Virtual rotational inertia control method and device considering positive and negative rotational inertia

Abstract

The invention provides a virtual rotational inertia control method and device considering positive and negative rotational inertia, relates to the technical field of power control, and aims to measure the grid-connected point frequency and the frequency change rate of a new energy station containing energy storage in real time in a millisecond-level period and judge whether the current frequency leaves or tends to the rated frequency. Constructing rotational inertia according to the following method: when the current frequency is far away from the rated frequency, constructing virtual negative rotational inertia if the current frequency tends to the rated frequency, otherwise, constructing positive rotational inertia if the current frequency leaves the rated frequency; and when the current frequency is close to the rated frequency, if the frequency change rate is very large and has an over-regulation risk, providing a conventional virtual rotational inertia, otherwise, when the over-regulation risk is small, enabling the rotational inertia to be 0, and meanwhile, carrying out instant recovery control on inertia energy storage to prepare energy for subsequent inertia control in time. The method shortens the time for recovering the power grid frequency to be safe and stable.

Description

Technical Field

[0001] The present invention relates to the field of power control technology, and in particular to a virtual rotational inertia control method and device taking into account positive and negative rotational inertia. Background Art

[0002] In the AC generator set, the motion equation of the AC generator set is as follows: .

[0003] In the above equation of motion of the AC generator set, P m is the prime mover power of the AC generator set, P e is the electromagnetic power at the AC generator end, that is, the load power, J a is the moment of inertia of the AC generator rotor in the AC generator set, The inertia power generated by the moment of inertia hinders the change of the generator speed and is superimposed on the power output of the prime mover. D is the damping coefficient, =2π f a is the angular velocity of the AC generator, f a is the power frequency of the power grid. Combining the above formula, we can see that P m constant, P e When the frequency of the generator changes, the generator rotor's moment of inertia hinders the generator's angular velocity, thus preventing rapid changes in the grid frequency, which is beneficial to the stability of the power system. In power systems with a high proportion of renewable energy, since wind power, photovoltaic power, and energy storage use inverters or converters to convert DC power into AC power, the rotor moment of inertia of the AC generator set does not exist. As a result, the frequency of the renewable energy power system fluctuates greatly, the frequency stability is poor, and the risk of frequency instability is high. To improve the frequency stability of renewable energy power systems, virtual synchronous generator technology (VSG) is often used. This allows renewable energy stations to simulate the moment of inertia of the AC generator set, i.e., virtual moment of inertia. This allows renewable energy power generation to be connected to the grid as a synchronous generator, achieving the goal of improving grid frequency stability.

[0004] However, the virtual moments of inertia constructed using conventional methods are all positive, and their effects on frequency stability have both positive and negative consequences. When the deviation between the actual grid frequency and the rated grid frequency increases over time, the conventional virtual moments of inertia provide the desired positive resistance, hindering the increase in this deviation and providing a positive effect on maintaining the frequency stability of the power system. However, when the deviation between the actual grid frequency and the rated grid frequency decreases over time, the current virtual positive moments of inertia still provide positive resistance, hindering the actual grid frequency from approaching the rated grid frequency, providing a negative effect on maintaining the frequency stability of the power system. To improve the grid's ability to quickly restore frequency stability, it is necessary to consider how to avoid these negative effects. Furthermore, virtual moments of inertia are achieved by simulating the kinetic energy of conventional generator rotors using various energy storage units, such as electrochemical ones. During the process of restoring grid frequency based on virtual moments of inertia, energy depletion often results in interruptions or discontinuities in the restoration process, which in turn reduces the grid's ability to quickly restore frequency stability. Summary of the Invention

[0005] The present invention provides a method and device for controlling virtual moment of inertia that takes into account positive and negative moments of inertia. The method is used to address the problem in the prior art that, during the process of stabilizing the grid frequency at the rated frequency based on the virtual moment of inertia, the virtual moment of inertia cannot be used to hinder the frequency recovery process, and the energy stored in the virtual moment of inertia cannot be recovered in time, resulting in a reduction in the ability of the grid frequency to quickly recover and stabilize. This improves the ability of the grid frequency to quickly recover and stabilize.

[0006] The present invention provides a virtual rotational inertia control method taking into account positive and negative rotational inertia, comprising the following steps.

[0007] Step 1: Obtain the current actual frequency of the grid connection point bus at every set period; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the new energy station or the new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model.

[0008] Step 2: Calculate the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus according to the current actual frequency and at least one historical actual frequency of the grid connection point bus.

[0009] Step 3: Obtain the dynamic change direction of the current actual frequency relative to the rated frequency based on the frequency change rate and the frequency deviation; the dynamic change direction includes: moving away from the rated frequency or moving toward the rated frequency.

[0010] Step 4: According to the frequency deviation and the direction of dynamic change, the current virtual moment of inertia is adjusted to the adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

[0011] According to a virtual moment of inertia control method that takes into account positive and negative moments of inertia, the present invention provides a method for adjusting the current virtual moment of inertia to an adaptive virtual moment of inertia based on a frequency deviation and a dynamic change direction. The method also includes setting the adaptive virtual moment of inertia to a standard virtual moment of inertia when the frequency deviation is less than a frequency deviation threshold and the absolute value of the frequency change rate is greater than a frequency change rate threshold.

[0012] According to a virtual rotational inertia control method taking into account positive and negative rotational inertia, provided by the present invention, the inertia energy storage capacity of a virtual synchronous generator model is recovered, including: when a target ratio of the current energy storage capacity to the total energy storage capacity of the virtual synchronous generator model is less than a set ratio threshold, charging the energy storage device of the virtual synchronous generator model, and adjusting the actual charging power to the target power based on a set recovery power power change rate; when the target ratio of the current energy storage capacity to the total energy storage capacity is greater than or equal to the ratio threshold, discharging the energy storage device of the virtual synchronous generator model, and adjusting the actual discharge power to the target power based on the set recovery power power change rate.

[0013] According to a virtual rotational inertia control method that takes into account positive and negative rotational inertia, the target ratio of the current energy storage capacity to the total energy storage capacity is 80%, the target power used when restoring the energy capacity is 50% of the rated power of the energy storage, and the power change rate of the restored energy capacity is taken as the power adjustment step / minute, where the power adjustment step is taken as 1% of the current available power generation capacity of the virtual generator set equivalent to the new energy station or the new energy station collection station.

[0014] According to a virtual rotational inertia control method taking into account positive and negative rotational inertia provided by the present invention, a positive virtual rotational inertia model is constructed based on the standard virtual rotational inertia, frequency deviation, rated frequency, frequency deviation threshold and a first adjustment index; and a negative virtual rotational inertia model is constructed based on the standard virtual rotational inertia, frequency deviation, rated frequency, frequency deviation threshold, a second adjustment index and a negative adjustment coefficient.

[0015] According to a virtual rotational inertia control method taking into account positive and negative rotational inertia provided by the present invention, the first adjustment index is 0.5, the second adjustment index is 0.5, the negative adjustment coefficient is 0.2, the setting period is 10ms, the frequency change rate threshold is 0.1Hz / s, and the frequency deviation threshold is 0.033Hz.

[0016] The present invention also provides a virtual rotational inertia control device taking into account positive and negative rotational inertia, comprising the following modules: a first acquisition module, a calculation module, a second acquisition module and a processing module.

[0017] The first acquisition module is used to obtain the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the new energy station or the new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model.

[0018] The calculation module is used to calculate the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus based on the current actual frequency and at least one historical actual frequency of the grid connection point bus.

[0019] The second acquisition module is used to obtain the dynamic change direction of the current actual frequency relative to the rated frequency according to the frequency change rate; wherein the dynamic change direction includes: a direction away from the rated frequency or a direction toward the rated frequency.

[0020] The processing module is used to adjust the current virtual moment of inertia to an adaptive virtual moment of inertia according to the frequency deviation and the dynamic change direction; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, thereby obtaining an adaptive virtual positive moment of inertia; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, thereby obtaining an adaptive virtual negative moment of inertia; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered.

[0021] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any of the above-mentioned virtual rotational inertia control methods taking into account positive and negative rotational inertia is implemented.

[0022] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the computer program implements any of the above-mentioned virtual rotational inertia control methods taking into account positive and negative rotational inertia.

[0023] The present invention further provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned virtual rotational inertia control methods taking into account positive and negative rotational inertia.

[0024] The virtual moment of inertia control method and device taking into account positive and negative moment of inertia provided by the present invention can first obtain the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station including energy storage, and the moment of inertia of the above-mentioned energy storage new energy station or the above-mentioned new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model. Thereafter, based on the current actual frequency and at least one historical actual frequency of the grid connection point bus, the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus are calculated. Then, based on the frequency change rate, the dynamic change direction of the current actual frequency relative to the rated frequency is obtained; wherein the dynamic change direction includes: away from the rated frequency direction or toward the rated frequency direction. Finally, based on the frequency deviation and the dynamic change In the direction of dynamic change, the current virtual moment of inertia is adjusted to the adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered. The present invention provides virtual rotational inertia to help the actual frequency approach the rated frequency regardless of whether the deviation between the actual frequency of the busbar at the grid connection point of a new energy station containing energy storage increases or decreases over time. At the same time, the inertia energy storage capacity of the virtual synchronous generator model is restored when the adaptive virtual rotational inertia is 0. By adding an inertia energy storage recovery control link, the inertia energy storage is instantly restored without affecting the rapid recovery and stable operation of the power grid frequency, and energy is promptly prepared for subsequent virtual rotational inertia control, so that the new energy station always has virtual inertia support capability. This solves the problem in the prior art that, in the process of stabilizing the power grid frequency at the rated frequency based on virtual rotational inertia, the virtual rotational inertia cannot be avoided. The obstruction of the frequency recovery process caused by the virtual rotational inertia and the inability to timely recover the virtual rotational inertia energy storage lead to a reduction in the ability of the power grid to quickly recover and stabilize. This achieves the purpose of improving the ability of the power grid to quickly recover and stabilize. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is one of the flow charts of the virtual moment of inertia control method taking into account the positive and negative moments of inertia provided by the present invention.

[0027] Figure 2 This is the second flow chart of the virtual moment of inertia control method taking into account the positive and negative moments of inertia provided by the present invention.

[0028] Figure 3 It is a structural schematic diagram of the virtual rotational inertia control device taking into account the positive and negative rotational inertia provided by the present invention.

[0029] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] The following combination Figure 1-Figure 2 The virtual moment of inertia control method taking into account positive and negative moments of inertia of the present invention is described.

[0032] Figure 1 This is one of the flow charts of the virtual moment of inertia control method taking into account the positive and negative moments of inertia provided by the present invention. Figure 1 As shown, the method includes the following S110~S140.

[0033] S110: Obtain the current actual frequency of the grid connection point bus at every set period; wherein, the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the above-mentioned new energy station or the above-mentioned new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model.

[0034] The set period may be a period in milliseconds, for example, the set period may be 10 ms.

[0035] Of course, it is understandable that the size of the set period includes but is not limited to 10ms in the above example, and can also be any value between 10ms and 20ms, for example, 15ms, 20ms, etc.

[0036] The new energy station collection station that includes energy storage is actually the grid connection point for the energy storage new energy station cluster.

[0037] A cluster of energy storage and renewable energy stations can be a microgrid containing renewable energy or energy storage, a regional power grid composed of multiple energy storage and renewable energy stations, or a regional power grid based on flexible direct current transmission composed of multiple energy storage and renewable energy stations. These small-scale power grids are connected to the large power grid at a public grid connection point. In the grid connection point branches (each branch corresponds to a small-scale power grid), these small-scale power grids can be equivalent to virtual synchronous generators. Based on the principle of the virtual synchronous generator's rotational inertia responding to frequency, inertia response support power is provided to the large power grid in the grid connection point branches, thereby achieving safe and stable support for the large power grid's frequency.

[0038] S120: Calculating a frequency change rate of the grid connection point bus and a deviation between the current actual frequency and a rated frequency of the grid connection point bus according to the current actual frequency and at least one historical actual frequency of the grid connection point bus.

[0039] For example, when calculating the frequency change rate, the actual frequency corresponding to the grid connection point bus at the current moment and each moment in the historical moments can be determined based on the current actual frequency of the grid connection point bus and at least one historical actual frequency of the grid connection point bus. Based on each moment and the actual frequency of the grid connection point bus corresponding to the moment, the frequency change rate of the grid connection point bus can be obtained as follows.

[0040] Frequency change rate of the grid-connected bus .in, is the actual frequency of the bus at the grid connection point, and t is the time.

[0041] For example, when calculating the deviation between the current actual frequency and the rated frequency of the grid bus, the deviation between the current actual frequency and the rated frequency of the grid = ,in, is the current actual frequency, is the rated frequency of the grid connection point (or can also be considered as the rated frequency of the power grid). In a specific implementation, the rated frequency of the grid connection point is, for example, 50 Hz.

[0042] S130: Obtaining a dynamic change direction of the current actual frequency relative to the rated frequency according to the frequency change rate and the frequency deviation; wherein the dynamic change direction includes: a direction away from the rated frequency or a direction toward the rated frequency.

[0043] The product of the frequency change rate and the frequency deviation can be obtained. When the product is greater than or equal to zero, the dynamic change direction is determined to be away from the rated frequency; when the product is less than zero, the dynamic change direction is determined to be toward the rated frequency.

[0044] The specific functional relationship is expressed as follows: , determine the dynamic change direction is away from the rated frequency direction; , determine that the direction of dynamic change is towards the rated frequency.

[0045] S140: Adjusting the current virtual moment of inertia to an adaptive virtual moment of inertia according to the frequency deviation and the dynamic change direction.

[0046] When the frequency leaves the rated frequency, positive inertia is constructed; when the frequency approaches the rated frequency, negative inertia is constructed; when the frequency stabilizes at the rated frequency, the inertia is reduced to 0 and the inertia energy storage is restored.

[0047] When the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

[0048] Specifically, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the actual frequency of the grid bus is constantly away from the rated frequency. In this case, it is necessary to prevent the frequency of the grid bus from moving away from the rated frequency. Since the virtual moment of inertia itself will maintain the frequency stability of the power system, in this case the virtual moment of inertia itself will prevent the actual frequency of the grid point from moving away from the rated frequency of the grid point. Therefore, the resistance effect of the current virtual moment of inertia on the frequency deviation can be enhanced based on the positive virtual moment of inertia model to obtain an adaptive positive virtual moment of inertia to increase the resistance provided by the virtual moment of inertia, further prevent the actual frequency of the grid bus from moving away from the rated frequency, and make the actual frequency of the grid bus quickly return to the rated frequency.

[0049] Specifically, when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is towards the rated frequency, since the conventional virtual moment of inertia itself will hinder the frequency change of the power system, including the change towards the rated frequency, the inertia power provided by the virtual moment of inertia at this time actually hinders the actual frequency of the power grid from approaching the rated frequency of the power grid, that is, it hinders the recovery process of the actual frequency to the rated frequency. Therefore, it is proposed to construct the current virtual moment of inertia based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and obtain an adaptive virtual negative moment of inertia, thereby boosting and accelerating the recovery process of the actual frequency of the power grid bus towards the rated frequency.

[0050] Specifically, when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, it can be considered that there is no need to intervene in the actual frequency through virtual rotational inertia at this time, and the adaptive virtual rotational inertia can be set to 0; at the same time, since there is no need to consume electric energy to generate virtual rotational inertia at this time, in order to ensure that the energy storage has sufficient electricity to provide rotational inertia for future working conditions where the frequency is not within the safe range, the inertia energy storage capacity of the virtual synchronous generator model can be restored at this time.

[0051] In a specific implementation, the implementation of the positive virtual rotational inertia model and the negative virtual rotational inertia model can be adjusted by those skilled in the art according to the degree of frequency deviation.

[0052] For example, the forward virtual moment of inertia model can be implemented by the following formula (1).

[0053] Formula (1): .

[0054] In formula (1), is the adaptive virtual moment of inertia, is the standard virtual moment of inertia ( For the method of obtaining , please refer to the corresponding description in the following text, which will not be described in detail here). is the first adjustment index, is the frequency deviation threshold.

[0055] When the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model. The adaptive positive virtual moment of inertia is obtained based on formula (1). , based on the adaptive virtual moment of inertia obtained by formula (1) is the adaptive positive virtual moment of inertia.

[0056] In some embodiments, the first regulation index The value can be 0.5, the frequency deviation threshold For example, it may be 0.033 Hz.

[0057] For example, the negative virtual moment of inertia model can be implemented by the following formula (2).

[0058] Formula (2): .

[0059] is the second adjustment index, It is a negative adjustment coefficient.

[0060] In some embodiments, the second regulation index The value can be 0.5, negative adjustment coefficient The value can be 0.2.

[0061] When the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overshoot. The adaptive negative virtual moment of inertia is obtained by: Based on formula (2), the adaptive virtual moment of inertia is obtained. , based on the adaptive virtual moment of inertia obtained by formula (2) is the adaptive negative virtual moment of inertia.

[0062] Based on formula (1) and formula (2) in the above example, S140 can be implemented by the following formula (3).

[0063] Formula (3): It should be noted that when the frequency deviation is greater than or equal to the frequency deviation threshold, stronger inertia support is provided, whereas when the frequency deviation is less than the frequency deviation threshold, smaller inertia support or no inertia support is provided.

[0064] For the above formulas (1) to (3), , can be calculated based on the expected inertia time constant of the new energy station or station cluster represented by the virtual generator , calculate the standard virtual moment of inertia J 0.

[0065] The standard virtual moment of inertia can be calculated using the following formula (4): J 0.

[0066] Formula (4): .

[0067] In formula (4), is the standard virtual moment of inertia, The current maximum available power of the new energy station or station cluster represented by the virtual generator, It is the expected inertia time constant of the new energy station or station cluster represented by the virtual generator.

[0068] It should be noted that This can be obtained from relevant standards formulated for the power grid system. For example, when the power grid system is connected to a new energy grid, the 2019 edition of the "Implementation Rules for Auxiliary Services Management of Grid-Connected Power Plants in Northeast China" stipulates that " The recommended value is 4 to 8 seconds. Based on the above regulations, you can flexibly choose the appropriate value according to the actual situation of your region. .

[0069] It should be noted that for grid connection points of renewable energy stations or aggregation stations (i.e., renewable energy station aggregation stations) that include energy storage, virtual rotational inertia is typically provided as an auxiliary service. The recommended inertia time constant of 4 to 8 seconds is actually the inertia time constant of most thermal power units. This means that renewable energy generation is expected to have a rotational inertia similar to that of thermal power units to help mitigate rapid fluctuations in power system frequency.

[0070] The virtual moment of inertia control method taking into account positive and negative moment of inertia provided by the present invention can first obtain the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station including energy storage, and the moment of inertia of the energy storage new energy station or collection station is a virtual moment of inertia provided based on a virtual synchronous generator model. Thereafter, based on the current actual frequency and at least one historical actual frequency of the grid connection point bus, the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus are calculated. Then, based on the frequency change rate, the dynamic change direction of the current actual frequency relative to the rated frequency is obtained; wherein the dynamic change direction includes: away from the rated frequency direction or toward the rated frequency direction. Finally, based on the frequency deviation and the dynamic change direction, the current actual frequency is obtained. The current virtual moment of inertia is adjusted to the adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered. The present invention provides virtual rotational inertia to help the actual frequency approach the rated frequency regardless of whether the deviation between the actual frequency of the busbar at the grid connection point of a new energy station containing energy storage increases or decreases over time. At the same time, the inertia energy storage capacity of the virtual synchronous generator model is restored when the adaptive virtual rotational inertia is 0. By adding an inertia energy storage recovery control link, the inertia energy storage is instantly restored without affecting the rapid recovery and stable operation of the power grid frequency, and energy is promptly prepared for subsequent virtual rotational inertia control, so that the new energy station always has virtual inertia support capability. This solves the problem in the prior art that, in the process of stabilizing the power grid frequency at the rated frequency based on virtual rotational inertia, the virtual rotational inertia cannot be avoided. The obstruction of the frequency recovery process caused by the virtual rotational inertia and the inability to timely recover the virtual rotational inertia energy storage lead to a reduction in the ability of the power grid to quickly recover and stabilize. This achieves the purpose of improving the ability of the power grid to quickly recover and stabilize.

[0071] In some embodiments, if the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is greater than the frequency change rate threshold, there is a risk of overshoot. In this case, to reduce the risk of overshoot, the adaptive virtual moment of inertia can be set to the standard virtual moment of inertia. Based on this, S140 can be implemented using the following formula (5).

[0072] Formula (5): J .

[0073] When the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, there is no risk of over-regulation and no need for inertia support (the virtual rotational inertia is 0). In this case, the inertia energy storage capacity of the virtual synchronous generator model can also be restored, that is, inertia energy storage recovery control is performed (for example, by controlling the power to control the speed of inertia energy storage recovery). Based on this, S140 can be implemented by the following formula (6).

[0074] Formula (6): J The goal of restoring the inertial energy storage capacity of the virtual synchronous generator model is to restore the remaining state of charge (SOC) of the battery or energy storage system (corresponding to providing electrical energy to the virtual synchronous generator model) to a set value. The charge and discharge power of the energy storage should slowly change to the target charge and discharge power to avoid significantly affecting the frequency of the grid-connected bus. When restoring the inertial energy storage capacity of the virtual synchronous generator model, the following rules are followed: when the target ratio of the current energy storage capacity of the virtual synchronous generator model to the total energy storage capacity is less than a set ratio threshold, the energy storage device of the virtual synchronous generator model is charged, and the actual charging power is adjusted to the target power based on the set recovery power power change rate; when the target ratio of the current energy storage capacity to the total energy storage capacity is greater than or equal to the ratio threshold, the energy storage device of the virtual synchronous generator model is discharged, and the actual discharge power is adjusted to the above target power based on the set recovery power power change rate.

[0075] The target ratio of the current energy storage capacity to the total energy storage capacity is the SOC. If the SOC is less than a set ratio threshold, indicating that the current energy storage capacity is low and charging is required, the actual charging power can be slowly adjusted to the target charging power at a set recovery power power change rate (set by those skilled in the art based on actual conditions). If the energy storage capacity SOC is greater than the ratio threshold, indicating that the current energy storage capacity is high and discharge is required, the actual discharge power can be slowly adjusted to the target discharge power at a set recovery power power change rate. It should be noted that the reason for slowly adjusting the actual charging power and actual discharge power is to avoid large frequency fluctuations. In a specific embodiment, the target ratio can be 80%, the target power is 50% of the energy storage rated power, and the recovery power change rate is set to a power adjustment step size per minute. The power adjustment step size is set to 1% of the current available generating capacity of the equivalent virtual generator set at the new energy station or aggregation station. This is because the power adjustment capability of the generator set is generally required to be greater than 2% of the rated capacity per minute. This means that the local virtual equivalent generator set can track and respond to power fluctuations generated during the energy storage charging process, thereby avoiding impacts on the grid frequency.

[0076] It should be noted that in formula (1), ,when and The deviation between In order to further prevent the current actual frequency from deviating from the rated frequency, the first amplification factor is used. ≥1, let the hindering effect of the virtual moment of inertia be Further strengthen the first amplification factor In, according to Frequency deviation threshold The ratio of the first frequency modulation index The first amplification factor is adjusted based on the frequency deviation: when the frequency deviation is small, a smaller first exponential trend coefficient greater than 1 is used. Correct the resistance of the virtual positive moment of inertia; when the frequency deviation is large, use a larger first exponential trend coefficient greater than 1 Corrected the resistance of the virtual positive moment of inertia.

[0077] In formula (2), the acceleration direction of the current actual frequency change is already favorable for and The deviation between them is reduced, and the current actual frequency is also greater than or equal to the frequency deviation threshold, that is, it is far from the rated frequency and is not easy to over-adjust. Therefore, it is necessary to continue to maintain or enhance the frequency acceleration, rather than hindering the acceleration of the current actual frequency change through the standard virtual moment of inertia. Therefore, negative virtual inertia is used to increase the acceleration of the current actual frequency change, further accelerating Towards This enhancement is achieved through the second amplification factor The second amplification factor first affects the standard damping effect. The proportional coefficient k3 is used to make an overall smaller adjustment so that the negative virtual moment of inertia is not as strong as the positive virtual moment of inertia to avoid over-adjustment. The value of k3 can be 0.2, for example. Then, the second amplification coefficient is adjusted according to and The second adjustment index k2 is used to adjust the second amplification factor based on the frequency deviation: when the frequency deviation is small, a smaller second exponential trend coefficient greater than 1 is used. Correct the virtual moment of inertia to assist; when the frequency deviation is large, use a larger second exponential trend coefficient greater than 1 Correct the virtual moment of inertia to assist, k The value of 2 can be 0.5, for example.

[0078] right In the case of order The reason for this setting is as follows: When the frequency deviation is less than the frequency deviation threshold △f s , that is, when the current actual frequency of the grid-connected bus is within the safe range, further judge whether the acceleration of the current actual frequency change will cause the current actual frequency to quickly exceed the safe range, or even if the current actual frequency change direction is close to , but after reaching f0, it will continue to change along the current direction and then deviate in the opposite direction Specifically, when the absolute value of the frequency change rate is greater than the set frequency deviation threshold B In this case, it is believed that the current actual frequency change acceleration is too fast, which will cause overshoot. Therefore, a positive virtual moment of inertia is required to hinder the frequency change trend and reduce the current actual frequency change acceleration. Since the frequency is still within the safe range at this time, there is no need to further strengthen the standard virtual inertia.

[0079] In some embodiments, as Figure 2 As shown, the overall processing flow of S140 may include the following S210 to S270.

[0080] S210: Determine whether the frequency deviation is greater than or equal to a set frequency deviation threshold.

[0081] If the judgment result is yes, that is, the frequency deviation is greater than or equal to the set frequency deviation threshold, execute S220; if the judgment result is no, that is, the frequency deviation is less than the set frequency deviation threshold, execute S230.

[0082] S220: Determine whether the dynamic change direction is away from the rated frequency direction.

[0083] If the judgment result is yes, that is, the dynamic change direction is away from the rated frequency, execute S240; if the judgment result is no, that is, the dynamic change direction is toward the rated frequency, execute S250.

[0084] S230: Determine whether the absolute value of the frequency change rate is less than or equal to a frequency change rate threshold.

[0085] If the judgment result is yes, that is, the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, execute S260; if the judgment result is no, that is, the absolute value of the frequency change rate is greater than the frequency change rate threshold, execute S270.

[0086] S240: Adaptive virtual moment of inertia .

[0087] S250: Adaptive virtual moment of inertia .

[0088] S260: Setting the adaptive virtual moment of inertia to 0, and recovering the inertia energy storage capacity of the virtual synchronous generator model.

[0089] S270: Setting the adaptive virtual moment of inertia to the standard virtual moment of inertia.

[0090] That is: let the adaptive virtual moment of inertia = standard virtual moment of inertia.

[0091] The virtual moment of inertia control device taking into account positive and negative moments of inertia provided by the present invention is described below, which can be used in correspondence with the virtual moment of inertia control method taking into account positive and negative moments of inertia described above.

[0092] Figure 3 Schematic diagram of the structure of the virtual moment of inertia control device taking into account the positive and negative moments of inertia provided by the present invention. Figure 3 As shown, the virtual moment of inertia control device 300 taking into account positive and negative moments of inertia includes: a first acquisition module 301 , a calculation module 302 , a second acquisition module 303 and a processing module 304 .

[0093] The first acquisition module 301 is used to obtain the current actual frequency of the grid connection point bus at every set period; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the energy storage new energy station or the new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model.

[0094] The calculation module 302 is used to calculate the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus according to the current actual frequency and at least one historical actual frequency of the grid connection point bus.

[0095] The second acquisition module 303 is configured to acquire a dynamic change direction of the current actual frequency relative to the rated frequency according to the frequency change rate; wherein the dynamic change direction includes: a direction away from the rated frequency or a direction toward the rated frequency.

[0096] The processing module 304 is used to adjust the current virtual moment of inertia to an adaptive virtual moment of inertia based on the frequency deviation and the direction of dynamic change. When the frequency deviation is greater than or equal to the set frequency deviation threshold and the direction of dynamic change is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, thereby obtaining an adaptive positive virtual moment of inertia. When the frequency deviation is greater than or equal to the frequency deviation threshold and the direction of dynamic change is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overshoot, thereby obtaining an adaptive negative virtual moment of inertia. When the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered.

[0097] In some embodiments, the processing module 304 is further configured to set the adaptive virtual moment of inertia to the standard virtual moment of inertia when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is greater than the frequency change rate threshold.

[0098] In some embodiments, the processing module 304 performs recovery processing on the inertia energy storage capacity of the virtual synchronous generator model, including: when the target ratio of the current energy storage capacity to the total energy storage capacity of the virtual synchronous generator model is less than the set ratio threshold, charging the energy storage device of the virtual synchronous generator model, and adjusting the actual charging power to the target power based on the set recovery capacity power change rate; when the target ratio of the current energy storage capacity to the total energy storage capacity is greater than or equal to the ratio threshold, discharging the energy storage device of the virtual synchronous generator model, and adjusting the actual discharge power to the target power based on the set recovery capacity power change rate.

[0099] In some embodiments, the target ratio of the current energy storage capacity to the total energy storage capacity is 80%, the target power used when restoring the capacity is 50% of the rated power of the energy storage, and the power change rate of the restored capacity is taken as the power adjustment step / minute, where the power adjustment step is taken as 1% of the current available power generation capacity of the virtual generator set equivalent to the new energy station or the new energy station collection station.

[0100] The speed of change of the restored power is taken as the power adjustment step / minute, where the power adjustment step is taken as 1% of the current available power generation capacity of the virtual generator set equivalent to the new energy station or the collection station, because the power adjustment capability of the generator set is usually required to be greater than 2% of the rated capacity of the unit / minute. This means that the power changes generated during the energy storage charging process can be tracked and responded by the local virtual equivalent generator set, thereby avoiding affecting the grid frequency.

[0101] In some embodiments, the positive virtual moment of inertia model is constructed based on the standard virtual moment of inertia, frequency deviation, rated frequency, frequency deviation threshold and first adjustment index; the negative virtual moment of inertia model is constructed based on the standard virtual moment of inertia, frequency deviation, rated frequency, frequency deviation threshold, second adjustment index and negative adjustment coefficient.

[0102] In some embodiments, the first adjustment index is 0.5, the second adjustment index is 0.5, the negative adjustment coefficient is 0.2, the setting period is 10 ms, the frequency change rate threshold is 0.1 Hz / s, and the frequency deviation threshold is 0.033 Hz.

[0103] The virtual moment of inertia control device taking into account the positive and negative moments of inertia provided by the present invention can first obtain the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy site or a new energy site collection station containing energy storage, and the moment of inertia of the above-mentioned new energy site or the above-mentioned new energy site collection station is a virtual moment of inertia provided based on a virtual synchronous generator model. Thereafter, based on the current actual frequency and at least one historical actual frequency of the grid connection point bus, the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus are calculated. Then, based on the frequency change rate, the dynamic change direction of the current actual frequency relative to the rated frequency is obtained; wherein the dynamic change direction includes: away from the rated frequency direction or toward the rated frequency direction. Finally, based on the frequency deviation and the dynamic change direction , adjusting the current virtual moment of inertia to an adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered. The present invention provides virtual rotational inertia to help the actual frequency approach the rated frequency regardless of whether the deviation between the actual frequency of the busbar at the grid connection point of a new energy station containing energy storage increases or decreases over time. At the same time, the inertia energy storage capacity of the virtual synchronous generator model is restored when the adaptive virtual rotational inertia is 0. By adding an inertia energy storage recovery control link, the inertia energy storage is instantly restored without affecting the rapid recovery and stable operation of the power grid frequency, and energy is promptly prepared for subsequent virtual rotational inertia control, so that the new energy station always has virtual inertia support capability. This solves the problem in the prior art that, in the process of stabilizing the power grid frequency at the rated frequency based on virtual rotational inertia, the virtual rotational inertia cannot be avoided. The obstruction of the frequency recovery process caused by the virtual rotational inertia and the inability to timely recover the virtual rotational inertia energy storage lead to a reduction in the ability of the power grid to quickly recover and stabilize. This achieves the purpose of improving the ability of the power grid to quickly recover and stabilize.

[0104] Figure 4 An example of a physical structure diagram of an electronic device is shown below. Figure 4As shown, the electronic device may include: a processor (processor) 410 , a communication interface (Communications Interface) 420 , a memory (memory) 430 and a communication bus 440 , wherein the processor 410 , the communication interface 420 , and the memory 430 communicate with each other via the communication bus 440 . The processor 410 can call the logic instructions in the memory 430 to execute the virtual rotational inertia control method taking into account the positive and negative rotational inertia, the method comprising: step 1: obtaining the current actual frequency of the grid connection point bus at every set period; wherein the grid connection point bus is the bus of the grid connection point of a new energy site or a new energy site collection station including energy storage, and the rotational inertia of the new energy site or the new energy site collection station is a virtual rotational inertia provided based on the virtual synchronous generator model; step 2: according to the current actual frequency and at least one historical actual frequency of the grid connection point bus, calculating the frequency change rate of the grid connection point bus and calculating the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus; step 3: according to the frequency change rate and the frequency deviation, obtaining the dynamic change direction of the current actual frequency relative to the rated frequency; wherein the dynamic change direction includes: away from the rated frequency direction or toward the rated frequency direction; step 4: based on According to the frequency deviation and the direction of dynamic change, the current virtual moment of inertia is adjusted to an adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is recovered.

[0105] Furthermore, the logic instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0106] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the virtual rotational inertia control method taking into account the positive and negative rotational inertia provided by the above methods, the method comprising: step 1: obtaining the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station containing energy storage, and the rotational inertia of the new energy station or the new energy station collection station is a virtual rotational inertia provided based on a virtual synchronous generator model; step 2: calculating the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus according to the current actual frequency and at least one historical actual frequency of the grid connection point bus; step 3: obtaining the dynamic change direction of the current actual frequency relative to the rated frequency according to the frequency change rate and the frequency deviation; wherein the dynamic The dynamic change direction includes: away from the rated frequency direction or toward the rated frequency direction; step 4: according to the frequency deviation and the dynamic change direction, the current virtual moment of inertia is adjusted to the adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency direction, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is toward the rated frequency direction, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

[0107] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the virtual moment of inertia control method taking into account the positive and negative moment of inertia provided by the above-mentioned methods, the method comprising: step 1: obtaining the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy site or a new energy site collection station containing energy storage, and the moment of inertia of the new energy site or the new energy site collection station is a virtual moment of inertia provided based on a virtual synchronous generator model; step 2: calculating the frequency change rate of the grid connection point bus and the frequency deviation between the current actual frequency and the rated frequency of the grid connection point bus based on the current actual frequency and at least one historical actual frequency of the grid connection point bus; step 3: obtaining the dynamic change direction of the current actual frequency relative to the rated frequency based on the frequency change rate and the frequency deviation; wherein the dynamic change direction includes: away from the rated frequency. Frequency direction or tending towards the rated frequency direction; Step 4: According to the frequency deviation and the dynamic change direction, the current virtual moment of inertia is adjusted to the adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is away from the rated frequency direction, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is tending towards the rated frequency direction, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

[0108] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0109] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods of each embodiment or certain portions of the embodiments.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A virtual moment of inertia control method taking into account positive and negative moments of inertia, characterized in that: include: Step 1: Obtaining the current actual frequency of the grid connection point bus at set intervals; wherein the grid connection point bus is the bus of the grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the new energy station or the new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model; Step 2: Calculating a frequency change rate of the grid connection point bus and a frequency deviation between the current actual frequency and a rated frequency of the grid connection point bus based on the current actual frequency and at least one historical actual frequency of the grid connection point bus; Step 3: Obtaining a dynamic change direction of the current actual frequency relative to the rated frequency based on the frequency change rate and the frequency deviation; wherein the dynamic change direction includes: a direction away from the rated frequency or a direction toward the rated frequency; Step 4: According to the frequency deviation and the dynamic change direction, the current virtual moment of inertia is adjusted to an adaptive virtual moment of inertia; wherein, when the frequency deviation is greater than or equal to the set frequency deviation threshold and the dynamic change direction is the direction away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model, and an adaptive positive virtual moment of inertia is obtained; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is the direction toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, and an adaptive negative virtual moment of inertia is obtained; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

2. The virtual moment of inertia control method taking into account positive and negative moments of inertia according to claim 1, characterized in that: The method of adjusting the current virtual moment of inertia to an adaptive virtual moment of inertia according to the frequency deviation and the dynamic change direction further includes: When the frequency deviation is smaller than the frequency deviation threshold and the absolute value of the frequency change rate is larger than the frequency change rate threshold, the adaptive virtual moment of inertia is set to a standard virtual moment of inertia.

3. The virtual moment of inertia control method taking into account positive and negative moments of inertia according to claim 2, characterized in that: The recovering process of the inertia energy storage quantity of the virtual synchronous generator model includes: When the target ratio of the current energy storage capacity to the total energy storage capacity of the virtual synchronous generator model is less than a set ratio threshold, charging the energy storage device of the virtual synchronous generator model, and adjusting the actual charging power to the target power based on the set recovery power change rate; When the target ratio of the current energy storage capacity to the total energy storage capacity is greater than or equal to the ratio threshold, the energy storage device of the virtual synchronous generator model is discharged, and the actual discharge power is adjusted to the target power based on the set recovery power change rate.

4. The virtual moment of inertia control method taking into account positive and negative moments of inertia according to claim 3, characterized in that: The target ratio of the current energy storage capacity to the total energy storage capacity is 80%, the target power used when restoring the energy is 50% of the rated power of the energy storage, and the power change rate of the restored energy is taken as the power adjustment step / minute, where the power adjustment step is taken as 1% of the current available power generation capacity of the new energy station or the new energy station collection station equivalent virtual generator set.

5. The virtual moment of inertia control method taking into account positive and negative moments of inertia according to any one of claims 1 to 4, characterized in that: The forward virtual moment of inertia model is constructed based on the standard virtual moment of inertia, the frequency deviation, the rated frequency, the frequency deviation threshold, and a first adjustment index; The negative virtual moment of inertia model is constructed based on the standard virtual moment of inertia, the frequency deviation, the rated frequency, the frequency deviation threshold, a second adjustment index, and a negative adjustment coefficient.

6. The virtual moment of inertia control method taking into account positive and negative moments of inertia according to claim 5, characterized in that: The first adjustment index is 0.5, the second adjustment index is 0.5, the negative adjustment coefficient is 0.2, the setting period is 10 ms, the frequency change rate threshold is 0.1 Hz / s, and the frequency deviation threshold is 0.033 Hz.

7. A virtual moment of inertia control device taking into account positive and negative moments of inertia, characterized in that: include: A first acquisition module is configured to acquire the current actual frequency of a grid connection point bus at set intervals; wherein the grid connection point bus is a bus of a grid connection point of a new energy station or a new energy station collection station that includes energy storage, and the moment of inertia of the new energy station or the new energy station collection station is a virtual moment of inertia provided based on a virtual synchronous generator model; a calculation module, configured to calculate a frequency change rate of the grid connection point bus and a frequency deviation between the current actual frequency and a rated frequency of the grid connection point bus based on the current actual frequency and at least one historical actual frequency of the grid connection point bus; A second acquisition module is configured to acquire a dynamic change direction of the current actual frequency relative to the rated frequency based on the frequency change rate; wherein the dynamic change direction includes: a direction away from the rated frequency or a direction toward the rated frequency; A processing module is configured to adjust the current virtual moment of inertia to an adaptive virtual moment of inertia according to the frequency deviation and the dynamic change direction; wherein, when the frequency deviation is greater than or equal to a set frequency deviation threshold and the dynamic change direction is the direction away from the rated frequency, the resistance effect of the current virtual moment of inertia on the frequency deviation is enhanced based on the positive virtual moment of inertia model to obtain the adaptive virtual positive moment of inertia; when the frequency deviation is greater than or equal to the frequency deviation threshold and the dynamic change direction is the direction toward the rated frequency, the current virtual moment of inertia is constructed based on the negative virtual moment of inertia model to assist frequency recovery and avoid overadjustment, thereby obtaining the adaptive virtual negative moment of inertia; when the frequency deviation is less than the frequency deviation threshold and the absolute value of the frequency change rate is less than or equal to the frequency change rate threshold, the adaptive virtual moment of inertia is set to 0, and the inertia energy storage capacity of the virtual synchronous generator model is restored.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the virtual rotational inertia control method taking into account the positive and negative rotational inertia as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the virtual rotational inertia control method taking into account positive and negative rotational inertia as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the virtual rotational inertia control method taking into account positive and negative rotational inertia as described in any one of claims 1 to 6 is implemented.

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