A communication delay compensation method and system for energy storage participating in power grid frequency regulation service

Abstract

The present invention provides a method and system for compensating for communication delay of energy storage participating in power grid frequency regulation service, the method comprising: obtaining the actual measurement quantity of the system of the energy storage participating in power grid frequency regulation service system to be compensated and presetting the regional power grid model so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system; obtaining the transfer function and actual communication delay time of the regional power grid model; presetting the Smith predictor compensator model based on the preset regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model; using the Smith predictor compensator model to compensate for the communication delay of energy storage participating in power grid frequency regulation service. The method performs communication delay compensation for the energy storage participating in power grid frequency regulation service system, which can effectively reduce the system communication delay, improve the communication capability of energy storage participating in power grid frequency regulation service, and help improve the capability of energy storage participating in power grid auxiliary frequency regulation.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid frequency regulation, and in particular to a communication delay compensation method and system for energy storage participating in power grid frequency regulation services. Background Art

[0002] In recent years, in order to solve the problem of resource and environmental shortage and to meet the strategic goal of sustainable low-carbon economic development of carbon peak and carbon neutrality, a large number of new energy sources have been connected to the power grid. However, its strong randomness and volatility lead to excessive frequency deviation of the power grid, and the original frequency regulation capability of the system is insufficient to meet the demand. With the access of energy storage power stations to the power grid, their control is fast and their response is flexible. They can participate in various types of auxiliary services such as power grid frequency regulation under different needs.

[0003] Traditional grid frequency regulation is to increase the capacity of generators on the supply side to adjust the system power. However, the access of new energy to the grid has greatly restricted the power response of the original generator sets. The rapidity and stability of frequency regulation are key factors to ensure the normal operation of the grid. The rapidity of existing frequency regulation methods does not take into account the influence of the communication delay between the control center and the energy storage power station during the frequency regulation process. In actual projects, the control center receives power information from the substation and then sends instructions to the substation through the control center. In this process, delayed signals are inevitably generated between the control center and the terminal equipment. As the delayed signals accumulate, the substation cannot accurately and synchronously receive the control signal, which increases the time required for system frequency regulation. The communication delay effect is obvious, which greatly affects the communication performance of energy storage participating in the grid frequency regulation service. Summary of the invention

[0004] The present invention aims to provide a method and system for compensating communication delay of energy storage participating in power grid frequency regulation service, so as to solve the above-mentioned technical problems, effectively enhance the communication delay compensation effect of energy storage participating in power grid frequency regulation service, reduce communication delay, and improve the communication capability of energy storage participating in power grid frequency regulation service.

[0005] In order to solve the above technical problems, the present invention provides a communication delay compensation method for energy storage participating in power grid frequency regulation service, comprising the following steps:

[0006] Perform periodic sampling measurements on the energy storage to be compensated and participate in the grid frequency regulation service system to obtain the actual measurement quantity of the system;

[0007] Preset a regional power grid model based on the energy storage to be compensated for participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system;

[0008] Obtain the transfer function and actual communication delay time of the regional power grid model;

[0009] Presetting the Smith predictor compensator model based on the preset regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model;

[0010] The Smith estimator compensator model is connected to the energy storage to be compensated participating in the grid frequency regulation service system to compensate for the communication delay of the energy storage participating in the grid frequency regulation service.

[0011] The above scheme constructs a regional power grid model that is the same as the power grid frequency regulation service system that the energy storage to be compensated participates in, and makes the model measurement quantity consistent with the actual measurement quantity of the system, so that the regional power grid model can be used to accurately describe the performance parameters of the power grid frequency regulation service system that the energy storage to be compensated participates in; then constructs a Smith predictive compensator model based on the regional power grid model, and makes the transfer function and estimated communication delay time of the Smith predictive compensator model the same as the transfer function and actual communication delay time of the regional power grid model; based on the principle of the Smith predictive compensator, by accurately modeling the power grid frequency regulation service system that the energy storage to be compensated participates in, and accurately obtaining the actual communication delay time, the transfer function and estimated communication delay time of the Smith predictive compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, thereby greatly improving the compensation effect of the Smith predictive compensator.

[0012] By using the above solution to compensate for the communication delay of the energy storage participating in the grid frequency regulation service system, the system communication delay can be effectively reduced, the communication capability of the energy storage participating in the grid frequency regulation service can be improved, and the ability of the energy storage participating in the grid auxiliary frequency regulation service can be improved.

[0013] Furthermore, the Smith estimator compensator model is connected to the energy storage to be compensated participating in the grid frequency regulation service system to compensate for the communication delay of the energy storage participating in the grid frequency regulation service, specifically:

[0014] After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows:

[0015]

[0016] Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p (s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t pis the estimated communication delay time; t1 and t2 are the delay time of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system;

[0017] In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

[0018] In the above scheme, when there is a large deviation between the Smith predictive compensator model parameters and the actual system parameters, its control performance will deteriorate sharply. In order to ensure the consistency between the Smith predictive compensator model and the actual system, the Smith predictive compensator model is debugged by constructing a regional power grid model that can reflect the actual system performance, thereby improving the accuracy of the model. By setting the transfer function of the Smith predictive compensator model to be the same as the transfer function of the regional power grid model, and making the estimated communication delay time of the Smith predictive compensator model the same as the actual communication delay time, the compensation communication delay effect of the Smith predictive compensator is greatly enhanced, effectively reducing the system communication delay and improving the communication capability of energy storage participating in the power grid frequency regulation service.

[0019] Furthermore, the regional power grid model is preset according to the energy storage to be compensated for participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, specifically:

[0020] A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit;

[0021] Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model;

[0022] Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

[0023] In the above scheme, the actual energy storage participating in the grid frequency regulation service system is a comprehensive system composed of multiple devices or devices connected. Therefore, in order to accurately model it, it is necessary to model each device or device one by one, and finally form a unified regional grid model to describe the actual energy storage participating in the grid frequency regulation service system. The regional grid model is composed of basic units such as the generator set speed regulator model unit, the generator set turbine model unit, the renewable energy photovoltaic power station model unit, the regional frequency deviation signal model unit and the PI controller communication delay model unit, which can accurately reflect the joint response of energy storage, generator sets, renewable energy and loads in turn, ensuring the accuracy of the regional grid model.

[0024] Furthermore, the regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

[0025] In the above scheme, in order to improve the scope of application of the regional power grid model and make it more in line with the actual energy storage participating in the power grid frequency regulation service system, this scheme fully considers the need to ensure that the battery operates at an appropriate SOC level when the energy storage participates in frequency regulation. Therefore, a low-pass filter is used to distribute different period control signals to different devices, thereby regressing the SOC of the energy storage and constructing an energy storage SOC regression correction model unit to simulate the situation where the battery needs to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

[0026] Further, the Smith predictor compensator model is preset based on the preset regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically:

[0027] Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model;

[0028] The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model;

[0029] The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

[0030] The above scheme aims at the frequency regulation communication delay of the system in which energy storage participates in the frequency regulation service of the power grid, accurately models this type of system, sets the transfer function of the Smith predictor compensator to be the same as the transfer function of the system model, and measures the actual communication delay of the system when the frequency is modulated under disturbance, and makes the estimated compensation time of the Smith predictor compensator the same as the actual communication delay of the system actually measured, which greatly enhances the effect of the Smith predictor compensator in compensating for the communication delay and helps to improve the ability of energy storage to participate in the auxiliary frequency regulation of the power grid.

[0031] The present invention also provides a communication delay compensation system for energy storage participating in power grid frequency regulation service, including a sampling measurement module, a regional power grid model construction module, a Smith estimator compensator model construction module and an access compensation module; wherein:

[0032] The sampling and measurement module is used to perform periodic sampling and measurement on the energy storage to be compensated participating in the power grid frequency regulation service system or the regional power grid model, and obtain the actual measurement quantity of the system, the model measurement quantity, the actual communication delay time or the estimated communication delay time;

[0033] The regional power grid model building module is used to preset the regional power grid model according to the energy storage to be compensated participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model;

[0034] The Smith predictive compensator model is used to preset the Smith predictive compensator model according to the regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictive compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model;

[0035] The access compensation module is used to access the Smith predictor compensator model to the energy storage to be compensated participating in the grid frequency regulation service system, and compensate for the communication delay of the energy storage participating in the grid frequency regulation service.

[0036] Furthermore, the access compensation module is used to access the Smith estimator compensator model to the energy storage to be compensated participating in the grid frequency regulation service system, and compensate for the communication delay of the energy storage participating in the grid frequency regulation service, specifically:

[0037] After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows:

[0038]

[0039] Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p(s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t p is the estimated communication delay time; t1 and t2 are the delay time of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system;

[0040] In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

[0041] Furthermore, the regional power grid model construction module is used to preset the regional power grid model according to the power grid frequency regulation service system participating in the energy storage to be compensated, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model, which is specifically:

[0042] A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit;

[0043] Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model;

[0044] Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

[0045] Furthermore, the regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

[0046] Further, the Smith predictor compensator model is used to preset the Smith predictor compensator model according to the regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically:

[0047] Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model;

[0048] The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model;

[0049] The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

[0050] The present invention also provides a communication delay compensation device for energy storage participating in power grid frequency regulation services, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the communication delay compensation method for energy storage participating in power grid frequency regulation services.

[0051] The present invention also provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the communication delay compensation method for energy storage participating in power grid frequency regulation services. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flow chart of a method for compensating communication delay when energy storage participates in power grid frequency regulation service provided by one embodiment of the present invention.

[0053] Figure 2 A schematic diagram of the implementation principle of the Smith predictor compensator provided in one embodiment of the present invention;

[0054] Figure 3 A schematic diagram of an energy storage SOC regression correction model unit provided by an embodiment of the present invention;

[0055] Figure 4 A schematic diagram of a regional power grid model provided by an embodiment of the present invention;

[0056] Figure 5 A connection diagram for performing compensation simulation on a Smith predictor compensator model provided by an embodiment of the present invention;

[0057] Figure 6 Different communication delay dynamic performance diagrams are introduced into the Smith predictor compensator model provided in one embodiment of the present invention;

[0058] Figure 7 A performance diagram of the Smith predictor compensator model provided in one embodiment of the present invention before and after the step disturbance is introduced;

[0059] Figure 8 A schematic diagram of the connection modules of a communication delay compensation system for energy storage participating in power grid frequency regulation services provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] See also Figure 1 The embodiment of the present invention provides a method for compensating communication delay when energy storage participates in power grid frequency regulation service, comprising the following steps:

[0062] S1: Perform periodic sampling measurement on the energy storage to be compensated participating in the grid frequency regulation service system to obtain the actual measurement quantity of the system;

[0063] S2: Preset a regional power grid model according to the power grid frequency regulation service system in which the energy storage to be compensated participates, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system;

[0064] S3: Obtain the transfer function and actual communication delay time of the regional power grid model;

[0065] S4: presetting the Smith predictor compensator model based on the preset regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model;

[0066] S5: Connect the Smith estimator compensator model to the power grid frequency regulation service system in which the energy storage to be compensated participates, and compensate for the communication delay of the power grid frequency regulation service in which the energy storage participates.

[0067] This embodiment constructs a regional power grid model that is identical to the power grid frequency regulation service system that the energy storage to be compensated participates in, and makes the model measurement consistent with the actual measurement of the system, so that the regional power grid model can be used to accurately describe the performance parameters of the power grid frequency regulation service system that the energy storage to be compensated participates in; then, a Smith predictor compensator model is constructed based on the regional power grid model, and the transfer function and estimated communication delay time of the Smith predictor compensator model are made identical to the transfer function and actual communication delay time of the regional power grid model; based on the principle of the Smith predictor compensator, the power grid frequency regulation service system that the energy storage to be compensated participates in is accurately modeled, and the actual communication delay time is accurately obtained, so that the transfer function and estimated communication delay time of the Smith predictor compensator model are made identical to the transfer function and actual communication delay time of the regional power grid model, thereby greatly improving the compensation effect of the Smith predictor compensator.

[0068] By compensating for the communication delay of the energy storage participating in the grid frequency regulation service system through this embodiment, the system communication delay can be effectively reduced, the communication capability of the energy storage participating in the grid frequency regulation service can be improved, and the capability of the energy storage participating in the grid auxiliary frequency regulation can be improved.

[0069] It should be noted that the actual measurement quantities of the system include energy storage output power deviation, photovoltaic output power deviation, generator output power deviation, photovoltaic output power deviation and load deviation. The above parameters can be obtained by direct measurement or calculation and will not be elaborated in this embodiment.

[0070] Furthermore, the Smith estimator compensator model is connected to the energy storage to be compensated participating in the grid frequency regulation service system to compensate for the communication delay of the energy storage participating in the grid frequency regulation service, specifically:

[0071] After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows:

[0072]

[0073] Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p (s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t p is the estimated communication delay time; t1 and t2 are the delay time of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system;

[0074] In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

[0075] In this embodiment, when there is a large deviation between the Smith predictive compensator model parameters and the actual system parameters, its control performance will deteriorate sharply. In order to ensure the consistency between the Smith predictive compensator model and the actual system, the Smith predictive compensator model is debugged by constructing a regional power grid model that can reflect the actual system performance, thereby improving the accuracy of the model. By setting the transfer function of the Smith predictive compensator model to be the same as the transfer function of the regional power grid model, and making the estimated communication delay time of the Smith predictive compensator model the same as the actual communication delay time, the compensation communication delay effect of the Smith predictive compensator is greatly enhanced, effectively reducing the system communication delay, and improving the communication capability of energy storage participating in the power grid frequency regulation service.

[0076] It should be noted that see Figure 2 The compensation principle of the Smith predictor compensator, where G c (s), G p (s), are the controller transfer function, the energy storage participating in the grid frequency regulation service system transfer function and the Smith predictor compensator model transfer function, R(s) and Y(s) are the input signal and output signal, respectively. p is the estimated communication delay time; t1 and t2 are the delay times of the forward channel and the reverse channel respectively.

[0077] It should be further explained that, according to the compensation principle of the Smith predictor compensator, when there is a large deviation between the parameters of the set Smith predictor compensator and the actual system parameters, the delay compensation effect is poor and the system stability will be affected. Therefore, the compensation effect of the Smith predictor on the communication delay depends on whether the controlled system can be accurately modeled and whether the actual communication delay of the system can be accurately obtained. Therefore, in this embodiment, the consistency between the Smith predictor compensator model and the actual system is strictly controlled, so that the Smith predictor compensator's effect of compensating for communication delay is greatly enhanced, effectively reducing the system communication delay and improving the communication capability of energy storage participating in the grid frequency regulation service.

[0078] Furthermore, the regional power grid model is preset according to the energy storage to be compensated for participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, specifically:

[0079] A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit;

[0080] Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model;

[0081] Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

[0082] In this embodiment, the actual energy storage participating in the grid frequency regulation service system is a comprehensive system formed by connecting multiple devices or apparatuses. Therefore, in order to accurately model it, it is necessary to model each device or apparatus one by one, and finally form a unified regional grid model to describe the actual energy storage participating in the grid frequency regulation service system. The regional grid model is composed of basic units such as the generator set speed regulator model unit, the generator set turbine model unit, the renewable energy photovoltaic power station model unit, the regional frequency deviation signal model unit, and the PI controller communication delay model unit, which can accurately reflect the joint response of energy storage, generator sets, renewable energy, and loads in turn, ensuring the accuracy of the regional grid model.

[0083] It should be noted that the regional power grid model is specifically as follows:

[0084]

[0085] Where: s is the Laplace operator, H is the grid inertia coefficient, D is the load damping coefficient, ΔP L is the load deviation, ΔP BESS is the energy storage output power deviation, ΔP m is the generator output power deviation, ΔP PVj is the photovoltaic output power deviation, j is the ordinal number of the photovoltaic power source participating in the frequency modulation, and m is the number of photovoltaic power sources participating in the frequency modulation.

[0086] More specifically, the generator set speed governor model unit is:

[0087]

[0088] Where: T g is the speed regulator time constant, ΔPg is the governor valve deviation, ΔP lpf is the speed regulator control input, and R is the primary frequency modulation droop coefficient.

[0089] The generator set turbine model unit is:

[0090]

[0091] Where: ΔP m is the generator output power deviation, T ch is the turbine time constant.

[0092] The renewable energy photovoltaic power station model units are:

[0093]

[0094] Where: ΔP PVj is the photovoltaic output power deviation, T PV is the photovoltaic power source time constant, ΔP solarj is the input deviation of the photovoltaic power source, j is the ordinal number of the photovoltaic power source participating in the frequency modulation, and m is the number of photovoltaic power sources participating in the frequency modulation.

[0095] The PI controller communication delay model unit is:

[0096] U PI (t-t1) = K P ΔACE(t-t1)+K I ∫ΔACE(t-t1)

[0097] Where: t1 is the communication delay, K P and K I is the PI controller parameter, U PI (t-t1) is the feedback signal.

[0098] The regional frequency deviation signal model unit is:

[0099] ΔACE=βΔf

[0100] Where: β is the natural frequency characteristic coefficient of the region, and ΔACE is the regional control deviation.

[0101] Furthermore, the regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

[0102] For details, see Figure 3 , the energy storage SOC regression correction model unit is specifically:

[0103]

[0104] Where: T LPF0 is the LPF time constant before adjustment, T LPF is the adjusted LPF time constant, SOC min -SOC max is the optimal SOC operating range, and α is the LPF adjustment coefficient. When the battery SOC is lower than the lower limit SOC min When the energy storage output P BESS Positive (discharging), or the battery SOC exceeds the upper limit SOC max When the energy storage output P BESS Negative (charging).

[0105] In this embodiment, in order to improve the scope of application of the regional power grid model and make it more in line with the actual energy storage participating in the power grid frequency regulation service system, this solution fully considers the need to ensure that the battery operates at an appropriate SOC level when the energy storage participates in the frequency regulation. Therefore, a low-pass filter is selected to distribute different period control signals to different devices, so as to perform regression correction on the SOC of the energy storage, and construct an energy storage SOC regression correction model unit to simulate the situation that the battery needs to operate at an appropriate SOC level when the energy storage participates in the frequency regulation. The regional power grid model established by the energy storage participating in the power grid frequency regulation service system with SOC regression correction can be found in Figure 4 .

[0106] Further, the Smith predictor compensator model is preset based on the preset regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically:

[0107] Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model;

[0108] The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model;

[0109] The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

[0110] This embodiment accurately models the type of system in which energy storage participates in the frequency regulation service system frequency regulation communication delay, sets the transfer function of the Smith predictor compensator to be the same as the transfer function of the system model, measures the actual communication delay of the system when the frequency is modulated under disturbance, and makes the estimated compensation time of the Smith predictor compensator the same as the actual measured communication delay of the system, thereby greatly enhancing the effect of the Smith predictor compensator in compensating for the communication delay and helping to improve the ability of energy storage to participate in the auxiliary frequency regulation of the power grid.

[0111] In order to further illustrate the effect of the solution provided by the present invention, this embodiment provides the actual process of the Smith predictor compensator model for compensation simulation, specifically:

[0112] Please see Figure 5 , connect the compensation simulation of the Smith predictor compensator model, and set the transfer function of the Smith predictor compensator model The transfer function G of the regional power grid model p (s) is the same, that is, the number and connection mode of each module of the original power grid model remain unchanged as the modules of the Smith predictor compensator, and the energy storage output power deviation ΔP of the system measured according to the sampling period BESS , load deviation ΔP L , Photovoltaic output power deviation ΔP PVj The estimated communication delay time t of the Smith predictor compensator model is set as follows: p It is the same as the actual communication delay time t measured in each sampling period, so the delay of regional power grid frequency regulation in which energy storage participates in the power grid frequency regulation service system can be dynamically compensated.

[0113] Furthermore, the Smith predictor compensator model considering the communication delay is established in MATLAB, and the parameters of the smart grid are set as follows: t =0.3, T g =0.2, H=5, D=1, R=0.05. In the energy storage frequency modulation scenario, the system communication delay compensation is performed based on the Smith predictor compensator, and the regression of the energy storage SOC is considered. Different communication delay dynamic performances are introduced, such as Figure 6 As shown in the figure, with the increase of delay t = 0s, 0.2s, and 0.5s, the frequency deviation range is also gradually increasing, which further illustrates that communication delay has an adverse effect on the frequency response of the energy storage participating in the grid frequency regulation service system, and when the communication delay exceeds a certain threshold, the frequency of the energy storage participating in the grid frequency regulation service system will exceed the specified value and further deteriorate.

[0114] Furthermore, in actual systems, communication delays are random, such as Figure 7 The random step ΔPL=0.1pu disturbance is set to simulate the actual situation, and the Smith predictor compensator model is used for delay compensation. It can be clearly seen that the delay compensation of the Smith predictor compensator model has good performance and can eliminate the adverse effects of communication delay. This embodiment can effectively illustrate the effectiveness of the compensation method.

[0115] This embodiment effectively reduces the defects of the Smith predictor compensator by modeling the energy storage participating in the grid frequency regulation service system, greatly improves its compensation effect, enhances the communication capability between the energy storage and the grid, and enhances the ability of the energy storage to participate in the grid frequency regulation service.

[0116] See also Figure 8 This embodiment provides a communication delay compensation system for energy storage participating in power grid frequency regulation services, which is used to implement a communication delay compensation method for energy storage participating in power grid frequency regulation services, specifically including a sampling measurement module, a regional power grid model construction module, a Smith estimator compensator model construction module and an access compensation module; wherein:

[0117] The sampling and measurement module is used to perform periodic sampling and measurement on the energy storage to be compensated participating in the power grid frequency regulation service system or the regional power grid model, and obtain the actual measurement quantity of the system, the model measurement quantity, the actual communication delay time or the estimated communication delay time;

[0118] The regional power grid model building module is used to preset the regional power grid model according to the energy storage to be compensated participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model;

[0119] The Smith predictive compensator model is used to preset the Smith predictive compensator model according to the regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictive compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model;

[0120] The access compensation module is used to access the Smith predictor compensator model to the energy storage to be compensated participating in the grid frequency regulation service system, and compensate for the communication delay of the energy storage participating in the grid frequency regulation service.

[0121] Furthermore, the access compensation module is used to access the Smith estimator compensator model to the energy storage to be compensated participating in the grid frequency regulation service system, and compensate for the communication delay of the energy storage participating in the grid frequency regulation service, specifically:

[0122] After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows:

[0123]

[0124] Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p (s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t p is the estimated communication delay time; t1 and t2 are the delay time of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system;

[0125] In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

[0126] Furthermore, the regional power grid model construction module is used to preset the regional power grid model according to the power grid frequency regulation service system participating in the energy storage to be compensated, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model, which is specifically:

[0127] A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit;

[0128] Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model;

[0129] Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

[0130] Furthermore, the regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

[0131] Further, the Smith predictor compensator model is used to preset the Smith predictor compensator model according to the regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically:

[0132] Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model;

[0133] The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model;

[0134] The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

[0135] This embodiment also provides a communication delay compensation device for energy storage participating in power grid frequency regulation services, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements the communication delay compensation method for energy storage participating in power grid frequency regulation services.

[0136] This embodiment also provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the communication delay compensation method for energy storage participating in power grid frequency regulation service.

[0137] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A communication delay compensation method for energy storage participating in power grid frequency regulation service, characterized in that: The following steps are involved: Perform periodic sampling measurements on the energy storage to be compensated and participate in the grid frequency regulation service system to obtain the actual measurement quantity of the system; Preset a regional power grid model based on the energy storage to be compensated for participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system; Obtain the transfer function and actual communication delay time of the regional power grid model; Presetting the Smith predictor compensator model based on the preset regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model; The Smith estimator compensator model is connected to the energy storage to be compensated for participating in the grid frequency regulation service system to compensate for the communication delay of the energy storage participating in the grid frequency regulation service. Specifically: After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows: Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p (s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t p To estimate the communication delay time; t1 and t2 are the delay times of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system; In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

2. A communication delay compensation method for energy storage participating in power grid frequency regulation service according to claim 1, characterized in that: The energy storage to be compensated participates in the grid frequency regulation service system to preset a regional grid model so that the model measurement quantity of the regional grid model is consistent with the actual measurement quantity of the system, specifically: A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit; Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model; Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

3. A communication delay compensation method for energy storage participating in power grid frequency regulation service according to claim 2, characterized in that: The regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

4. A communication delay compensation method for energy storage participating in power grid frequency regulation service according to claim 1 or 3, characterized in that: The Smith predictor compensator model is preset based on the preset regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically: Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model; The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model; The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

5. A communication delay compensation system for energy storage participating in power grid frequency regulation service, characterized in that: It includes a sampling measurement module, a regional power grid model building module, a Smith estimation compensator model building module and an access compensation module; wherein: The sampling and measurement module is used to perform periodic sampling and measurement on the energy storage to be compensated participating in the power grid frequency regulation service system or the regional power grid model, and obtain the actual measurement quantity of the system, the model measurement quantity, the actual communication delay time or the estimated communication delay time; The regional power grid model building module is used to preset the regional power grid model according to the energy storage to be compensated participating in the power grid frequency regulation service system, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model; The Smith predictive compensator model is used to preset the Smith predictive compensator model according to the regional power grid model so that the transfer function and the estimated communication delay time of the Smith predictive compensator model are the same as the transfer function and the actual communication delay time of the regional power grid model; The access compensation module is used to access the Smith estimator compensator model to the energy storage participating in the grid frequency regulation service system to be compensated, and compensate for the communication delay of the energy storage participating in the grid frequency regulation service, specifically: After the Smith predictor compensator model is connected to the energy storage to be compensated and participates in the grid frequency regulation service system, its overall closed-loop transfer function is as follows: Where: G Smith (s) represents the overall closed-loop transfer function; G c (s) represents the controller transfer function; G p (s) represents the transfer function of the energy storage participating in the grid frequency regulation service system, which is the same as the transfer function of the regional grid model; represents the transfer function of the Smith predictor compensator model; t p is the estimated communication delay time; t1 and t2 are the delay time of the forward channel and the reverse channel respectively, and t = t1 + t2, where t represents the actual communication delay time; is the delay term of the forward path, is the delay term of the Smith predictor compensator model, It is the delay item for energy storage to participate in the grid frequency regulation service system; In the formula, we have: t p =t1+t2, at this time, the delay term of the Smith estimated compensator model is offset by the delay term of the energy storage participating in the grid frequency regulation service system, thereby compensating for the communication delay of the energy storage participating in the grid frequency regulation service.

6. A communication delay compensation system for energy storage participating in power grid frequency regulation service according to claim 5, characterized in that: The regional power grid model building module is used to preset the regional power grid model according to the power grid frequency regulation service system participating in the energy storage to be compensated, so that the model measurement quantity of the regional power grid model is consistent with the actual measurement quantity of the system, and obtain the transfer function of the regional power grid model, which is specifically: A regional power grid model is preset according to the power grid frequency regulation service system in which the energy storage to be compensated participates, including a generator set speed regulator model unit, a generator set turbine model unit, a renewable energy photovoltaic power station model unit, a regional frequency deviation signal model unit, and a PI controller communication delay model unit; Adjusting relevant parameters of the regional power grid model and obtaining model measurements of the regional power grid model; Determine whether the model measurement quantity is consistent with the actual system measurement quantity. If so, the preset regional power grid model is consistent with the energy storage to be compensated participating in the power grid frequency regulation service system. Otherwise, readjust the relevant parameters of the regional power grid model.

7. A communication delay compensation system for energy storage participating in power grid frequency regulation service according to claim 6, characterized in that: The regional power grid model also includes an energy storage SOC regression correction model unit, which is used to simulate the situation where the battery needs to be ensured to operate at an appropriate SOC level when the energy storage participates in frequency regulation.

8. A communication delay compensation system for energy storage participating in power grid frequency regulation service according to claim 5 or 7, characterized in that: The Smith predictor compensator model is used to preset the Smith predictor compensator model according to the regional power grid model so that the transfer function and estimated communication delay time of the Smith predictor compensator model are the same as the transfer function and actual communication delay time of the regional power grid model, specifically: Presetting the Smith predictive compensator model based on the preset regional power grid model so that the Smith predictive compensator model is consistent with the regional power grid model; The input quantity of the regional power grid model is obtained according to the actual measurement quantity of the system, and is used as the input quantity of the Smith predictive compensator model, so that the transfer function of the Smith predictive compensator model is the same as the transfer function of the regional power grid model; The estimated communication delay time of the Smith predictor compensator model is set to be the same as the actual communication delay time of the regional power grid model.

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