Source-network-load-storage multi-resource inertia quantitative calculation method and device, equipment and medium

Abstract

The invention relates to the technical field of power system automation, in particular to a source-grid-load-storage multi-resource inertia quantitative calculation method, device and equipment and a medium, and the method comprises the steps: constructing a power supply side inertia support model based on the output characteristics of a conventional synchronous generator, wind power generation and photovoltaic power generation, and calculating the equivalent inertia of a power supply side; inertia support models of a power grid side, a load side and an energy storage side are respectively constructed by combining inertia characteristics of a direct-current power transmission system, a motor, flywheel energy storage and electrochemical energy storage; deducing a unified inertia calculation model of source-network-load-storage multi-resource collaborative support according to the inertia support model of each side and the commissioning capacity proportion; the inertia of each resource side of the power grid is integrated and calculated by deriving the performance of the internal source-grid-load-storage resources of the power grid in different commissioning ratios, and a source-grid-load-storage multi-resource inertia quantitative calculation method is obtained, so that inertia quantification of multi-resource cooperative support is realized, and the system frequency stability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system automation, and in particular to a method, device, equipment and medium for quantitatively calculating the inertia of a source-grid-load-storage multi-resource. Background Art

[0002] In modern new power systems, with the increasing proportion of renewable energy power generation and the increasing proportion of flexible resources such as energy storage, the overall inertia level of new power systems has dropped significantly, the frequency regulation capability has been greatly weakened, and the frequency safety and stability issues of the system have become increasingly prominent. In traditional power systems, synchronous generators can provide effective inertia support for frequency disturbances due to their mechanical rotational inertia. However, new energy sources such as wind power and photovoltaics are connected to the grid through power electronic equipment and do not have active inertia support characteristics, resulting in a decrease in the overall inertia level of the system, thereby increasing the risk of frequency fluctuations or even collapse of the power system when disturbed.

[0003] To meet this challenge, diversified flexible resources such as source-grid-load-storage have been gradually introduced into the power system, and the frequency stability of the system has been improved by building functions such as virtual inertia support and primary frequency regulation. The inherent rotational inertia support of traditional synchronous generator sets is achieved by the kinetic energy of their own mechanical rotating parts, mainly relying on the rotation form of the generator rotor and the shaft system. However, since renewable energy power generation has no mechanical rotating parts, its inertia support can only be achieved through virtual inertia control methods. Usually, the response speed and ability of this type of single resource inertia support are relatively weak. Therefore, the comprehensive frequency regulation resources of source-grid-load-storage have become a hot topic in the current inertia support research.

[0004] In the current related research, various types of source-grid-load-storage frequency regulation resources can participate in system inertia support and primary frequency regulation through various typical control strategies. There are related quantitative calculation models for the equivalent inertia of a single source of various flexible resources, but there is no clear inertia calculation model that takes into account all sources of source-grid-load-storage in the power system; in the related research considering the inertia support of multiple resources in the new power system, there is no consideration of the proportion of commissioned capacity when the source-grid-load-storage resources of the power system provide inertia support, which cannot provide a comprehensive reference for the safe operation of the power system under actual working conditions. For example, the literature "Fast Estimation Method of Equivalent Virtual Inertia of Wind Farm" [J]. Li Shichun et al. Power System Technology, 2021, 45(12): 4683-4692. It only considers the inertia support characteristics and inertia calculation of wind power generation on the power supply side of the power system; the literature "Research Framework and Prospects of Inertia Assessment of Power Systems" [J]. Zhang Wuqi et al. Proceedings of the CSEE, 2021, 41(20): 6842-6856. Although various resources are taken into account, the actual operating capacity proportion of each flexible inertia support Jiyuan is not considered.

[0005] In summary, existing research lacks a unified quantitative calculation method for system equivalent inertia considering system source-grid-load-storage frequency regulation resources under different operating ratios, and has the following problems: existing inertia calculations are mostly concentrated on a single resource type, failing to comprehensively consider the synergistic support role of multiple resources such as source-grid-load-storage; in addition, there is a lack of a unified calculation model for the system equivalent inertia of various types of resources under different operating ratios, making it difficult to provide comprehensive reference and guidance for safe operation under actual power system conditions.

[0006] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0007] The present invention provides a method, device, equipment and medium for quantitatively calculating the inertia of multiple resources including source, grid, load and storage, thereby effectively solving the problems in the background technology.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is: a quantitative calculation method of inertia of source-grid-load-storage multi-resources, comprising the following steps:

[0009] S10: Based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, a model of inertia support on the power supply side in the power system is constructed, the inertia support characteristics on the power supply side are quantified, and the equivalent inertia on the power supply side is calculated;

[0010] S20: Based on the equivalent inertia of the power source side and considering the inertia support characteristics provided by the DC power transmission system, a model of inertia support on the grid side in the power system is constructed, and the inertia support characteristics on the grid side are calculated;

[0011] S30: Based on the calculation result of the grid-side inertia support and in combination with the inertia support characteristics of the motor, a model of the load-side inertia support in the power system is constructed, and the load-side equivalent inertia is calculated;

[0012] S40: Based on the characteristic analysis of the load side inertia support, through the virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, a model of the inertia support on the energy storage side in the power system is constructed, and the inertia support capacity of the energy storage side is calculated;

[0013] S50: Based on the inertia support models of the power supply side, the grid side, the load side and the energy storage side, combined with the proportion of the operating capacity of each resource, a unified inertia calculation model taking into account the collaborative support of multiple resources of source-grid-load-storage is derived to quantify the equivalent inertia of the power system under actual operating conditions.

[0014] Further, in step S10, the model of equivalent inertia of the synchronous generator in the power supply side includes:

[0015]

[0016] In the formula, E G is the total equivalent inertia of the synchronous generator on the power supply side, E Gi is the theoretical inertia value of the i-th generator, H i is the inertia time constant of the i-th generator, S i is the capacity of the i-th generator.

[0017] Furthermore, in step S10, based on the output characteristics of the wind power generation, an aggregated equivalent virtual inertia time constant model of the wind farm is constructed to quantify the inertia support characteristics of the power supply side, and the aggregated equivalent inertia time constant model of the wind farm includes:

[0018]

[0019] In the formula, H eqWF is the equivalent inertia time constant of wind farm aggregation, P is the number of wind turbine pole pairs, J eq is the virtual inertia of the wind turbine, ω s0 is the initial synchronous angular velocity of the wind turbine system, S Ni is the capacity of the i-th wind turbine, H eqi It is only the inertial response effect of the i-th wind turbine, and m is the number of doubly-fed wind turbines in the wind farm.

[0020] Furthermore, in step S10, the model of equivalent inertia of photovoltaic power generation in the power supply side includes:

[0021]

[0022] In the formula, H dc is the equivalent inertia time constant of the capacitor, C is the equivalent capacitance, U dc0 is the steady-state value of DC voltage, k1 is the control parameter of the virtual inertia control branch, and s is the Laplace operator.

[0023] Further, in step S20, considering the inertia support characteristics provided by the DC transmission system, a model of inertia support on the grid side of the power system is constructed, including a mathematical model for calculating the effective moment of inertia of the DC transmission system, wherein the effective moment of inertia is jointly determined by the potential energy provided by the system capacitor and the magnetic field energy provided by the inductor, and the model of inertia support on the grid side of the power system includes:

[0024]

[0025] In the formula, Jv is the moment of inertia of the synchronous machine, ΔE cm Provide the maximum potential energy for the capacitors at both ends of the converter station, ΔE lm Provides the maximum magnetic field energy for the inductor components of the DC system, L eq is the equivalent inductance of the flexible DC system, I dc0 is the DC current in steady-state operation, ω gm are the grid angular frequency, U SMm is the submodule capacitor voltage, I dcm The limitation of DC current in the inertia response stage, N is the total number of submodules put into operation in the upper and lower bridge arms of the converter during steady-state operation; C SM is the capacitance value of a single submodule.

[0026] Furthermore, in step S20, an inertia time constant model of the DC power transmission system is calculated to quantify the grid-side inertia support characteristics, and the inertia time constant model of the DC power transmission system includes:

[0027]

[0028] In the formula, H MMC is the inertia time constant of the DC system, J v is the moment of inertia of the synchronous machine, ω MMCO is the rated angular frequency of the converter station, P m is the rated power of the DC system.

[0029] Further, in step S30, when constructing the mathematical model of the load-side inertia support in the power system, based on the characteristics of the asynchronous motor as the main electrical equipment on the load side, a transient reactance after-potential phase motion equation model containing equivalent inertia under the electromechanical time scale of the asynchronous motor is established, and the model includes:

[0030] H im (s)sΔω s =ΔP e -ΔP m ;

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] In the formula, H im (s) is the inertia time constant of the asynchronous motor, Δωs is the system synchronous angular velocity increment, ΔP e is the useful power, ΔP m is the mechanical power change, s is the Laplace transform, Y1 is the dynamic coupling of inertia and inductance, affecting the mechanical characteristics, Y2 is the electromagnetic response and power characteristic change, Y3 is the combined influence of impedance and inertia, Y4 is the dynamic effect of power characteristics, rotor impedance and inductance, L r is the rotor inductance, L m is the mutual inductance of the stator and rotor, u'0 is the magnetic permeability of the material, s slip0 is the slip rate, ω s0 is the potential frequency, R r is the rotor resistance.

[0037] Further, in step S40, when constructing the mathematical model of the inertia support on the energy storage side in the power system, the equivalent inertia of the battery energy storage system is represented by an inertia time constant, and the model of the equivalent inertia time constant of the battery energy storage system includes:

[0038]

[0039] In the formula, H Ceq is the equivalent inertia time constant of the battery energy storage system, J Ceq is the equivalent inertia of the battery energy storage system, ω n is the rated rotational angular velocity, S N is the rated power, C eq is the equivalent capacitance, U CN It is the rated voltage of the capacitive energy storage body.

[0040] Further, in step S50, the equivalent inertia of the new power system under multiple resources is jointly provided by the source-grid-load-storage diversified inertia support resources, wherein the power supply side is provided by traditional generators, wind turbines, and photovoltaic equipment, the grid side is provided by a DC virtual synchronous machine, the load side is provided by a synchronous motor and an asynchronous motor, and the energy storage side is provided by a flywheel energy storage and a battery energy storage. The model of the equivalent inertia of the new power system under multiple resources includes:

[0041] E sys =E TR +E WF +E PV +E HVDC +E GD +E im +E FES +E Ceq ;

[0042] In the formula, E TR 、E WF 、EPV 、E HVDC 、E GD 、E im 、E FES 、E Ceq They are the inertia provided by traditional synchronous generator sets, wind turbines, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage.

[0043] Furthermore, the total capacity S of each inertia source of source-grid-load-storage is derived by integrating the inertia coordination support characteristics of the source-grid-load-storage multi-resources. sys Models include:

[0044]

[0045] In the formula, S Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , η cn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

[0046] Furthermore, based on the model of equivalent inertia of the new power system under multiple resources and the total capacity of each inertia source of the source-grid-load-storage, the equivalent inertia time constant of the power system of source-grid-load-storage is calculated to quantify the inertia support capacity of the system under different working conditions. The model of equivalent inertia time constant of the power system of source-grid-load-storage includes:

[0047]

[0048] In the formula, E sys is the equivalent inertia of the new power system under multiple resources, S sys is the total capacity of each inertia source, grid, load and storage, E TR 、E WF 、E PV 、E HVDC 、EGD 、E im 、E FES 、E Ceq are the inertia provided by traditional synchronous generator sets, wind turbine sets, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage, respectively. Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , η cn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

[0049] The present invention also includes a source-grid-load-storage multi-resource inertia quantitative calculation device, using the above method, including:

[0050] The power supply side inertia support unit is used to build a model of the power supply side inertia support in the power system based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, quantify the power supply side inertia support characteristics, and calculate the equivalent inertia of the power supply side;

[0051] A grid-side inertia support unit, configured to construct a grid-side inertia support model in a power system based on the equivalent inertia of the power supply side and taking into account the inertia support characteristics provided by the DC power transmission system, and calculate the grid-side inertia support characteristics;

[0052] A load-side inertia support unit, configured to construct a model of load-side inertia support in a power system based on the calculation result of the grid-side inertia support and in combination with the inertia support characteristics of the motor, and calculate the load-side equivalent inertia;

[0053] The energy storage side inertia support unit is used to construct a model of the energy storage side inertia support in the power system based on the characteristic analysis of the load side inertia support, through a virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, and calculate the inertia support capacity of the energy storage side;

[0054] The unified inertia calculation unit is used to derive a unified inertia calculation model taking into account the coordinated support of multiple resources of source-grid-load-storage according to the inertia support models of the power supply side, the grid side, the load side and the energy storage side, in combination with the proportion of the commissioned capacity of each resource, so as to quantify the equivalent inertia of the power system under actual operating conditions.

[0055] The present invention also includes a computer device, including 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 method described above is implemented.

[0056] The present invention also includes a storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0057] The beneficial effects of the present invention are:

[0058] The present invention can provide a method for calculating the overall inertia of the system under the background of the current large-scale new energy access new power system. This calculation method is different from the previous quantitative calculation of the power grid inertia considering a single resource side. Instead, it integrates the inertia of each resource side of the power grid by deducing the performance of the source-grid-load-storage resources inside the power grid at different operating proportions, and obtains a quantitative calculation method for the inertia taking into account the source-grid-load-storage multiple resources. This has guiding significance for the quantitative calculation of the inertia of the current new power system containing a variety of flexible inertia support resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 A flow chart of a quantitative calculation method of inertia of multiple resources of source-grid-load-storage;

[0061] Figure 2 The physical structure and control structure diagram of the photovoltaic grid-connected system;

[0062] Figure 3 It is a schematic diagram of the structure of the inertia quantitative calculation device for source-grid-load-storage multi-resources;

[0063] Figure 4 A schematic diagram of the structure of a computer device. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0065] like Figure 1 As shown: A quantitative calculation method for inertia of source-grid-load-storage multi-resources includes the following steps:

[0066] S10: Based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, a model of inertia support on the power supply side in the power system is constructed, the inertia support characteristics on the power supply side are quantified, and the equivalent inertia on the power supply side is calculated;

[0067] S20: Based on the equivalent inertia on the power supply side and considering the inertia support characteristics provided by the DC transmission system, a model of the inertia support on the grid side in the power system is constructed, and the inertia support characteristics on the grid side are calculated;

[0068] S30: Based on the calculation result of the grid-side inertia support and in combination with the inertia support characteristics of the motor, a model of the load-side inertia support in the power system is constructed, and the load-side equivalent inertia is calculated;

[0069] S40: Based on the characteristic analysis of load-side inertia support, through the virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, a model of inertia support on the energy storage side in the power system is constructed, and the inertia support capacity of the energy storage side is calculated;

[0070] S50: Based on the inertia support models of the power supply side, grid side, load side and energy storage side, combined with the proportion of the operating capacity of each resource, a unified inertia calculation model taking into account the collaborative support of multiple resources such as source-grid-load-storage is derived to quantify the equivalent inertia of the power system under actual operating conditions, and provide guidance for system frequency stability analysis and multi-resource optimization configuration.

[0071] The present invention can provide a method for calculating the overall inertia of the system under the background of the current large-scale new energy access new power system. This calculation method is different from the previous quantitative calculation of the power grid inertia considering a single resource side. Instead, it integrates the inertia of each resource side of the power grid by deducing the performance of the source-grid-load-storage resources inside the power grid at different operating proportions, and obtains a quantitative calculation method for the inertia taking into account the source-grid-load-storage multiple resources. This has guiding significance for the quantitative calculation of the inertia of the current new power system containing a variety of flexible inertia support resources.

[0072] By comprehensively considering the inertia support characteristics of multiple resources including source-grid-load-storage, and combining the characteristics of different resources and their operating capacity ratio, a unified inertia calculation method is proposed, which realizes the inertia quantification of multi-resource collaborative support and improves the system frequency stability.

[0073] This method covers a variety of inertia support resources such as traditional power generation (synchronous generators), new energy (wind power, photovoltaics), direct current transmission, loads (motors) and energy storage (flywheel energy storage, electrochemical energy storage), etc., constructs inertia support models on different resource sides, and calculates their equivalent inertias respectively. Compared with the existing technology that only focuses on the inertia support characteristics of a single resource (such as wind power or photovoltaics), this method has a more comprehensive calculation and provides a system-level inertia support solution for the power system.

[0074] The unified inertia calculation model finally derived can quantify the equivalent inertia of the power system under different operating conditions, providing a reliable theoretical basis for frequency stability analysis. At the same time, this method can optimize the scheduling and operation strategy of multiple resources such as source-grid-load-storage according to system requirements and resource allocation, and improve system operation efficiency.

[0075] Against the backdrop of increasing penetration of new energy, wind power, photovoltaics and other power generation resources without mechanical inertia have made frequency regulation of power systems more difficult. This solution builds a virtual inertia support model and utilizes flywheel energy storage, electrochemical energy storage and virtual synchronous generator strategies to make up for the problem of insufficient inertia of new energy power generation, providing technical support for the safe and stable operation of new energy power systems.

[0076] This method divides the inertia support characteristics of four types of resources, namely source, network, load and storage, into independent modules for analysis and modeling, which is convenient for individual optimization and for integrating into the system model when new resource types (such as other energy storage forms or electric vehicles) are subsequently expanded, and has good scalability.

[0077] The inertia calculation on the power supply side mainly includes traditional synchronous generators, wind power generation, and photovoltaic power generation. For a single traditional generator, the theoretical value of inertia represents the rotor kinetic energy of the generator at the rated angular velocity, in MW·s. The model includes:

[0078]

[0079] In the formula, E Gi is the theoretical inertia value of the i-th generator, H i is the inertia time constant of the i-th generator, S i is the capacity of the i-th generator, J i is the moment of inertia of the i-th generator, ω n is the rated angular speed of the generator rotor.

[0080] In a power system containing only conventional synchronous generator sets, the theoretical value of the system equivalent inertia is the sum of the inertias of the generators in the system;

[0081] As a preference of the above embodiment, in step S10, the model of equivalent inertia of the synchronous generator in the power supply side includes:

[0082]

[0083] In the formula, E G is the total equivalent inertia of the synchronous generator on the power supply side, E Gi is the theoretical inertia value of the i-th generator, H i is the inertia time constant of the i-th generator, S i is the capacity of the i-th generator.

[0084] By defining the total equivalent inertia E of the synchronous generator G and the inertia time constant H of a single machine i , which can accurately reflect the actual contribution of the generator to the inertia support of the power system, thereby improving the accuracy of inertia calculation.

[0085] The change in kinetic energy during the inertial response of a wind turbine can be expressed by the change in rotor speed and the inherent moment of inertia:

[0086]

[0087] Where P, S N ,J DFIG ,ω r0 , Δω r They are the number of wind turbine pole pairs, rated capacity, inherent moment of inertia, initial rotor angular velocity and rotor angular velocity increment;

[0088] After implementing virtual inertial control on the wind turbine, the wind turbine speed is coupled with the system angular velocity, and the kinetic energy change during the inertial response process can also be expressed by the system synchronous angular velocity change and the virtual moment of inertia:

[0089]

[0090] In the formula, J eq ,ω s0 ,Δω s are the virtual moment of inertia of wind turbine, the initial synchronous angular velocity of the system and the increment of the synchronous angular velocity of the system respectively;

[0091] According to the above two ΔE k The calculation model of the wind turbine generator system can be obtained as follows:

[0092]

[0093] According to J eq The calculation model and inertia time constant definition of the wind turbine can be defined as:

[0094]

[0095] In the formula, ω nom is the rated angular velocity of the wind turbine, H DFIG is the inherent inertia time constant, H eq It only represents the inertial response effect of a single wind turbine. If the total inertial response effect of the wind farm is to be described, the wind farm aggregate equivalent virtual inertial time constant H should be used. eqWF express;

[0096] According to the definition, the generator inertia time constant is the ratio of the stored kinetic energy to the rated capacity at the rated speed of the generator. The stored kinetic energy of a single wind turbine can be expressed by the virtual equivalent inertia and synchronous speed:

[0097]

[0098] Among them, E ki To store kinetic energy for a single wind turbine, J eq is the virtual inertia of the wind turbine, ω s is the system synchronous angular velocity, P is the number of wind turbine pole pairs, S Ni is the capacity of the i-th wind turbine;

[0099] When the wind farm contains m doubly-fed wind turbines, the wind farm is equivalent to one turbine, and the wind farm aggregate equivalent inertia time constant H eqWF Equal to the ratio of total kinetic energy stored in the wind farm to total capacity:

[0100] In this embodiment, in step S10, based on the output characteristics of wind power generation, an aggregated equivalent virtual inertia time constant model of the wind farm is constructed to quantify the inertia support characteristics of the power supply side. The aggregated equivalent inertia time constant model of the wind farm includes:

[0101]

[0102] In the formula, H eqWF is the equivalent inertia time constant of wind farm aggregation, P is the number of wind turbine pole pairs, J eq is the virtual inertia of the wind turbine, ω s0 is the initial synchronous angular velocity of the wind turbine system, S Ni is the capacity of the i-th wind turbine, H eqi It is only the inertial response effect of the i-th wind turbine, and m is the number of doubly-fed wind turbines in the wind farm.

[0103] By aggregating the equivalent virtual inertia time constant model, the inertia response characteristics of multiple wind turbines are described in a unified manner, which effectively overcomes the problem of inaccurate assessment of the overall inertia support of the actual wind farm by single-machine inertia analysis and improves the accuracy of the inertia support capacity calculation on the power supply side.

[0104] The DC capacitor of the photovoltaic grid-connected system is mainly used to balance the output power of DC / DC and the input power of DC / AC. Its dynamic characteristics can be expressed as:

[0105]

[0106] Where U dc is the voltage of the DC capacitor, C is the equivalent capacitance, P PV is the active power of photovoltaic, P G is the grid-side active power;

[0107] In order to simulate the inertia time constant of the synchronous generator, the changing DC voltage is analogized to the changing synchronous machine rotor speed to provide virtual inertia, and the result is:

[0108]

[0109] In the formula, H dc is the equivalent inertia time constant of the capacitor. Integrating both ends of the above equation, we get:

[0110]

[0111] Where, f is the synchronous machine frequency, f ref is the rated frequency of the grid voltage, U dc0 Represents the steady-state value of the DC voltage; because the capacitor voltage fluctuates in a small range, its small signal can be linearized to obtain:

[0112] 2H dc Δf=CU dc0 ΔU dc ;

[0113] Where Δf is the frequency deviation of the system, U dc0 Indicates the steady-state value of DC voltage, ΔU dc is the DC voltage difference, according to Figure 2 In the virtual inertia control, RoCoF with a low-pass filter is introduced as the control instruction. The deviation between RoCoF and DC voltage has the following relationship:

[0114]

[0115] Among them, s is the Laplace operator, k1 is the control parameter of the virtual inertia control branch, and the expression of the equivalent inertia of the photovoltaic grid-connected system is obtained by the above two equations.

[0116] Wherein, in step S10, the model of equivalent inertia of photovoltaic power generation on the power supply side includes:

[0117]

[0118] In the formula, H dcis the equivalent inertia time constant of the capacitor, C is the equivalent capacitance, U dc0 is the steady-state value of DC voltage, k1 is the control parameter of the virtual inertia control branch, and s is the Laplace operator.

[0119] By defining the equivalent inertia model of photovoltaic power generation, the inertial support role of the DC side capacitor in the photovoltaic power generation system is quantified, which makes up for the deficiency that the traditional photovoltaic system cannot directly provide inertia support, thereby improving the accuracy and practicality of inertia modeling.

[0120] From the above formula, we can know that the equivalent inertia of the photovoltaic grid-connected system is proportional to the steady-state DC voltage, DC capacitance, and control parameters of the control branch. Due to the limited energy storage of DC capacitors, the simulated equivalent inertia cannot be compared with the mechanical inertia of synchronous machines. Therefore, photovoltaics are required to provide additional active support capabilities. In theory, active control instructions can be added to call the photovoltaic reserve margin to provide frequency support for the system. After the disturbance occurs, the photovoltaic reserve margin can be equivalent to the increased mechanical power of the synchronous machine to obtain additional system inertia:

[0121]

[0122] Where P m is the mechanical power of the synchronous machine, Δf is the frequency deviation of the system, P e is the electromagnetic power, and k2 is the control parameter of the virtual primary frequency modulation control branch.

[0123] The rotor kinetic energy of the synchronous machine is the main source of inertia in the current power system. For the DC system, it contains a variety of energy storage elements. The energy is stored in the capacitor and inductor in the form of electric potential energy and magnetic field energy, and has a certain energy margin. It is the main source of inertia support energy;

[0124] As a preferred embodiment of the above, in step S20, considering the inertia support characteristics provided by the DC power transmission system, a model of inertia support on the grid side of the power system is constructed, including a mathematical model for calculating the effective moment of inertia of the DC power transmission system, where the effective moment of inertia is jointly determined by the potential energy provided by the system capacitor and the magnetic field energy provided by the inductor. The model of inertia support on the grid side of the power system includes:

[0125]

[0126] In the formula, J v is the moment of inertia of the synchronous machine, ΔE cm Provide the maximum potential energy for the capacitors at both ends of the converter station, ΔE lm Provides the maximum magnetic field energy for the inductor components of the DC system, L eq is the equivalent inductance of the flexible DC system, I dc0 is the DC current in steady-state operation, ωgm are the grid angular frequency, U SMm is the submodule capacitor voltage, I dcm The limitation of DC current in the inertia response stage, N is the total number of submodules put into operation in the upper and lower bridge arms of the converter during steady-state operation; C SM is the capacitance value of a single submodule.

[0127] By calculating the potential energy provided by capacitors and the magnetic field energy provided by inductors in DC transmission systems, their inertia support capabilities are accurately quantified, overcoming the limitation of traditional DC systems that fail to fully consider the contribution of capacitor and inductor characteristics to inertia, thereby significantly improving the accuracy of inertia calculations.

[0128] In this embodiment, in step S20, the inertia time constant model of the DC power transmission system is calculated to quantify the grid-side inertia support characteristics. The inertia time constant model of the DC power transmission system includes:

[0129]

[0130] In the formula, H MMC is the inertia time constant of the DC system, J v is the moment of inertia of the synchronous machine, ω MMCO is the rated angular frequency of the converter station, P m is the rated power of the DC system.

[0131] By explicitly defining the inertial time constant H MMC The calculation model of the moment of inertia J v 、Rated angular frequency of converter station ω MMCO and rated power P m Combined with the above, the inertia support capability of the DC transmission system is accurately quantified, thereby improving the accuracy of the grid-side inertia support characteristic assessment.

[0132] Among them, in step S30, when constructing the mathematical model of the load-side inertia support in the power system, based on the characteristics of the asynchronous motor as the main electrical equipment on the load side, its direct grid connection mode can generally be regarded as connecting with power generation equipment such as power plants through transmission lines, and establishing the potential phase motion equation model of the transient reactance containing equivalent inertia under the electromechanical time scale of the asynchronous motor, the model includes:

[0133] H im (s)sΔω s =ΔP e -ΔP m ;

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] In the formula, H im (s) is the inertia time constant of the asynchronous motor, Δω s is the system synchronous angular velocity increment, ΔP e is the useful power, ΔP m is the mechanical power change, s is the Laplace transform, Y1~Y4 are the key coefficients in the asynchronous motor dynamics model, which are respectively: Y1 is the dynamic coupling of inertia and inductance, affecting the mechanical characteristics, Y2 is the electromagnetic response and power characteristic change, Y3 is the combined influence of impedance and inertia, Y4 is the dynamic effect of power characteristics, rotor impedance and inductance, L r is the rotor inductance, L m is the mutual inductance of the stator and rotor, u'0 is the magnetic permeability of the material, s slip0 is the slip rate, ω s0 is the potential frequency, R r is the rotor resistance.

[0140] f'(ω r0 ) is the differential form of the rotor speed. For the rotor speed f'(ω r0 )have

[0141] By establishing the phase motion equation of the potential after the transient reactance of the asynchronous motor, the dynamic processes of the asynchronous motor, such as the inertia characteristics, electromagnetic response characteristics and power characteristics, are fully described, overcoming the problem of lack of accurate description of the dynamic coupling relationship in traditional load-side inertia modeling and significantly improving the accuracy of the model.

[0142] Step S40: Based on the characteristic analysis of the load side inertia support, through the virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, a mathematical model of the inertia support on the energy storage side in the power system is constructed, and the inertia support capacity of the energy storage side is calculated;

[0143] Inertia in a flywheel energy storage system refers to the ability of the flywheel rotor to resist speed changes. In modern power systems, flywheel energy storage systems often use virtual synchronous generator control strategies to simulate the inertial response of synchronous generators. When calculating equivalent inertia, per-unit calculation is used to define the virtual inertia coefficient H of the flywheel energy storage system VSG. FES ,have to:

[0144]

[0145] In the formula, JFES is the moment of inertia coefficient, ω0 is the rated rotation angular frequency, S N is the rated power.

[0146] The electrochemical energy storage system itself does not have physical mechanical inertia because it has no rotating parts. The battery is connected to the grid through a power electronics interface, so its inertia response depends on virtual inertia control strategies, such as virtual synchronous generator (VSG) control;

[0147] The voltage on the capacitor has the same expression as that of a linear motion object and a rotating motion object after a sudden excitation or external force. Therefore, for a capacitor that stores energy in the form of potential energy, the capacitance is a measure of the inertia of the potential energy. The inertia of the capacitor to the potential energy can be characterized by the capacitance value under rated conditions, and its nominal unit is farad (F). The equivalent inertia of the battery energy storage system, the model includes:

[0148]

[0149] In the formula, C eq is the equivalent capacitance, that is, the measure of electric potential energy inertia, and the calculation model is as follows:

[0150]

[0151] In the formula, S CN , U CN ,I CN , T CN The rated capacity, rated voltage, rated current and rated charge and discharge time of the capacitive energy storage body are respectively n is the rated rotational angular velocity;

[0152] As a preferred embodiment of the above, in step S40, when constructing a mathematical model of the inertia support on the energy storage side in the power system, the equivalent inertia of the battery energy storage system is represented by an inertia time constant, and the model of the equivalent inertia time constant of the battery energy storage system includes:

[0153]

[0154] In the formula, H Ceq is the equivalent inertia time constant of the battery energy storage system, J Ceq is the equivalent inertia of the battery energy storage system, ω n is the rated rotational angular velocity, S N is the rated power, C eq is the equivalent capacitance, U CN It is the rated voltage of the capacitive energy storage body.

[0155] By adopting the inertia time constant model and combining the key physical parameters of the battery energy storage system (such as equivalent inertia JCeq , rated rotational angular velocity ω n , Rated power S N etc.), quantifying the contribution of the battery energy storage system to inertia support, thereby effectively improving the accuracy of inertia calculation on the energy storage side.

[0156] Step S50: Based on the inertia support mathematical models of the power supply side, the grid side, the load side and the energy storage side, combined with the operating capacity proportion of each resource, a unified inertia calculation model taking into account the coordinated support of multiple resources of source-grid-load-storage is derived to quantify the equivalent inertia of the power system under actual operating conditions:

[0157] Define η as the proportion of operational capacity, where the mathematical expression of η is:

[0158]

[0159] In the formula, n represents the capacity of the resource type in operation, N represents the total capacity of the resource type, and the equivalent theoretical inertia of the system E is G , wind farm aggregate equivalent inertia time constant H eqWF , Photovoltaic grid-connected system equivalent inertia H dc have to:

[0160]

[0161] Among them, E TR , H Ri , S Ri , η Ri are the inertia of the traditional generator, the inertia time constant of the i-th traditional generator set, the capacity and the proportion of the operating capacity, E WF , H WFq , S WFq , η WFq They are the virtual inertia provided by the new energy wind turbines, the virtual inertia time constant, capacity and operating capacity proportion of the qth wind turbine; E PV , H PVh , S PVh , η PVh They are the virtual inertia provided by the photovoltaic equipment, the virtual inertia time constant of the h-th photovoltaic equipment, the capacity and the proportion of the operational capacity;

[0162] The inertia time constant H of the DC system MMC And the calculation formula of the operating capacity ratio η, we get:

[0163]

[0164] In the formula, E HVDC , H DCj , S DCj , η DCjThey are the inertia provided by the virtual synchronous machine of DC transmission, the inertia time constant of the jth virtual synchronous machine of DC transmission, the capacity of the DC power exchange station and the proportion of the operational capacity;

[0165] By formula H im (s) and the proportion of operating capacity η are obtained:

[0166]

[0167] In the formula, E im , H imq , S imq , η imq are the inertia provided by the asynchronous motor, the inertia time constant of the pth asynchronous motor, the capacity of the pth asynchronous motor, and the proportion of the operational capacity of the pth asynchronous motor;

[0168] The virtual inertia coefficient H of the flywheel energy storage system VSG FES 、Inertia time constant H of battery energy storage system Ceq And the calculation formula of the operating capacity ratio η, we get:

[0169]

[0170] In the formula, E FES , H FESm , S Fm , η Fm are the inertia provided by the flywheel energy storage system, the inertia time constant of the mth flywheel energy storage power station, the capacity of the mth flywheel energy storage power station and the proportion of the operational capacity of the mth flywheel energy storage power station; E Ceq , H Ceqn , S cn , η cn They are respectively the inertia provided by the battery energy storage system, the inertia time constant of the nth battery energy storage power station, the capacity of the connected nth battery energy storage system, and the proportion of the operational capacity of the connected nth battery energy storage system.

[0171] In this embodiment, in step S50, the equivalent inertia of the new power system under multiple resources is jointly provided by the source-grid-load-storage diversified inertia support resources, wherein the power supply side is provided by traditional generators, wind turbines, and photovoltaic equipment, the grid side is provided by DC virtual synchronous machines, the load side is provided by synchronous motors and asynchronous motors, and the energy storage side is provided by flywheel energy storage and battery energy storage. The model of the equivalent inertia of the new power system under multiple resources includes:

[0172] E sys =E TR +E WF +E PV +E HVDC +E GD+E im +E FES +E Ceq ;

[0173] In the formula, E TR 、E WF 、E PV 、E HVDC 、E GD 、E im 、E FES 、E Ceq They are the inertia provided by traditional synchronous generator sets, wind turbines, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage.

[0174] The model comprehensively considers the inertia support characteristics of diversified resources such as source-grid-load-storage, and uniformly quantifies the contribution of different types of resources to the grid inertia. By introducing the equivalent inertia model, it overcomes the limitation of single resource in traditional inertia calculation methods and improves the comprehensiveness and accuracy of the calculation results. The model clarifies the inertia support sources of multiple resources on the power supply side, grid side, load side and energy storage side, and can comprehensively reflect the inertia characteristics of the new power system under different operating scenarios, providing accurate basic data for frequency stability analysis and optimization.

[0175] Among them, the inertia coordination support characteristics of multiple resources of source-grid-load-storage are integrated to derive the total capacity S of each inertia source of source-grid-load-storage sys Models include:

[0176]

[0177] In the formula, S Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , η cn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

[0178] By integrating the capacity of multiple resources such as source, grid, load and storage and the proportion of operating capacity, the model can comprehensively quantify the contribution of different inertia sources to the inertia support of the power grid, and provide accurate basic data for the frequency stability and inertia optimization of the new power system. By introducing the parameters of the proportion of operating capacity, the model combines the theoretical capacity with the actual operating status, truly reflecting the inertia contribution of each resource under operating conditions, which is helpful to dynamically analyze the inertia support capacity of the power system under different operating conditions.

[0179] As a preferred embodiment of the above, the total capacity S of each inertia source of source-grid-load-storage is calculated by defining the equivalent inertia time constant and calculating the total capacity S of each inertia source of source-grid-load-storage. sys Based on the above formula, the equivalent inertia model of the new power system under multiple resources and the total capacity of each inertia source of source-grid-load-storage are used to calculate the equivalent inertia time constant of the power system of source-grid-load-storage, which is used to quantify the inertia support capacity of the system under different working conditions. The model of the equivalent inertia time constant of the power system of source-grid-load-storage includes:

[0180]

[0181] In the formula, E sys is the equivalent inertia of the new power system under multiple resources, S sys is the total capacity of each inertia source of source-grid-load-storage,

[0182] E TR 、E WF 、E PV 、E HVDC 、E GD 、E im 、E FES 、E Ceq are the inertia provided by traditional synchronous generator sets, wind turbine sets, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage, respectively. Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , ηcn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

[0183] Through the model of equivalent inertia time constant of the power system of source-grid-load-storage, the inertia characteristics of the power system under the coordinated support of multiple resources are quantified. The model integrates the inertia sources of the power supply side, grid side, load side and energy storage side, so that the inertia support capacity of the system under different working conditions can be accurately reflected, which is suitable for frequency stability analysis of complex power grid operation scenarios; the model combines the total inertia and total capacity of the power system to dynamically quantify the equivalent inertia time constant, adapt to the resource support characteristics under different operation ratios and capacity distributions, and provide an important basis for inertia optimization and frequency control when the proportion of new energy is high.

[0184] The present invention also includes a source-grid-load-storage multi-resource inertia quantitative calculation device, using the above method, such as Figure 3 As shown, including:

[0185] The power supply side inertia support unit is used to build a model of the power supply side inertia support in the power system based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, quantify the power supply side inertia support characteristics, and calculate the equivalent inertia of the power supply side;

[0186] The grid-side inertia support unit is used to construct a model of the grid-side inertia support in the power system based on the equivalent inertia of the power supply side and consider the inertia support characteristics provided by the DC transmission system, and calculate the grid-side inertia support characteristics;

[0187] The load side inertia support unit is used to construct a model of the load side inertia support in the power system based on the calculation results of the grid side inertia support and the inertia support characteristics of the motor, and calculate the load side equivalent inertia;

[0188] The energy storage side inertia support unit is used to analyze the characteristics of the load side inertia support. Through the virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, the energy storage side inertia support model in the power system is constructed, and the inertia support capacity of the energy storage side is calculated;

[0189] The unified inertia calculation unit is used to derive a unified inertia calculation model that takes into account the coordinated support of multiple resources such as source-grid-load-storage based on the inertia support models of the power supply side, grid side, load side and energy storage side, combined with the proportion of the operating capacity of each resource, to quantify the equivalent inertia of the power system under actual operating conditions.

[0190] See also Figure 4A computer device 400 provided in an embodiment of the present application includes: a processor 410 and a memory 420, wherein the memory 420 stores a computer program executable by the processor 410, and when the computer program is executed by the processor 410, the above method is executed.

[0191] The embodiment of the present application further provides a storage medium 430 on which a computer program is stored. When the computer program is run by the processor 410, the above method is executed.

[0192] Among them, the storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable red-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0193] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0194] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0195] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0196] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0197] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0198] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0199] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0200] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A quantitative calculation method for inertia of source-grid-load-storage multi-resources, characterized in that: The steps include: S10: Based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, a model of inertia support on the power supply side in the power system is constructed, the inertia support characteristics on the power supply side are quantified, and the equivalent inertia on the power supply side is calculated; S20: Based on the equivalent inertia of the power source side and considering the inertia support characteristics provided by the DC power transmission system, a model of inertia support on the grid side in the power system is constructed, and the inertia support characteristics on the grid side are calculated; S30: Based on the calculation result of the grid-side inertia support and in combination with the inertia support characteristics of the motor, a model of the load-side inertia support in the power system is constructed, and the load-side equivalent inertia is calculated; S40: Based on the characteristic analysis of the load side inertia support, through the virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, a model of the inertia support on the energy storage side in the power system is constructed, and the inertia support capacity of the energy storage side is calculated; S50: Based on the inertia support models of the power supply side, the grid side, the load side and the energy storage side, combined with the proportion of the operating capacity of each resource, a unified inertia calculation model taking into account the collaborative support of multiple resources of source-grid-load-storage is derived to quantify the equivalent inertia of the power system under actual operating conditions.

2. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1 is characterized in that: In step S10, the model of equivalent inertia of the synchronous generator in the power supply side includes: In the formula, E G is the total equivalent inertia of the synchronous generator on the power supply side, E Gi is the theoretical inertia value of the i-th generator, H i is the inertia time constant of the i-th generator, S i is the capacity of the i-th generator.

3. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1 is characterized in that: In step S10, based on the output characteristics of the wind power generation, an aggregated equivalent virtual inertia time constant model of the wind farm is constructed to quantify the inertia support characteristics of the power supply side. The aggregated equivalent inertia time constant model of the wind farm includes: In the formula, H eqWF is the equivalent inertia time constant of wind farm aggregation, P is the number of wind turbine pole pairs, J eq is the virtual inertia of the wind turbine, ω s0 is the initial synchronous angular velocity of the wind turbine system, S Ni is the capacity of the i-th wind turbine, H eqi It is only the inertial response effect of the i-th wind turbine, and m is the number of doubly-fed wind turbines in the wind farm.

4. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1 is characterized in that: In step S10, the model of equivalent inertia of photovoltaic power generation in the power supply side includes: In the formula, H dc is the equivalent inertia time constant of the capacitor, C is the equivalent capacitance, U dc0 is the steady-state value of DC voltage, k1 is the control parameter of the virtual inertia control branch, and s is the Laplace operator.

5. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1 is characterized in that: In step S20, considering the inertia support characteristics provided by the DC power transmission system, a model of inertia support on the grid side of the power system is constructed, including a mathematical model for calculating the effective moment of inertia of the DC power transmission system, wherein the effective moment of inertia is jointly determined by the potential energy provided by the system capacitor and the magnetic field energy provided by the inductor. The model of inertia support on the grid side of the power system includes: In the formula, J v is the moment of inertia of the synchronous machine, ΔE cm Provide the maximum potential energy for the capacitors at both ends of the converter station, ΔE lm Provides the maximum magnetic field energy for the inductor components of the DC system, L eq is the equivalent inductance of the flexible DC system, I dc0 is the DC current in steady state operation, ω gm are the grid angular frequency, U SMm is the submodule capacitor voltage, I dcm The limitation of DC current in the inertia response stage, N is the total number of submodules put into operation in the upper and lower bridge arms of the converter during steady-state operation; C SM is the capacitance value of a single submodule.

6. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1, characterized in that: In step S20, an inertia time constant model of a DC power transmission system is calculated to quantify the grid-side inertia support characteristics. The inertia time constant model of the DC power transmission system includes: In the formula, H MMC is the inertia time constant of the DC system, J v is the moment of inertia of the synchronous machine, ω MMCO is the rated angular frequency of the converter station, P m is the rated power of the DC system.

7. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1, characterized in that: In step S30, when constructing the mathematical model of the load-side inertia support in the power system, based on the characteristics of the asynchronous motor as the main electrical equipment on the load side, a transient reactance after-potential phase motion equation model containing equivalent inertia in the electromechanical time scale of the asynchronous motor is established, and the model includes: H im (s)sΔω s =ΔP e -ΔP m ; In the formula, H im (s) is the inertia time constant of the asynchronous motor, Δω s is the system synchronous angular velocity increment, ΔP e is the useful power, ΔP m is the mechanical power change, s is the Laplace transform, Y1 is the dynamic coupling of inertia and inductance, affecting the mechanical characteristics, Y2 is the electromagnetic response and power characteristic change, Y3 is the combined influence of impedance and inertia, Y4 is the dynamic effect of power characteristics, rotor impedance and inductance, L r is the rotor inductance, L m is the mutual inductance of the stator and rotor, u'0 is the magnetic permeability of the material, s slip0 is the slip rate, ω s0 is the potential frequency, R r is the rotor resistance.

8. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1, characterized in that: In step S40, when constructing the mathematical model of the inertia support on the energy storage side in the power system, the equivalent inertia of the battery energy storage system is represented by an inertia time constant, and the model of the equivalent inertia time constant of the battery energy storage system includes: In the formula, H Ceq is the equivalent inertia time constant of the battery energy storage system, J Ceq is the equivalent inertia of the battery energy storage system, ω n is the rated rotational angular velocity, S N is the rated power, C eq is the equivalent capacitance, U CN It is the rated voltage of the capacitive energy storage body.

9. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 1, characterized in that: In step S50, the equivalent inertia of the new power system under multiple resources is jointly provided by the source-grid-load-storage diversified inertia support resources, wherein the power supply side is provided by traditional generators, wind turbines, and photovoltaic equipment, the grid side is provided by a DC virtual synchronous machine, the load side is provided by a synchronous motor and an asynchronous motor, and the energy storage side is provided by a flywheel energy storage and a battery energy storage. The model of the equivalent inertia of the new power system under multiple resources includes: AND sys =And TR +E WF +E PV +E HVDC +E GD +E im +E FES +E Ceq ; In the formula, E TR 、E WF 、E PV 、E HVDC 、E GD 、E im 、E FES 、E Ceq They are the inertia provided by traditional synchronous generator sets, wind turbines, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage.

10. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 9, characterized in that: Based on the inertia coordination support characteristics of the source-grid-load-storage multi-resources, the total capacity S of each inertia source of source-grid-load-storage is derived. sys Models include: In the formula, S Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , η cn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

11. The method for quantitatively calculating the inertia of source-grid-load-storage multi-resources according to claim 10, characterized in that: Based on the model of equivalent inertia of the new power system under multiple resources and the total capacity of each inertia source of the source-grid-load-storage, the equivalent inertia time constant of the power system of source-grid-load-storage is calculated to quantify the inertia support capacity of the system under different working conditions. The model of equivalent inertia time constant of the power system of source-grid-load-storage includes: In the formula, E sys is the equivalent inertia of the new power system under multiple resources, S sys is the total capacity of each inertia source, grid, load and storage, E TR 、E WF 、E PV 、E HVDC 、E GD 、E im 、E FES 、E Ceq are the inertia provided by traditional synchronous generator sets, wind turbine sets, photovoltaics, DC virtual synchronous machines, asynchronous motors, flywheel energy storage, and battery energy storage, respectively. Ri , η Ri are the capacity and operating capacity proportion of the i-th traditional generator set, S WFq , η WFq are the capacity and operating capacity of the qth wind turbine generator set, S PVh , η PVh are the capacity and operating capacity proportion of the h-th photovoltaic equipment, S DCj , η DCj are the capacity and operating capacity proportion of the jth DC power station, S GDl , η DGl are the capacity and operating capacity ratio of synchronous motors, S imq , η imq are respectively the capacity of the pth asynchronous motor and the proportion of commissioned capacity, S cn , η cn They are the capacity of the nth battery energy storage system connected and the proportion of operating capacity.

12. A quantitative calculation device for inertia of multiple resources of source-grid-load-storage, characterized in that: Use of the method according to any one of claims 1 to 11, comprising: The power supply side inertia support unit is used to build a model of the power supply side inertia support in the power system based on the output characteristics of traditional synchronous generators, wind power generation and photovoltaic power generation, quantify the power supply side inertia support characteristics, and calculate the equivalent inertia of the power supply side; A grid-side inertia support unit, configured to construct a grid-side inertia support model in a power system based on the equivalent inertia of the power supply side and taking into account the inertia support characteristics provided by the DC power transmission system, and calculate the grid-side inertia support characteristics; A load-side inertia support unit, configured to construct a model of load-side inertia support in a power system based on the calculation result of the grid-side inertia support and in combination with the inertia support characteristics of the motor, and calculate the load-side equivalent inertia; The energy storage side inertia support unit is used to construct a model of the energy storage side inertia support in the power system based on the characteristic analysis of the load side inertia support, through a virtual synchronous generator control strategy, combined with the inertia characteristics of flywheel energy storage and electrochemical energy storage, and calculate the inertia support capacity of the energy storage side; The unified inertia calculation unit is used to derive a unified inertia calculation model taking into account the coordinated support of multiple resources of source-grid-load-storage according to the inertia support models of the power supply side, the grid side, the load side and the energy storage side, in combination with the proportion of the commissioned capacity of each resource, so as to quantify the equivalent inertia of the power system under actual operating conditions.

13. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 11 is implemented.

14. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 11 is implemented.

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