Flexible load rapid frequency modulation method and device

Abstract

The embodiments of the present disclosure provide a flexible load rapid frequency regulation method and device, which relates to the field of load frequency regulation technology. The method includes: obtaining a frequency signal; according to the frequency signal, enabling the DC / AC converter and the DC / DC converter to generate a load power command signal through an internal frequency-power control strategy; according to the load power command signal, forming a voltage command signal and / or a frequency command signal of the load port through a load sensitivity online identification method and a load control strategy; according to the voltage command signal and / or the frequency command signal of the load port, realizing load power regulation through a voltage and current double closed loop to adjust the voltage of the common DC bus; according to the change of the common DC bus voltage, enabling the AC / DC converter to adjust the grid frequency change through the bus voltage until the frequency is controlled within a safe range. In this way, the frequency regulation speed can be improved, a frequency regulation response speed of seconds can be achieved, and the frequency safety problem of the AC grid caused by insufficient inertia can be avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of load frequency regulation, and in particular to a method and device for rapid frequency regulation of a flexible load. Background Art

[0002] At present, with the continuous and rapid development of renewable energy power generation, the proportion of traditional synchronous generator power supplies in the power system will gradually decrease. A large number of new energy power generation equipment with no inertia and low inertia will be involved in the power system, resulting in a continuous decline in the rotational inertia of the power system, which reduces the power system's ability to resist disturbances and may threaten the safe operation of the power grid. It is urgent to explore new resources from multiple angles of source, network, load and storage to smooth out grid disturbances and frequency fluctuations.

[0003] In recent years, synchronous phase regulators have also been used to increase system inertia, which has had a certain effect on strengthening the frequency support of power systems. For small synchronous power grids with a high proportion of renewable energy, the effect of increasing system inertia by using phase regulators is more obvious. However, for large power grids, the frequency response effect is less obvious, and operation and maintenance are relatively complex. In the field of renewable energy power generation, virtual inertia methods based on inverter grid connection, namely virtual synchronous generator (VSG) technology, have been proposed both domestically and internationally. VSG technology has moved from the laboratory to small-scale industrial demonstration applications. VSG technology is applied to wind power generation, giving its units the characteristics of synchronous generators, thereby improving the frequency characteristics of the system. Combining VSG technology with photovoltaic power generation can effectively increase the inertia level of photovoltaic power generation systems, thereby improving the frequency characteristics of the system.

[0004] However, current technologies fail to consider the load side. Leveraging user resources to participate in grid regulation is an economically viable approach. Load participation in "source-load interaction" is a new operational model for the Energy Internet, significantly improving the frequency stability of renewable energy power systems. Power load demand management and flexible control are current research hotspots in academia and industry. Current technologies primarily focus on long-term regulation issues, such as load participation in peak shaving and valley filling and renewable energy consumption. Load frequency regulation primarily addresses medium-term secondary frequency regulation, resulting in poor controllability. Summary of the Invention

[0005] The present disclosure provides a method and device for rapid frequency regulation of a flexible load.

[0006] According to a first aspect of the present disclosure, a method for rapid frequency regulation of a flexible load is provided, comprising:

[0007] Obtain frequency signal;

[0008] According to the frequency signal, the DC / AC converter and the DC / DC converter generate a load power command signal through an internal frequency-power control strategy;

[0009] According to the load power command signal, a voltage command signal and / or a frequency command signal of the load port is formed by using a load sensitivity online identification method and a load control strategy;

[0010] According to the voltage command signal and / or frequency command signal of the load port, the load power is regulated through the voltage and current double closed loop to adjust the voltage of the common DC bus;

[0011] According to the change of the common DC bus voltage, the AC / DC converter adjusts the grid frequency change through the bus voltage until the frequency is controlled within a safe range.

[0012] In some implementations of the first aspect, causing the DC / AC converter and the DC / DC converter to generate a load power command signal using an internal frequency-power control strategy based on the frequency signal includes:

[0013] Calculate the corresponding angular frequency according to the frequency signal;

[0014] The calculated angular frequency is subtracted from the angular frequency corresponding to the system rated frequency to form an angular frequency difference;

[0015] Multiplying the angular frequency difference by the frequency adjustment coefficient yields the corresponding power change;

[0016] A load power command signal is generated according to the power variation.

[0017] In some implementations of the first aspect, generating a load power command signal according to the power variation includes:

[0018] The load power command signal is obtained by subtracting the active power sampling value of the AC side load from the sum of the power change and the rated active power of the AC side load.

[0019] In some implementations of the first aspect, the load sensitivity online identification method includes:

[0020] Record k Time and t k-1 The voltage, frequency and power values ​​at the moment;

[0021] And substitute into the formula and Calculate the parameter value K up and K fp , where K up K is the voltage-power sensitivity parameter in load sensitivity; fp It is the frequency-power sensitivity parameter in load sensitivity.

[0022] In some implementations of the first aspect, the method further includes:

[0023] According to the parameter value Kup and K fp , calculate the maximum allowable frequency deviation range and the adjustable load power within the voltage range.

[0024] In some implementations of the first aspect, forming a voltage command signal and / or a frequency command signal at a load port by using an online load sensitivity identification method and a load control strategy based on the load power command signal includes:

[0025] Calculate the maximum allowable frequency deviation range and the adjustable load power within the voltage range based on the load sensitivity parameters;

[0026] According to the adjustable load power, compare it with the load power command signal;

[0027] According to the comparison result, voltage regulation or frequency regulation is selected to realize load power change, and voltage command signal and frequency command signal are formed according to the voltage regulation or frequency regulation result.

[0028] In some implementations of the first aspect, forming a voltage command signal at a load port includes:

[0029] According to the load power command signal, the voltage or frequency adjustment value is formed through the load sensitivity online identification method and load control strategy;

[0030] The voltage command signal is formed by subtracting the voltage or frequency adjustment value from the rated voltage value.

[0031] In some implementations of the first aspect, adjusting the load power through a voltage-current dual closed loop according to a voltage command signal at a load port includes:

[0032] The voltage difference signal is generated by subtracting the dq axis voltage reference value of the AC side from the dq axis voltage sampling value of the AC side load;

[0033] According to the voltage difference signal, the inductor dq current reference value is output through the PI link;

[0034] The difference between the inductor dq current reference value and the inductor dq current sampling value is used to form a current difference signal;

[0035] According to the current difference signal, the actual output value of the dq axis voltage is output through the PI link;

[0036] According to the actual output value of the dq axis voltage, after 2r / 3s coordinate transformation, the ABC three-phase voltage output value is output;

[0037] According to the ABC three-phase voltage output value, the DC / AC converter is controlled through the PWM modulation module to adjust the AC side load power.

[0038] In some implementations of the first aspect, causing the AC / DC converter to adjust the grid frequency change through the bus voltage according to the change of the common DC bus voltage includes:

[0039] According to the frequency signal, the DC / AC converter and the DC / DC converter control the load power to change, so that the common DC bus power changes with the load power change, and the grid frequency changes with the common DC bus power change.

[0040] According to a second aspect of the present disclosure, a flexible load rapid frequency modulation device is provided, characterized in that it includes:

[0041] An acquisition module, used to obtain real-time frequency from the power grid;

[0042] The power calculation module is used to calculate the power regulation required by the difference between the grid frequency and the rated frequency according to the obtained grid frequency;

[0043] Load sensitivity online identification module, used to calculate the sensitivity parameters of the load;

[0044] The determination module is used to calculate the load voltage and frequency regulation to obtain the final voltage and frequency regulation plan.

[0045] This disclosure provides a method for rapid frequency regulation of flexible loads. This method fully utilizes load-side resources to rapidly fine-tune voltage and frequency across a load group. This allows loads to adjust in real time to changes in grid frequency without impacting normal power supply. This enables a source-load interactive operation mode, improves the controllability of the power system's source side, and effectively mitigates frequency disturbances. Compared to existing technologies, the proposed method offers rapid frequency regulation, achieving a sub-second frequency response speed. This method avoids AC grid frequency security issues caused by insufficient inertia, providing frequency security assurance for the large-scale grid integration of renewable energy sources.

[0046] It should be understood that the contents described in the Summary of the Invention section are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for a better understanding of the present disclosure and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0048] Figure 1 A flowchart of a method for rapid frequency modulation of a flexible load provided in an embodiment of the present disclosure;

[0049] Figure 2 Flowchart of the internal frequency-power control strategy of the DC / AC converter and DC / DC converter;

[0050] Figure 3 This is a flow chart of the load sensitivity online identification method;

[0051] Figure 4 This is a functional structure diagram of the flexible load control device;

[0052] Figure 5 This is a frequency change diagram of an embodiment of the present disclosure;

[0053] Figure 6 This is a voltage change diagram of an embodiment of the present disclosure;

[0054] Figure 7 This is a power variation diagram of an embodiment of the present disclosure;

[0055] Figure 8 A schematic structural diagram of a flexible load rapid frequency modulation device provided in an embodiment of the present disclosure;

[0056] Figure 9 A schematic diagram of a terminal provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0058] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0059] In the present disclosure, a method for rapid frequency regulation of flexible loads is provided, which can make full use of the resources on the load side, implement rapid fine-tuning of the voltage and frequency of the load group, and adjust the load in real time according to the changes in the grid frequency without affecting the normal power supply, thereby realizing a source-load interactive operation mode, improving the controllability of the source side of the power system, and effectively smoothing out frequency disturbances.

[0060] Figure 1 A flowchart of a method for rapid frequency modulation of a flexible load provided in an embodiment of the present disclosure.

[0061] like Figure 1 As shown in FIG, the flexible load rapid frequency regulation method includes:

[0062] S101: Acquire frequency signal.

[0063] S102: Based on the frequency signal, the DC / AC converter and the DC / DC converter generate a load power command signal through an internal frequency-power control strategy.

[0064] Figure 2 The figure is a flow chart of the internal frequency-power control strategy of the DC / AC converter and the DC / DC converter.

[0065] like Figure 2 As shown, in S102, according to the frequency signal, the DC / AC converter and the DC / DC converter generate a load power command signal through an internal frequency-power control strategy, including:

[0066] S201: Calculate the corresponding angular frequency according to the frequency signal;

[0067] S202: Subtracting the calculated angular frequency from the angular frequency corresponding to the system rated frequency to form an angular frequency difference;

[0068] S203: Multiplying the angular frequency difference by the frequency adjustment coefficient to obtain a corresponding power change;

[0069] S204: Generate a load power command signal according to the power change.

[0070] According to the embodiments of the present disclosure, information such as frequency and period can be easily obtained from the frequency signal, thereby easily calculating the angular frequency. Therefore, calculating the power variation based on the angular frequency difference is simple, accurate, and the generated load power command signal is highly reliable.

[0071] In some embodiments, generating a load power command signal according to the power variation includes:

[0072] The load power command signal is obtained by subtracting the active power sampling value of the AC side load from the sum of the power change and the rated active power of the AC side load.

[0073] According to the embodiments of the present disclosure, a load power command signal is obtained according to a simple addition and subtraction algorithm, and the calculation method is simple and highly accurate.

[0074] S103: Based on the load power command signal, a voltage command signal and / or a frequency command signal of the load port is formed through a load sensitivity online identification method and a load control strategy.

[0075] In S103, the load sensitivity online identification method includes:

[0076] Record k Time and t k-1 The voltage, frequency and power values ​​at the moment;

[0077] And substitute into the formula and Calculate the parameter value K up and K fp , where K up K is the voltage-power sensitivity parameter in load sensitivity; fp It is the frequency-power sensitivity parameter in load sensitivity.

[0078] Figure 3 This is the flow chart of the load sensitivity online identification method.

[0079] like Figure 3 As shown, if load identification is performed, the voltage, frequency, and load power at time t0 are recorded, and k = 1;

[0080] Let t k =t k-1 +△k;

[0081] Record k-1 , t k Substitute the time data into the formula to calculate t k-1 -t k Voltage and frequency characteristic coefficients of the segment;

[0082] If the disturbance ends, the load identification is completed. If the disturbance does not end, set k = k + 1 and recalculate t k , until the disturbance ends.

[0083] According to an embodiment of the present disclosure, since the parameter value K up and K fp It is related to voltage, frequency and power, so the parameter value K at two adjacent moments is up and K fp As a frequency-power sensitivity parameter, we can have a clear understanding of load sensitivity.

[0084] In some embodiments, the method further comprises:

[0085] According to the parameter value K up and K fp , calculate the maximum allowable frequency deviation range and the adjustable load power within the voltage range.

[0086] According to an embodiment of the present disclosure, since the parameter value K up and K fpIt is related to voltage, frequency and power. Therefore, the maximum allowable frequency deviation range and the adjustable load power within the voltage range are calculated based on these two parameter values, which are in line with the actual voltage and frequency conditions.

[0087] In S103, based on the load power command signal, a voltage command signal and / or a frequency command signal of the load port is formed by using a load sensitivity online identification method and a load control strategy, including:

[0088] Calculate the maximum allowable frequency deviation range and the adjustable load power within the voltage range based on the load sensitivity parameters;

[0089] According to the adjustable load power, compare it with the load power command signal;

[0090] According to the comparison result, voltage regulation or frequency regulation is selected to realize load power change, and voltage command signal and frequency command signal are formed according to the voltage regulation or frequency regulation result.

[0091] According to the embodiments of the present disclosure, by regulating the voltage or frequency of the load power, the voltage of the common DC bus can be transformed relatively easily and safely, facilitating subsequent adjustment of the bus voltage to adjust the grid frequency change, thereby forming a closed loop until the frequency is controlled within the specified range.

[0092] In S103, forming a voltage command signal for the load port includes:

[0093] According to the load power command signal, the voltage or frequency adjustment value is formed through the load sensitivity online identification method and load control strategy;

[0094] The voltage command signal is formed by subtracting the voltage or frequency adjustment value from the rated voltage value.

[0095] According to the disclosed embodiments, the load port has voltage and frequency conversion capabilities, enabling it to adjust its output based on the power grid frequency regulation requirements for load group power increases or decreases. The voltage or frequency adjustment value is subtracted from the rated voltage value to form a voltage command signal, facilitating subsequent regulation of the common DC bus voltage.

[0096] S104: According to the voltage command signal and / or frequency command signal of the load port, load power is regulated through a voltage-current dual closed loop to adjust the voltage of the common DC bus.

[0097] In S104, according to the voltage command signal of the load port, load power is regulated through the voltage and current double closed loop, including:

[0098] The voltage difference signal is generated by subtracting the dq axis voltage reference value of the AC side from the dq axis voltage sampling value of the AC side load;

[0099] According to the voltage difference signal, the inductor dq current reference value is output through the PI link;

[0100] The difference between the inductor dq current reference value and the inductor dq current sampling value is used to form a current difference signal;

[0101] According to the current difference signal, the actual output value of the dq axis voltage is output through the PI link;

[0102] According to the actual output value of the dq axis voltage, after 2r / 3s coordinate transformation, the ABC three-phase voltage output value is output;

[0103] According to the ABC three-phase voltage output value, the DC / AC converter is controlled through the PWM modulation module to adjust the AC side load power.

[0104] Specifically, in this control scheme, the voltage outer loop takes the difference between the given voltage and the feedback voltage and sends it to the PI regulator, which generates the reference value for the inner loop current control. The voltage reference value generated by the inner loop is used to perform PWM modulation through coordinate transformation to generate the switch tube control signal to adjust the port voltage and frequency. The values ​​of the closed loop are all values ​​in the dq coordinate system, and the dq axis values ​​are converted through the three-phase signal sampling values, that is, the conversion from the three-phase stationary coordinate to the two-phase rotating coordinate (3s / 2r). Generally, the three-phase stationary coordinate is converted to the two-phase stationary coordinate system αβ coordinate system, and then the two-phase stationary coordinate is converted to the two-phase rotating coordinate system dq coordinate system. Its conversion matrix is ​​as follows: Where θ is the distance between the d-axis and α The angle between the axes.

[0105] According to the embodiments of the present disclosure, a double closed loop is performed based on the voltage difference signal, the current difference signal, etc., so that the voltage of the common DC bus is transformed; it is convenient for the AC / DC converter to adjust the grid frequency change through the bus voltage, thereby forming a closed loop to control the frequency.

[0106] S105: According to the change of the common DC bus voltage, the AC / DC converter adjusts the grid frequency change through the bus voltage until the frequency is controlled within a safe range.

[0107] In S105, according to the change of the common DC bus voltage, causing the AC / DC converter to adjust the grid frequency change through the bus voltage includes:

[0108] According to the frequency signal, the DC / AC converter and the DC / DC converter control the load power to change, so that the common DC bus power changes with the load power change, and the grid frequency changes with the common DC bus power change.

[0109] According to an embodiment of the present disclosure, according to the change of the common DC bus voltage, the DC / AC converter and the AC / DC converter adjust the grid frequency change through the bus voltage, thereby forming a closed loop to achieve frequency regulation within a safe range.

[0110] Figure 4 This is the functional structure diagram of the flexible load control device.

[0111] like Figure 4 As shown, in a specific embodiment, for the system simulation model built by the present disclosure, the reference power is 100kW, the load power per unit value is 0.625pu, the maximum load frequency adjustment range is ±0.2Hz, and the voltage adjustment range is ±0.05pu. The voltage-power sensitivity of the load sensitivity obtained by the load sensitivity online identification method is 1.95, and the frequency-power sensitivity is -0.25. The initial steady-state voltage per unit value of the load is 1, and the frequency is 50Hz. Then, within the maximum frequency adjustment range (±0.2Hz) and the voltage adjustment range (±0.05pu), the corresponding adjustable load range accounts for 6.2% of the total load. Compared with considering only voltage adjustment, the 6.1% adjustment range can be achieved, which increases the adjustable capacity by 0.1%. When the grid frequency changes, the load power command signal is generated by the internal frequency-power control strategy to calculate the active power demand as -0.05pu.

[0112] Figure 5 This is a frequency change diagram of an embodiment of the present disclosure.

[0113] Figure 6 2 is a voltage change diagram of an embodiment of the present disclosure.

[0114] Figure 7 This is a power variation diagram of an embodiment of the present disclosure.

[0115] The AC voltage, frequency waveform and load active power tracking situation on the load side are as follows: Figure 5 shown.

[0116] like Figure 5 As shown in the figure: A small frequency perturbation is added at 1.5 seconds and lasts for 1 second. The frequency-power sensitivity can be calculated from this perturbation. The actual frequency adjustment is done in 6-8 seconds.

[0117] like Figure 6 As shown in the figure: A small voltage perturbation is added at 3 seconds and lasts for 2 seconds. The voltage-power sensitivity can be calculated from this perturbation. The actual voltage regulation is measured in 6-8 seconds.

[0118] like Figure 7 As shown: 1.5-2.5 seconds is the power change when frequency disturbance is applied, 3-5 seconds is the power change when voltage disturbance is applied, and 6-8 seconds is the power change during actual regulation.

[0119] In summary, the disclosed method for rapid frequency regulation of flexible loads utilizes the relationship between load power and frequency, i.e., reducing load power as grid frequency decreases and increasing load power as grid frequency increases, to obtain a frequency signal from the system. Based on the feedback frequency signal, the DC / AC converter and the DC / DC converter control the load port voltage and frequency using their internal control strategies. Load power is regulated based on the load port voltage and frequency, thereby varying the voltage of the common DC bus. Based on changes in the common DC bus voltage, the AC / DC converter adjusts the grid frequency via the bus voltage, thus forming a closed loop until the frequency is controlled within a specified range. The disclosed multi-port flexible load rapid frequency regulation control device, based on power electronics technology, includes a grid-connected port for connecting to the grid, capable of responding to grid frequency according to specific response characteristics and rapidly implementing power regulation. The device also includes multiple AC and DC load ports for connecting to flexible load groups. The load ports have voltage and frequency conversion capabilities, capable of changing their output based on the grid frequency regulation requirements for increasing or decreasing load group power. This device can fully utilize flexible load resources and improve frequency security issues caused by insufficient inertia in new power systems.

[0120] It should be noted that for the aforementioned method embodiments, for simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present disclosure is not limited by the order of the actions described, because according to the present disclosure, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present disclosure.

[0121] The above is an introduction to the method embodiment. The following is a further explanation of the solution disclosed in the present disclosure through an apparatus embodiment.

[0122] Figure 8 A schematic structural diagram of a flexible load rapid frequency modulation device provided in an embodiment of the present disclosure.

[0123] like Figure 8 As shown, the flexible load rapid frequency regulation device includes:

[0124] An acquisition module 801 is used to obtain real-time frequency from the power grid;

[0125] The power calculation module 802 is used to calculate the power regulation required by the difference between the obtained grid frequency and the rated frequency;

[0126] The load sensitivity online identification module 803 is used to calculate the sensitivity parameters of the load;

[0127] The determination module 804 is used to calculate the load voltage and frequency regulation to obtain the final voltage and frequency regulation scheme.

[0128] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0129] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0130] Figure 9 Schematic diagram of a terminal provided by an embodiment of the present disclosure. Figure 9 As shown, the terminal 9 of this embodiment includes: a processor 90, a memory 91, and a computer program 92 stored in the memory 91 and executable on the processor 90. When the processor 90 executes the computer program 92, the steps of the above-mentioned various digital twin operation-driven distribution network planning method embodiments are implemented, such as Figure 1 Steps 101 to 105 are shown. When the processor 90 executes the computer program 92, the functions of the modules / units in the above-mentioned device embodiments are realized, for example Figure 8 Functionality of modules / units 801 to 804 shown.

[0131] Exemplarily, the computer program 92 may be divided into one or more modules / units, which are stored in the memory 91 and executed by the processor 90 to implement the present disclosure. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 92 in the terminal 9. For example, the computer program 92 may be divided into Figure 8 Modules / units 801 to 804 are shown.

[0132] The terminal 9 can be a computing device such as a desktop computer, a notebook, a palmtop computer, a cloud server, etc. The terminal 9 can include, but is not limited to, a processor 90 and a memory 91. It can be understood by those skilled in the art that Figure 9 It is only an example of terminal 9 and does not constitute a limitation on terminal 9. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0133] The processor 90 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0134] The memory 91 can be an internal storage unit of the terminal 9, such as a hard disk or memory of the terminal 9. The memory 91 can also be an external storage device of the terminal 9, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 9. Furthermore, the memory 91 can also include both the internal storage unit of the terminal 9 and an external storage device. The memory 91 is used to store the computer program and other programs and data required by the terminal. The memory 91 can also be used to temporarily store data that has been output or is about to be output.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0136] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0137] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0138] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0139] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0140] In addition, the functional units in the various embodiments of the present disclosure may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0141] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present disclosure implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned digital twin operation-driven distribution network planning method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0142] The embodiments described above are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure, and should all be included in the scope of protection of the present disclosure.

Claims

1. A flexible load rapid frequency modulation method, characterized in that: include: Obtain frequency signal; According to the frequency signal, the DC / AC converter and the DC / DC converter generate a load power command signal through an internal frequency-power control strategy; According to the load power command signal, a voltage command signal and / or a frequency command signal of the load port is formed by an online load sensitivity identification method and a load control strategy; wherein the online load sensitivity identification method includes: Record k Time and t k-1 The voltage, frequency and power values ​​at the moment; And substitute into the formula and Calculate the parameter value K up and K fp , where K up K is the voltage-power sensitivity parameter in load sensitivity; fp It is the frequency-power sensitivity parameter in load sensitivity; According to the voltage command signal and / or frequency command signal of the load port, load power is regulated through a voltage-current dual closed loop to adjust the voltage of the common DC bus; wherein, according to the voltage command signal of the load port, load power is regulated through a voltage-current dual closed loop, including: The voltage difference signal is generated by subtracting the dq axis voltage reference value of the AC side from the dq axis voltage sampling value of the AC side load; According to the voltage difference signal, the inductor dq current reference value is output through the PI link; The inductor dq current reference value and the inductor dq current sampling value are subtracted to form a current difference signal; According to the current difference signal, the actual output value of the dq axis voltage is output through the PI link; According to the actual output value of the dq axis voltage, after 2r / 3s coordinate transformation, the ABC three-phase voltage output value is output; According to the ABC three-phase voltage output value, the DC / AC converter is controlled through the PWM modulation module to adjust the AC side load power; According to the change of the common DC bus voltage, the AC / DC converter adjusts the grid frequency change through the bus voltage until the frequency is controlled within a safe range.

2. The method according to claim 1, characterized in that The step of causing the DC / AC converter and the DC / DC converter to generate a load power command signal through an internal frequency-power control strategy according to the frequency signal includes: Calculate the corresponding angular frequency according to the frequency signal; The calculated angular frequency is subtracted from the angular frequency corresponding to the system rated frequency to form an angular frequency difference; Multiplying the angular frequency difference by the frequency adjustment coefficient to obtain a corresponding power change; A load power command signal is generated according to the power variation.

3. The method according to claim 2, characterized in that Generating a load power command signal according to the power variation includes: The load power command signal is obtained by subtracting the active power sampling value of the AC side load from the sum of the power change and the rated active power of the AC side load.

4. The method according to claim 1, wherein The method further comprises: According to the parameter value K up and K fp , calculate the maximum allowable frequency deviation range and the adjustable load power within the voltage range.

5. The method according to claim 4, characterized in that According to the load power command signal, a voltage command signal and / or a frequency command signal of a load port is formed by using a load sensitivity online identification method and a load control strategy, including: Calculate the maximum allowable frequency deviation range and adjustable load power within the voltage range based on the load sensitivity parameters; According to the adjustable load power, compare it with the load power command signal; According to the comparison result, voltage regulation or frequency regulation is selected to realize load power change, and voltage command signal and frequency command signal are formed according to the voltage regulation or frequency regulation result.

6. The method according to claim 1, characterized in that The voltage command signal forming the load port includes: According to the load power command signal, the voltage or frequency adjustment value is formed through the load sensitivity online identification method and load control strategy; The voltage or frequency adjustment value is subtracted from the rated voltage value to form a voltage command signal.

7. The method according to claim 1, characterized in that The step of causing the AC / DC converter to adjust the grid frequency change by using the bus voltage according to the change of the common DC bus voltage includes: According to the frequency signal, the DC / AC converter and the DC / DC converter control the load power to change, so that the common DC bus power changes with the load power change, and the grid frequency changes with the common DC bus power change.

8. A flexible load rapid frequency modulation device for realizing the flexible load rapid frequency modulation according to any one of claims 1 to 7, characterized in that: include: An acquisition module, used to obtain real-time frequency from the power grid; The power calculation module is used to calculate the power regulation required by the difference between the grid frequency and the rated frequency according to the obtained grid frequency; Load sensitivity online identification module, used to calculate the sensitivity parameters of the load; The determination module is used to calculate the load voltage and frequency regulation to obtain the final voltage and frequency regulation plan.

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