Quantitative evaluation method for system reactive power reserve adequacy and related device

Abstract

The invention provides a system reactive power reserve adequacy quantitative evaluation method and a related device, and the method comprises the steps: carrying out the time domain simulation of a system according to a set system mode and fault, and detecting the weakest part of transient voltage; a virtual standard reactive power source is added to the weakest transient voltage; time domain simulation is carried out again, after the system fault is cleared, a standard reactive power source is put into use according to a specific mode, and whether the critical transient voltage of the system is stable or not is judged; if not, the current maximum value is adjusted, and time domain simulation is carried out again; and if yes, taking the reactive power corresponding to the maximum current value as the reactive power reserve adequacy under the set system mode and fault when the critical transient voltage of the system is stable. The reactive power charge reserve adequacy determined by the method can be used for quantitatively evaluating the balance relationship between the reactive power reserve and the reactive power demand of the system, and can also provide a theoretical basis for optimizing the excitation control parameters of the generator and the operation and control of a receiving end power grid.

Description

Technical Field

[0001] The invention belongs to the technical field of power system safety and stability analysis, and in particular relates to a quantitative evaluation method and related device for system reactive power reserve margin. Background Art

[0002] With the increasing number of DC transmission lines and their centralized feeding into the load center, the reactive characteristics of the receiving power system undergo complex changes when it suffers from serious faults such as short circuits. On the one hand, power transfer will lead to a significant increase in reactive power loss in the AC channel; on the other hand, the reactive power consumption of the DC converter station and the asynchronous motor load during the fault period increases sharply. These factors work together to significantly change the reactive power flow of the system. In the transient process following the fault, reactive power and voltage influence and restrict each other, and the dynamic response characteristics of the reactive power source largely determine the transient voltage stability level of the system. Once the dynamic reactive power reserve is insufficient, the system is very likely to experience a long-term deep voltage drop, which will cause transient voltage instability, which will seriously threaten the safe and reliable operation of the power system, and may even cause large-scale power outages, causing huge losses to the social economy. Therefore, in-depth research on the reactive power reserve of the system and accurate assessment of the reactive power reserve adequacy are of great significance to ensure the stable operation of the power system.

[0003] At present, although there have been some relevant research and technical means in the field of reactive reserve assessment of power systems, there are still many shortcomings. Traditional assessment methods often lack the ability to accurately quantify and analyze the dynamic balance relationship between reactive reserve and reactive demand under complex fault conditions. Some methods rely too much on empirical models or simplified calculations, and cannot fully consider the impact of actual complex situations such as multiple DC drop points, different types of loads, and multiple fault combinations on reactive reserves. In addition, the existing technology is obviously lacking in providing an accurate and effective theoretical basis for optimizing generator excitation control parameters and receiving-end power grid operation control, and it is difficult to meet the strict requirements of modern power systems for high safety stability and the ability to resist serious fault risks. This urgently requires a more scientific, comprehensive and accurate quantitative assessment method for system reactive reserve adequacy to fill the gaps in existing technologies, effectively solve the reactive reserve-related problems faced by the current power system, and promote the sustainable development of the power industry. Summary of the invention

[0004] In view of this, the present invention provides a quantitative evaluation method and related device for system reactive reserve margin, so as to accurately quantify the balance relationship between system reactive reserve and reactive demand, provide theoretical support for optimizing generator excitation control parameters and receiving-end power grid operation and control, and improve the safe and stable operation level of DC multi-drop receiving-end system and its ability to resist serious AC fault risks.

[0005] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for quantitatively evaluating the reactive power reserve margin of a system, comprising the following steps:

[0007] Perform time domain simulation of the system according to the set system mode and faults to detect the weakest point of transient voltage;

[0008] A virtual standard reactive power source is added at the weakest point of transient voltage; the maximum current of the standard reactive power source is determined according to the voltage difference between the weakest point of transient voltage and the critical transient voltage stability point;

[0009] Re-run the time domain simulation, and after the system fault is cleared, put the standard reactive power source into operation in a specific manner, and determine whether the system has critical transient voltage stability;

[0010] If not, adjust the maximum current value and re-perform the time domain simulation;

[0011] If so, the reactive power corresponding to the maximum current value when the system has critical transient voltage stability is used as the reactive power reserve margin under the setting system mode and fault.

[0012] Furthermore, a virtual standard reactive power source is added at the weakest point of transient voltage, including:

[0013] When the system is in the initial transient voltage stability, the maximum current is set to inductive;

[0014] When the system is in the initial transient voltage instability, the maximum current is set to capacitive.

[0015] Further, the specific method is:

[0016] The input process is simulated as a first-order low-pass filtering process that tracks the maximum current of the standard reactive power source.

[0017] Furthermore, the reactive power is calculated as follows:

[0018] Q = U E *I C

[0019] Where Q is reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

[0020] In a second aspect, the present invention provides a quantitative evaluation device for system reactive power reserve margin, comprising:

[0021] The simulation module is used to perform time domain simulation on the system according to the set system mode and fault, and detect the weakest point of transient voltage; it is also used to add a virtual standard reactive power source at the weakest point of transient voltage; the maximum current of the standard reactive power source is determined according to the voltage difference between the weakest point of transient voltage and the critical transient voltage stability; it is also used to re-perform time domain simulation, and after the system fault is cleared, put the standard reactive power source into use in a specific manner, and judge whether the system has critical transient voltage stability;

[0022] The reactive power judgment module is used to adjust the maximum current value when the system does not have critical transient voltage stability, and re-perform time domain simulation through the simulation module; it is also used to use the reactive power corresponding to the maximum current value as the reactive power reserve margin under setting system mode and fault when the system has critical transient voltage stability.

[0023] Furthermore, a virtual standard reactive power source is added at the weakest point of transient voltage, including:

[0024] When the system is in the initial transient voltage stability, the maximum current is set to inductive;

[0025] When the system is in the initial transient voltage instability, the maximum current is set to capacitive.

[0026] Further, the specific method is:

[0027] The input process is simulated as a first-order low-pass filtering process that tracks the maximum current of the standard reactive power source.

[0028] Furthermore, the reactive power is calculated as follows:

[0029] Q = U E *I C

[0030] Where Q is reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

[0031] In a third aspect, the present invention provides a computer device, the device comprising a processor and a memory:

[0032] The memory is used to store the computer program and send the instructions of the computer program to the processor;

[0033] The processor executes the method for quantitatively evaluating system reactive power reserve margin according to the instructions of the computer program as described in the first aspect.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for quantitatively evaluating system reactive power reserve adequacy as in the first aspect.

[0035] In summary, the present invention provides a quantitative evaluation method and related device for the system reactive reserve margin, including performing time domain simulation on the system according to the set system mode and fault, detecting the weakest point of transient voltage; adding a virtual standard reactive source at the weakest point of transient voltage; the current maximum value of the standard reactive source is determined according to the voltage difference between the weakest point of transient voltage and the critical transient voltage stability; re-performing time domain simulation, and after the system fault is cleared, putting in the standard reactive source in a specific way, and judging whether the system has critical transient voltage stability; if not, adjusting the current maximum value, and re-performing time domain simulation; if so, the reactive power corresponding to the current maximum value when the system has critical transient voltage stability is used as the reactive reserve margin under the set system mode and fault. The reactive reserve margin quantified by the present invention can be used to quantitatively evaluate the balance between reactive reserve and reactive demand of the system, and can also provide a theoretical basis for optimizing the excitation control parameters of the generator and the operation and control of the receiving power grid, thereby further improving the safe and stable operation level of the DC multi-drop receiving system and the ability to resist the risk of serious AC faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0037] Figure 1 A flowchart of a method for quantitatively evaluating system reactive power reserve adequacy provided by an embodiment of the present invention;

[0038] Figure 2 A flowchart of a method for quantitatively evaluating system reactive power reserve margin provided by another embodiment of the present invention;

[0039] Figure 3 A block diagram of a quantitative evaluation device for system reactive power reserve margin provided by another embodiment of the present invention;

[0040] Figure 4 A block diagram of a computer device provided in accordance with another embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] See also Figure 1 The embodiment of the present invention provides a quantitative evaluation method for system reactive power reserve margin, comprising the following steps:

[0043] S1: Perform time domain simulation of the system according to the set system mode and faults to detect the weakest point of transient voltage.

[0044] It should be noted that time domain simulation is a method of simulating and analyzing the dynamic behavior of a system in the time domain. In the power system, by establishing a mathematical model of the system, considering the electrical characteristics of various components (such as generators, transformers, lines, loads, etc.) and their interconnection relationships, and then gradually calculating the state variables of the system at different times (such as voltage, current, power, etc.) on the time axis, the actual operation process of the system under set working conditions (such as fault occurrence, fault clearance, etc.) is simulated.

[0045] During a power system failure and subsequent recovery, the voltage at different locations will change to varying degrees. The weakest transient voltage point refers to the specific location in the entire system where the voltage drops the most and is most likely to experience voltage instability when a fault occurs and for a period of time thereafter (transient process).

[0046] This step can fully and accurately simulate the operating state of the system under the actual working conditions that may be encountered by performing time domain simulation according to the set system mode (such as the system operation mode, network topology, etc.) and fault conditions, and then find the weakest point of transient voltage. This provides a basis for subsequent targeted analysis and resolution of the reactive power reserve problem at this weak point.

[0047] S2: Add a virtual standard reactive power source at the weakest point of transient voltage; the maximum current of the standard reactive power source is determined according to the voltage difference between the weakest point of transient voltage and the critical transient voltage stability point.

[0048] It should be noted that the virtual standard reactive power source is a reactive power source with standard characteristics that is assumed to be added during the simulation analysis process. It can output reactive power according to the set rules and is used to analyze the impact of adding reactive power compensation at a specific location on the transient voltage stability of the system.

[0049] This step determines the maximum current of the standard reactive power source based on the voltage difference between the weakest transient voltage point and the critical transient voltage stability point. If the voltage difference between this point and the critical stable state is large, it means that a larger reactive power compensation is needed to improve the voltage stability, and the determined maximum current will be correspondingly larger; otherwise, it will be smaller. At the same time, the initial attribute (inductive or capacitive) of the maximum current is determined based on whether the initial transient voltage of the system is stable. This is based on the different characteristics of the effects of inductive and capacitive reactive power on voltage (inductive reactive power can indicate that there is more reactive power reserve under certain circumstances, and capacitive reactive power is used when reactive power needs to be supplemented).

[0050] S3: Re-perform time domain simulation, and after the system fault is cleared, put the standard reactive power source into operation in a specific manner, and determine whether the system has critical transient voltage stability.

[0051] It should be noted that critical transient voltage stability means that during the transient process after a power system fails, the voltage is in a critical state, that is, a slight adverse effect (such as insufficient reactive power reserve) may lead to voltage instability (the voltage drops sharply and cannot return to the normal operating range), but if the current reactive power balance and other conditions can be maintained, the system can maintain stable operation.

[0052] In this step, in the new system state after the fault is cleared, the reactive source is put into operation in a specific manner that conforms to the gradual characteristics of the actual reactive source when it is put into operation, and then the voltage and other state variables of each point in the system are continued to be calculated through time domain simulation. By observing the voltage changes and comparing them with the critical transient voltage stability state, it is determined whether the system has reached the critical transient voltage stability.

[0053] S4: If not, adjust the maximum current value and perform time domain simulation again.

[0054] It should be noted that according to the latest status of system voltage and other state variables obtained in the previous round of time domain simulation, the degree of insufficient or excessive reactive compensation is analyzed, and then the maximum current of the standard reactive source is reasonably adjusted (such as increasing or decreasing the current value, or changing its inductive / capacitive properties), and then the time domain simulation is repeated in the same way as in step S3 to continue to observe whether the system can achieve critical transient voltage stability.

[0055] S5: If yes, the reactive power corresponding to the maximum current value when the system has critical transient voltage stability is used as the reactive power reserve margin under the set system mode and fault.

[0056] It should be noted that when the system has critical transient voltage stability, the reactive power corresponding to the maximum current at this time is used as the reactive power reserve margin for setting the system mode and fault conditions. This realizes the quantitative evaluation of the reactive power reserve margin of the system under specific working conditions, and provides specific data basis for subsequent judgment on whether the reactive power reserve of the system is sufficient and whether further optimization is needed.

[0057] This embodiment provides a quantitative evaluation method for the reactive reserve margin of a system. First, the weakest transient voltage of the system under the set working conditions is found through time domain simulation, and then a virtual standard reactive source is added to the weak point, and the maximum current is continuously adjusted. The reactive source is put into use in a specific way and the time domain simulation is re-performed to observe whether the system reaches the critical transient voltage stability. Through such repeated adjustment and observation process, the maximum current value that can make the system reach the critical transient voltage stability is finally found, and then the corresponding reactive value is calculated according to the maximum current value, which is used as the reactive reserve margin of the system under the set system mode and fault. The core implementation principle is based on the in-depth understanding of the mutual influence between reactive power and voltage in the power system during the fault and subsequent recovery process, and the reactive reserve margin of the system is quantitatively evaluated by simulating and adjusting reactive compensation. This method does not generally evaluate the reactive reserve of the entire system, but first accurately locates the weakest transient voltage, and then performs subsequent reactive compensation analysis and evaluation on the weak point, so that the reactive reserve amount that the system really needs under specific working conditions can be found more accurately, which improves the pertinence and accuracy of the evaluation.

[0058] In one embodiment, adding a virtual standard reactive power source at the weakest point of transient voltage also includes:

[0059] When the system is in the initial transient voltage stability, the maximum current is set to inductive;

[0060] When the system is in the initial transient voltage instability, the maximum current is set to capacitive.

[0061] Inductive reactive power is mainly generated by inductive components. In AC circuits, the inductive current lags behind the voltage. When the system's initial transient voltage is stable, the maximum current is set to inductive (positive value), which means that the system's dynamic reactive power reserve exceeds the reactive power demand. Inductive reactive power can maintain voltage stability or even raise voltage to a certain extent.

[0062] Capacitive reactive power is mainly generated by capacitor components, and the capacitive current leads the voltage. When the system's initial transient voltage is unstable, that is, when voltage drops and other unstable conditions occur, capacitive reactive power needs to be added to increase the voltage, so the maximum current is set to capacitive (negative value). This is because capacitive reactive power can compensate for the inductive reactive power in the system and quickly provide reactive power to support voltage recovery.

[0063] This method of setting the maximum current (IC) attribute according to whether the initial transient voltage of the system is stable or not is an important part of the quantitative evaluation method of the reactive reserve adequacy. It provides reasonable initial conditions for the subsequent observation of the system reactive-voltage dynamic process by adjusting the output of the virtual standard reactive source.

[0064] When I C When it is inductive (positive value), it means that the system is in a good reactive power reserve state at the beginning. In the subsequent time domain simulation, the voltage stability changes of the system under different reactive power reserve levels can be observed by appropriately adjusting the size of this inductive reactive power. C When it is capacitive (negative value), it is for the situation that the system has experienced transient voltage instability. From the beginning, it is determined that capacitive reactive power needs to be added to improve voltage stability. The subsequent adjustment process is also centered on how to find the appropriate capacitive reactive power compensation amount to make the system reach critical transient voltage stability. Such a setting can more accurately simulate and analyze the reactive power reserve requirements of the system under different initial states, thereby more effectively evaluating the system reactive power reserve margin.

[0065] In one embodiment, a specific method is: the switching process is simulated as a first-order low-pass filtering process that tracks the maximum current value of a standard reactive power source.

[0066] In this embodiment, the input process of the standard reactive power source is simulated as a first-order low-pass filtering process. When the reactive power source is input, its input amount does not reach the maximum value instantly, but gradually changes to reach the maximum value like after a first-order low-pass filtering. This is similar to the processing of the input signal by a first-order low-pass filter. After the input signal (corresponding to the reactive power source input amount) goes through a "processing process" with time characteristics, the output (the reactive power actually input into the system) gradually reaches a stable value.

[0067] The maximum current of the standard reactive source is a parameter closely related to the evaluation of the reactive reserve margin of the system. In the previous step, the maximum current of the standard reactive source was determined by determining the weakest point of the transient voltage and the voltage difference between it and the critical transient voltage stability. This maximum current represents the maximum current value that the reactive source needs to output when the system reaches the critical transient voltage stability. Its size reflects the amount of reactive compensation required by the system under specific working conditions.

[0068] This method of simulating the input process as a first-order low-pass filtering process that tracks the maximum current value of the standard reactive source is more in line with the physical characteristics of reactive source input in actual power systems.

[0069] In one embodiment, reactive power is calculated as follows:

[0070] Q = U E *I C

[0071] Where Q is reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

[0072] Figure 2 The present invention is a process of a quantitative evaluation method for a system reactive power reserve margin obtained by combining the specific input mode and reactive power calculation proposed in the above embodiment.

[0073] Based on the same inventive concept, the embodiment of the present application also provides a quantitative assessment device for system reactive power reserve margin for implementing the quantitative assessment method for system reactive power reserve margin involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiment of the quantitative assessment device for system reactive power reserve margin provided below can be referred to the limitations of the quantitative assessment method for system reactive power reserve margin above, and will not be repeated here.

[0074] See also Figure 3 The embodiment of the present invention provides a quantitative evaluation device for system reactive power reserve margin, comprising:

[0075] The simulation module is used to perform time domain simulation on the system according to the set system mode and fault, and detect the weakest point of transient voltage; it is also used to add a virtual standard reactive power source at the weakest point of transient voltage; the maximum current of the standard reactive power source is determined according to the voltage difference between the weakest point of transient voltage and the critical transient voltage stability; it is also used to re-perform time domain simulation, and after the system fault is cleared, put the standard reactive power source into use in a specific manner, and judge whether the system has critical transient voltage stability;

[0076] The reactive power judgment module is used to adjust the maximum current value when the system does not have critical transient voltage stability, and re-perform time domain simulation through the simulation module; it is also used to use the reactive power corresponding to the maximum current value as the reactive power reserve margin under setting system mode and fault when the system has critical transient voltage stability.

[0077] Furthermore, a virtual standard reactive power source is added at the weakest point of transient voltage, including:

[0078] When the system is in the initial transient voltage stability, the maximum current is set to inductive;

[0079] When the system is in the initial transient voltage instability, the maximum current is set to capacitive.

[0080] Further, the specific method is:

[0081] The input process is simulated as a first-order low-pass filtering process that tracks the maximum current of the standard reactive power source.

[0082] Furthermore, the reactive power is calculated as follows:

[0083] Q = U E *I C

[0084] Where Q is reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

[0085] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0086] Reference Figure 4 An embodiment of the present invention further provides a computer device, comprising: a memory and a processor and a computer program stored in the memory. When the computer program is executed on the processor, a quantitative evaluation method for system reactive power reserve margin as described in any one of the above methods is implemented.

[0087] The computer device may be a desktop computer, a notebook, a PDA, a cloud server or other computing device. The computer device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Figure 4 It is only an example of a computer device and does not constitute a limitation of the computer device. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0088] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0089] In some embodiments, the memory may be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. In other embodiments, the memory may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device. Further, the memory may include both an internal storage unit and an external storage device of the computer device. The memory is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory may also be used to temporarily store data that has been output or is to be output.

[0090] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for quantitatively evaluating the reactive power reserve adequacy of a system as described in any one of the above methods is implemented.

[0091] In this embodiment, if the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, USB flash drive, mobile hard disk, disk or optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0092] An embodiment of the present invention provides a computer program product, including a computer program, which, when executed by a processor, implements a method for quantitatively evaluating system reactive power reserve adequacy as described in any one of the above methods.

[0093] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0094] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0095] In the embodiments disclosed in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A quantitative evaluation method for system reactive power reserve margin, characterized in that: The steps include: Perform time domain simulation of the system according to the set system mode and faults to detect the weakest point of transient voltage; Adding a virtual standard reactive power source at the weakest point of the transient voltage; The maximum current value of the standard reactive power source is determined according to the voltage difference between the weakest point of the transient voltage and the critical transient voltage stability point; Re-perform time domain simulation, and after the system fault is cleared, put the standard reactive power source into use in a specific manner, and determine whether the system has critical transient voltage stability; If not, adjusting the maximum current value and re-performing the time domain simulation; If so, the reactive power corresponding to the maximum current value when the system has critical transient voltage stability is used as the reactive power reserve margin under setting system mode and fault.

2. The quantitative evaluation method for system reactive power reserve margin according to claim 1 is characterized in that: Adding a virtual standard reactive power source at the weakest point of the transient voltage, further comprising: When the system is in the initial transient voltage stability, the maximum current value is set to be inductive; When the system is in the initial transient voltage instability, the maximum current value is set to be capacitive.

3. The quantitative evaluation method for system reactive power reserve margin according to claim 1 is characterized in that: The specific method is: The switching process is simulated as a first-order low-pass filtering process that tracks the maximum current value of the standard reactive power source.

4. The quantitative evaluation method for system reactive power reserve margin according to claim 1 is characterized in that: The reactive power is calculated according to the following formula: Q = U E *I C Where Q is the reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

5. A quantitative evaluation device for system reactive power reserve margin, characterized in that: include: The simulation module is used to simulate the system in the time domain according to the set system mode and faults, and detect the weakest point of transient voltage; It is also used to add a virtual standard reactive power source at the weakest point of the transient voltage; the maximum current value of the standard reactive power source is determined according to the voltage difference between the weakest point of the transient voltage and the critical transient voltage stability; it is also used to re-perform the time domain simulation, and after the system fault is cleared, put the standard reactive power source into use in a specific manner, and judge whether the system has a critical transient voltage stability; The reactive power judgment module is used to adjust the maximum current value and re-perform time domain simulation through the simulation module when the system does not have critical transient voltage stability; it is also used to use the reactive power corresponding to the maximum current value as the reactive reserve margin for setting the system mode and fault when the system has critical transient voltage stability.

6. The quantitative evaluation device for system reactive power reserve margin according to claim 5, characterized in that: Adding a virtual standard reactive power source at the weakest point of the transient voltage, further comprising: When the system is in the initial transient voltage stability, the maximum current value is set to be inductive; When the system is in the initial transient voltage instability, the maximum current value is set to be capacitive.

7. The quantitative evaluation device for system reactive power reserve margin according to claim 5, characterized in that: The specific method is: The switching process is simulated as a first-order low-pass filtering process that tracks the maximum current value of the standard reactive power source.

8. The quantitative evaluation device for system reactive power reserve margin according to claim 5, characterized in that: The reactive power is calculated according to the following formula: Q = U E *I C Where Q is the reactive power. A negative value indicates insufficient reactive power reserve. E is the critical voltage, I C is the maximum current value.

9. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store a computer program and send instructions of the computer program to the processor; The processor executes a method for quantitatively evaluating system reactive power reserve adequacy according to any one of claims 1 to 7 according to instructions of the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, a quantitative evaluation method for system reactive power reserve margin is implemented according to any one of claims 1 to 7.

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