Voltage control method and device suitable for new energy storage system

Abstract

The application provides a voltage control method and device suitable for a new energy storage system. The method comprises the following steps: detecting the difference between the voltage reference value and the voltage reference value of the coupling point of the storage system; when the difference is greater than or equal to the threshold value, determining the reactive power control link coefficient according to the voltage reference value and the adaptive coefficient calculation formula; otherwise, maintaining the current operating state; bringing the reactive power control link coefficient into the reactive power voltage control link equation to determine the target reactive power voltage, and controlling the voltage based on the target reactive power voltage to realize the autonomous support of reactive power. The application determines the difference between the voltage reference value and the voltage reference value to judge the system voltage state in a more intuitive way. Accordingly, the control strategy of the reactive power control link is determined according to the difference and the threshold value, and the coefficient of the reactive power control link is adjusted based on the voltage reference value, thereby meeting the demand for autonomous response capability of reactive power and improving the stability of reactive power voltage control.

Description

Technical Field

[0001] This invention belongs to the field of new energy storage system control technology, and in particular relates to a voltage control method and device suitable for new energy storage systems. Background Technology

[0002] The trend of new energy power sources such as wind and solar power becoming the mainstay is becoming increasingly prominent. Currently, wind and photovoltaic power generation systems mainly rely on power electronic grid-connected converters to connect to the grid; therefore, inverter control becomes the core of microgrid control. Common inverter control strategies include: constant voltage and constant frequency (VPS). V / f ) control, constant power ( P / Q Control, droop control, and virtual synchronizer control, etc.

[0003] V / f The control strategy refers to controlling the inverter to output at the rated frequency and voltage, but this method is not suitable for parallel operation. P / Q Control is achieved through an outer power loop and an inner current loop, ensuring the inverter always follows the given power output. It can be equivalent to a current source and exhibits high impedance. Droop control incorporates the grid-connected control strategy of synchronous generators into the control system, combining it with the inverter's power output characteristics to derive the basic principle of droop control. Virtual synchronous machine control technology enables the grid-connected converter to autonomously construct the amplitude and frequency of the AC voltage. Compared to traditional power decoupling vector control technology, virtual synchronous control not only provides better active and rapid support for grid frequency and near-field voltage but also has significant advantages in stable operation in weak grids.

[0004] However, in reactive power droop control, the reactive power of the converter varies with line impedance and is easily affected by harmonic injection, resulting in poor robustness. Therefore, reactive power control with reactive power differential compensation is adopted. However, in typical virtual synchronous machine control, the parameters of the reactive power control link are fixed, leading to a continuous weakening of reactive power support capability as voltage fluctuations gradually decrease, making it difficult to meet the reactive power voltage support requirements. Summary of the Invention

[0005] This application provides a voltage control method and device suitable for new energy storage systems to solve the problem that fixed parameters in the reactive power control process cannot meet the reactive power voltage support requirements.

[0006] In a first aspect, embodiments of this application provide a voltage control method suitable for new energy storage systems, including: The difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system is detected. When the difference is greater than or equal to the threshold, the reactive power control coefficient is determined according to the voltage per unit value and the adaptive coefficient calculation formula; otherwise, the current operating state is maintained. Substitute the coefficients of the reactive power control link into the reactive power voltage control link equation to determine the target reactive power voltage, and then perform voltage control based on the target reactive power voltage to achieve autonomous reactive power support.

[0007] In one possible implementation, the equation for the reactive voltage control loop is: in, ; E * represents the effective value of the virtual excitation electromotive force; , For reactive power control coefficients; U n、 V o represents the voltage reference value and the actual voltage value, respectively; This refers to the reactive power of the energy storage system. For complex variables in the Laplace transform; This is the voltage droop control coefficient.

[0008] In one possible implementation, determining the reactive power control element coefficients based on the per-unit voltage value and the adaptive coefficient calculation formula includes: When the voltage per-unit value is within the set per-unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And according to the voltage fluctuation amplitude and the voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control link coefficient is determined based on different schemes.

[0009] In one possible implementation, the voltage fluctuation amplitude is... and the voltage change rate Determine the coefficients of the reactive power control system, including: The voltage fluctuation amplitude and the voltage change rate Substitute into the following formulas respectively: in, Deq、Dqq For reactive power control coefficients; Ka , Kb , Kc , K0 , K1, K2 , K3 The coefficient for calculating the reactive power control link coefficient is the per-unit value of the coupling point voltage within the set per-unit value range.

[0010] In one possible implementation, when the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control element coefficient is determined based on different schemes, including: The reactive power control element coefficients are determined according to the following scheme. Deq : in, ; N 1 represents the upper limit of the set per-unit value range; N 2 is the lower limit of the set per-unit value range; The reactive power control element coefficients are determined according to the following scheme. Dqq : in, ; N 1 represents the upper limit of the set per-unit value range; N 2 is the lower limit of the set per-unit value range.

[0011] In one possible implementation, the set per-unit value range is 0.75pu≤ Up.u. ≤1.15pu.

[0012] Secondly, embodiments of this application provide a voltage control device suitable for new energy storage systems, comprising: The detection module is used to detect the difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system. The coefficient determination module is used to determine the reactive power control link coefficient based on the voltage per unit value and the adaptive coefficient calculation formula when the difference is greater than or equal to the threshold; otherwise, it maintains the current operating state. The voltage determination module is used to input the reactive power control coefficients into the reactive power voltage control equation to determine the target reactive power voltage, so as to perform voltage control based on the target reactive power voltage and realize autonomous reactive power support.

[0013] In one possible implementation, the coefficient determination module is specifically used for: When the voltage per-unit value is within the set per-unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And according to the voltage fluctuation amplitude and the voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control link coefficient is determined based on different schemes.

[0014] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method as described in the first aspect or any possible implementation of the first aspect above.

[0015] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as described in the first aspect or any possible implementation of the first aspect.

[0016] This application provides a voltage control method and apparatus suitable for new energy storage systems. By determining the difference between the per-unit voltage value and a reference value, and using this difference as a reference quantity, the system voltage state can be judged in a more intuitive way. Accordingly, the control strategy of the reactive power control link is determined based on the difference and a threshold value, and the coefficients of the reactive power control link are adjusted based on the per-unit voltage value, thereby meeting the required reactive power autonomous response capability and improving the stability of reactive power voltage control. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the implementation of a voltage control method for new energy storage systems provided in an embodiment of this application. Figure 2 This is a flowchart illustrating the implementation of a voltage control method for new energy storage systems provided in another embodiment of this application; Figure 3 This is a flowchart illustrating the implementation of a voltage control method for new energy storage systems provided in another embodiment of this application; Figure 4 The figure shows the simulation results of voltage fluctuation at the coupling point of an energy storage system based on traditional virtual synchronous machine control. Figure 5 The figure shows the simulation results of voltage fluctuation at the coupling point of an energy storage system controlled by the method provided in the embodiments of this application. Figure 6 This is a schematic diagram of the structure of a voltage control device suitable for new energy storage systems provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0020] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0021] Unless otherwise stated, the term "multiple" means two or more. The character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B. The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0022] The terms used in this application are for describing embodiments only and are not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, the term “and / or” as used herein means including one or more of the associated listed elements and all possible combinations thereof. Additionally, when used in this application, the terms “comprise” and its variations “comprises” and / or “comprising” refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitation, an element defined by the phrase “comprising an…” does not exclude the presence of additional identical elements in the process, method, or apparatus that includes said element.

[0023] In this application, each embodiment focuses on describing the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, then the relevant parts can be referred to the description of the method section.

[0024] This application aims to address the shortcomings of existing algorithms by optimizing the control method of the reactive power control link of the traditional virtual synchronous machine under different voltage drop scenarios. The goal is to improve the reactive power autonomous support capability of the virtual synchronous machine control method during small voltage drops at the coupling point, before voltage fluctuations enter the voltage ride-through process, and during the initial voltage ride-through process. To this end, a segmented adaptive voltage support control method for reactive power compensation control parameters suitable for new energy storage systems is proposed. The solution provided in this application is applicable to wind power storage systems in practical implementation. When used in other new energy storage systems, the type and size of the calculation coefficients can be adjusted according to the applicable field.

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a flowchart illustrating the implementation of a voltage control method for new energy storage systems according to an embodiment of this application. Figure 1 As shown, the method includes the following steps: S101 detects the difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system.

[0027] In power systems, per-unit voltage values ​​are typically calculated based on rated voltage. Rated voltage refers to the voltage value designed or specified for equipment or systems under normal conditions. The formula for calculating per-unit voltage values ​​is: Per-unit voltage value = (Actual voltage / Rated voltage) × 100% The actual voltage refers to the voltage value that is actually measured or observed, while the rated voltage is the reference voltage used for reference.

[0028] In this embodiment, per-unit voltage values ​​help compare the performance of systems or devices at different voltage levels. Since per-unit voltage values ​​are dimensionless, they eliminate unit differences between different voltage levels, thus simplifying the power system analysis process. Furthermore, using the difference between the per-unit voltage value and a reference value as a reference quantity for judging the system voltage state is more intuitive and simple.

[0029] In addition, compared to the fluctuation of voltage values, the per-unit voltage value is less affected by short-term fluctuations. Adjusting the reactive power control coefficient based on the per-unit voltage value can improve the stability of reactive power voltage control.

[0030] S102: When the difference is greater than or equal to the threshold, determine the reactive power control coefficient according to the voltage per unit value and the adaptive coefficient calculation formula; otherwise, maintain the current operating state.

[0031] Here, when the difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system is greater than or equal to the threshold, the reactive power voltage support requirement may not be met. Therefore, an intervention control strategy needs to be implemented to achieve autonomous reactive power support and meet the voltage support requirement. Conversely, if the difference is less than the threshold, the voltage fluctuation is small, and the reactive power support capability is sufficient to meet the reactive power voltage support requirement, then the current state remains unchanged.

[0032] S103, substitute the reactive power control coefficients into the reactive power voltage control equation to determine the target reactive power voltage, and perform voltage control based on the target reactive power voltage to achieve autonomous reactive power support.

[0033] In this embodiment, the difference between the per-unit voltage value and a reference value is determined and used as a reference quantity to judge the system voltage state in a more intuitive way. Accordingly, the control strategy of the reactive power control link is determined based on the difference and a threshold, and the coefficients of the reactive power control link are adjusted based on the per-unit voltage value, thereby meeting the required reactive power autonomous response capability and improving the stability of reactive power voltage control.

[0034] In one possible implementation, the reactive voltage control equation is as follows: in, ; E * represents the effective value of the virtual excitation electromotive force; , For reactive power control coefficients; U n、 V o represents the voltage reference value and the actual voltage value, respectively; This refers to the reactive power of the energy storage system. For complex variables in the Laplace transform; This is the voltage droop control coefficient.

[0035] Traditional virtual synchronous machine (VSM) technology often employs droop control in the reactive power voltage link. However, the reactive power of the droop-controlled converter varies with line impedance and is susceptible to harmonic injection, making precise reactive power distribution impossible. This control strategy has poor robustness and struggles to achieve accurate reactive power distribution.

[0036] In the embodiments of this application, see Figure 2According to the wind-storage integrated system topology diagram shown in the embodiments of this application, unlike the reactive power control of traditional virtual synchronous machine technology, a reactive power and voltage control strategy with differential compensation is adopted, and a flux feedback loop and reactive power compensation mechanism are incorporated. The above-mentioned reactive power and voltage control equations are the equations after adding the flux feedback loop and reactive power compensation.

[0037] After introducing flux linkage feedback and reactive power differential compensation, the transient process of the system becomes more complex. Differences in parameter values ​​within the control loop can affect controller performance; therefore, appropriate reactive power control coefficients must be selected based on actual requirements. D eq 、D qq Parameters are set to ensure that the performance of the reactive power control system meets requirements. Specifically, based on the voltage drop and voltage change rate, the reactive power control coefficients are adjusted for situations where voltage fluctuations are small or the voltage drop is just entering the voltage ride-through phase. This allows the energy storage system to respond promptly and support voltage fluctuations.

[0038] In one possible implementation, the reactive power control element coefficients are determined based on the per-unit voltage value and the adaptive coefficient calculation formula, including: When the voltage per unit value is within the set per unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And based on the voltage fluctuation amplitude and voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range or greater than the upper limit of the set per-unit value range, the reactive power control coefficient is determined based on different schemes.

[0039] In voltage control strategies, the per-unit voltage value is a crucial parameter. The per-unit voltage value is the ratio between the actual voltage value and the rated voltage value, reflecting the degree of voltage fluctuation. When the per-unit voltage value exceeds the set range—that is, when the per-unit voltage value is less than the lower limit of the set range or greater than the upper limit—the voltage fluctuation is excessive, which can affect the operation of electrical equipment. To address this issue, we use fixed parameters to support rated reactive power. Fixed parameters ensure that the power system can provide stable reactive power even when voltage fluctuations are large, thus guaranteeing voltage stability. This method is highly effective when voltage fluctuations are large, but may lead to wasted reactive power when voltage fluctuations are small.

[0040] Accordingly, when the voltage per-unit value is within the set range, this embodiment introduces an adaptive coefficient calculation formula to dynamically adjust the reactive power control link coefficient. When the voltage per-unit value is within the set range, the adaptive coefficient calculation formula can automatically adjust the reactive power control link coefficient according to voltage changes, thereby achieving more precise control. This method can provide stable reactive power support when voltage fluctuations are large, and avoid reactive power waste when voltage fluctuations are small.

[0041] In this embodiment, a partitioned approach is adopted for voltage fluctuations at different coupling points. A strategy is employed to achieve rated reactive power support with fixed parameters and to dynamically adjust the reactive power control coefficients using an adaptive coefficient calculation formula. This reduces the inadequacy of fixed coefficients in the reactive power voltage support process and improves the operating efficiency of the power system while ensuring voltage stability.

[0042] In one possible implementation, based on the voltage fluctuation amplitude and voltage change rate Determine the coefficients of the reactive power control system, including: Voltage fluctuation amplitude and voltage change rate Substitute into the following formulas respectively: in, Deq、Dqq For reactive power control coefficients; Ka , Kb , Kc , K0 , K1 , K2 , K3 The coefficient is used to calculate the reactive power control coefficient within the set per-unit value range of the coupling point voltage.

[0043] In one possible implementation, when the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control coefficient is determined based on different schemes, including: The reactive power control element coefficients are determined according to the following scheme. Deq : in, ; N 1 represents the upper limit of the per-unit value range; N 2 represents the lower limit of the per-unit value range; The reactive power control element coefficients are determined according to the following scheme. Dqq : in, ;N 1 represents the upper limit of the per-unit value range; N 2 is the lower limit of the per-unit value range.

[0044] In one possible implementation, the per-unit value range is set to 0.75pu≤ Up.u. ≤1.15pu.

[0045] like Figure 3 This is an implementation flow of a voltage control method suitable for new energy storage systems, illustrated according to a specific embodiment. For example... Figure 3 As shown, the per-unit value range is set to 0.75pu≤ Up.u. For values ​​≤1.15 PU, the adaptive coefficient is calculated using the following formula: in, Deq、Dqq For reactive power control coefficients; This is the per-unit value of the coupling point voltage; Kqa、Kq0 The reactive power control coefficient is the factor when the per-unit voltage at the coupling point is greater than 1.15 pu. Kqb , Kq1 The reactive power control coefficient is defined as the per-unit value of the coupling point voltage being less than 0.75 pu. Ka , Kb , Kc , K0 , K1 , K2 , K3 The coefficients for calculating the reactive power control link coefficients are for coupling point voltage per unit values ​​within the range of 0.75pu~1.15pu.

[0046] in, K qa 、K q0 , K qb , K q1 The calibration value is determined based on the specific equipment parameters of the new energy storage system during actual implementation, in order to adapt to the stable operation of new energy storage systems with different compositions.

[0047] To analyze the capability of the voltage control method proposed in this application for new energy storage systems, voltage fluctuation simulations of the coupling point of the energy storage system were performed based on both traditional virtual synchronous machine control and the control method provided in this application. Specific simulation results are presented below. Figure 4 and Figure 5 As shown.

[0048] Reference Figure 4The reactive power autonomous response curves under different voltage dips and rises at the coupling point under traditional virtual synchronous machine control reveal that, due to the fixed coefficients of the reactive power control links in the traditional virtual synchronous machine, the reactive power autonomous response capability weakens as the voltage dip decreases. This makes it impossible to achieve effective reactive power autonomous response when the coupling point voltage approaches or initially enters the low-voltage crossing region. Similarly, as the voltage rise decreases, the fixed coefficients of the reactive power control links in the traditional virtual synchronous machine also weaken the reactive power autonomous response capability, making it difficult to achieve the required reactive power autonomous response when the coupling point voltage rise has not yet entered the high-voltage crossing region.

[0049] Reference Figure 5 Using a voltage control method for wind-storage systems proposed in this invention, the reactive power autonomous response under different degrees of voltage dips and rises at the coupling point was analyzed. Fixed-coefficient control was still adopted when the coupling point voltage was within the variable coefficient range and the voltage fluctuation did not exceed the threshold set by the control strategy. When the coupling point voltage fluctuation exceeded the threshold set by the control strategy or entered the variable coefficient range, the reactive power response differed from the fixed-parameter control of the reactive power link in traditional synchronous machines as the degree of voltage dip decreased. Based on the control method proposed in this invention, the reactive power response decreased slightly as the degree of voltage dip decreased, but the decrease was very small compared to not using the method proposed in this invention, achieving a reactive power autonomous response that met the requirements. Similarly, when the coupling point voltage fluctuation exceeded the threshold set by the control strategy or entered the variable coefficient range, the reactive power autonomous response capability was effectively improved as the degree of voltage rise decreased, achieving a reactive power autonomous response that met the requirements.

[0050] In summary, this invention employs an adaptive voltage active support control method suitable for wind-storage systems. Addressing the drawbacks of fixed reactive power parameters under traditional synchronous machine control, it proposes a variable-coefficient adjustment method for the reactive power control link based on virtual synchronous machine control. For situations where the coupling point voltage approaches the low-voltage ride-through limit and during the initial low-voltage ride-through, a variable-coefficient handling method is adopted to improve the reactive power autonomous response capability of the virtual synchronous machine control. Finally, a typical energy storage system model was built on an electromagnetic transient software simulation platform to verify the proposed variable-coefficient adjustment method for the reactive power control link based on virtual synchronous machine control. Figure 4 and Figure 5 Simulation results show that the proposed method effectively solves the problem caused by the fixed parameters of the reactive power link in the traditional virtual synchronous machine control, effectively improves its reactive power response capability, and mitigates the impact of near-field voltage problems, thus having good practical engineering application value.

[0051] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0052] The following are device embodiments of this application. For details not described in detail, please refer to the corresponding method embodiments described above.

[0053] Figure 6 This is a schematic diagram of the structure of a voltage control device suitable for a new energy storage system according to an embodiment of this application, as shown below. Figure 6 As shown, for ease of explanation, only the parts related to the embodiments of this application are shown, such as... Figure 6 As shown, the device includes: Detection module 601 is used to detect the difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system; The coefficient determination module 602 is used to determine the reactive power control link coefficient based on the voltage per unit value and the adaptive coefficient calculation formula when the difference is greater than or equal to the threshold; otherwise, it maintains the current operating state. The voltage determination module 603 is used to input the reactive power control coefficients into the reactive power voltage control equation to determine the target reactive power voltage, so as to perform voltage control based on the target reactive power voltage and realize autonomous reactive power support.

[0054] In one possible implementation, the coefficient determination module 602 is specifically used for: When the voltage per unit value is within the set per unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And based on the voltage fluctuation amplitude and voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range or greater than the upper limit of the set per-unit value range, the reactive power control coefficient is determined based on different schemes.

[0055] In this embodiment, the difference between the per-unit voltage value and a reference value is determined and used as a reference quantity to judge the system voltage state in a more intuitive way. Accordingly, the control strategy of the reactive power control link is determined based on the difference and a threshold, and the coefficients of the reactive power control link are adjusted based on the per-unit voltage value, thereby meeting the required reactive power autonomous response capability and improving the stability of reactive power voltage control.

[0056] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 7As shown, the electronic device 7 in this embodiment includes: a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and executable on the processor 70. When the processor 70 executes the computer program 72, it implements the steps in the various voltage control method embodiments applicable to new energy storage systems described above, for example... Figure 1 The steps shown. Alternatively, when the processor 70 executes the computer program 72, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 6 The functions of each module are shown.

[0057] For example, the computer program 72 can be divided into one or more modules / units, which are stored in the memory 71 and executed by the processor 70 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 72 in the electronic device 7. For example, the computer program 72 can be divided into... Figure 6 The modules shown.

[0058] The electronic device 7 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. The electronic device 7 may include, but is not limited to, a processor 70 and a memory 71. Those skilled in the art will understand that... Figure 7 This is merely an example of electronic device 7 and does not constitute a limitation on electronic device 7. It may include more or fewer components than shown, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0059] The processor 70 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0060] The memory 71 can be an internal storage unit of the electronic device 7, such as a hard disk or memory. The memory 71 can also be an external storage device of the electronic device 7, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory 71 can include both internal and external storage units of the electronic device 7. The memory 71 is used to store the computer program and other programs and data required by the electronic device. The memory 71 can also be used to temporarily store data that has been output or will be output.

[0061] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to 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 embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0062] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0063] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art 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 application.

[0064] In the embodiments provided in this application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0065] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0066] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0067] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above-described embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the voltage control method embodiments applicable to new energy storage systems described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0068] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A voltage control method suitable for new energy storage systems, characterized in that, include: The difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system is detected. When the difference is greater than or equal to the threshold, the reactive power control coefficient is determined according to the voltage per unit value and the adaptive coefficient calculation formula; otherwise, the current operating state is maintained. Substitute the reactive power control coefficients into the reactive power voltage control equation to determine the target reactive power voltage, and then perform voltage control based on the target reactive power voltage to achieve autonomous reactive power support. The equation for the reactive voltage control link is as follows: in, ; E * represents the effective value of the virtual excitation electromotive force; , For reactive power control coefficients; U n、 V o represents the voltage reference value and the actual voltage value, respectively; This refers to the reactive power of the energy storage system. Complex variables in the Laplace transform; This is the voltage droop control coefficient; The step of determining the reactive power control link coefficients based on the voltage per-unit value and the adaptive coefficient calculation formula includes: When the voltage per-unit value is within the set per-unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And according to the voltage fluctuation amplitude and the voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control link coefficient is determined based on different schemes; Wherein, according to the voltage fluctuation amplitude and the voltage change rate Determine the coefficients of the reactive power control system, including: The voltage fluctuation amplitude and the voltage change rate Substitute them into the following formulas respectively: in, Deq、Dqq For reactive power control coefficients; Ka , Kb , Kc , K 0 、K 1. K 2. K 3 is the coefficient for calculating the reactive power control link coefficient within the set per-unit value range of the coupling point voltage per unit value.

2. The voltage control method for new energy storage systems according to claim 1, characterized in that, When the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control link coefficient is determined based on different schemes, including: The reactive power control element coefficients are determined according to the following scheme. Deq : in, ; N 1 represents the upper limit of the set per-unit value range; N 2 is the lower limit of the set per-unit value range; The reactive power control element coefficients are determined according to the following scheme. Dqq : in, ; N 1 represents the upper limit of the set per-unit value range; N 2 is the lower limit of the set per-unit value range.

3. The voltage control method for new energy storage systems according to claim 1 or 2, characterized in that, The set per-unit value range is 0.75pu≤ Up.u. ≤1.15pu.

4. A voltage control device suitable for new energy storage systems, characterized in that, include: The detection module is used to detect the difference between the per-unit voltage value and the reference value at the coupling point of the energy storage system. The coefficient determination module is used to determine the reactive power control link coefficient based on the voltage per unit value and the adaptive coefficient calculation formula when the difference is greater than or equal to the threshold; otherwise, it maintains the current operating state. The voltage determination module is used to input the reactive power control coefficients into the reactive power voltage control equation to determine the target reactive power voltage, so as to perform voltage control based on the target reactive power voltage and realize reactive power autonomous support. The equation for the reactive voltage control link is as follows: in, ; E * represents the effective value of the virtual excitation electromotive force; , For reactive power control coefficients; U n、 V o represents the voltage reference value and the actual voltage value, respectively; This refers to the reactive power of the energy storage system. Complex variables in the Laplace transform; This is the voltage droop control coefficient; Specifically, the coefficient determination module is used for: When the voltage per-unit value is within the set per-unit value range, the voltage fluctuation amplitude of the coupling point voltage of the energy storage system is obtained. and voltage change rate And according to the voltage fluctuation amplitude and the voltage change rate Determine the coefficients of the reactive power control element; When the voltage per-unit value is less than the lower limit of the set per-unit value range and greater than the upper limit of the set per-unit value range, the reactive power control link coefficient is determined based on different schemes; Wherein, according to the voltage fluctuation amplitude and the voltage change rate When determining the reactive power control coefficient, the voltage fluctuation amplitude is considered. and the voltage change rate Substitute them into the following formulas respectively: in, Deq、Dqq For reactive power control coefficients; Ka , Kb , Kc , K 0 、K 1. K 2. K 3 is the coefficient for calculating the reactive power control link coefficient within the set per-unit value range of the coupling point voltage per unit value.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 3 above.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 3 above.

Images