Power grid frequency stability control method and device based on virtual inertia

Abstract

The application discloses a kind of power grid frequency stability control method and device based on virtual inertia.Therein, the method comprises: obtaining the current frequency of target power grid, determining the frequency deviation between current frequency and rated frequency;When the frequency deviation is greater than the frequency deviation threshold, determine the power response of thermal power unit primary frequency modulation and the first power change of electrolytic aluminum load response delay;Control electrolytic aluminum load to participate in the primary frequency modulation of target power grid;During the primary frequency modulation process, the second power change of electrolytic aluminum load response delay is determined according to the frequency deviation;According to the power response and the second power change, the active power shortage of electrolytic aluminum load is reduced to rated power, so that the frequency of target power grid is kept within the predetermined range.The application solves the technical problems that the existing technology has limited and uncertain adjustable capacity of electrolytic aluminum load, it is difficult to provide timely power support and good frequency modulation effect for power grid, and the frequency modulation response speed is slow.

Description

Technical Field

[0001] This invention relates to the field of load frequency regulation in power grid systems, and more specifically, to a power grid frequency stability control method and apparatus based on virtual inertia. Background Technology

[0002] To address frequency stability issues on the power supply side, existing control strategies primarily focus on two aspects: the power system's own regulation capabilities and external auxiliary frequency regulation control. Regarding the power system's own regulation capabilities, existing literature mainly optimizes and improves controller parameters; however, the design process is complex and computationally challenging, making it difficult to apply to practical power systems. Therefore, in terms of external auxiliary frequency regulation control, research on load-side resource adjustment response to grid frequency stability control has become a major focus. Commercial load response mainly involves users increasing or decreasing their electricity demand to participate in grid peak shaving; however, its adjustable capacity is limited and subject to human uncertainty, making it difficult to provide timely power support and good frequency regulation effects to the grid. Industrial loads, mainly including high-energy-consuming industries such as electrolytic aluminum and blast furnaces, possess advantages such as large regulation capacity, large temperature storage time constant, and fast regulation response time. Rational utilization of these loads can improve the flexibility of grid frequency.

[0003] However, most current control methods that consider the participation of electrolytic aluminum loads in system frequency regulation focus on saturated reactors and the primary frequency regulation response of the system. These methods suffer from limited adjustment margin and slow frequency regulation response. Furthermore, large power fluctuations in the electrolytic aluminum loads participating in frequency regulation are detrimental to the safety of industrial production.

[0004] The existing technologies mentioned above suffer from the limitations and uncertainties of the adjustable capacity of electrolytic aluminum load, making it difficult to provide timely power support and good frequency regulation for the power grid, and the frequency regulation response speed is slow. No effective solution has yet been proposed. Summary of the Invention

[0005] This invention provides a power grid frequency stabilization control method and apparatus based on virtual inertia, which at least solves the technical problems in the prior art where the limited and uncertain adjustable capacity of electrolytic aluminum load makes it difficult to provide timely power support and good frequency regulation effect to the power grid, and the frequency regulation response speed is slow.

[0006] According to one aspect of the present invention, a power grid frequency stabilization control method based on virtual inertia is provided, comprising: acquiring the current frequency of a target power grid; determining the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid requiring frequency stabilization control; when the frequency deviation is greater than a frequency deviation threshold, determining, based on the frequency deviation, a power response quantity of a thermal power unit for primary frequency regulation and a first power change quantity of an electrolytic aluminum load response delay, wherein the thermal power unit is a power generation device of the target power grid, the power response quantity refers to the power increase or decrease value when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response to the frequency deviation, and the first power change quantity refers to the current power response quantity of the target power grid. The difference between the power rate and the rated power; controlling the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid according to the power response and the first power change; during the participation of the electrolytic aluminum load in the primary frequency regulation of the target power grid, determining the second power change of the electrolytic aluminum load response delay according to the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid and the frequency deviation, wherein the second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia; reducing the active power deficit of the electrolytic aluminum load to the rated power according to the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

[0007] Optionally, before obtaining the current frequency of the target power grid, the method further includes: obtaining the active power currently consumed on the DC side of the rectifier circuit of the electrolytic aluminum system; determining the power deviation between the active power and the rated active power of the electrolytic aluminum load; and obtaining the current deviation of the target power grid based on the power deviation using a first formula, wherein the first formula is: ΔI d K represents the current deviation. d T represents the proportionality coefficient. d ΔP represents the time constant. de The power deviation is represented; the current deviation is processed by a proportional-integral controller to generate a control signal; the control signal is input to a power drive module based on pulse width modulation to trigger a pulse to adjust the firing angle of the thyristor in the rectifier circuit; the active power is controlled using the functional relationship between the active power and the firing angle.

[0008] Optionally, the active power is controlled using the functional relationship between the active power and the firing angle, including: establishing a rectification equivalent model of the electrolytic cell in the aluminum electrolysis system; and obtaining the average DC-side output voltage of the rectifier circuit using a second formula based on the firing angle, wherein the second formula is: U d U is the average value of the DC-side output voltage of the rectifier circuit. L The effective value of the line voltage of the rectifier circuit is input, and ∝ is the firing angle of the rectifier circuit; based on the rectifier equivalent model, the relationship between voltage and current in the rectifier circuit is established using the third formula, wherein the third formula is: I d E represents the average DC-side output current of the rectifier circuit. d Let L denote the back electromotive force, s be the Laplace operator, and L be the back electromotive force. d To reflect the equivalent inductance of the dynamic response process within the electrolytic cell, R d The equivalent resistance of the electrolytic cell is given; the functional relationship between the active power and the firing angle is expressed using a fourth formula, and the active power is controlled using this functional relationship, wherein the fourth formula is: P d This indicates the active power.

[0009] Optionally, determining the power response of the primary frequency regulation of the thermal power unit based on the frequency deviation includes: determining the power response of the primary frequency regulation of the thermal power unit using a fifth formula based on the frequency deviation, wherein the fifth formula is: ΔP G T represents the power response quantity. g K is the inertial time constant of the thermal power unit. g Δω is the gain coefficient of the speed controller in the electrolytic aluminum system, and Δω is the frequency deviation.

[0010] Optionally, determining the first power change amount of the electrolytic aluminum load response delay based on the frequency deviation includes: determining the first power change amount of the electrolytic aluminum load response delay using a sixth formula based on the frequency deviation, wherein the sixth formula is: ΔP L K represents the first power change. L1 T is the primary frequency modulation coefficient. L This is the load response delay factor.

[0011] Optionally, during the primary frequency regulation process of the electrolytic aluminum load participating in the target power grid, determining the second power change amount of the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation includes: determining the second power change amount of the electrolytic aluminum load response delay using a seventh formula based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation, wherein the seventh formula is: ΔP L ′ K represents the second power change. L2 K is the inertial response coefficient. L1 T is the primary frequency modulation coefficient. L Δω is the overall system delay coefficient, Δω is the frequency deviation, and s is the Laplace operator.

[0012] Optionally, the electrolytic aluminum load participating in the primary frequency regulation of the target power grid further includes: obtaining additional power based on the frequency deviation using an eighth formula, wherein the eighth formula is: ΔP J =-sK L2 Δω, ΔP J Let be the additional power, s be the Laplace operator, and K be the value of K. L2 Δω is the inertial response coefficient, and Δω is the frequency deviation; the additional power is used to provide inertial support power to the target power grid.

[0013] Optionally, reducing the active power deficit of the electrolytic aluminum load to rated power based on the power response and the second power change to control the frequency of the target power grid and maintain the frequency of the target power grid within a predetermined range includes: establishing a unified model based on the primary frequency regulation and inertial response using the ninth formula based on the power response and the second power change, wherein the ninth formula is: T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit, and D be the system active power deficit. G K is the equivalent damping coefficient. L D is the equivalent frequency regulation factor of the load. GL To account for the equivalent damping coefficient of load inertia response, the active power deficit is reduced to the rated power according to the unified model in order to perform frequency stability control on the target power grid frequency.

[0014] According to another aspect of the present invention, a power grid frequency stabilization control device based on virtual inertia is also provided, comprising: a first determining unit, configured to acquire the current frequency of a target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid requiring frequency stabilization control; and a second determining unit, configured to, when the frequency deviation is greater than a frequency deviation threshold, determine, based on the frequency deviation, a power response quantity of a thermal power unit for primary frequency regulation and a first power change quantity of an electrolytic aluminum load response delay, wherein the thermal power unit is a power generation device of the target power grid, the power response quantity refers to the power increase or decrease when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response to the frequency deviation, and the first power change quantity refers to the difference between the current power and the rated frequency of the target power grid. The difference between power values; a first control unit, used to control the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid according to the power response amount and the first power change amount; a third determining unit, used to determine the second power change amount of the electrolytic aluminum load response delay according to the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid and the frequency deviation during the process of the electrolytic aluminum load participating in the primary frequency regulation of the target power grid, wherein the second power change amount refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia; a second control unit, used to reduce the active power deficit of the electrolytic aluminum load to the rated power according to the power response amount and the second power change amount, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

[0015] Optionally, the power grid frequency stabilization control device based on virtual inertia further includes: a first acquisition unit, configured to acquire the active power currently consumed on the DC side of the rectifier circuit of the electrolytic aluminum system before acquiring the current frequency of the target power grid; a fourth determination unit, configured to determine the power deviation between the active power and the rated active power of the electrolytic aluminum load; and a second acquisition unit, configured to obtain the current deviation of the target power grid according to the power deviation using a first formula, wherein the first formula is: ΔI d K represents the current deviation. d T represents the proportionality coefficient. d ΔP represents the time constant. deThe system includes: a power deviation unit; a generation unit for processing the current deviation through a proportional-integral controller to generate a control signal; a trigger unit for inputting the control signal into a power drive module based on pulse width modulation to trigger a pulse to adjust the firing angle of the thyristor in the rectifier circuit; and a third control unit for controlling the active power using the functional relationship between the active power and the firing angle.

[0016] Optionally, the third control unit includes: a first establishing module, used to establish a rectifier equivalent model of the electrolytic cell in the aluminum electrolysis system; and a first acquiring module, used to obtain the average DC-side output voltage of the rectifier circuit according to the firing angle using a second formula, wherein the second formula is: U d U is the average value of the DC-side output voltage of the rectifier circuit. L The input is the effective value of the line voltage of the rectifier circuit, and ∝ is the firing angle of the rectifier circuit; the second establishment module is used to establish the relationship between voltage and current in the rectifier circuit based on the rectifier equivalent model using a third formula, wherein the third formula is: I d E represents the average DC-side output current of the rectifier circuit. d Let L denote the back electromotive force, s be the Laplace operator, and L be the back electromotive force. d To reflect the equivalent inductance of the dynamic response process within the electrolytic cell, R d The equivalent resistance of the electrolytic cell; a first control module, used to express the functional relationship between the active power and the firing angle using a fourth formula, and to control the active power using the functional relationship, wherein the fourth formula is: P d This indicates the active power.

[0017] Optionally, the first control unit includes: a first determining module, configured to determine the power response of the thermal power unit's primary frequency regulation based on the frequency deviation using a fifth formula, wherein the fifth formula is: ΔP G T represents the power response quantity. g K is the inertial time constant of the thermal power unit. g Δω is the gain coefficient of the speed controller in the electrolytic aluminum system, and Δω is the frequency deviation.

[0018] Optionally, the first control unit further includes: a second determining module, configured to determine the first power change amount of the electrolytic aluminum load response delay based on the frequency deviation using a sixth formula, wherein the sixth formula is: ΔP LK represents the first power change. L1 T is the primary frequency modulation coefficient. L This is the load response delay factor.

[0019] Optionally, the third determining unit includes: a third determining module, configured to determine the second power change in the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation using a seventh formula, wherein the seventh formula is: ΔP L ′ K represents the second power change. L2 K is the inertial response coefficient. L1 T is the primary frequency modulation coefficient. L Δω is the overall system delay coefficient, Δω is the frequency deviation, and s is the Laplace operator.

[0020] Optionally, the first control unit further includes: a second acquisition module, configured to obtain additional power based on the frequency deviation using an eighth formula, wherein the eighth formula is: ΔP J =-sK L2 Δω, ΔP J Let be the additional power, s be the Laplace operator, and K be the value of K. L2 Δω is the inertia response coefficient, and Δω is the frequency deviation; the support module is used to provide inertia support power to the target power grid using the additional power.

[0021] Optionally, the second control unit includes: a third establishment module, configured to establish a unified model based on the primary frequency modulation and inertial response using a ninth formula based on the power response and the second power change, wherein the ninth formula is: T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit, and D be the system active power deficit. G K is the equivalent damping coefficient. L D is the equivalent frequency regulation factor of the load. GL To account for the equivalent damping coefficient of load inertia response; the second control module is used to reduce the active power deficit to the rated power according to the unified model, so as to perform frequency stability control on the target power grid frequency.

[0022] According to another aspect of the present invention, a power grid frequency stabilization control system based on virtual inertia is also provided, wherein the power grid frequency stabilization control system based on virtual inertia uses any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0023] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein the program executes any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0024] According to another aspect of the present invention, a processor is also provided, the processor being configured to run a program, wherein the program, when running, executes any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0025] In this embodiment of the invention, the current frequency of the target power grid is obtained, and the frequency deviation between the current frequency and the rated frequency of the target power grid is determined. The target power grid is a power grid requiring frequency stabilization control. When the frequency deviation exceeds a frequency deviation threshold, the power response of the thermal power unit during primary frequency regulation and the first power change during the electrolytic aluminum load response delay are determined based on the frequency deviation. The thermal power unit is the power generation equipment of the target power grid. The power response refers to the increase or decrease in power when the thermal power unit restores the frequency of the target power grid to its rated frequency through primary frequency regulation response to the frequency deviation. The first power change refers to the difference between the current power and the rated power of the target power grid. The electrolytic aluminum load is controlled to participate in the primary frequency regulation of the target power grid based on the power response and the first power change. During the primary frequency regulation of the target power grid, the second power change of the electrolytic aluminum load response delay is determined based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation. The second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia. The active power deficit of the electrolytic aluminum load is reduced to the rated power based on the power response and the second power change to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range. The above technical solutions achieve the goal of optimizing primary frequency regulation by utilizing virtual inertia during the participation of electrolytic aluminum loads in the target power grid, reducing the active power deficit of the electrolytic aluminum loads to the rated power, and keeping the frequency of the target power grid within a predetermined range. This achieves the effect of outputting a large supporting power in a short time after power disturbance through virtual inertia control, fully utilizing the flexible adjustment advantage of electrolytic aluminum loads, improving the frequency regulation response speed of the target power grid, and thus solving the technical problems in the prior art where the limited and uncertain adjustable capacity of electrolytic aluminum loads makes it difficult to provide timely power support and good frequency regulation effect to the power grid, and the frequency regulation response speed is slow. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0027] Figure 1 This is a hardware structure block diagram of a mobile terminal for a power grid frequency stability control method based on virtual inertia according to an embodiment of the present invention.

[0028] Figure 2 This is a flowchart of a power grid frequency stabilization control method based on virtual inertia according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the active power control model for electrolytic aluminum load according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the rectifier equivalent model of the electrolytic cell in the electrolytic aluminum system according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of a system frequency response model considering virtual inertia response according to an embodiment of the present invention;

[0032] Figure 6 This is a flowchart of an optional power grid frequency stabilization control method based on virtual inertia according to an embodiment of the present invention;

[0033] Figure 7(a) is a schematic diagram of the frequency variation curve of electrolytic aluminum load under a small photovoltaic power disturbance scenario according to an embodiment of the present invention;

[0034] Figure 7(b) is a schematic diagram of the active power variation curve of electrolytic aluminum load under a small photovoltaic power disturbance scenario according to an embodiment of the present invention;

[0035] Figure 8(a) is a schematic diagram of the frequency variation curve of electrolytic aluminum load under a small photovoltaic power disturbance scenario according to an embodiment of the present invention;

[0036] Figure 8(b) is a schematic diagram of the active power variation curve of electrolytic aluminum load under a small photovoltaic power disturbance scenario according to an embodiment of the present invention;

[0037] Figure 9 This is a schematic diagram of a power grid frequency stabilization control device based on virtual inertia according to an embodiment of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] As described in the background section, existing technologies suffer from limited and uncertain adjustable capacity of electrolytic aluminum loads, making it difficult to provide timely power support and good frequency regulation for the power grid, and the frequency regulation response speed is also slow. To address these shortcomings, this invention provides a power grid frequency stabilization control method and apparatus based on virtual inertia.

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0042] The methods and embodiments provided in this invention can be executed on a mobile terminal, a computer terminal, or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a power grid frequency stability control method based on virtual inertia, according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0043] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the power grid frequency stabilization control method based on virtual inertia in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0044] According to an embodiment of the present invention, a method embodiment of a power grid frequency stability control method based on virtual inertia is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0045] Figure 2 This is a flowchart of a power grid frequency stability control method based on virtual inertia according to an embodiment of the present invention, such as... Figure 2 As shown, the method includes the following steps:

[0046] Step S202: Obtain the current frequency of the target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that requires frequency stabilization control.

[0047] Optionally, the frequency deviation mentioned above is the difference between the current frequency and the rated frequency of the target power grid.

[0048] According to the above embodiments of the present invention, before step S202, that is, before obtaining the current frequency of the target power grid, the method further includes: obtaining the active power currently consumed on the DC side of the rectifier circuit of the electrolytic aluminum system; determining the power deviation between the active power and the rated active power of the electrolytic aluminum load; and obtaining the current deviation of the target power grid using a first formula based on the power deviation, wherein the first formula is: ΔI d K represents the current deviation. d T represents the proportionality coefficient. d ΔP represents the time constant. de The current deviation is represented by a proportional-integral controller; the current deviation is processed to generate a control signal; the control signal is input to the power drive module based on pulse width modulation to trigger the pulse to adjust the firing angle of the thyristor in the rectifier circuit; the active power is controlled by the functional relationship between active power and firing angle.

[0049] The following is combined with Figure 3 The embodiments of the present invention will be described in detail below. Figure 3 This is a schematic diagram of the active power control model for electrolytic aluminum load according to an embodiment of the present invention. Figure 3 As shown, in the electrolytic cell, based on the deviation ΔP between the rated power and the actual power... de Perform constant current control, and then use the formula: The calculated current deviation ΔI d Wherein, the time constant T d and proportionality coefficient K d It can be calculated from the electrolytic cell model parameters and its dynamic process, then ΔI d After passing through the PI controller (proportional-integral controller), the control current deviation can be obtained. Then, in the adjustment and limiting stage, the control current is limited to the allowable range according to the power regulation margin of the electrolytic series. Finally, the control signal is input to the PWM module (power drive module based on pulse width modulation) to generate a trigger pulse to control the trigger angle α. By adjusting the thyristor trigger angle α, the active power response of the electrolytic aluminum load is achieved, thereby controlling the active power on the DC side of the rectifier circuit. This enables the electrolytic aluminum load to have a large active power regulation capability, laying the foundation for the electrolytic aluminum load to participate in the frequency regulation of the target power grid system.

[0050] In the above embodiments of the present invention, the active power is controlled using a functional relationship between active power and firing angle, including: establishing a rectification equivalent model of the electrolytic cell in the aluminum electrolysis system; and obtaining the average DC-side output voltage of the rectifier circuit using a second formula based on the firing angle, wherein the second formula is: U d U is the average value of the DC-side output voltage of the rectifier circuit. LLet be the effective value of the line voltage of the input rectifier circuit, and ∝ be the firing angle of the rectifier circuit. Based on the rectifier equivalent model, the relationship between voltage and current in the rectifier circuit is established using the third formula, where the third formula is: I d E represents the average value of the DC-side output current of the rectifier circuit. d Let L denote the back electromotive force, s be the Laplace operator, and L be the back electromotive force. d To reflect the equivalent inductance of the dynamic response process within the electrolytic cell, R d Let be the equivalent resistance of the electrolytic cell; the fourth formula is used to express the functional relationship between active power and firing angle, and this functional relationship is used to control the active power. The fourth formula is: P d This indicates active power.

[0051] The following is combined with Figure 4 The embodiments of the present invention will be described in detail below. Figure 4 This is a schematic diagram of the rectifier equivalent model of the electrolytic cell in the electrolytic aluminum system according to an embodiment of the present invention.

[0052] Since the load on the electrolytic aluminum cell is a critical load, the current fluctuation within the cell is relatively small during normal production. Therefore, when modeling the electrolytic cell, its variation can be ignored, and the electrolytic cell can be equivalent to a constant resistor R. d0 and back electromotive force E d The series model is used, but considering the need to study the dynamic response process of the electrolytic cell when electrolytic aluminum participates in the system frequency modulation, and also considering the influence of the anode effect on the internal resistance of the electrolytic cell, an equivalent inductance L reflecting the dynamic response process inside the cell is introduced. d and the variable resistor R that reflects the anode effect p The equivalent resistance of the electrolytic cell can then be denoted as: R d =R d0 +R p .

[0053] like Figure 4 As shown, considering the advantages of thyristor rectification, such as a large adjustment range and fast adjustment speed, this embodiment uses a three-phase thyristor fully controlled rectifier circuit based on firing angle control to establish an equivalent model of the electrolytic aluminum rectification characteristics. The rectifier transformer is essentially a step-down transformer, transforming AC voltage based on the principle of electromagnetic induction to supply appropriate voltage to the rectifier system. During operation, one of the upper and lower sets of thyristors in the three-phase bridge rectifier circuit is in a conducting state, forming a power supply loop to the load. Therefore, the rectified output voltage pulsates six times per cycle, and each pulsation waveform is the same. Therefore, only one pulse needs to be calculated when calculating its average value. Using the formula: Calculate the average DC output voltage U of the thyristor rectifier circuit. d , among which, U dU is the average value of the DC-side output voltage of the rectifier circuit. L ∝ is the effective value of the line voltage of the input rectifier circuit, and ∝ is the firing angle of the rectifier circuit. When there is a resistive-inductive load, the adjustment range is 0° to 90°, which can realize full-range voltage regulation.

[0054] Based on the above equivalent rectification model, the relationship between voltage and current is established: Then perform a Laplace transform on it: Then we can obtain the functional relationship between the active power consumed on the DC side of the thyristor rectifier circuit and the firing angle: Therefore, by adjusting the thyristor firing angle ∝, the active power response of the electrolytic aluminum load can be accurately achieved, thereby improving the voltage regulation capability and response speed of the rectifier, enabling the electrolytic aluminum load to have a greater power support capability, and laying the foundation for the electrolytic aluminum load to participate in the system frequency regulation.

[0055] Step S204: When the frequency deviation is greater than the frequency deviation threshold, determine the power response of the thermal power unit for primary frequency regulation and the first power change during the response delay of the electrolytic aluminum load based on the frequency deviation. Here, the thermal power unit is the power generation equipment of the target power grid, the power response refers to the power value that increases or decreases when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response to the frequency deviation, and the first power change refers to the difference between the current power and the rated power of the target power grid.

[0056] Optionally, the aforementioned primary frequency regulation refers to the regulation performed by the generator's speed governor. Primary frequency regulation is a feedback closed-loop control that adopts a local response method. When the grid frequency increases, the primary frequency regulation process requires the unit to utilize its heat storage to quickly reduce the load.

[0057] According to the above embodiments of the present invention, in step S204, regarding how to determine the power response of the primary frequency regulation of the power unit, the power response of the primary frequency regulation of the thermal power unit can be determined based on the frequency deviation, including: determining the power response of the primary frequency regulation of the thermal power unit using a fifth formula based on the frequency deviation, wherein the fifth formula is: ΔP G T represents the power response. g K is the inertial time constant of the thermal power unit. g Δω represents the gain coefficient of the speed controller in the electrolytic aluminum system, and Δω represents the frequency deviation.

[0058] The primary frequency modulation of the system can be simplified to a first-order inertial element: Where, ΔP G T represents the power response. g K is the inertial time constant of the thermal power unit. gThe gain coefficient of the speed governor in the electrolytic aluminum system is used to restore the frequency of a thermal power unit by increasing or decreasing power when the frequency deviation is detected by the primary frequency regulation response. In this process, the increased or decreased power is the power response of the thermal power unit during the primary frequency regulation.

[0059] According to the above embodiments of the present invention, in step S204, regarding how to determine the first power change amount of the electrolytic aluminum load response delay, the first power change amount of the electrolytic aluminum load response delay can be determined based on the frequency deviation, including: determining the first power change amount of the electrolytic aluminum load response delay using a sixth formula based on the frequency deviation, wherein the sixth formula is: ΔP L K represents the first power change. L1 T is the primary frequency modulation coefficient. L This is the load response delay factor.

[0060] Electrolytic aluminum loads employing active power control strategies have a certain active power support capability when the system frequency is disturbed. In other words, electrolytic aluminum loads can work together with the primary frequency regulation of synchronous thermal power units to restore the system frequency, thereby improving the system frequency's anti-interference capability.

[0061] Step S206: Control the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid based on the power response and the first power change.

[0062] The model for the electrolytic aluminum load participating in the primary frequency regulation response of the system can be expressed as: Among them, T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit (including electrolytic aluminum load and other loads in the power grid system), and D be the system inertial time constant. G K is the equivalent damping coefficient. L1 T is the primary frequency modulation coefficient. L Let T be the overall system delay coefficient, Δω be the frequency deviation, and s be the Laplace operator; for a given power system, when the load response delay coefficient T... L At a given time, the system's frequency modulation control strategy is mainly determined by the frequency modulation coefficient K. L1 It is determined that increasing the frequency regulation coefficient is beneficial to improving the frequency regulation response speed. However, due to the constraint of the load's frequency regulation capacity, the frequency regulation range is limited, and the maximum regulation capability of the electrolytic aluminum load cannot be utilized. Therefore, the selection of frequency regulation parameters needs to consider a trade-off between the relative stability of the electrolytic aluminum load and its regulation capability, which has certain limitations. Therefore, in order to further improve the speed of frequency response, the above embodiments of the present invention, based on the inertia response principle of synchronous generators, introduce virtual inertia for control on the basis of the electrolytic aluminum load participating in the primary frequency regulation response, as described in the following steps.

[0063] Step S208: During the primary frequency regulation process of the electrolytic aluminum load participating in the target power grid, the second power change of the electrolytic aluminum load response delay is determined based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation. The second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia.

[0064] According to the above embodiments of the present invention, in step S208, during the primary frequency regulation process of the electrolytic aluminum load participating in the target power grid, determining the second power change amount of the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation includes: determining the second power change amount of the electrolytic aluminum load response delay using a seventh formula based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation, wherein the seventh formula is: ΔP L ′ K represents the second power change. L2 K is the inertial response coefficient. L1 T is the primary frequency modulation coefficient. L Let ω be the overall system delay coefficient, Δω be the frequency deviation, and s be the Laplace operator.

[0065] Since there may be inherent delays in signal transmission and artificially added delays such as low-pass filters during actual control processes, the overall effect of various delays can be approximated as a first-order inertial element, and its time constant can be attributed to the overall system delay coefficient T. L After optimizing the primary frequency modulation using virtual inertia, the second power change during the load response delay of electrolytic aluminum can be obtained as follows:

[0066] According to the above embodiments of the present invention, in step S208, the participation of the electrolytic aluminum load in the primary frequency regulation of the target power grid may further include: obtaining the additional power based on the frequency deviation using an eighth formula, wherein the eighth formula is: ΔP J =-sK L2 Δω, ΔP J For additional power, s is the Laplace operator, and K L2 Δω is the inertial response coefficient, and Δω is the frequency deviation; additional power is used to provide inertial support power to the target power grid.

[0067] Based on the participation of the electrolytic aluminum load in the primary frequency modulation response, virtual inertia control is introduced, and the additional power ΔP is obtained by monitoring the frequency deviation and frequency change rate signals. J =-sK L2 Δω can provide inertia support power for the system, that is, it can output a large support power in a short time after the power disturbance.

[0068] Step S210: Based on the power response and the second power change, reduce the active power deficit of the electrolytic aluminum load to the rated power to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

[0069] Optionally, the aforementioned predetermined range refers to the frequency range in which the target power grid system is in a stable phase.

[0070] According to the above embodiments of the present invention, in step S210, reducing the active power deficit of the electrolytic aluminum load to the rated power based on the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range, includes: establishing a unified model based on primary frequency regulation and inertial response using the ninth formula based on the power response and the second power change, wherein the ninth formula is: T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit, and D be the system active power deficit. G K is the equivalent damping coefficient. L D is the equivalent frequency regulation factor of the load. GL To account for the equivalent damping coefficient of load inertia response, the active power deficit is reduced to the rated power according to the unified model in order to achieve frequency stability control of the target power grid frequency.

[0071] The following is combined Figure 5 The embodiments of the present invention will be described in detail below. Figure 5 This is a schematic diagram of a system frequency response model considering virtual inertia response according to an embodiment of the present invention. Figure 5 As shown, the unified model of primary frequency regulation and inertial response based on electrolytic aluminum load can be expressed as: Among them, K L =K L1 -K L2 / T L , K L D is the equivalent frequency regulation factor of the load. GL The equivalent damping coefficient is used to account for the load inertia response; Figure 5 This indicates the ΔP generated by the system speed controller adjustment. G And the ΔP generated by the electrolytic aluminum load frequency modulation control strategy considering virtual inertia response L ′ The active power deficit can be reduced through negative feedback, which helps to quickly reduce frequency deviation and thus improve the system's frequency response speed and accuracy.

[0072] The above methods can fully leverage the advantages of flexible load adjustment in electrolytic aluminum production, improving the system's frequency response speed while ensuring safe production. However, they cannot completely eliminate the adverse effects of response delay. Nevertheless, steady-state error and delay response within the allowable range are reasonable.

[0073] As can be seen from the above, through the above steps, according to the technical solution provided by the above embodiments of the present invention, the current frequency of the target power grid can be obtained, and the frequency deviation between the current frequency and the rated frequency of the target power grid can be determined. The target power grid is the power grid that requires frequency stabilization control. When the frequency deviation is greater than the frequency deviation threshold, the power response of the thermal power unit for primary frequency regulation and the first power change of the electrolytic aluminum load response delay are determined based on the frequency deviation. The thermal power unit is the power generation equipment of the target power grid. The power response refers to the power increase or decrease that the thermal power unit adds or decreases when the frequency of the target power grid recovers to the rated frequency through primary frequency regulation response to the frequency deviation. The first power change refers to the difference between the current power and the rated power of the target power grid. The electrolytic aluminum load is controlled to participate in the primary frequency regulation of the target power grid based on the power response and the first power change. During the process of the electrolytic aluminum load participating in the primary frequency regulation of the target power grid, the inertia response... The second power change in the response delay of the electrolytic aluminum load is determined by the response coefficient, primary frequency regulation coefficient, overall delay coefficient of the target power grid, and frequency deviation. The second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia. Based on the power response and second power change, the active power deficit of the electrolytic aluminum load is reduced to the rated power to control the frequency of the target power grid, keeping it within a predetermined range. This achieves the goal of optimizing the primary frequency regulation of the target power grid using virtual inertia during the electrolytic aluminum load's participation, reducing the active power deficit of the electrolytic aluminum load to the rated power, and keeping the target power grid frequency within a predetermined range. It also achieves the effect of outputting a large supporting power in a short time after power disturbances through virtual inertia control, fully utilizing the flexible adjustment advantage of the electrolytic aluminum load and improving the frequency regulation response speed of the target power grid.

[0074] Therefore, the technical solution provided by the above embodiments of the present invention solves the technical problems in the prior art where the limited and uncertain adjustable capacity of electrolytic aluminum load makes it difficult to provide timely power support and good frequency regulation effect to the power grid, and the frequency regulation response speed is slow.

[0075] Another embodiment of the present invention will now be described with reference to the accompanying drawings. Figure 6 This is a flowchart of an optional power grid frequency stability control method based on virtual inertia according to an embodiment of the present invention. Figure 6As shown, firstly, the adjustable capacity of the electrolytic aluminum load is assessed based on the operating status of each device in the electrolytic aluminum system. Then, it is determined whether the current frequency of the isolated power grid system exceeds a set threshold. This can be understood as determining whether the frequency deviation of the current isolated power grid system exceeds the minimum frequency deviation. When the frequency deviation between the current frequency and the rated frequency of the system does not exceed the set threshold (minimum frequency deviation, the same below), the frequency of the current system is considered relatively stable, and the electrolytic aluminum load does not need to participate in its frequency regulation. When the frequency deviation exceeds the set threshold, the electrolytic aluminum load is controlled to cooperate with the primary frequency regulation of the synchronous thermal power unit to achieve system frequency recovery, and virtual inertia is introduced to optimize the primary frequency regulation process. Then, the load power reference value is modified based on the system frequency response model, and constant power control is performed according to the reference value to effectively adjust the power of the electrolytic aluminum load, thereby realizing the frequency regulation function of the electrolytic aluminum load to maintain the stability of the target power grid frequency.

[0076] To verify the effectiveness and accuracy of the proposed control method, an isolated electrolytic aluminum industrial microgrid system with high-penetration photovoltaic power was tested in the above embodiments of the present invention. The system is equipped with two 100MW nano-hydrogen generator sets and one 100MW photovoltaic generator set. The electrolytic aluminum power supply adopts a dual-circuit power supply, with a busbar equipped with a 220 / 10kV rectifier transformer. The rated capacity is 100MW, the regulation capability is ±20% of the rated capacity, and the load power response ramp rate can reach ±10MW / min, exhibiting a large power regulation capacity and a fast frequency response capability. Furthermore, in this embodiment, the grid frequency is adjusted by setting photovoltaic fluctuations.

[0077] If the photovoltaic output power suddenly decreases after 5 seconds, the system frequency will drop. In this embodiment, this frequency change problem is addressed by using control without virtual inertia and by using different frequency modulation parameters, and the frequency regulation performance of these control methods is compared.

[0078] In view of the situation where photovoltaic power fluctuates slightly during the operation of microgrid systems, the above embodiments of the present invention will be described in detail below with reference to Figures 7(a) and 7(b). Figure 7(a) is a schematic diagram of the frequency change curve of electrolytic aluminum load under the scenario of small photovoltaic power disturbance according to the embodiment of the present invention, and Figure 7(b) is a schematic diagram of the active power change curve of electrolytic aluminum load under the scenario of small photovoltaic power disturbance according to the embodiment of the present invention.

[0079] As shown in Figures 7(a) and 7(b), using a larger frequency modulation coefficient has a better frequency recovery effect, but the load power fluctuation is large and the electrolytic aluminum load capacity participating in frequency modulation is large. After adding inertia response control, the system frequency can be restored to the allowable operating range, and the load power response speed is fast, the active power capacity adjustment fluctuation is small, and the load power capacity participating in frequency modulation can be fully utilized, which is conducive to the stable production of electrolytic aluminum load.

[0080] In view of the situation where photovoltaic power fluctuates significantly during the operation of microgrid systems, the above embodiments of the present invention will be described in detail below with reference to Figures 8(a) and 8(b). Figure 8(a) is a schematic diagram of the frequency change curve of electrolytic aluminum load under the scenario of small photovoltaic power disturbance according to the embodiment of the present invention, and Figure 8(b) is a schematic diagram of the active power change curve of electrolytic aluminum load under the scenario of small photovoltaic power disturbance according to the embodiment of the present invention.

[0081] As shown in Figures 8(a) and 8(b), when the electrolytic aluminum load participates in frequency regulation with a small frequency regulation parameter, it cannot fully utilize the load regulation capability of the electrolytic aluminum, which will lead to frequency exceeding the limit. Only a larger frequency regulation parameter can fully utilize the load regulation capability of the electrolytic aluminum and obtain better frequency stability performance, but it also has the problem of large power fluctuation. Considering the influence of frequency steady-state deviation, frequency regulation response speed and load regulation capacity, the control strategy of inertia response and appropriate frequency regulation coefficient is the optimal frequency regulation scheme. Compared with a single primary frequency regulation response, the minimum point of system frequency drop is significantly improved under this scheme. Moreover, by monitoring the frequency change rate through the differential element, it can respond to frequency changes in advance, which is conducive to improving the speed and accuracy of frequency recovery and load power frequency regulation response.

[0082] Compare Figure 7(a), Figure 7(b) and 8(a) Figure 8(b) shows that when facing frequency disturbance scenarios of different degrees, the speed advantage of inertial response is not obvious in small disturbance scenarios, but when the frequency fluctuates significantly, inertial response can significantly improve the speed of frequency response. This verifies the effectiveness and necessity of the frequency control method considering inertial response proposed in the above embodiments of the present invention. Through the technical solution provided by the above embodiments of the present invention, the system can ensure frequency stability by using primary frequency regulation and virtual inertial control involving electrolytic aluminum load when the system frequency fluctuates due to sudden changes in photovoltaic output.

[0083] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0085] According to embodiments of the present invention, a power grid frequency stabilization control device based on virtual inertia is also provided for implementing the above-described power grid frequency stabilization control method based on virtual inertia. Figure 9 This is a schematic diagram of a power grid frequency stabilization control device based on virtual inertia according to an embodiment of the present invention, as shown below. Figure 9 As shown, the device includes: a first determining unit 91, a second determining unit 93, a first determining unit 95, a third determining unit 97, and a second determining unit 99. The following is a detailed description of the power grid frequency stabilization control device based on virtual inertia.

[0086] The first determining unit 91 is used to obtain the current frequency of the target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that needs to be frequency stabilized.

[0087] The second determining unit 93 is used to determine the power response of the thermal power unit during primary frequency regulation and the first power change during the response delay of the electrolytic aluminum load based on the frequency deviation when the frequency deviation is greater than the frequency deviation threshold. The thermal power unit is the power generation equipment of the target power grid. The power response refers to the power value that the thermal power unit increases or decreases when the frequency deviation of the target power grid is restored to the rated frequency through primary frequency regulation. The first power change refers to the difference between the current power and the rated power of the target power grid.

[0088] The first control unit 95 is used to control the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid according to the power response and the first power change.

[0089] The third determining unit 97 is used to determine the second power change amount of the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation during the primary frequency regulation process of the electrolytic aluminum load participating in the target power grid. The second power change amount refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia.

[0090] The second control unit 99 is used to reduce the active power deficit of the electrolytic aluminum load to the rated power based on the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

[0091] It should be noted that the first determining unit 91, the second determining unit 93, the first controlling unit 95, the third determining unit 97, and the second controlling unit 99 mentioned above correspond to steps S202 to S210 in the above embodiments. The five units and the corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments.

[0092] As can be seen from the above, in the scheme described in the above embodiments of the present invention, the first determining unit can be used to obtain the current frequency of the target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that needs to be frequency stabilized; then, when the frequency deviation is greater than the frequency deviation threshold, the second determining unit uses the frequency deviation to determine the power response of the thermal power unit for primary frequency regulation and the first power change amount of the electrolytic aluminum load response delay, wherein the thermal power unit is the power generation equipment of the target power grid, the power response amount refers to the power value that increases or decreases when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response frequency deviation, and the first power change amount refers to the difference between the current power and the rated power of the target power grid; then, the first control unit uses the first control unit to control the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid according to the power response amount and the first power change amount; then, the third determining unit uses the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid. During the process, the second power change in the response delay of the electrolytic aluminum load is determined based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation. The second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia. Finally, the second control unit reduces the active power deficit of the electrolytic aluminum load to the rated power based on the power response and the second power change, thereby controlling the frequency of the target power grid and keeping it within a predetermined range. This achieves the goal of optimizing the primary frequency regulation of the target power grid using virtual inertia during the electrolytic aluminum load's participation, reducing the active power deficit of the electrolytic aluminum load to the rated power, and keeping the frequency of the target power grid within a predetermined range. It also achieves the effect of outputting a large supporting power in a short time after power disturbances through virtual inertia control, fully utilizing the flexible adjustment advantage of the electrolytic aluminum load and improving the frequency regulation response speed of the target power grid.

[0093] Therefore, the technical solution provided by the above embodiments of the present invention solves the technical problems in the prior art where the limited and uncertain adjustable capacity of electrolytic aluminum load makes it difficult to provide timely power support and good frequency regulation effect to the power grid, and the frequency regulation response speed is slow.

[0094] Optionally, the power grid frequency stabilization control device based on virtual inertia further includes: a first acquisition unit, used to acquire the active power currently consumed on the DC side of the rectifier circuit of the electrolytic aluminum system before acquiring the current frequency of the target power grid; a fourth determination unit, used to determine the power deviation between the active power and the rated active power of the electrolytic aluminum load; and a second acquisition unit, used to obtain the current deviation of the target power grid according to the power deviation using a first formula, wherein the first formula is: ΔI d K represents the current deviation. d T represents the proportionality coefficient.d ΔP represents the time constant. de The system includes: a power deviation unit; a generation unit, which processes the current deviation through a proportional-integral controller to generate a control signal; a trigger unit, which inputs the control signal to a pulse-width modulation-based power drive module to trigger a pulse to adjust the firing angle of the thyristors in the rectifier circuit; and a third control unit, which controls the active power using a functional relationship between active power and firing angle.

[0095] Optionally, the third control unit includes: a first establishing module for establishing a rectifier equivalent model of the electrolytic cell in the aluminum electrolysis system; and a first acquiring module for obtaining the average DC-side output voltage of the rectifier circuit based on the firing angle using a second formula, wherein the second formula is: U d U is the average value of the DC-side output voltage of the rectifier circuit. L The input is the effective value of the line voltage of the rectifier circuit, and ∝ is the firing angle of the rectifier circuit; the second module is used to establish the relationship between voltage and current in the rectifier circuit based on the rectifier equivalent model and using the third formula, where the third formula is: I d E represents the average value of the DC-side output current of the rectifier circuit. d Let L denote the back electromotive force, s be the Laplace operator, and L be the back electromotive force. d To reflect the equivalent inductance of the dynamic response process within the electrolytic cell, R d The equivalent resistance of the electrolytic cell; the first control module is used to express the functional relationship between active power and firing angle using the fourth formula, and to control the active power using this functional relationship, wherein the fourth formula is: P d This indicates active power.

[0096] Optionally, the first control unit includes: a first determining module, configured to determine the power response of the primary frequency regulation of the thermal power unit based on the frequency deviation using a fifth formula, wherein the fifth formula is: ΔP G T represents the power response. g K is the inertial time constant of the thermal power unit. g Δω represents the gain coefficient of the speed controller in the electrolytic aluminum system, and Δω represents the frequency deviation.

[0097] Optionally, the first control unit includes: a second determining module, configured to determine the first power change during the electrolytic aluminum load response delay based on the frequency deviation using a sixth formula, wherein the sixth formula is: ΔP L K represents the first power change. L1 T is the primary frequency modulation coefficient. L This is the load response delay factor.

[0098] Optionally, the third determining unit includes: a third determining module, used to determine the second power change in the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation using the seventh formula, wherein the seventh formula is: ΔP L ′ K represents the second power change. L2 K is the inertial response coefficient. L1 T is the primary frequency modulation coefficient. L Let ω be the overall system delay coefficient, Δω be the frequency deviation, and s be the Laplace operator.

[0099] Optionally, the first control unit further includes: a second acquisition module, used to obtain the additional power based on the frequency deviation using an eighth formula, wherein the eighth formula is: ΔP J =-sK L2 Δω, ΔP J For additional power, s is the Laplace operator, and K L2 Δω is the inertial response coefficient, and Δω is the frequency deviation; the support module is used to provide inertial support power to the target power grid using additional power.

[0100] Optionally, the second control unit includes: a third establishment module, used to establish a unified model based on primary frequency modulation and inertial response using the ninth formula based on the power response and the second power change, wherein the ninth formula is: T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit, and D be the system active power deficit. G K is the equivalent damping coefficient. L D is the equivalent frequency regulation factor of the load. GL To account for the equivalent damping coefficient of load inertia response; the second control module is used to reduce the active power deficit to the rated power according to the unified model, so as to perform frequency stability control on the target power grid frequency.

[0101] According to another aspect of the present invention, a power grid frequency stabilization control system based on virtual inertia is also provided, wherein the power grid frequency stabilization control system based on virtual inertia uses any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0102] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein the program executes any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0103] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any communication device in a group of communication devices.

[0104] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: obtaining the current frequency of the target power grid, determining the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that requires frequency stabilization control; when the frequency deviation is greater than a frequency deviation threshold, determining the power response of the thermal power unit for primary frequency regulation and the first power change of the electrolytic aluminum load response delay based on the frequency deviation, wherein the thermal power unit is the power generation equipment of the target power grid, the power response refers to the increase or decrease in power value when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response to the frequency deviation, and the first power change refers to the power value of the target power grid that is increased or decreased when the thermal power unit responds to the frequency deviation for primary frequency regulation to restore the frequency of the target power grid to the rated frequency, and the first power change refers to the power response of the thermal power unit for primary frequency regulation response to the frequency deviation to restore the frequency of the target power grid to the rated frequency. The difference between the current power and the rated power of the grid; controlling the electrolytic aluminum load to participate in the primary frequency regulation of the target grid based on the power response and the first power change; during the process of the electrolytic aluminum load participating in the primary frequency regulation of the target grid, determining the second power change of the electrolytic aluminum load response delay based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target grid, and the frequency deviation, wherein the second power change refers to the difference between the current power and the rated power after optimizing the primary frequency regulation using virtual inertia; reducing the active power deficit of the electrolytic aluminum load to the rated power based on the power response and the second power change, so as to control the frequency of the target grid and keep the frequency of the target grid within a predetermined range.

[0105] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: obtaining the current active power consumed on the DC side of the rectifier circuit of the electrolytic aluminum system; determining the power deviation between the active power and the rated active power of the electrolytic aluminum load; and obtaining the current deviation of the target power grid based on the power deviation using a first formula, wherein the first formula is: ΔI d K represents the current deviation. d T represents the proportionality coefficient. d ΔP represents the time constant. de The current deviation is represented by a proportional-integral controller; the current deviation is processed to generate a control signal; the control signal is input to the power drive module based on pulse width modulation to trigger the pulse to adjust the firing angle of the thyristor in the rectifier circuit; the active power is controlled by the functional relationship between active power and firing angle.

[0106] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: establishing a rectifier equivalent model of the electrolytic cell in the aluminum electrolysis system; obtaining the average DC-side output voltage of the rectifier circuit using a second formula based on the firing angle, wherein the second formula is: U d U is the average value of the DC-side output voltage of the rectifier circuit. L Let be the effective value of the line voltage of the input rectifier circuit, and ∝ be the firing angle of the rectifier circuit. Based on the rectifier equivalent model, the relationship between voltage and current in the rectifier circuit is established using the third formula, where the third formula is: I d E represents the average value of the DC-side output current of the rectifier circuit. d Let L denote the back electromotive force, s be the Laplace operator, and L be the back electromotive force. d To reflect the equivalent inductance of the dynamic response process within the electrolytic cell, R d Let be the equivalent resistance of the electrolytic cell; the fourth formula is used to express the functional relationship between active power and firing angle, and this functional relationship is used to control the active power. The fourth formula is: P d This indicates active power.

[0107] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: determining the power response of the primary frequency regulation of the thermal power unit based on the frequency deviation using a fifth formula, wherein the fifth formula is: ΔP G T represents the power response. g K is the inertial time constant of the thermal power unit. g Δω represents the gain coefficient of the speed controller in the electrolytic aluminum system, and Δω represents the frequency deviation.

[0108] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: determining a first power change in the electrolytic aluminum load response delay based on a sixth formula according to the frequency deviation, wherein the sixth formula is: ΔP L K represents the first power change. L1 T is the primary frequency modulation coefficient. L This is the load response delay factor.

[0109] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: determining the second power change in the electrolytic aluminum load response delay using a seventh formula based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation, wherein the seventh formula is: ΔP L ′K represents the second power change. L2 K is the inertial response coefficient. L1 T is the primary frequency modulation coefficient. L Let ω be the overall system delay coefficient, Δω be the frequency deviation, and s be the Laplace operator.

[0110] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: obtaining additional power based on the frequency deviation using an eighth formula, wherein the eighth formula is: ΔP J =-sK L2 Δω, ΔP J For additional power, s is the Laplace operator, and K L2 Δω is the inertial response coefficient, and Δω is the frequency deviation; additional power is used to provide inertial support power to the target power grid.

[0111] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: establishing a unified model based on primary frequency modulation and inertial response using the ninth formula based on the power response and the second power change, wherein the ninth formula is: T ∑ Let D be the system inertial time constant, ΔP be the system active power deficit, and D be the system active power deficit. G K is the equivalent damping coefficient. L D is the equivalent frequency regulation factor of the load. GL To account for the equivalent damping coefficient of load inertia response, the active power deficit is reduced to the rated power according to the unified model in order to achieve frequency stability control of the target power grid frequency.

[0112] According to another aspect of the present invention, a processor is also provided, which is used to run a program, wherein the program executes any of the above-described power grid frequency stabilization control methods based on virtual inertia.

[0113] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0114] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0115] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0116] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0117] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0118] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0119] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A power grid frequency stability control method based on virtual inertia, characterized in that, include: Obtain the current frequency of the target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that requires frequency stabilization control; When the frequency deviation is greater than the frequency deviation threshold, the power response of the thermal power unit for primary frequency regulation and the first power change during the electrolytic aluminum load response delay are determined based on the frequency deviation. The thermal power unit is the power generation equipment of the target power grid. The power response refers to the power value that increases or decreases when the thermal power unit restores the frequency of the target power grid to the rated frequency through primary frequency regulation response to the frequency deviation. The first power change refers to the difference between the current power and the rated power of the target power grid. The electrolytic aluminum load is controlled to participate in the primary frequency regulation of the target power grid based on the power response and the first power change. During the primary frequency regulation process of the electrolytic aluminum load participating in the target power grid, the second power change in the response delay of the electrolytic aluminum load is determined using the seventh formula based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation. The seventh formula is: , This represents the second power change. The inertial response coefficient is... This is the primary frequency modulation coefficient. This represents the overall system delay coefficient. The frequency deviation is denoted as s, the Laplace operator is s, and the second power change refers to the difference between the current power and the rated power after optimizing the primary frequency modulation using virtual inertia. The active power deficit of the electrolytic aluminum load is reduced to the rated power based on the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

2. The power grid frequency stabilization control method based on virtual inertia according to claim 1, characterized in that, Before obtaining the current frequency of the target power grid, the following is also included: Obtain the current active power consumed on the DC side of the rectifier circuit of the electrolytic aluminum system; Determine the power deviation between the active power and the rated active power of the electrolytic aluminum load; The current deviation of the target power grid is obtained using a first formula based on the power deviation, wherein the first formula is: , This indicates the amount of current deviation. This represents the proportionality coefficient. Represents the time constant. This indicates the power deviation; The current deviation is processed by a proportional-integral controller to generate a control signal; The control signal is input to the power drive module based on pulse width modulation to trigger the pulse to adjust the firing angle of the thyristor in the rectifier circuit; The active power is controlled by utilizing the functional relationship between the active power and the firing angle.

3. The power grid frequency stabilization control method based on virtual inertia according to claim 2, characterized in that, Controlling the active power using the functional relationship between the active power and the firing angle includes: Establish a rectification equivalent model for the electrolytic cell in the aforementioned aluminum electrolysis system; The average DC-side output voltage of the rectifier circuit is obtained using the second formula based on the firing angle, wherein the second formula is: , The average value of the DC-side output voltage of the rectifier circuit. The input is the effective value of the line voltage of the rectifier circuit. The firing angle of the rectifier circuit; Based on the aforementioned rectifier equivalent model, the relationship between voltage and current in the rectifier circuit is established using the third formula, wherein the third formula is: , This represents the average DC-side output current of the rectifier circuit. Let s denote the back electromotive force, and s be the Laplace operator. The equivalent inductance is used to reflect the dynamic response process within the electrolytic cell. The equivalent resistance of the electrolytic cell; The fourth formula represents the functional relationship between the active power and the firing angle, and this functional relationship is used to control the active power. The fourth formula is: , This indicates the active power.

4. The power grid frequency stabilization control method based on virtual inertia according to claim 1, characterized in that, Determining the power response of a thermal power unit's primary frequency regulation based on the frequency deviation includes: The power response of the thermal power unit for primary frequency regulation is determined using the fifth formula based on the frequency deviation, wherein the fifth formula is: , This represents the power response quantity. Let be the inertial time constant of the thermal power unit. This refers to the speed controller gain coefficient of the electrolytic aluminum system. The frequency deviation is mentioned.

5. The power grid frequency stabilization control method based on virtual inertia according to claim 1, characterized in that, The first power change in the electrolytic aluminum load response delay is determined based on the frequency deviation, including: The first power change during the electrolytic aluminum load response delay is determined using the sixth formula based on the frequency deviation, wherein the sixth formula is: , This represents the first power change. This is the primary frequency modulation coefficient. This is the load response delay factor.

6. The power grid frequency stabilization control method based on virtual inertia according to claim 1, characterized in that, The electrolytic aluminum load participating in the primary frequency regulation of the target power grid also includes: The additional power is obtained using the eighth formula based on the frequency deviation, wherein the eighth formula is: , Let be the additional power, and s be the Laplace operator. The inertial response coefficient is... The frequency deviation; The additional power is used to provide inertia support power to the target power grid.

7. The power grid frequency stabilization control method based on virtual inertia according to claim 1, characterized in that, The active power deficit of the electrolytic aluminum load is reduced to the rated power based on the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range, including: Based on the power response and the second power change, a unified model based on the primary frequency modulation and inertial response is established using the ninth formula, wherein the ninth formula is: , Let be the system's inertial time constant. This is due to a deficiency in the system's active power. This is the equivalent damping coefficient. This is the equivalent frequency regulation coefficient for the load. The equivalent damping coefficient is used to account for the load inertia response; The active power deficit is reduced to the rated power according to the unified model in order to perform frequency stability control on the target power grid frequency.

8. A power grid frequency stabilization control device based on virtual inertia, characterized in that, include: The first determining unit is used to obtain the current frequency of the target power grid and determine the frequency deviation between the current frequency and the rated frequency of the target power grid, wherein the target power grid is a power grid that needs to be frequency stabilized. The second determining unit is used to determine the power response of the thermal power unit for primary frequency regulation and the first power change during the response delay of the electrolytic aluminum load based on the frequency deviation when the frequency deviation is greater than the frequency deviation threshold. The thermal power unit is the power generation equipment of the target power grid. The power response refers to the power value that increases or decreases when the thermal power unit restores the frequency of the target power grid to the rated frequency by responding to the frequency deviation through primary frequency regulation. The first power change refers to the difference between the current power and the rated power of the target power grid. The first control unit is used to control the electrolytic aluminum load to participate in the primary frequency regulation of the target power grid according to the power response and the first power change. The third determining unit is used to determine the second power change amount of the electrolytic aluminum load response delay during the primary frequency regulation process of the target power grid, based on the inertia response coefficient, the primary frequency regulation coefficient, the overall delay coefficient of the target power grid, and the frequency deviation, using a seventh formula, wherein the seventh formula is: , This represents the second power change. The inertial response coefficient is... This is the primary frequency modulation coefficient. This represents the overall system delay coefficient. The frequency deviation is denoted as s, the Laplace operator is s, and the second power change refers to the difference between the current power and the rated power after optimizing the primary frequency modulation using virtual inertia. The second control unit is used to reduce the active power deficit of the electrolytic aluminum load to the rated power according to the power response and the second power change, so as to control the frequency of the target power grid and keep the frequency of the target power grid within a predetermined range.

9. A processor, characterized in that, The processor is used to run a program, wherein the program executes the power grid frequency stabilization control method based on virtual inertia as described in any one of claims 1 to 7.

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