Inverter control method and system based on power value setting

Abstract

The invention discloses an inverter control method and system based on power value setting, and the method comprises the steps: building a first control model, and calculating a first voltage difference value in a fault state according to the first control model; according to the first voltage difference value, a to-be-injected current level is judged in combination with a preset first switching threshold value; and presetting a first current constraint, and controlling the first control model parameter after current injection according to the first current constraint. The inverter control technology is clear in principle and low in difficulty, power instruction switching is carried out on the basis of traditional VSG control, enough reactive power can be output on the premise that inertia support is provided for a power grid system, the current amplitude limiting link is added in the control link for the problem of over-current possibly occurring in the inverter during the fault period, and the control efficiency is improved. And safe and stable operation of the inverter is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter fault ride-through, and in particular to an inverter control method and system based on power value setting. Background Art

[0002] In order to accelerate the transformation of energy structure, the distribution network is gradually developing towards high penetration of renewable energy. The increase in the proportion of new energy with inverter as the interface has reduced the inertia and damping ratio of the existing power grid. At the same time, considering the inverter's own overcurrent capacity, the safety and stability of the power grid operation has decreased. Further research is needed on the fault ride-through control of distributed power sources in the distribution network under fault conditions.

[0003] In order to solve the distribution network's demand for the ability to actively support grid voltage after the access of distributed power sources, the grid-connected converter based on the virtual synchronous generator can participate in the regulation of grid voltage and frequency by simulating the characteristics of the synchronous generator, thereby improving the equivalent inertia and damping of the grid, while maintaining the characteristics of its own power electronic equipment. The control structure is flexible and changeable, and the response speed is fast, which can effectively deal with stability issues during grid operation.

[0004] After a power grid failure, the virtual synchronous control inverter is limited by the overcurrent characteristics of power electronic devices and is unable to support a large short-circuit current, which may cause more serious harm after the failure. At the same time, after a power grid failure, the voltage at the grid connection point drops, and the inverter's voltage tolerance is insufficient, resulting in disconnection from the grid and causing chain failures.

[0005] Therefore, in view of the insufficient voltage support capacity and overcurrent phenomenon of distributed power sources at the current stage, it is necessary to study the fault ride-through control strategy of the distributed power interface inverter under fault conditions. Summary of the invention

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides an inverter control method and system based on power value setting, which can solve the problems mentioned in the background technology.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In the first aspect, the present invention provides an inverter control method based on power value setting, including: establishing a first control model, and calculating a first voltage difference under a fault state according to the first control model; judging a current level to be injected according to the first voltage difference and a preset first switching threshold; presetting a first current constraint, and controlling the first control model parameters after the injection of current according to the first current constraint.

[0010] As a preferred solution of the inverter control method based on power value setting described in the present invention, the step of determining the level of the current to be injected based on the first voltage difference and a preset first switching threshold value includes:

[0011] Preset a plurality of switching thresholds as the first switching threshold, wherein the switching threshold is a voltage threshold or a related numerical threshold that can directly or indirectly obtain the voltage threshold;

[0012] Several switching thresholds correspond to several injection current levels.

[0013] As a preferred solution of the inverter control method based on power value setting described in the present invention, the first current constraint includes:

[0014] The first current constraint is an arbitrary constraint designed according to the overcurrent capability of the target inverter;

[0015] The first current constraint includes at least a current limit constraint and a positive and negative sequence constraint.

[0016] As a preferred solution of the inverter control method based on power value setting described in the present invention, wherein: the preset first current constraint, and controlling the first control model parameter after the injection current according to the first current constraint, comprises:

[0017] After determining the level of the current to be injected, injecting the current according to the level of the current to be injected;

[0018] Calculate the first current value under the fault state calculated by the first control model;

[0019] The first current value after the injected current is constrained according to the first current constraint.

[0020] As a preferred solution of the inverter control method based on power value setting described in the present invention, wherein: the step of determining the level of the current to be injected according to the first voltage difference and the preset first switching threshold value further comprises:

[0021] The first switching threshold includes a first threshold and a second threshold;

[0022] The current levels to be injected include a first level, a second level and a third level;

[0023] The level of the current to be injected is divided into levels by changing the inverter power by injecting the current.

[0024] As a preferred solution of the inverter control method based on power value setting described in the present invention, wherein: the first voltage difference includes: representing the first voltage difference by a voltage drop level.

[0025] As a preferred solution of the inverter control method based on power value setting described in the present invention, wherein: the step of determining the level of the current to be injected according to the first voltage difference and the preset first switching threshold value further comprises:

[0026] determining a voltage drop level according to the first voltage difference;

[0027] Performing a first switching threshold determination according to the voltage drop level;

[0028] A current of a corresponding current level is injected according to the first switching threshold determination result.

[0029] In a second aspect, the present invention provides an inverter control system based on power value setting, comprising:

[0030] A model building module, used to build a first control model, and calculate a first voltage difference under a fault state according to the first control model;

[0031] A level determination module, configured to determine a level of the current to be injected according to the first voltage difference and a preset first switching threshold;

[0032] The control module is used to preset a first current constraint and control a first control model parameter after the current is injected according to the first current constraint.

[0033] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned method when executing the computer program.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes an inverter control method and system based on power value setting, establishes a first control model, calculates a first voltage difference under a fault state according to the first control model; judges the current level to be injected according to the first voltage difference in combination with a preset first switching threshold; presets a first current constraint, and controls the first control model parameters after the current is injected according to the first current constraint. The inverter control technology principle of the present application is clear and the difficulty is relatively low. The present application switches the power command on the traditional VSG control, and can output sufficient reactive power while providing inertial support to the power grid system. The present application addresses the overcurrent problem that may occur in the inverter during a fault, and adds a current limiting link in the control link to maintain the safe and stable operation of the inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0037] Figure 1 A method flow chart of an inverter control method and system based on power value setting provided by one embodiment of the present invention;

[0038] Figure 2 A flowchart of an inverter control strategy based on power value setting of an inverter control method and system based on power value setting provided by an embodiment of the present invention;

[0039] Figure 3 A structural diagram of adding positive and negative sequence current control to suppress negative sequence current under asymmetric fault of an inverter control method based on power value setting and a system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] Reference Figure 1-Figure 3 , which is the first embodiment of the present invention, provides an inverter control method and system based on power value setting, including:

[0043] In the existing related technologies, there are some problems, such as the inverter may not be able to provide sufficient reactive power support during the fault ride-through process, or the overcurrent protection mechanism of the inverter may not work effectively during the fault, resulting in damage to the inverter.

[0044] The present application provides a method that can effectively solve the above-mentioned problems. Next, multiple embodiments will be combined to explain in detail how to implement the inverter control method based on power value setting.

[0045] Figure 1 A method flow chart of an inverter control method and system based on power value setting is shown, including:

[0046] S101, establishing a first control model, and calculating a first voltage difference under a fault state according to the first control model;

[0047] In an optional embodiment, in order to realize the control of the inverter, the first control model selected to be established is generally an inverter-related control model. For example, the first control model can be a virtual synchronous generator (VSG) control model. The model can simulate the dynamic characteristics of the synchronous generator, including inertia, damping, and voltage and frequency regulation capabilities. In a fault state, the difference between the inverter output voltage and the grid voltage, that is, the first voltage difference, can be calculated through the model.

[0048] In an optional embodiment, the first control model may also be other types of control models, such as a model based on proportional integral derivative (PID) control, or other models that can adapt to the inverter fault ride-through control requirements. These models can be designed and adjusted according to the specific working environment and requirements of the inverter.

[0049] In an optional embodiment, the fault state may include many types of faults, such as short circuit fault, overload fault, voltage drop, etc. Under these fault states, the difference between the output voltage of the inverter and the grid voltage will be different, so the first control model needs to be able to accurately calculate the first voltage difference under these different fault states.

[0050] In the embodiments of the present application, the fault state is not limited, and the method designed in the present application can be used for inverter control after various fault states and has universal applicability.

[0051] In the embodiment of the present application, the first control model is an inverter control model, and the specific establishment steps may be as follows:

[0052] According to the generator motion equation and excitation voltage equation, the VSG (virtual synchronous generator) outer loop control equation is established as follows:

[0053]

[0054] Among them, J is the virtual inertia, D is the virtual damping, ω is the angular velocity, P ref and P e is the active power reference value and output value, E is the internal potential, Q ref and Q e is the reactive power reference value and output value, D q is the voltage coefficient, V pcc and V N The grid connection point voltage and voltage rating;

[0055] Furthermore, according to the three-element method of current during fault, the current expression between the inverter and the grid can be obtained as:

[0056]

[0057] Among them, R g and X g is the line resistance and reactance, V is the inverter output voltage, V g is the grid voltage, V gF is the grid voltage during the fault period;

[0058] In the embodiment of the present application, it is considered that the line impedance between the inverter and the grid is inductive, and the inverter output power is:

[0059]

[0060] Where δ is the power angle, V g is the grid voltage;

[0061] It should be noted that establishing the first control model and calculating the first voltage difference under the fault state according to the first control model can accurately evaluate the voltage difference between the inverter and the grid during the fault, and provide necessary data support for the subsequent fault ride-through control strategy.

[0062] It should be noted that, in a fault state, the difference between the inverter output voltage and the grid voltage is a key factor affecting whether the inverter can effectively participate in the grid voltage and frequency regulation. By establishing the first control model and calculating the first voltage difference, a quantitative reference standard can be provided for the inverter fault ride-through control, thereby achieving precise control of the inverter output power.

[0063] In an optional embodiment, the first voltage difference can directly or indirectly represent the voltage change before and after the fault in various ways, for example, the first voltage difference can be represented by a voltage drop level. The voltage drop level can be the difference between the grid voltage before and after the fault occurs, or the difference between the grid voltage and the rated voltage during the fault. Through such a representation method, the degree of influence of the fault on the grid voltage can be more intuitively understood, thereby providing a more accurate control basis for the fault ride-through control of the inverter.

[0064] In an optional embodiment, the calculation of the first voltage difference may also be optimized in combination with the control target of the inverter. For example, if the control target of the inverter is to provide sufficient reactive power support, then when calculating the first voltage difference, more attention may be paid to the change of reactive power, thereby optimizing the reactive output of the inverter to meet the needs of the power grid.

[0065] In the embodiment of the present application, the first voltage difference includes: representing the first voltage difference by a voltage drop level.

[0066] In an optional embodiment, the calculation of the first voltage difference may be adjusted in combination with the operating state of the inverter. For example, when the inverter operates under different load conditions, the calculation method of the first voltage difference may be different to adapt to different operating environments and requirements.

[0067] In summary, the inverter control method and system based on power value setting provided in the embodiment of the present application can accurately evaluate the voltage difference between the inverter and the power grid during the fault by establishing a first control model and calculating the first voltage difference under the fault state, and provide necessary data support for the subsequent fault ride-through control strategy. At the same time, by optimizing the calculation method of the first voltage difference, the fault ride-through control effect of the inverter can be further improved to meet the control requirements of the power grid on the inverter.

[0068] S102, determining a level of current to be injected according to the first voltage difference and a preset first switching threshold;

[0069] In the embodiment of the present application, judging the level of the current to be injected according to the first voltage difference and the preset first switching threshold value includes:

[0070] Preset a plurality of switching thresholds as the first switching threshold, the switching threshold being a voltage threshold or a related numerical threshold that can directly or indirectly obtain the voltage threshold;

[0071] Several switching thresholds correspond to several injection current levels.

[0072] In an optional embodiment, the number of switching thresholds and the size of the switching thresholds may be determined according to actual needs of technicians;

[0073] In an optional embodiment, the switching threshold is designed to protect the power system with severe voltage drops by injecting current by judging the voltage difference. Therefore, relevant technicians can design the switching threshold according to the actual protection accuracy required, for example, design multiple voltage thresholds to achieve precise control of different voltage drop levels. For example, a lower voltage threshold can be set for slight voltage drops, while a higher voltage threshold is used for severe voltage drops. In this way, it can be ensured that when a voltage drop occurs, the inverter can respond in time and inject appropriate current to support the stable operation of the power grid.

[0074] In an optional embodiment, the switching threshold may also be set in consideration of the capacity of the inverter and the load of the power grid. For example, if the inverter has a larger capacity, a higher switching threshold may be set to provide more reactive power support; on the contrary, if the power grid is heavily loaded, a lower switching threshold may need to be set to avoid overload.

[0075] In an optional embodiment, the numerical thresholds related to the voltage threshold that can be directly or indirectly obtained may be current thresholds, power thresholds, frequency thresholds, etc. These thresholds may be associated with the voltage threshold to achieve more comprehensive system protection.

[0076] It should be noted that the relevant technical personnel design the numerical threshold value related to the voltage threshold that can be directly or indirectly obtained, which is essentially to obtain the voltage threshold, so such operations should all be within the protection scope of this application.

[0077] In the embodiment of the present application, judging the level of the current to be injected according to the first voltage difference and the preset first switching threshold value further includes:

[0078] The first switching threshold includes a first threshold and a second threshold;

[0079] The current levels to be injected include the first level, the second level and the third level;

[0080] The level of the current to be injected is divided into different levels by changing the inverter power by injecting the current.

[0081] In an optional embodiment, the first level of current may correspond to a slight voltage drop, in which case the inverter injects a smaller current to provide basic reactive power support; the second level of current corresponds to a moderate voltage drop, in which case the inverter injects an increased current to provide more reactive power support; the third level of current corresponds to a severe voltage drop, in which case the inverter injects a maximum current to maintain stable operation of the power grid as much as possible.

[0082] In the embodiment of the present application, judging the level of the current to be injected according to the first voltage difference and the preset first switching threshold value further includes:

[0083] determining a voltage drop level according to the first voltage difference;

[0084] Performing a first switching threshold determination according to the voltage drop level;

[0085] A current of a corresponding current level is injected according to the first switching threshold determination result.

[0086] In an optional embodiment, different thresholds correspond to different current levels of current injection. For example, when the voltage difference exceeds the first threshold but does not reach the second threshold, the inverter will inject the second level of current to provide a moderate degree of reactive power support; when the voltage difference exceeds the second threshold, the inverter will inject the third level of current to provide the maximum degree of reactive power support. In this way, the inverter can dynamically adjust its output current according to the actual needs of the power grid, thereby providing effective voltage support during faults while avoiding equipment damage caused by overload.

[0087] It should be noted that the setting of the preset first switching threshold is based on comprehensive consideration of grid stability and inverter safety. By setting these thresholds reasonably, it can be ensured that the inverter can provide sufficient reactive power support during the fault ride-through process and will not be damaged by overload, thereby achieving efficient and safe operation of the inverter.

[0088] S103, presetting a first current constraint, and controlling a first control model parameter after the current is injected according to the first current constraint.

[0089] In the embodiment of the present application, the first current constraint includes:

[0090] The first current constraint is an arbitrary constraint designed according to the overcurrent capability of the target inverter;

[0091] The first current constraint includes at least a current limit constraint and a positive and negative sequence constraint.

[0092] In an optional embodiment, the first current constraint may be a current limit value, which is used to ensure that the inverter is not damaged due to overcurrent during a fault. The current limit value is usually set based on the maximum allowable current of the inverter to prevent the inverter output current from exceeding its rated value, thereby protecting the inverter from damage.

[0093] In an optional embodiment, the setting of the current limit constraint also takes into account the operating environment and load conditions of the inverter. For example, when the grid load is heavy, the current limit value may need to be reduced to avoid inverter overload; while when the load is light, the current limit value may be appropriately increased to fully utilize the capacity of the inverter.

[0094] In an optional embodiment, positive and negative sequence constraints are used to handle asymmetric faults in the power grid, such as single-phase ground faults. In these cases, the grid voltage and current will contain positive and negative sequence components. By setting positive and negative sequence constraints, it can be ensured that the inverter can effectively suppress the negative sequence current during the fault, thereby maintaining the stable operation of the power grid.

[0095] In the embodiment of the present application, the first current constraint is to stipulate that the maximum grid-side current cannot exceed 1.1 times the rated current, so the maximum apparent power during the fault is Smax:

[0096]

[0097] Among them, I max is the maximum current that the inverter can withstand, V pcc is the grid connection point voltage;

[0098] In the embodiment of the present application, the active power output by the inverter in normal conditions and during a fault is respectively:

[0099]

[0100] Considering the power angle stability, the inverter power reference value is maintained as follows during the fault period:

[0101]

[0102] To meet the reactive current that should be injected into the grid when the voltage drops seriously, the reference values ​​of active power and reactive power are taken as:

[0103]

[0104] Among them, K q is the reactive power coefficient, S is the apparent power during the fault period;

[0105] Calculate the voltage drop level U for switching the active power and reactive power command values h :

[0106]

[0107] In the embodiment of the present application, the first current constraint is preset, and the first control model parameter after the current is injected is controlled according to the first current constraint, including:

[0108] After determining the level of the current to be injected, injecting the current according to the level of the current to be injected;

[0109] Calculate a first current value under a fault state calculated by a first control model;

[0110] The first current value after the current injection is constrained according to the first current constraint.

[0111] In the embodiment of the present application, considering the asymmetric fault in the power grid, the voltage and current loop part in the inverter control adopts positive and negative sequence separation, suppresses the negative sequence component in the inverter output current, and sets the reference values ​​of the dq axis components of the negative sequence current to zero;

[0112] In the embodiment of the present application, the current limit is set according to the overcurrent capacity of the inverter to achieve safe operation;

[0113] The maximum current output by the inverter is limited to 1.1 times the rated current. The specific steps include:

[0114] It is considered that the maximum three-phase current output by the inverter is:

[0115]

[0116] Among them I + and I - are positive and negative sequence currents respectively, μ is the maximum value of the phase angle;

[0117] In order to ensure that the inverter provides sufficient reactive power, the reference current of the positive and negative sequence of the q axis is preferably determined as:

[0118]

[0119] According to the specified maximum 1.1 times rated current, the reference current of the positive and negative sequence of the d-axis is determined as:

[0120]

[0121] In summary, the present invention proposes an inverter control method based on power value setting, establishes a first control model, calculates a first voltage difference under a fault state according to the first control model; judges the current level to be injected according to the first voltage difference in combination with a preset first switching threshold; presets a first current constraint, and controls the first control model parameters after the injected current according to the first current constraint. The inverter control technology principle of the present application is clear and the difficulty is relatively low. The present application switches the power command on the traditional VSG control, and can output sufficient reactive power while providing inertial support to the power grid system. The present application addresses the overcurrent problem that may occur in the inverter during a fault, and adds a current limiting link in the control link to maintain the safe and stable operation of the inverter.

[0122] Example 2

[0123] In an alternative embodiment, the following is established: Figure 2 The flowchart of the inverter control strategy based on power value setting is shown, that is, the first switching threshold judgment logic schematic diagram, wherein, when it is judged that the voltage value at the grid connection point is greater than 0.9pu, P ref =S,Q ref =0, then the process ends. When it is determined that the voltage value at the grid connection point is not greater than 0.9pu, the process proceeds to the second step of determining whether the voltage value during the fault period is greater than 0.9pu. If so, considering the power angle stability, the inverter power reference value during the fault period is maintained as follows:

[0124]

[0125] If yes, the reactive current that should be injected into the grid when the voltage drop is serious, the reference values ​​of active power and reactive power are taken as:

[0126]

[0127] Among them, K q is the reactive power coefficient, S is the apparent power during the fault period;

[0128] Figure 3The structure diagram of adding positive and negative sequence current control to suppress negative sequence current after an asymmetric fault occurs under the condition of the maximum current that the given inverter can withstand. The positive sequence voltage reference value of the positive sequence part is input to the respective PI controller. The output of the PI controller passes through the ωL link (representing the voltage drop on the inductor) and is then added to the original input to form a new voltage command. After the new voltage command is transformed by dq / αβ, the three-phase voltage command is obtained, and the required switching signal is generated through PWM modulation. In the negative sequence part, the negative sequence voltage reference value passes through the PI controller and the ωL link to form a new voltage command. The new voltage command also needs to be transformed by dq / αβ, but in the opposite direction, and finally superimposed on the three-phase voltage command generated by the positive sequence part. PI controller: proportional integral controller, used to adjust the deviation so that the system reaches the desired state. ωL link: represents the response of the inductor element to the current change, simulating the voltage drop on the inductor. dq / αβ transformation: converts the signal in the rectangular coordinate system (dq) into the signal in the stationary coordinate system (αβ) to facilitate the subsequent three-phase transformation. PWM modulator: Converts voltage commands into pulse-width modulated signals suitable for driving power electronic switches.

[0129] Example 3

[0130] This embodiment also provides an inverter control system based on power value setting, including:

[0131] A model building module, used to build a first control model, and calculate a first voltage difference under a fault state according to the first control model;

[0132] A level determination module, used for determining the level of the current to be injected according to the first voltage difference and a preset first switching threshold;

[0133] The control module is used to preset a first current constraint and control a first control model parameter after the current is injected according to the first current constraint.

[0134] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0135] This embodiment also provides an electronic device, which includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a busbar pressure loss load transfer analysis method is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0136] This embodiment also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method proposed in the above embodiment is implemented.

[0137] The storage medium proposed in this embodiment and the method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0138] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0139] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0140] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0141] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0142] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0143] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1A step that specifies a function in one or more boxes.

[0144] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0145] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An inverter control method based on power value setting, characterized in that: include: Establishing a first control model, and calculating a first voltage difference under a fault state according to the first control model; Determine the level of the current to be injected according to the first voltage difference and a preset first switching threshold; A first current constraint is preset, and a first control model parameter after the current is injected is controlled according to the first current constraint.

2. The inverter control method based on power value setting according to claim 1, characterized in that: The step of determining the level of the current to be injected according to the first voltage difference and in combination with a preset first switching threshold value comprises: Preset a plurality of switching thresholds as the first switching threshold, wherein the switching threshold is a voltage threshold or a related numerical threshold that can directly or indirectly obtain the voltage threshold; Several switching thresholds correspond to several injection current levels.

3. The inverter control method based on power value setting according to claim 2, characterized in that: The first current constraint comprises: The first current constraint is an arbitrary constraint designed according to the overcurrent capability of the target inverter; The first current constraint includes at least a current limit constraint and a positive and negative sequence constraint.

4. The inverter control method based on power value setting according to claim 3, characterized in that: The preset first current constraint and controlling the first control model parameter after the current is injected according to the first current constraint include: After determining the level of the current to be injected, injecting the current according to the level of the current to be injected; Calculate the first current value under the fault state calculated by the first control model; The first current value after the injected current is constrained according to the first current constraint.

5. The inverter control method based on power value setting according to claim 4, characterized in that: The step of determining the level of the current to be injected according to the first voltage difference and a preset first switching threshold value further comprises: The first switching threshold includes a first threshold and a second threshold; The current levels to be injected include a first level, a second level and a third level; The level of the current to be injected is divided into levels by changing the inverter power by injecting the current.

6. The inverter control method based on power value setting according to claim 5, characterized in that: The first voltage difference includes: representing the first voltage difference by a voltage drop level.

7. The inverter control method based on power value setting according to claim 6, characterized in that: The step of determining the level of the current to be injected according to the first voltage difference and a preset first switching threshold value further comprises: determining a voltage drop level according to the first voltage difference; Performing a first switching threshold determination according to the voltage drop level; A current of a corresponding current level is injected according to the first switching threshold determination result.

8. An inverter control system based on power value setting, characterized in that: include: A model building module, used to build a first control model, and calculate a first voltage difference under a fault state according to the first control model; A level determination module, configured to determine a level of the current to be injected according to the first voltage difference and a preset first switching threshold; The control module is used to preset a first current constraint and control a first control model parameter after the current is injected according to the first current constraint.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the busbar pressure loss load transfer analysis method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the busbar voltage loss load transfer analysis method according to any one of claims 1 to 7.

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