Power control method and apparatus, electronic device, and readable storage medium

Abstract

The embodiment of the application provides a power control method, device, electronic equipment and readable storage medium, and relates to the technical field of converter control. The embodiment of the application constructs a first preset power relationship through electromagnetic power and mechanical power of a virtual synchronous generator, constructs a second preset power relationship through armature impedance and inductance of the virtual synchronous generator, obtains mechanical power of the virtual synchronous generator according to the first preset power relationship and a power scheduling instruction after the power scheduling instruction is obtained, obtains excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, and then controls power entering a power grid according to the mechanical power and the excitation voltage. In this way, deviation caused by directly inputting a power instruction is avoided, and the accuracy of power control is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter control, in particular to a power control method and device, electronic equipment and readable storage medium. BACKGROUND

[0002] In recent years, in order to solve the problem of small damping, poor anti-interference ability and poor anti-fluctuation ability in the power grid, the application of energy storage devices in the power grid is more and more widely. As a direct current system, the battery and other energy storage devices must use the converter when they are integrated into the alternating current power grid.

[0003] The control of the traditional converter is executed according to the power instruction, and it cannot suppress the fluctuation of the power grid in an instant. Therefore, the virtual synchronous generator control becomes a new control strategy, which simulates the mechanical inertia of the traditional generator by using the storage capacity of the battery, strengthens the damping of the power grid, and improves the power quality.

[0004] At present, when the converter uses the virtual synchronous generator to control the power entering the power grid, if the armature resistance of the virtual synchronous generator is large, a large amount of electromagnetic power will be consumed. At this time, if the power instruction is directly used as the input power of the virtual synchronous generator, the output power of the virtual synchronous generator will deviate greatly from the power instruction, thereby generating a large control deviation. SUMMARY

[0005] Based on the above research, the present application provides a power control method, device, electronic equipment and readable storage medium to reduce the deviation caused by directly inputting the power instruction.

[0006] Embodiments of the present application can be implemented in the following way:

[0007] In a first aspect, the present application provides a power control method, which comprises:

[0008] obtaining a power scheduling instruction;

[0009] obtaining the mechanical power of the virtual synchronous generator according to a first preset power relationship and the power scheduling instruction, wherein the first preset power relationship is constructed according to the electromagnetic power and the mechanical power of the virtual synchronous generator;

[0010] obtaining the excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction, wherein the second preset power relationship is constructed according to the armature impedance and the inductive reactance of the virtual synchronous generator;

[0011] controlling the power entering the power grid according to the mechanical power and the excitation voltage.

[0012] In an optional implementation, before the step of obtaining the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, the method further comprises:

[0013] establishing a synchronous rotating coordinate system based on a direct axis and a quadrature axis, and constructing a power relationship of the power grid in the synchronous rotating coordinate system;

[0014] obtaining a correlation relationship between a power angle, an excitation voltage of the virtual synchronous generator and a current entering the power grid according to an armature impedance and a reactance of the virtual synchronous generator;

[0015] obtaining a second preset power relationship according to the correlation relationship and the power relationship of the power grid.

[0016] In an optional implementation, the step of constructing the power relationship of the power grid in the synchronous rotating coordinate system comprises:

[0017] constructing the power relationship of the power grid according to a direct axis current, a direct axis voltage, a quadrature axis current and a quadrature axis voltage of the power grid in the synchronous rotating coordinate system based on symmetry of three-phase voltage and three-phase current, wherein the power relationship of the power grid comprises an active power relationship and a reactive power relationship of the power grid;

[0018] the power relationship of the power grid:

[0019]

[0020] wherein, P is an active power; Q is a reactive power; V d is a direct axis voltage; I d is a direct axis current; V q is a quadrature axis voltage; I q is a quadrature axis current; V0 is a zero axis voltage; I0 is a zero axis current; V g is a power grid voltage.

[0021] In an optional implementation, the step of obtaining the correlation relationship between the power angle, the excitation voltage of the virtual synchronous generator and the current entering the power grid according to the armature impedance and the reactance of the virtual synchronous generator comprises:

[0022] obtaining the correlation relationship between the power angle, the excitation voltage of the virtual synchronous generator and the current entering the power grid according to the armature impedance and the reactance of the virtual synchronous generator through the following formula:

[0023]

[0024] wherein, E fis an excitation voltage of the virtual synchronous generator; δ is a power angle of the virtual synchronous generator; X is an inductive reactance of the virtual synchronous generator; and R is a resistance of the virtual synchronous generator.

[0025] In an optional embodiment, the step of obtaining a second preset power relationship according to the correlation relationship and a power relationship of the power grid comprises:

[0026] The second preset power relationship is obtained according to the correlation relationship and a power relationship of the power grid by the following formula:

[0027]

[0028] wherein, P g is active power entering the power grid; and Q g is reactive power entering the power grid.

[0029] In an optional embodiment, the step of obtaining an excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power dispatching instruction comprises:

[0030] A power relationship diagram of the virtual synchronous generator is constructed according to the second preset power relationship, and a first center of the power relationship diagram is determined;

[0031] A first distance between the first center and the power dispatching instruction is calculated based on the power relationship diagram;

[0032] The excitation voltage of the virtual synchronous generator is calculated according to the first distance.

[0033] In an optional embodiment, the step of calculating the first distance between the first center and the power dispatching instruction based on the power relationship diagram comprises:

[0034] The first distance between the first center and the power dispatching instruction is calculated based on the power relationship diagram by the following formula:

[0035]

[0036] The step of calculating the excitation voltage of the virtual synchronous generator according to the first distance comprises:

[0037] The excitation voltage of the virtual synchronous generator is calculated according to the first distance by the following formula:

[0038]

[0039] wherein, r is the first distance; P ref is active power in the power dispatching instruction; and Qref is the reactive power in the power scheduling instruction;E f is the excitation voltage of the virtual synchronous generator; X is the inductance of the virtual synchronous generator, and R is the resistance of the virtual synchronous generator;V g is the grid voltage.

[0040] In an optional embodiment, before the mechanical power of the virtual synchronous generator is obtained according to the first preset power relationship and the power scheduling instruction, the method further comprises:

[0041] According to the electromagnetic power and the mechanical power of the virtual synchronous generator, the first preset power relationship is obtained based on the steady state of the grid by the following formula:

[0042]

[0043] wherein, P ref is the active power in the power scheduling instruction; Q ref is the reactive power in the power scheduling instruction; P m is the mechanical power of the virtual synchronous generator; P e is the electromagnetic power of the virtual synchronous generator; I d is the direct-axis current; I q is the quadrature-axis current; V g is the grid voltage; X is the inductance of the virtual synchronous generator, and R is the resistance of the virtual synchronous generator.

[0044] In an optional embodiment, after the excitation voltage of the virtual synchronous generator is obtained, the method further comprises:

[0045] According to the second preset power relationship, a power relationship diagram of the virtual synchronous generator is constructed, and a first center of the power relationship diagram is determined;

[0046] According to the maximum power output when the converter is connected to the grid and the reactive power of the grid, an effective power range in the power relationship diagram is determined, and a second center, a first tangent point and a second tangent point of the effective power range are determined;

[0047] A second distance between the first center and the second center, a third distance between the first center and the first tangent point, and a fourth distance between the first center and the second tangent point are calculated;

[0048] According to the second distance, the third distance and the fourth distance, a power angle range of the virtual synchronous generator is calculated.

[0049] In a second aspect, an embodiment of the present application provides a power control device, comprising:

[0050] an instruction obtaining module, configured to obtain a power scheduling instruction;

[0051] a parameter analyzing module, configured to obtain mechanical power of the virtual synchronous generator according to a first preset power relationship and the power scheduling instruction, wherein the first preset power relationship is constructed according to electromagnetic power and mechanical power of the virtual synchronous generator;

[0052] the parameter analyzing module, configured to obtain excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction, wherein the second preset power relationship is constructed according to armature impedance and reactance of the virtual synchronous generator;

[0053] a control module, configured to control power entering a power grid according to the mechanical power and the excitation voltage.

[0054] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor implements the power control method of any of the preceding embodiments when executing the program.

[0055] In a fourth aspect, a readable storage medium is provided, which includes a computer program, and the computer program controls an electronic device in which the readable storage medium is located to execute the power control method of any of the preceding embodiments when running.

[0056] The power control method, device, electronic device, and readable storage medium provided by the embodiments of the present application can construct a first preset power relationship according to electromagnetic power and mechanical power of a virtual synchronous generator, construct a second preset power relationship according to armature impedance and reactance of the virtual synchronous generator, obtain mechanical power of the virtual synchronous generator according to the first preset power relationship and a power scheduling instruction after obtaining the power scheduling instruction, obtain excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, and then control power entering a power grid according to the mechanical power and the excitation voltage, so that deviation caused by directly inputting a power instruction is avoided, and the accuracy of power control is improved. BRIEF DESCRIPTION OF DRAWINGS

[0057] The technical solutions and other beneficial effects of the present application will become apparent after a specific embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0058] Figure 1 A structural schematic diagram of an electronic device provided by the embodiments of the present application.

[0059] Figure 2A flowchart of the power control method provided by the embodiment of the present application.

[0060] Figure 3 An equivalent circuit diagram of the virtual synchronous generator and the power grid provided by the embodiment of the present application.

[0061] Figure 4 A power relationship diagram provided by the embodiment of the present application.

[0062] Figure 5 Another power relationship diagram provided by the embodiment of the present application.

[0063] Figure 6 A wiring diagram of the energy storage and off-grid system provided by the embodiment of the present application.

[0064] Figure 7 A control flowchart of the virtual synchronous generator provided by the embodiment of the present application.

[0065] Figure 8 An outer loop control flowchart of the converter provided by the embodiment of the present application.

[0066] Figure 9 A voltage and current waveform diagram when R is 2.5Ω provided by the embodiment of the present application.

[0067] Figure 10 A voltage and current waveform diagram when R is 5Ω provided by the embodiment of the present application.

[0068] Figure 11 A power change diagram provided by the embodiment of the present application.

[0069] Figure 12 A block diagram of the power control device provided by the embodiment of the present application.

[0070] The reference signs: 100-electronic device; 10-power control device; 11-instruction obtaining module; 12-parameter analyzing module; 13-control module; 14-relationship constructing module; 20-memory; 30-processor; 40-communication unit. DETAILED DESCRIPTION

[0071] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the person skilled in the art without creative labor are within the protection scope of the present application.

[0072] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0073] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0075] The disclosure below provides many different embodiments or examples for implementing various aspects of the present application. Throughout the disclosure, specific examples of components and arrangements are described. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application can be applied to different examples without departing from the scope of the present application. Furthermore, the present application provides various examples of specific processes and materials. However, those skilled in the art can realize that other processes can be applied and / or other materials can be used.

[0076] With the increasing environmental pressure and the transformation of energy structure, the proportion of new generation of new energy power generation devices represented by photovoltaic and wind turbines in the power system is increasing. Unlike traditional power generation devices, new energy power generation devices are more distributed and have small inertia, which leads to smaller damping of the entire power grid, poor anti-interference ability and poor anti-fluctuation.

[0077] In recent years, to solve the above-mentioned problems, energy storage devices are increasingly widely used in power grids. Among them, electrochemical energy storage has good charge and discharge performance, rapid regulation, and smooth output, and is currently the most outstanding. As a direct current system, batteries and other energy storage devices must be connected to the alternating current power grid, and thus must use a converter. As a control system, the converter plays a key role in maximizing the use of batteries and ensuring the safety of the power grid.

[0078] The control of traditional converters is performed according to power instructions, and cannot suppress fluctuations that occur instantaneously in the power grid. Therefore, virtual synchronous generator control has become a new control strategy, which uses the storage capacity of batteries to simulate the mechanical inertia of traditional generators, strengthens the damping of the power grid, and improves the power quality. Microgrids are power systems that promote the local consumption of distributed energy sources. They do not have mechanical power generation devices and therefore do not have inertia. They must rely on virtual synchronous generators to provide grid inertia, and this control strategy has become the main control method for new energy generation.

[0079] A synchronous generator is a voltage source system, while an energy storage converter is a current source control when connected to the grid. As long as it is within the frequency dead zone, the energy storage only needs to accept power scheduling and output power according to the instructions. When off-grid, it is a voltage source control and needs to output stable voltage and frequency. When switching between on-grid and off-grid, especially unplanned off-grid, it needs to support the power grid to ensure smooth transition of the microgrid. Its power control mechanism and control strategy are more complex than those of traditional generators.

[0080] For grid-connected and off-grid, some virtual synchronous generator control uses different control methods, if you need to switch, you can only stop and restart, not to intelligent conversion, smooth transition requirements. Some virtual synchronous generator control uses a combination of voltage source, current source control method, can make the same control strategy in three working conditions can achieve the control requirements, but must be based on the virtual synchronous generator armature resistance is 0 or very small premise.

[0081] And in solving the problem of current oscillation, increasing the system damping is an effective method, in the current control of inverter, virtual resistance has the function of inhibiting current oscillation, accordingly, the armature resistance of virtual synchronous generator can also play this role. Energy storage converter in the process of grid-connected and off-grid switching, easy to produce current oscillation, increase the virtual armature resistance can produce obvious inhibitory effect.

[0082] At present, if the armature resistance is large when the converter uses virtual synchronous generator to control the power entering the grid, more electromagnetic power will be consumed, at this time, if the power instruction is directly used as the input power of the virtual synchronous generator, that is, the mechanical power of the virtual generator, the output power of the virtual synchronous generator will deviate greatly from the power instruction, resulting in a large deviation between the power entering the grid and the power instruction.

[0083] Based on the above research, the embodiment provides a power control method, device, electronic equipment and readable storage medium, a first preset power relationship is constructed through the electromagnetic power and mechanical power of the virtual synchronous generator, a second preset power relationship is constructed through the armature impedance and inductance of the virtual synchronous generator, after obtaining the power scheduling instruction, the mechanical power of the virtual synchronous generator is obtained according to the first preset power relationship and the power scheduling instruction, the excitation voltage of the virtual synchronous generator is obtained according to the second preset power relationship and the power scheduling instruction, and then the power entering the grid is controlled according to the mechanical power and the excitation voltage, so that the deviation caused by directly inputting the power instruction is avoided, and the accuracy of power control is improved.

[0084] Please refer to Figure 1 , Figure 1 A structural schematic diagram of the electronic equipment provided in the embodiment. The electronic equipment can include a power control device 10, a memory 20, a processor 30 and a communication unit 40, the memory 20 stores machine readable instructions executable by the processor 30, when the electronic equipment 100 runs, the processor 30 and the memory 20 communicate through the bus, the processor 30 executes the machine readable instructions, and performs the power control method.

[0085] The memory 20, the processor 30, and the communication unit 40 are electrically connected to each other directly or indirectly to realize the transmission or interaction of signals. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The power control device 10 includes at least one software function module stored in the memory 20 in the form of software or firmware. The processor 30 is configured to execute the executable modules (for example, the software function modules or computer programs included in the power control device 10) stored in the memory 20.

[0086] The memory 20 can be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0087] In some embodiments, the processor 30 is configured to execute one or more functions described in the embodiments. In some embodiments, the processor 30 can include one or more processing cores (for example, a single-core processor (S) or a multi-core processor (S)).

[0088] By way of example only, the processor 30 can include a central processing unit (CPU), an application specific integrated circuit (ASIC), an application specific instruction-set processor (ASIP), a graphics processing unit (GPU), a physics processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), or a microprocessor, or any combination thereof.

[0089] For ease of illustration, only one processor is described in the electronic device 100. However, it should be noted that the electronic device 100 in the present embodiment can also include multiple processors, and thus the steps performed by one processor described in the present embodiment can also be jointly performed by multiple processors or individually performed by multiple processors. For example, if a processor of a server performs steps A and B, it should be understood that steps A and B can also be jointly performed by two different processors or individually performed in one processor. For example, a processor performs step A, a second processor performs step B, or the processor and the second processor jointly perform steps A and B.

[0090] In the present embodiment, the memory 20 is configured to store a program, and the processor 30 is configured to execute the program after receiving an execution instruction. The method defined by the flow disclosed in any of the embodiments of the present embodiment can be applied in the processor 30 or implemented by the processor 30.

[0091] The communication unit 40 is configured to establish a communication connection between the electronic device 100 and other devices through a network, and configured to transceive data through the network.

[0092] In some embodiments, the network can be any type of wired or wireless network, or a combination thereof. By way of example only, the network can include a wired network, a wireless network, a fiber optic network, a telecommunications network, an intranet, the Internet, a Local Area Network (LAN), a Wide Area Network (WAN), a Wireless Local Area Network (WLAN), a Metropolitan Area Network (MAN), a Wide Area Network (WAN), a Public Switched Telephone Network (PSTN), a Bluetooth network, a ZigBee network, or a Near Field Communication (NFC) network, among others, or any combination thereof.

[0093] In the present embodiment, the electronic device 100 can be any device capable of processing and analyzing data. Optionally, in the present embodiment, the electronic device 100 is a converter control device.

[0094] It can be understood that, Figure 1 The structure shown is merely schematic. The electronic device 100 can also have more or fewer components than Figure 1 shown, or have a different configuration than Figure 1 shown. Figure 1 Each component shown can be implemented in hardware, software, or a combination thereof.

[0095] Based on the implementation architecture, Figure 1 the present embodiment provides a power control method, which is executed by the electronic device Figure 1 shown. The steps of the power control method provided by the present embodiment will be described in detail below based on the structure diagram of the electronic device 100 Figure 1 shown. Please refer to Figure 2 , the power control method provided by the present embodiment includes steps S101 to S104.

[0096] Step S101: Obtain a power scheduling instruction.

[0097] The power scheduling instruction represents a target power entering the power grid, including an active power instruction and a reactive power instruction. The power scheduling instruction can be sent by a host computer or a scheduling center. When the power of the power grid needs to be controlled, the target power that the power grid needs to reach can be sent to the electronic device in the form of a power scheduling instruction. It should be noted that, in the present embodiment, the power grid is a microgrid.

[0098] Step S102: obtaining the mechanical power of the virtual synchronous generator according to the first preset power relationship and the power scheduling instruction.

[0099] Currently, if the armature resistance is large, the converter will consume more electromagnetic power when using the virtual synchronous generator to control the power entering the power grid. At this time, if the power instruction is directly used as the input power of the virtual synchronous generator, i.e., the mechanical power of the virtual generator, the output power of the virtual synchronous generator will deviate greatly from the power instruction. Therefore, in order to reduce the deviation, in the embodiment, after obtaining the power scheduling instruction, the power scheduling instruction needs to be converted. Specifically, the active power instruction in the power scheduling instruction is converted into the mechanical power corresponding to the virtual synchronous generator, and the reactive power instruction in the power scheduling instruction is converted into the excitation voltage of the virtual synchronous generator. In this way, when the power of the power grid is controlled, the power grid can reach the required power value.

[0100] In the embodiment, the first preset power relationship can be constructed based on the relationship between the electromagnetic power and the mechanical power of the virtual synchronous generator. After obtaining the power scheduling instruction, the active power in the power scheduling instruction can be converted into the mechanical power of the virtual synchronous generator according to the first preset power relationship.

[0101] After converting the active power in the power scheduling instruction into the mechanical power of the virtual synchronous generator according to the first preset power relationship, step S103 needs to be performed to convert the reactive power in the power scheduling instruction, i.e., to calculate the excitation voltage of the virtual synchronous generator.

[0102] Step S103: obtaining the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction.

[0103] The second preset power relationship is constructed according to the armature impedance and the inductive reactance of the virtual synchronous generator. In the embodiment, the second preset power relationship includes the relationship between the excitation voltage, the power angle and the power entering the power grid of the virtual synchronous generator. Therefore, after obtaining the power scheduling instruction, the power scheduling instruction is substituted into the second preset power relationship, and the excitation voltage of the virtual synchronous generator can be obtained.

[0104] Step S104: controlling the power entering the power grid according to the mechanical power and the excitation voltage.

[0105] After obtaining the mechanical power and the excitation voltage of the virtual synchronous generator, the control of the power entering the power grid can be realized according to the mechanical power and the excitation voltage of the virtual synchronous generator.

[0106] Optionally, in this embodiment, after obtaining the mechanical power and excitation voltage of the virtual synchronous generator, the mechanical power can be converted into a power angle using a virtual synchronous generator model (VSG). Then, the power angle and excitation voltage are converted into three-phase voltages, which, through virtual armature resistance and inductance, act on the power grid to form an output current, thereby controlling the power entering the power grid. This avoids deviations caused by directly inputting power commands when the armature resistance is large.

[0107] The power control method provided in this embodiment constructs a first preset power relationship through the electromagnetic power and mechanical power of the virtual synchronous generator, and a second preset power relationship through the armature impedance and inductive reactance of the virtual synchronous generator. After obtaining the power dispatch command, the mechanical power of the virtual synchronous generator can be obtained based on the first preset power relationship and the power dispatch command. The excitation voltage of the virtual synchronous generator can be obtained based on the second power relationship and the power dispatch command. Then, the power entering the power grid is controlled based on the mechanical power and the excitation voltage. In this way, the deviation caused by directly inputting the power command is avoided, and the accuracy of power control is improved.

[0108] In this embodiment, the link between the virtual synchronous generator and the power grid can be equivalent to, for example: Figure 3 The circuit diagram shown. Figure 3 In this context, the virtual synchronous generator is considered a controllable voltage source, where δ is the voltage phase, i.e., the power angle of the virtual synchronous generator, and E... f It is the voltage amplitude, i.e., the excitation voltage of the virtual synchronous generator. R and L are the armature impedance and inductive reactance of the virtual synchronous generator, respectively. V g This refers to the grid voltage. Since a virtual synchronous generator is essentially a converter, the R and L settings are generally based on the parameters of the converter's filter inductor. Because the converter operates in a high-frequency switching mode, it is prone to LC resonance in the circuit, requiring increased system damping to suppress resonance.

[0109] For virtual synchronous generators, an increase in armature impedance leads to greater electromagnetic power consumption, resulting in a significant deviation between the power supplied to the grid and the power command, thus causing substantial control deviation. To reduce this control deviation, this embodiment considers the influence of the armature impedance and inductive reactance of the virtual synchronous generator. A power relationship for the virtual synchronous generator is constructed based on its armature impedance and inductive reactance. Based on this power relationship, the received power dispatch command is converted to obtain the mechanical power P of the virtual synchronous generator. m and excitation voltage E f Then, based on the mechanism model of the virtual synchronous generator, the power entering the grid is controlled, which reduces control deviation and facilitates the implementation of the controller.

[0110] In the embodiment, the step of constructing the second preset power relationship of the virtual synchronous generator according to the armature impedance and the inductive impedance of the virtual synchronous generator can include:

[0111] (1) establishing a synchronous rotating coordinate system based on a direct axis and a quadrature axis, and constructing a power relationship of the power grid in the synchronous rotating coordinate system.

[0112] (2) obtaining a correlation relationship of a power angle, an excitation voltage and a current entering the power grid according to the armature impedance and the inductive impedance of the virtual synchronous generator.

[0113] (3) obtaining the second preset power relationship according to the correlation relationship and the power relationship of the power grid.

[0114] In the embodiment, the step of constructing the power relationship of the power grid in the synchronous rotating coordinate system includes:

[0115] According to the direct-axis current, the direct-axis voltage, the quadrature-axis current and the quadrature-axis voltage of the power grid in the synchronous rotating coordinate system, the power relationship of the power grid is constructed based on the symmetry of the three-phase voltage and the three-phase current.

[0116] The power relationship of the power grid includes an active power relationship and a reactive power relationship.

[0117] Specifically, the synchronous rotating coordinate system based on the direct axis (d-axis) and the quadrature axis (q-axis) is established with the power grid as a reference, the power grid voltage (V d ,V q ) is set as (V g , 0), the current entering the power grid is (I d , I q ), it is assumed that the three-phase voltage and the three-phase current are symmetrical, then the zero sequence components V0 and I0 are both 0, and the power relationship of the current entering the power grid is:

[0118]

[0119] wherein P is the active power, Q is the reactive power, V d is the direct-axis voltage, I d is the direct-axis current, V q is the quadrature-axis voltage, I q is the quadrature-axis current, V0 is the zero-axis voltage, I0 is the zero-axis current, and V g is the power grid voltage.

[0120] Correspondingly, the step of obtaining the correlation relationship of the power angle, the excitation voltage and the current entering the power grid according to the armature impedance and the inductive impedance of the virtual synchronous generator can include:

[0121] According to the armature impedance and the inductive reactance of the virtual synchronous generator, the relationship between the power angle, the excitation voltage of the virtual synchronous generator and the current entering the power grid is obtained by the following formula:

[0122]

[0123] wherein, E f is the excitation voltage of the virtual synchronous generator; δ is the power angle of the virtual synchronous generator, X is the inductive reactance of the virtual synchronous generator, and R is the impedance of the virtual synchronous generator.

[0124] After obtaining the relationship between the power angle, the excitation voltage of the virtual synchronous generator and the current entering the power grid, and the power relationship of the power grid, the second preset power relationship can be obtained according to the relationship and the power relationship of the power grid.

[0125] In this embodiment, the step of obtaining the second preset power relationship according to the relationship and the power relationship of the power grid can include:

[0126] The second preset power relationship is obtained according to the relationship and the power relationship of the power grid by the following formula:

[0127]

[0128] wherein, P g is the active power entering the power grid, and Q g is the reactive power entering the power grid.

[0129] In this embodiment, after obtaining the relationship between the power angle, the excitation voltage of the virtual synchronous generator and the current entering the power grid, and the power relationship of the power grid, the second preset power relationship can be obtained by substituting the relationship into the power relationship of the power grid.

[0130] After the second preset power relationship of the virtual synchronous generator is constructed, when applied, after receiving the power scheduling instruction, the reactive power in the power scheduling instruction can be converted into the excitation voltage of the virtual synchronous generator according to the second preset power relationship.

[0131] Correspondingly, in this embodiment, the step of obtaining the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction can include:

[0132] According to the second preset power relationship, a power relationship diagram of the virtual synchronous generator is constructed, and a first center of the power relationship diagram is determined.

[0133] Based on the power relationship diagram, a first distance between the first center and the power scheduling instruction is calculated.

[0134] According to the first distance, the excitation voltage of the virtual synchronous generator is calculated.

[0135] The second preset power relationship is as follows: Based on the second preset power relationship, with power as the coordinate system and grid voltage (V) as the coordinate system... g Using (0, 0) as a reference point, a vector diagram representing the parameter relationship can be constructed, i.e. Figure 4 The power relationship diagram is shown. Figure 4 The sector shown represents the range of active and reactive power values. The x-coordinate of each point in the sector represents active power, and the y-coordinate represents reactive power. The center of the sector is [missing information]. In this embodiment, the center of the sector is the first center.

[0136] After constructing the power relationship graph, the first distance between the first center and the power scheduling command can be calculated based on the power relationship graph.

[0137] Optionally, the first distance between the first center and the power scheduling command can be calculated using the following formula:

[0138]

[0139] Where r is the first distance, P ref Q represents the active power in the power dispatch command. ref E represents reactive power in power dispatch instructions. f V is the excitation voltage of the virtual synchronous generator; X is the inductive reactance of the virtual synchronous generator; R is the impedance of the virtual synchronous generator; g This is the grid voltage.

[0140] After obtaining the first distance, the excitation voltage of the virtual synchronous generator can be obtained by converting the first distance.

[0141] In this embodiment, the excitation voltage of the virtual synchronous generator is calculated based on the first distance using the following formula:

[0142]

[0143] In this embodiment, after converting the reactive power in the power dispatch command into the excitation voltage of the virtual synchronous generator, it is also necessary to convert the active power in the power dispatch command into the mechanical power of the virtual synchronous generator.

[0144] In this embodiment, the active power in the power scheduling command can be converted into the mechanical power of the virtual synchronous generator based on the first preset power relationship.

[0145] Optionally, in the embodiment, the first preset power relationship can be constructed according to the electromagnetic power and the mechanical power of the virtual synchronous generator in the steady state of the power grid, specifically, the first preset power relationship can be obtained through the following process:

[0146] In the embodiment, the power scheduling instruction is (P ref , Q ref ), P ref is the reference value of the active power P g into the power grid, and Q ref is the reference value of the reactive power Q g into the power grid.

[0147] The active power into the power grid is generated by the mechanical power P m of the virtual synchronous generator, and the mechanical power and the electromagnetic power of the virtual synchronous generator are equal in the steady state of the power grid, based on which, in the embodiment, the first preset power relationship can be obtained through the following formula:

[0148]

[0149] wherein, P ref is the active power in the power scheduling instruction; Q ref is the reactive power in the power scheduling instruction; P m is the mechanical power of the virtual synchronous generator; P e is the electromagnetic power of the virtual synchronous generator; I d is the direct-axis current; I q is the quadrature-axis current; V g is the grid voltage; X is the inductance of the virtual synchronous generator, and R is the resistance of the virtual synchronous generator.

[0150] Based on the above formula, it can be seen that the difference between P m and P ref is directly related to the resistance R, if the resistance R is set to be very small, the difference between P m and P ref can be ignored, P ref is directly taken as P m , and becomes the input of the virtual synchronous generator, but if the resistance R is set to be very large, the difference between P m and P ref needs to be considered.

[0151] After obtaining the first preset power relationship, when applying, after obtaining the power scheduling instruction, the power scheduling instruction is substituted into the first preset power relationship, the mechanical power of the virtual synchronous generator can be obtained.

[0152] After the excitation voltage and the mechanical power of the virtual synchronous generator are obtained through the above transformation, the mechanical power is converted into a power angle through a virtual synchronous generator model (VSG), and then the power entering the power grid can be controlled based on the power angle and the excitation voltage.

[0153] In order to ensure that the virtual synchronous machine works in a reasonable power angle range and ensure the stability of the control system, in the embodiment, the power angle range of the virtual synchronous generator can be analyzed and calculated by using the relationship between the output power range of the converter and the power of the virtual synchronous generator, and the power angle value output by the virtual synchronous generator model (VSG) is limited by the power angle range.

[0154] In the embodiment, the step of analyzing and calculating the power angle range of the virtual synchronous generator by using the relationship between the output power range of the converter and the power of the virtual synchronous generator can include:

[0155] According to the second preset power relationship, a power relationship diagram of the virtual synchronous generator is constructed, and a first center of the power relationship diagram is determined.

[0156] According to the maximum power output by the converter when the converter accesses the power grid and the reactive power of the power grid, an effective power range in the power relationship diagram is determined, as well as a second center of the effective power range, a first tangent point of the effective power range, and a second tangent point of the effective power range.

[0157] The second distance between the first center and the second center, the third distance between the first center and the first tangent point, and the fourth distance between the first center and the second tangent point are calculated.

[0158] According to the second distance, the third distance, and the fourth distance, the power angle range of the virtual synchronous generator is calculated.

[0159] The power relationship diagram of the virtual synchronous generator is as shown in Figure 4 The first center in the power relationship diagram is

[0160] Since the virtual synchronous generator is essentially a converter, and the output power of the converter has a limited capacity, it cannot fully meet all the value ranges represented by the sector in Figure 4 Therefore, in the embodiment, the effective power range in the power relationship diagram is determined according to the maximum power output by the converter when the converter accesses the power grid and the reactive power of the power grid.

[0161] Optionally, in the embodiment, the effective power range in the power relationship diagram can be determined according to the maximum power output by the converter when the converter accesses the power grid and the reactive power of the power grid through the following process:

[0162] Assuming that the DC voltage of the converter is large enough, the maximum current that can be output is Ilim The inductive reactance of the filter inductor is X. v The impedance is negligible. After connection to the grid, the converter can output its maximum power:

[0163] R lim =I lim ·(V g +I lim ·X v )

[0164] When the converter output power is 0, the power grid needs to generate reactive power. Based on this, in this embodiment, as Figure 5 As shown, the effective power range of the converter is based on With R as the center, lim A circle with radius , i.e. Figure 5 The shaded area in the image.

[0165] After determining the effective power range in the power relationship diagram, the second center of the effective power range is the center of the circle within the effective power range. Figure 5 The center of the shaded circle, the first tangent point of the effective power range, and the second tangent point of the effective power range are the tangent points from the first center to the shaded circle.

[0166] After obtaining the second center of the effective power range, the first tangent point of the effective power range, and the second tangent point of the effective power range, the second distance between the first center and the second center is the distance between the two center points, which can be calculated using the following formula:

[0167]

[0168] Where r0 is the second distance between the first center and the second center, R is the impedance of the virtual synchronous generator, and V g X is the grid voltage. v X is the inductive reactance of the converter's filter inductor, and X is the inductive reactance of the virtual synchronous generator.

[0169] The third distance between the first center and the first tangent point, and the fourth distance between the first center and the second tangent point, constitute the first center. The distance to the point of tangency of the shaded circle can be expressed as:

[0170]

[0171] Where r1 is the third distance, r2 is the fourth distance, r0 is the second distance, and R lim This is the maximum power that the converter can output.

[0172] After obtaining the second, third, and fourth distances, the power angle range of the virtual synchronous generator can be calculated based on these distances.

[0173] From Figure 5 , it can be known that the angle of the second distance r0 is

[0174] From Figure 5 , it can be known that

[0175] Through the above formula, the expression of can be obtained, and from Figure 5 , it can be known that ranges between From the power relationship of the virtual synchronous generator, the phase of the power (P g , Q g ) entering the power grid can be obtained. Substituting the phase into the formula, the power angle range of the virtual synchronous generator can be obtained:

[0176]

[0177] After obtaining the power angle range of the virtual synchronous generator, the converter can be controlled within the capability range, so as to avoid the conflict between the inner loop and the outer loop of the converter controller, thereby avoiding system instability.

[0178] In order to describe the power control method provided in the embodiment, a 50kVA energy storage and off-grid system is taken as an example for illustration. The parameters of the 50kVA energy storage and off-grid system are shown in Table 1, and the wiring diagram can be as shown in Figure 6 .

[0179] Table 1:

[0180] Item Value Grid Power 50 kVA AC Filter Inductance 1.5 mH AC Filter Capacitance 10 uF Grid Line Voltage 380V

[0181] The 50kVA energy storage and off-grid system adopts virtual synchronous generator (VSG) control. The control flow chart of the virtual synchronous generator (VSG) is as shown in Figure 7 . The speed of the virtual synchronous generator is expressed by a first-order differential equation as follows:

[0182]

[0183] Figure 7 In the formula, s is the Laplace operator; θ g is the measured grid phase, J is the moment of inertia, ω R is the rotor angular velocity, D is the damping coefficient, T m is the generator mechanical torque, is the rotor phase, T e is the generator electromagnetic torque, which is obtained by calculating the voltage, current and frequency of the virtual synchronous generator, and ωω is the grid angular velocity. g ω is the grid angular velocity.

[0184] The whole outer loop control process is shown in Figure 8 P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. ref P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. ref P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. m P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. f P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. m P represents the external input active power instruction, Q represents the external input reactive power instruction, and P and E are obtained by converting the first preset power relationship and the second preset power relationship. Figure 8 The dashed part in the middle represents the control of the frequency and voltage exceeding the amplitude limiting, indicating that the system can quickly respond when the grid is abnormal. PI represents a proportional integral controller. For example, when unplanned off-grid occurs, the dashed part ensures uninterrupted operation. ΔP represents the power adjustment amount when the grid frequency ω exceeds the allowed range [ω, ω ]. m ΔP represents the power adjustment amount when the grid frequency ω exceeds the allowed range [ω, ω ]. meas ΔP represents the power adjustment amount when the grid frequency ω exceeds the allowed range [ω, ω ]. min ΔP represents the power adjustment amount when the grid frequency ω exceeds the allowed range [ω, ω ]. max ΔE represents the voltage adjustment amount when the grid voltage V exceeds the allowed range [V, V ]. f ΔE represents the voltage adjustment amount when the grid voltage V exceeds the allowed range [V, V ]. PCC ΔE represents the voltage adjustment amount when the grid voltage V exceeds the allowed range [V, V ]. min ΔE represents the voltage adjustment amount when the grid voltage V exceeds the allowed range [V, V ]. max ΔE represents the voltage adjustment amount when the grid voltage V exceeds the allowed range [V, V ].

[0185] Through outer loop control, the converter is converted into a voltage source controlled by E and δ as shown in Figure 3 . f The control inner loop is the control of the loop current, which adopts conventional proportional integral control, and specific reference can be made to the prior art, which will not be described here.

[0186] The above virtual synchronous generator control system is used, J=2, D=20, X=1.5mH, simulation is carried out. It is assumed that the system is connected to the grid to output 50kW active power, the load is 18kW, the grid is disconnected at 2s, and R is set to 2.5Ω and 5Ω respectively. The voltage and current waveforms of the converter output are shown in Figure 9 and Figure 10 . Figure 9 is the voltage and current waveform diagram when R is 2.5Ω, Figure 10 is the voltage and current waveform diagram when R is 5Ω.

[0187] From Figure 9 and Figure 10 , it can be seen that when R=2.5Ω, even if it has far exceeded the actual value, but when suddenly switched to off-grid, the voltage and current still have obvious oscillation; when R=5Ω, under the same working condition, when switched to off-grid, there is no oscillation of voltage and current, smooth switching is achieved.

[0188] Keep R as 5Ω, set the output active power target to jump from 50kW to-30kW at 2s, and the reactive power target to maintain at 0, the simulation gets the power change graph as shown in Figure 11 .

[0189] From Figure 11 , it can be seen that the actual value of the active power (Pmeas) obtained by conversion basically follows the change of the target value of the active power (Pref), proving that the power conversion method is feasible. The actual value of the reactive power (Qmeas) deviates slightly from the target value of the reactive power (Qref) because the power command does not use closed-loop control, resulting in a certain static error.

[0190] The power control method provided in the embodiment uses the converter to simulate the working characteristics of the virtual synchronous generator, increases the inertia of the power grid, and improves the anti-interference ability of the system. At the same time, by analyzing the mutual relationship of the power scheduling command (P ref , Q ref ), the mechanical power P m of the virtual synchronous generator, the armature resistance R, the inductance X, etc., a power relationship graph is constructed, and the expression of the excitation voltage E f is obtained according to the power relationship graph. Based on the steady state of the power grid, the expression of the mechanical power P m of the virtual synchronous generator is obtained, and according to the expressions of the mechanical power P m and the excitation voltage E f , the power scheduling command (P ref， Q ref ) is converted into the P m and E f of the generator. When the armature resistance is large, this conversion avoids the deviation caused by directly inputting the power scheduling command.

[0191] If an additional power control loop is added outside the virtual synchronous generator control, although the power deviation can be eliminated in theory, the virtual synchronous generator is a large inertia system, and the parameters of the external control loop are difficult to determine, which easily leads to system instability, and the power control method provided in the embodiment is more suitable for actual application.

[0192] At the same time, the power control method provided in the embodiment uses the output power range of the converter and the power relationship of the synchronous generator to analyze and calculate the power angle range of the virtual synchronous generator, so as to ensure that the virtual synchronous generator works within a reasonable power angle range, which is beneficial to keeping the control system stable.

[0193] Based on the same inventive concept, please refer to Figure 12 , the embodiment provides a power control device 10 applied toFigure 1 The electronic devices shown, such as Figure 12 As shown, the power control device 10 provided in this embodiment includes an instruction acquisition module 11, a parameter analysis module 12, and a control module 13.

[0194] The instruction acquisition module 11 is used to acquire power scheduling instructions.

[0195] The parameter analysis module 12 is used to obtain the mechanical power of the virtual synchronous generator according to the first preset power relationship and the power scheduling command; the first preset power relationship is constructed based on the electromagnetic power and mechanical power of the virtual synchronous generator.

[0196] The parameter analysis module 12 is used to obtain the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power dispatch command. The second preset power relationship is constructed based on the armature impedance and inductive reactance of the virtual synchronous generator.

[0197] The control module 13 is used to control the power entering the power grid based on the mechanical power and the excitation voltage.

[0198] In the optional implementation, please refer to the following: Figure 12 The power control device 10 also includes a relationship construction module 14, which, before obtaining the excitation voltage of the virtual synchronous generator based on the second preset power relationship and the power dispatch command, is used to:

[0199] Establish a synchronous rotating coordinate system based on the direct axis and the quadrature axis, and construct the power relationship of the power grid under the synchronous rotating coordinate system.

[0200] Based on the armature impedance and inductive reactance of the virtual synchronous generator, the correlation between the power angle, excitation voltage, and current entering the power grid of the virtual synchronous generator is obtained.

[0201] Based on the correlation and the power relationship of the power grid, a second preset power relationship is obtained.

[0202] In an optional implementation, the relationship building module 14 is used for:

[0203] Based on the symmetry of three-phase voltage and three-phase current, in a synchronous rotating coordinate system, the power relationship of the power grid is constructed according to the direct-axis current, direct-axis voltage, quadrature-axis current and quadrature-axis voltage of the power grid. The power relationship of the power grid includes the active power relationship and the reactive power relationship of the power grid.

[0204] The power relationship of the power grid:

[0205]

[0206] Where P is active power; Q is reactive power; V dis the direct-axis voltage; I d is the direct-axis current; V q is the quadrature-axis voltage; I q is the quadrature-axis current; V0 is the zero-axis voltage; I0 is the zero-axis current; V g is the grid voltage.

[0207] In an optional embodiment, the relationship building module 14 is configured to:

[0208] According to the armature impedance and the inductive reactance of the virtual synchronous generator, the relationship between the power angle, the excitation voltage and the current entering the grid of the virtual synchronous generator is obtained by the following formula:

[0209]

[0210] wherein, E f is the excitation voltage of the virtual synchronous generator; δ is the power angle of the virtual synchronous generator, X is the inductive reactance of the virtual synchronous generator, and R is the impedance of the virtual synchronous generator.

[0211] In an optional embodiment, the relationship building module 14 is configured to:

[0212] According to the relationship and the power relationship of the grid, the second preset power relationship is obtained by the following formula:

[0213]

[0214] wherein, P g is the active power entering the grid, and Q g is the reactive power entering the grid.

[0215] In an optional embodiment, the parameter analysis module 12 is configured to:

[0216] According to the second preset power relationship, a power relationship diagram of the virtual synchronous generator is built, and a first center of the power relationship diagram is determined.

[0217] Based on the power relationship diagram, a first distance between the first center and the power scheduling instruction is calculated.

[0218] According to the first distance, the excitation voltage of the virtual synchronous generator is calculated.

[0219] In an optional embodiment, the parameter analysis module 12 is configured to:

[0220] Based on the power relationship diagram, the first distance between the first center and the power scheduling instruction is calculated by the following formula:

[0221]

[0222] According to the first distance, the excitation voltage of the virtual synchronous generator is calculated by the following formula:

[0223]

[0224] wherein r is the first distance, P ref is the active power in the power scheduling instruction; Q ref is the reactive power in the power scheduling instruction; E f is the excitation voltage of the virtual synchronous generator; X is the inductance of the virtual synchronous generator, and R is the resistance of the virtual synchronous generator; V g is the grid voltage.

[0225] In an optional embodiment, before the mechanical power of the virtual synchronous generator is obtained according to the first preset power relationship and the power scheduling instruction, the relationship construction module 14 is configured to:

[0226] According to the electromagnetic power and the mechanical power of the virtual synchronous generator, the first preset power relationship is obtained based on the steady state of the grid by the following formula:

[0227]

[0228] wherein P ref is the active power in the power scheduling instruction; Q ref is the reactive power in the power scheduling instruction; P m is the mechanical power of the virtual synchronous generator; P e is the electromagnetic power of the virtual synchronous generator; I d is the direct-axis current; I q is the quadrature-axis current; V g is the grid voltage; X is the inductance of the virtual synchronous generator, and R is the resistance of the virtual synchronous generator.

[0229] In an optional embodiment, after the excitation voltage of the virtual synchronous generator is obtained, the parameter analysis module 12 is configured to:

[0230] According to the second preset power relationship, a power relationship diagram of the virtual synchronous generator is constructed, and a first center of the power relationship diagram is determined.

[0231] According to the maximum power output when the converter is connected to the grid and the reactive power of the grid, an effective power range in the power relationship diagram is determined, as well as a second center of the effective power range, a first tangent point of the effective power range, and a second tangent point of the effective power range.

[0232] A second distance between the first center and the second center, a third distance between the first center and the first tangent point, and a fourth distance between the first center and the second tangent point are calculated.

[0233] According to the second distance, the third distance and the fourth distance, the power angle range of the virtual synchronous generator is calculated.

[0234] The power control device provided by the embodiment of the present application constructs a first preset power relationship through the relationship between the electromagnetic power and the mechanical power of the virtual synchronous generator, constructs a second preset power relationship through the armature impedance and the reactance of the virtual synchronous generator, obtains the mechanical power of the virtual synchronous generator according to the first preset power relationship and the power scheduling instruction after obtaining the power scheduling instruction, obtains the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, and then controls the power entering the power grid according to the mechanical power and the excitation voltage, so that the deviation caused by directly inputting the power instruction is avoided, and the accuracy of power control is improved.

[0235] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the power control device 10 described above can refer to the corresponding process in the foregoing method, and will not be described in detail here.

[0236] On the basis of the foregoing, the embodiment provides a readable storage medium, which comprises a computer program, and the computer program controls an electronic device where the readable storage medium is located to execute the power control method described in any one of the foregoing embodiments when running.

[0237] The readable storage medium can be, but is not limited to, a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0238] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the readable storage medium described above can refer to the corresponding process in the foregoing method, and will not be described in detail here.

[0239] To sum up, the power control method, device, electronic device and readable storage medium provided by the embodiment of the present application construct a first preset power relationship through the electromagnetic power and the mechanical power of the virtual synchronous generator, construct a second preset power relationship through the armature impedance and the reactance of the virtual synchronous generator, obtain the mechanical power of the virtual synchronous generator according to the first preset power relationship and the power scheduling instruction after obtaining the power scheduling instruction, obtain the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, and then control the power entering the power grid according to the mechanical power and the excitation voltage, so that the deviation caused by directly inputting the power instruction is avoided, and the accuracy of power control is improved.

[0240] The above describes in detail a power control method, device, electronic equipment and readable storage medium provided by an embodiment of the present application. The principle and implementation manner of the present application are described by applying specific examples. The above embodiment description is only used to help understand the technical solutions of the present application and the core idea thereof. Those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power control method, characterized by, The method comprises: acquiring a power scheduling instruction; obtaining mechanical power of a virtual synchronous generator according to a first preset power relationship and the power scheduling instruction, wherein the first preset power relationship is constructed according to electromagnetic power and mechanical power of the virtual synchronous generator; Before the step of obtaining mechanical power of a virtual synchronous generator according to a first preset power relationship and the power scheduling instruction, the method further comprises: obtaining the first preset power relationship according to electromagnetic power and mechanical power of the virtual synchronous generator based on power grid steady state through the following formula: wherein, is the active power in the power schedule instruction; is the reactive power in the power schedule instruction; is the mechanical power of the virtual synchronous generator; is the electromagnetic power of the virtual synchronous generator; is the direct axis current; is the quadrature axis current; is the grid voltage; is the inductance of the virtual synchronous generator, is the impedance of the virtual synchronous generator; obtaining excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction, wherein the second preset power relationship is constructed according to armature impedance and reactance of the virtual synchronous generator; Before the step of obtaining excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction, the method further comprises: establishing a synchronous rotating coordinate system based on direct axis and quadrature axis, and constructing power relationship of the power grid in the synchronous rotating coordinate system; obtaining the correlation between power angle, excitation voltage and current entering the power grid according to armature impedance and reactance of the virtual synchronous generator; obtaining the second preset power relationship according to the correlation and the power relationship of the power grid; controlling power entering the power grid according to the mechanical power and the excitation voltage.

2. The power control method of claim 1, wherein, The step of constructing the power relationship of the power grid in the synchronous rotating coordinate system comprises: constructing the power relationship of the power grid according to direct axis current, direct axis voltage, quadrature axis current and quadrature axis voltage of the power grid in the synchronous rotating coordinate system based on symmetry of three-phase voltage and three-phase current, wherein the power relationship of the power grid comprises active power relationship and reactive power relationship of the power grid; The power relationship of the power grid: wherein, is the active power; is the reactive power; is the direct axis voltage; is the direct axis current; is the quadrature axis voltage; is the quadrature axis current; is the zero axis voltage; is the zero axis current; is the grid voltage.

3. The power control method of claim 2, wherein, The step of obtaining the correlation between power angle, excitation voltage and current entering the power grid according to armature impedance and reactance of the virtual synchronous generator comprises: obtaining the correlation between power angle, excitation voltage and current entering the power grid according to armature impedance and reactance of the virtual synchronous generator through the following formula: wherein, is an excitation voltage of the virtual synchronous generator; is a power angle of the virtual synchronous generator, is a reactance of the virtual synchronous generator, is an impedance of the virtual synchronous generator.

4. The power control method of claim 3, wherein, The step of obtaining the second preset power relationship according to the correlation and the power relationship of the power grid comprises: obtaining the second preset power relationship according to the correlation and the power relationship of the power grid through the following formula: wherein, Pgrid is the active power into the grid, Qgrid is the reactive power into the grid.

5. The power control method of claim 1, wherein, The step of obtaining excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction comprises: constructing a power relationship diagram of the virtual synchronous generator according to the second preset power relationship, and determining a first center of the power relationship diagram; calculating a first distance between the first center and the power scheduling instruction based on the power relationship diagram; obtaining excitation voltage of the virtual synchronous generator according to the first distance.

6. The power control method of claim 5, wherein, The step of calculating a first distance between the first center and the power scheduling instruction based on the power relationship diagram comprises: The first distance between the first center and the power scheduling instruction is calculated according to the power relationship diagram by the following formula: The step of calculating the excitation voltage of the virtual synchronous generator according to the first distance comprises: The excitation voltage of the virtual synchronous generator is calculated according to the first distance by the following formula: wherein, is a first distance, is an active power in the power schedule instruction; is a reactive power in the power schedule instruction; is an excitation voltage of the virtual synchronous generator; is a reactance of the virtual synchronous generator, is an impedance of the virtual synchronous generator; is a grid voltage.

7. The power control method of claim 1, wherein, After obtaining the excitation voltage of the virtual synchronous generator, the method further comprises: According to the first distance, the power relationship diagram of the virtual synchronous generator is constructed, and a first center of the power relationship diagram is determined; According to the maximum power output when the converter is connected to the power grid and the reactive power of the power grid, an effective power range in the power relationship diagram is determined, and a second center of the effective power range, a first tangent point of the effective power range and a second tangent point of the effective power range are determined; The second distance between the first center and the second center, the third distance between the first center and the first tangent point and the fourth distance between the first center and the second tangent point are calculated; The power angle range of the virtual synchronous generator is calculated according to the second distance, the third distance and the fourth distance.

8. A power control device, characterized by Comprise: An instruction acquisition module is configured to acquire a power scheduling instruction; A parameter analysis module is configured to obtain mechanical power of a virtual synchronous generator according to a first preset power relationship and the power scheduling instruction, wherein the first preset power relationship is constructed according to electromagnetic power and mechanical power of the virtual synchronous generator; Before the parameter analysis module obtains the mechanical power of the virtual synchronous generator according to the first preset power relationship and the power scheduling instruction, the method further comprises: According to the electromagnetic power and the mechanical power of the virtual synchronous generator, a first preset power relationship is obtained based on power grid steady state by the following formula: wherein, is the active power in the power schedule instruction; is the reactive power in the power schedule instruction; is the mechanical power of the virtual synchronous generator; is the electromagnetic power of the virtual synchronous generator; is the direct axis current; is the quadrature axis current; is the grid voltage; is the reactance of the virtual synchronous generator, is the impedance of the virtual synchronous generator; The parameter analysis module is configured to obtain excitation voltage of the virtual synchronous generator according to a second preset power relationship and the power scheduling instruction, wherein the second preset power relationship is constructed according to armature impedance and reactance of the virtual synchronous generator; Before the parameter analysis module obtains the excitation voltage of the virtual synchronous generator according to the second preset power relationship and the power scheduling instruction, the method further comprises: A synchronous rotating coordinate system based on direct axis and quadrature axis is established, and a power relationship of the power grid is constructed in the synchronous rotating coordinate system; According to the armature impedance and the reactance of the virtual synchronous generator, a correlation between power angle, excitation voltage and current entering the power grid is obtained; According to the correlation and the power relationship of the power grid, a second preset power relationship is obtained; A control module is configured to control power entering the power grid according to the mechanical power and the excitation voltage.

9. An electronic device, comprising: The readable storage medium comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the power control method of any one of claims 1 to 7 when executing the program.

10. A readable storage medium, characterized by, The readable storage medium comprises a computer program, and the computer program controls the electronic device where the readable storage medium is located to execute the power control method of any one of claims 1 to 7 when running.

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