determined, and based on the values ​​of the parameters to be solved, the droop control curve of the target frequency regulation equipment is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation equipment and the frequency of the power system within the frequency interval.

[0143] In a possible implementation manner, the first processing unit 72 is specifically configured to:

[0144] If the difference is a positive number, it is determined that the target frequency modulation equipment includes a photovoltaic inverter and an energy storage converter, and the working state of the energy storage converter is controlled to be a charging state.

[0145] If the difference is a negative number, it is determined that the target frequency modulation equipment includes a charging pile and an energy storage converter, and the working state of the energy storage converter is controlled to be a discharge state.

[0146] In a possible implementation manner, the frequency modulation action interval includes a first interval and a second interval; the second processing unit 73 is specifically configured to:

[0147] If the target frequency regulation equipment includes a photovoltaic inverter and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the first interval; wherein the sum of the rated frequency of the power system and the first preset threshold is the first boundary point of the first interval, and the sum of the rated frequency and the second preset threshold is the second boundary point of the first interval; and the second preset threshold is greater than the first preset threshold.

[0148] If the target frequency modulation equipment includes a charging pile and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the second interval; wherein the difference between the rated frequency and the second preset threshold is the first boundary point of the second interval, and the difference between the rated frequency and the first preset threshold is the second boundary point of the second interval.

[0149] In a possible implementation, the preset curve expression is a quadratic polynomial curve, and the parameters to be solved include quadratic term coefficients, linear term coefficients, and a constant term; the second processing unit 73 is specifically used to solve the preset curve expression according to the power output value of the target frequency modulation device at the first boundary point, the second boundary point, and the midpoint of the frequency interval, and determine the value of the quadratic term coefficient, the value of the linear term coefficient, and the value of the constant term in the preset curve expression.

[0150] According to the values ​​of the quadratic term coefficient, the linear term coefficient and the constant term in the preset curve expression, the droop control curve of the target frequency modulation device is obtained.

[0151] In a possible implementation manner, after the third processing unit 74, the device 7 further includes: a monitoring unit, configured to:

[0152] Monitor power system frequency.

[0153] If the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is determined that the power system frequency is in a stable state, and the output power of the target frequency modulation device is controlled to be restored to the output power before the frequency modulation.

[0154] In a possible implementation manner, after the monitoring unit, the device 7 further includes an optimization unit, which is specifically configured to:

[0155] according to The evaluation index of joint frequency modulation is calculated.

[0156] Among them, Q f is the evaluation index, T is the time interval, t over is the time when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value during the period T, f N is the rated frequency, Δf over The absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold, f over is the frequency value when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value, Δf is a first preset threshold.

[0157] Based on the evaluation index, the expected frequency modulation speed information is adjusted.

[0158] In a possible implementation manner, after the acquiring unit 71, the device 7 further includes: a fourth processing unit, configured to:

[0159] If the power system frequency is not in the frequency regulation action interval, the absolute value of the difference between the power system frequency and the rated frequency is determined.

[0160] If the absolute value of the difference is less than the first preset threshold, the new energy frequency modulation flexible polymer is instructed to maintain the current working state.

[0161] If the absolute value of the difference is greater than the second preset threshold, it is determined that a fault occurs in the power system and a fault prompt message is output.

[0162] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0163] Those of ordinary skill in the art will appreciate that the templates, units, and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0164] If the module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned auxiliary frequency modulation method embodiments based on the new energy frequency modulation flexible polymer. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electric carrier signal, telecommunication signal and software distribution medium.

[0165] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. An auxiliary frequency modulation method based on new energy frequency modulation flexible polymer, characterized in that: The method comprises: Obtaining the power system frequency, and determining whether the power system frequency is within the frequency modulation action range; If the power system frequency is within the frequency modulation action interval, the target frequency modulation device in the new energy frequency modulation flexible aggregate is determined according to the difference between the power system frequency and the rated frequency; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate; Based on the preset expected frequency modulation speed information, a droop control curve of the target frequency modulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the frequency of the power system, and the expected frequency modulation speed information is used to indicate the slope of the droop control curve corresponding to the target frequency modulation device; based on the droop control curve, the output power of the target frequency modulation device is adjusted to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

2. The auxiliary frequency modulation method based on new energy frequency modulation flexible polymer according to claim 1 is characterized in that: The step of obtaining the droop control curve of the target frequency modulation device based on the preset expected frequency modulation speed information includes: Obtaining the frequency interval in which the droop control curve acts; Based on the expected frequency modulation speed information, determining the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval; Obtaining a preset curve expression; wherein the preset curve expression includes parameters to be solved; According to the power output values ​​of the target frequency regulation device at the boundary points and the median points of the frequency interval, the values ​​of the parameters to be solved in the preset curve expression are determined, and based on the values ​​of the parameters to be solved, the droop control curve of the target frequency regulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation device within the frequency interval and the frequency of the power system.

3. The auxiliary frequency modulation method based on new energy frequency modulation flexible polymer according to claim 2 is characterized in that: The step of determining the target frequency regulation device in the new energy frequency regulation flexible aggregate according to the difference between the power system frequency and the rated frequency includes: If the difference is a positive number, it is determined that the target frequency modulation device includes a photovoltaic inverter and an energy storage converter, and the working state of the energy storage converter is controlled to be a charging state; If the difference is a negative number, it is determined that the target frequency modulation device includes a charging pile and an energy storage converter, and the working state of the energy storage converter is controlled to be a discharging state.

4. The auxiliary frequency modulation method based on the new energy frequency modulation flexible polymer according to claim 3 is characterized in that: The frequency modulation action interval includes a first interval and a second interval; The obtaining of the frequency interval of the droop control curve comprises: If the target frequency modulation device includes a photovoltaic inverter and an energy storage converter, the frequency interval in which the droop control curve acts is determined to be the first interval; wherein the sum of the rated frequency of the power system and the first preset threshold is the first boundary point of the first interval, and the sum of the rated frequency and the second preset threshold is the second boundary point of the first interval; and the second preset threshold is greater than the first preset threshold; If the target frequency modulation equipment includes a charging pile and an energy storage inverter, the frequency interval in which the droop control curve acts is determined to be the second interval; wherein the difference between the rated frequency and the second preset threshold is the first boundary point of the second interval, and the difference between the rated frequency and the first preset threshold is the second boundary point of the second interval.

5. The auxiliary frequency modulation method based on new energy frequency modulation flexible polymer according to claim 4 is characterized in that: The preset curve expression is a quadratic polynomial curve, and the parameters to be solved include the quadratic term coefficient, the linear term coefficient and the constant term; The step of determining the value of the parameter to be solved in the preset curve expression according to the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval, and obtaining the droop control curve of the target frequency modulation device based on the value of the parameter to be solved includes: Solving the preset curve expression according to the power output values ​​of the target frequency modulation device at the first boundary point, the second boundary point and the median point of the frequency interval to determine the value of the quadratic term coefficient, the value of the linear term coefficient and the value of the constant term in the preset curve expression; According to the values ​​of the quadratic term coefficient, the linear term coefficient and the constant term in the preset curve expression, the droop control curve of the target frequency modulation device is obtained.

6. The auxiliary frequency modulation method based on new energy frequency modulation flexible polymer according to any one of claims 1 to 5, characterized in that: After adjusting the output power of the target frequency regulation device based on the droop control curve to assist the thermal power unit in regulating the frequency of the power system, the method further includes: Monitoring of power system frequency; If the absolute value of the difference between the power system frequency and the rated frequency is less than the first preset threshold, it is determined that the power system frequency is in a stable state, and the output power of the target frequency modulation device is controlled to be restored to the output power before the frequency modulation.

7. The auxiliary frequency modulation method based on the new energy frequency modulation flexible polymer according to claim 6 is characterized in that: After determining that the power system frequency is in a stable state, the method further includes: according to Calculate and obtain the evaluation index of joint frequency modulation; Among them, Q f is the evaluation index, T is the time interval, t over is the time when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value during the time period T, N is the rated frequency, Δf over is the deviation of the absolute value of the difference between the power system frequency and the rated frequency exceeding the first preset threshold, f over is the frequency value when the absolute value of the difference between the power system frequency and the rated frequency exceeds the first preset threshold value, Δf is the first preset threshold; Based on the evaluation index, the expected frequency modulation speed information is adjusted.

8. The auxiliary frequency modulation method based on new energy frequency modulation flexible polymer according to any one of claims 1 to 5, characterized in that: After obtaining the power system frequency and determining whether the power system frequency is within the frequency modulation action interval, the method further includes: If the power system frequency is not in the frequency regulation action interval, determining the absolute value of the difference between the power system frequency and the rated frequency; If the absolute value of the difference is less than the first preset threshold, the new energy frequency modulation flexible polymer is instructed to maintain the current working state; If the absolute value of the difference is greater than a second preset threshold, it is determined that a fault occurs in the power system, and a fault prompt message is output.

9. An auxiliary frequency modulation device based on a new energy frequency modulation flexible polymer, characterized in that: The device comprises: An acquisition unit, used to acquire the power system frequency and determine whether the power system frequency is within the frequency modulation action range; The first processing unit is used to determine the target frequency modulation device in the new energy frequency modulation flexible aggregate according to the difference between the power system frequency and the rated frequency if the power system frequency is within the frequency modulation action interval; wherein the new energy frequency modulation flexible aggregate includes a photovoltaic inverter, an energy storage converter and a charging pile, and the target frequency modulation device is one or more devices in the new energy frequency modulation flexible aggregate; A second processing unit is used to obtain a droop control curve of the target frequency modulation device based on preset expected frequency modulation speed information; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency modulation device and the power system frequency, and the expected frequency modulation speed information is used to indicate the curve slope of the droop control curve corresponding to the target frequency modulation device; The third processing unit is used to adjust the output power of the target frequency regulation device based on the droop control curve to assist the thermal power unit in regulating the frequency of the power system and maintain the frequency stability of the power system.

10. The auxiliary frequency modulation device based on the new energy frequency modulation flexible polymer according to claim 9 is characterized in that: The second processing unit is specifically configured to: Obtaining the frequency interval in which the droop control curve acts; Based on the expected frequency modulation speed information, determining the power output value of the target frequency modulation device at the boundary point and the median point of the frequency interval; Obtaining a preset curve expression; wherein the preset curve expression includes parameters to be solved; According to the power output values ​​of the target frequency regulation device at the boundary points and the median points of the frequency interval, the values ​​of the parameters to be solved in the preset curve expression are determined, and based on the values ​​of the parameters to be solved, the droop control curve of the target frequency regulation device is obtained; wherein the droop control curve is used to indicate the corresponding relationship between the output frequency of the target frequency regulation device within the frequency interval and the frequency of the power system.

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