Constant-volume site selection method and device for parallel connection device, medium and terminal equipment

Abstract

The invention discloses a constant-volume site selection method and device for a parallel connection device, a medium and terminal equipment. According to the invention, the target voltage of the end user and the equivalent topological graph of the direct-current remote supply parallel device are analyzed, and the optimal equipment capacity and the corresponding alternating-current line length of the device under different conditions are calculated by using the nonlinear programming solver; comprise lengths from a transformer area head to a device rectification side, parallel connection of an AC line and an inversion side to a user side, and then the optimal installation position of the device is determined. The problem that in the prior art, the constant-volume site selection of the direct-current remote supply parallel device cannot be accurately carried out is solved.

Description

Technical Field

[0001] The present invention relates to the field of volume-fixed site selection for parallel devices, and in particular to a volume-fixed site selection method, device, medium and terminal equipment for parallel devices. Background Art

[0002] Low voltage problems are common at the end of power grid stations and remote areas. Power quality problems such as low voltage caused by long power supply radius seriously affect the life and production of low-voltage users. Traditional low-voltage solutions are mostly to install voltage regulators, which have limited adjustment range and range, and the on-site effect is not significant. The user experience is average, and the power supply quality of low-voltage users at the end of the station cannot be improved. The DC remote supply device uses power electronic converters to convert electrical energy from AC to DC, greatly reducing line losses and ensuring normal power consumption for end users. It has significant effects, a large adjustment range, and can achieve stepless voltage regulation.

[0003] In the existing power supply field, although DC remote supply devices have attracted attention due to their significant advantages in reducing line losses and improving voltage stability for end users, in practical applications, accurate sizing and site selection of these devices has always been a technical challenge. Traditional power system planning and design methods often focus on the optimization of AC power grids, while there is a lack of in-depth research and mature solutions for the integration and layout of DC technology.

[0004] The existing technology faces several major challenges in the capacity and site selection of DC devices:

[0005] (1) Technical complexity: DC remote supply devices involve complex components such as power electronic converters, and their operating characteristics are significantly different from those of AC systems. This requires planners to be familiar with not only traditional AC grid design, but also the specific requirements and limitations of DC technology. (2) Lack of standardized methods: Currently, there is no unified industry standard or widely recognized methodology for the sizing and site selection of DC remote supply devices. This makes their application in different regions and under different grid conditions complex and difficult to replicate. (3) System interactivity: The integration of DC devices affects the dynamic behavior of the entire grid, including voltage stability, power flow, and fault response. Existing technologies make it difficult to fully evaluate the impact of these interactions on grid performance, especially at the end of the grid and in remote areas. (4) Economic evaluation: The economic benefit evaluation of DC remote supply devices needs to consider equipment cost, installation cost, operation and maintenance cost, and indirect benefits brought about by improved power quality. Existing methods often find it difficult to accurately calculate these factors, which affects the accuracy of site selection decisions. (5) Limitations of planning tools: Existing power system planning tools and software are mostly designed for AC systems and lack sufficient support for the characteristics of DC devices. This limits planners' ability to simulate and optimize DC device performance during capacity and site selection.

[0006] Therefore, although DC remote power supply devices provide an effective solution in theory, in the actual power system planning and implementation, how to accurately size and site these devices to maximize technical advantages and optimize cost-effectiveness is still a difficult problem in the existing technology. Summary of the invention

[0007] The present invention provides a method, device, medium and terminal equipment for determining the capacity and site selection of a parallel device, so as to solve the problem that the prior art cannot accurately determine the capacity and site selection of a DC remote supply parallel device.

[0008] In a first aspect, the present application provides a method for determining the capacity and site selection of a DC remote power supply parallel device, comprising:

[0009] Obtain the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device;

[0010] Calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram;

[0011] According to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or the length of each first AC line, the length of each second AC line and the length of each third AC line are obtained by solving;

[0012] Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user;

[0013] According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

[0014] This application can understand the needs and structure of the power system in detail by obtaining the target voltage value of each end user and the equivalent topological diagram of each DC remote supply parallel device. Secondly, using these topological diagrams, this application can calculate the equipment capacity expression of each DC remote supply parallel device. Then, by applying a nonlinear programming solver and combining the target voltage value and equipment capacity expression of the end user, this application can systematically solve the equipment capacity required for each DC remote supply parallel device under different circumstances, as well as the corresponding AC line length, including each first AC line length (from the station head to the rectifier side of the DC remote supply device), each second AC line length (AC line in parallel with the DC remote supply device), and each third AC line length (from the inverter side of the DC remote supply device to the end user). The data of these line lengths are crucial for determining the optimal installation location of the DC remote supply parallel device. Finally, based on these line lengths, this application can determine the optimal installation address of each DC remote supply parallel device under various circumstances. The present application provides a comprehensive and systematic optimization strategy, which not only ensures that the power supply meets the needs of end users, but also improves the efficiency and reliability of the power system, so as to solve the problem of the inability to accurately determine the capacity and site selection of DC remote supply parallel devices in the prior art.

[0015] As a preferred embodiment of the first aspect, the equipment capacity expression of each DC remote power supply parallel device is calculated according to the equivalent topology diagram, specifically:

[0016] Obtaining each station head voltage, each expected output current and the equivalent impedance value of each end user in each topological diagram;

[0017] According to each substation head voltage, each expected output current and the equivalent impedance value of each end user in each topological diagram, Kirchhoff's law voltage equation group and Kirchhoff's current law equation group are solved to obtain the equipment capacity expression of each DC remote supply parallel device.

[0018] In this preferred embodiment, the present application can accurately capture the electrical characteristics of key nodes in the power system by using an equivalent topological diagram to obtain the station head voltage, expected output current and equivalent impedance value of the end user of each DC remote supply parallel device. Provides necessary input parameters for subsequent calculations. Then, based on these parameters, the present application uses Kirchhoff's law voltage equation group and Kirchhoff's current law equation group to solve. These two equation groups are basic tools in circuit analysis and can describe the distribution law of voltage and current in the circuit. Through this process, the present application can obtain the equipment capacity expression of each DC remote supply parallel device, which not only includes the power demand of the device, but also reflects its actual role in the power grid. Such an equipment capacity expression is crucial for optimizing the design and operation of the power system because it can predict and adjust the operating state of the device to meet the dynamic needs of the power grid and improve the efficiency of power transmission. The present application can improve the stability and reliability of the power system, while reducing energy consumption and operating costs, and realizing efficient management and utilization of power resources.

[0019] As a preferred embodiment of the first aspect, the installation addresses of the DC remote power supply parallel devices are obtained according to the lengths of the first AC lines, the lengths of the second AC lines, and the lengths of the third AC lines, specifically:

[0020] According to the equipment capacity expressions of each DC remote supply parallel device and the first constraint condition, each first equipment capacity is obtained by solving;

[0021] Obtaining a first installation address according to each first device capacity, each first AC line length, each second AC line length, and each third AC line length;

[0022] The first constraint condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user.

[0023] In this preferred embodiment, the present application, in the case of not presetting the installation address and equipment capacity, can effectively reduce the initial investment and operating cost of the DC remote supply parallel device by setting the fixed capacity site selection problem as minimizing the equipment capacity. Using a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and specific constraints, the present application can accurately calculate the minimum equipment capacity required under the premise of meeting the power grid performance requirements. This process not only optimizes resource allocation, but also improves the economy of the system. Subsequently, based on the calculated minimum equipment capacity, together with the specific length parameters of the AC line, the optimal installation location of the device, i.e., the first installation address, can be determined. The determination of this position takes into account the total length of the AC line from the station head to the rectifier side of the DC remote supply device, the AC line parallel to the DC remote supply device, and the AC line from the inverter side of the DC remote supply device to the end user, ensuring the rationality of the line configuration and the efficiency of power transmission. Through mathematical modeling and optimization algorithms, the present application not only ensures the reliability and efficiency of power supply, but also provides a scientific and systematic decision support for power grid planning and the site selection of DC devices, thereby reducing construction and operation costs while improving power quality, and achieving a dual improvement in economic and social benefits.

[0024] As a preferred embodiment of the first aspect, the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device are solved to obtain each equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length, specifically:

[0025] According to the equipment capacity expression of each DC remote supply parallel device and the second constraint condition, the target voltage value of each first largest end user is obtained by solving;

[0026] According to the first maximum user target voltage values, one or more addresses are selected from the preset second installation addresses;

[0027] Wherein, the first sub-condition of the second constraint condition is to solve the target voltage value of each first maximum end user under the condition that the capacity of each preset second device remains unchanged;

[0028] The second sub-condition of the second constraint condition is that each first maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

[0029] In this preferred embodiment, the present application sets the goal of the fixed capacity site selection problem as verifying whether the target voltage value of the first largest end user can reach the preset target voltage value of the end user, so as to ensure that the power supply meets the specific needs of the user. By using a nonlinear programming solver, combined with the equipment capacity expression and the second constraint of the DC remote supply parallel device, the maximum end user voltage that can be achieved under a given equipment capacity can be accurately calculated. This step is the key to ensuring the quality of power supply. Subsequently, based on the calculated target voltage value of the first largest user, the present application can be screened in the preset second installation address, and those addresses that can achieve or exceed the preset voltage value can be selected, thereby ensuring that the selected address can provide users with stable and expected power services. Through precise mathematical modeling and optimization algorithms, the present application not only improves the reliability of power supply and user satisfaction, but also optimizes resource allocation, reduces unnecessary equipment investment and energy waste, and achieves a dual improvement in economic benefits and service quality.

[0030] As a preferred embodiment of the first aspect, the installation addresses of the DC remote power supply parallel devices are obtained according to the lengths of the first AC lines, the lengths of the second AC lines, and the lengths of the third AC lines, specifically:

[0031] According to the equipment capacity expression of each DC remote supply parallel device and the third constraint condition, the target voltage value of each second largest end user is obtained by solving;

[0032] Each third installation address is obtained based on the target voltage value of each second maximum end user, the AC line length from the substation head to the rectifier side of the DC remote power supply device, each first AC line length, each second AC line length and each third AC line length.

[0033] The third constraint condition includes a first sub-condition, a second sub-condition and a third sub-condition;

[0034] The first sub-condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user;

[0035] The second sub-condition is that each second maximum end-user target voltage value is greater than or equal to the target voltage value of each end user;

[0036] The third sub-condition is to solve the target voltage value of each second largest end user under the condition that the preset capacity of each third device remains unchanged.

[0037] In this preferred embodiment, the present application can optimize the layout of the DC remote supply parallel device and ensure the efficiency and quality of power supply by solving the fixed capacity site selection problem to find the third installation address that can achieve the target voltage value of the second largest end user. Using a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and the third constraint, the present application can calculate the maximum end-user voltage that can be achieved under the specific equipment capacity limit. This step is crucial to improving the efficiency of the power system. By considering the length of the AC line from the station head to the rectifier side of the DC remote supply device, the parallel AC line of the DC remote supply device, and the AC line length from the inverter side of the DC remote supply device to the end user, the present application can accurately determine the best installation location, that is, the third installation address, which not only meets the constraint of the total length of the line, but also ensures that the voltage value reaches or exceeds the preset target. In addition, by ensuring that the target voltage value of the second largest end user is greater than or equal to the preset target voltage value of the end user, the present application can guarantee the quality of power supply at the user end. Through precise mathematical modeling and optimization algorithms, this application not only improves the reliability of power supply and user satisfaction, but also optimizes resource allocation, ensures the economy and efficiency of the power system, and achieves a dual improvement in technical performance and economic benefits.

[0038] As a preferred embodiment of the first aspect, it also includes:

[0039] According to the equipment capacity expressions of each DC remote supply parallel device and the fourth constraint condition, the fourth equipment capacities corresponding to each DC remote supply parallel device are obtained by solving;

[0040] The fourth constraint condition is that each third maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

[0041] In this preferred embodiment, the present application can achieve cost-effectiveness optimization by setting the goal of the fixed capacity site selection problem to minimize the fourth equipment capacity, while ensuring that the power supply meets the specific needs of users. The present application uses a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and the fourth constraint, to accurately calculate the minimum equipment capacity required at a given installation address. This step is crucial for controlling project costs and improving system efficiency. The present application ensures that the operation of the device at the fourth installation address not only meets the basic power supply requirements, but also provides stable and reliable power services by ensuring that the third maximum end-user target voltage value is greater than or equal to the preset end-user target voltage value. Through precise mathematical modeling and optimization algorithms, the present application not only ensures the quality and reliability of power supply, but also optimizes the configuration and use of equipment, reduces unnecessary over-configuration of equipment, and thus achieves a dual improvement in economic benefits and service quality.

[0042] In a second aspect, the present application provides a device for determining the volume and location of a parallel device. The device for determining the volume and location of a parallel device comprises an acquisition module, a calculation module and a solution module;

[0043] The acquisition module is used to obtain the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device;

[0044] The calculation module is used to calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram;

[0045] The solving module is used to solve and obtain each equipment capacity of each DC remote supply parallel device or each first AC line length, each second AC line length and each third AC line length according to the target voltage value of the end user and the equipment capacity expression of each DC remote supply parallel device;

[0046] Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user;

[0047] According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

[0048] This device uses three modules to divide the work and coordinate the work to better determine the capacity and site selection of the parallel device of the DC remote supply. This application can understand the needs and structure of the power system in detail by obtaining the target voltage value of each end user and the equivalent topological diagram of each DC remote supply parallel device. Secondly, using these topological diagrams, this application can calculate the equipment capacity expression of each DC remote supply parallel device. Then, by applying a nonlinear programming solver and combining the target voltage value and equipment capacity expression of the end user, this application can systematically solve the equipment capacity required for each DC remote supply parallel device under different circumstances, as well as the corresponding AC line length, including each first AC line length (from the station area head to the rectifier side of the DC remote supply device), each second AC line length (AC line in parallel with the DC remote supply device), and each third AC line length (DC remote supply device inverter side to the end user). The data of these line lengths are crucial to determining the optimal installation location of the DC remote supply parallel device. Finally, based on these line lengths, this application can determine the optimal installation address of each DC remote supply parallel device under various circumstances. The present application provides a comprehensive and systematic optimization strategy, which not only ensures that the power supply meets the needs of end users, but also improves the efficiency and reliability of the power system, so as to solve the problem of the inability to accurately determine the capacity and site selection of DC remote supply parallel devices in the prior art.

[0049] In a third aspect, the present application provides a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute a method for selecting a location for a constant capacity of a parallel device as described. The beneficial effect is the same as the method for selecting a location for a constant capacity of a parallel device provided in the first aspect of the present application.

[0050] In a fourth aspect, the present application provides a terminal device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements any one of the constant capacity site selection methods for parallel devices described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 : A flow chart of an embodiment of a method for selecting a location for a constant capacity of a parallel device provided in the present application;

[0052] Figure 2 : A schematic diagram of the actual topology of the DC remote power supply parallel device provided in this application;

[0053] Figure 3 : A schematic diagram of the structural equivalent topology of the DC remote supply parallel device provided in this application;

[0054] Figure 4 : A structural schematic diagram of an embodiment of a constant volume site selection device for a parallel device provided in the present application. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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.

[0056] Embodiment 1

[0057] Please refer to Figure 1 , which is a method for constant capacity site selection of a parallel device provided in an embodiment of the present invention.

[0058] In this embodiment, the process of the method for selecting a site for a constant capacity of a parallel device in the present application is described in detail through steps S01-S03.

[0059] When the DC remote parallel supply device is not started, the AC line transmits power from the substation to the end user. The long power supply line increases the AC line loss, causing the voltage of the end user to drop. Too low a voltage will affect the quality of the user's electricity. When the DC remote parallel supply device is started, the rectifier of the device is used to maintain the stability of the DC voltage. The inverter of the device can be regarded as a current source output. The inverter current increases and the original AC line current decreases, thereby raising the voltage of the end user to achieve the purpose of low voltage management. Figure 2 As shown. Therefore, when determining the capacity and address of the equipment, the rectifier and inverter can be regarded as equivalent current sources, and the DC remote supply parallel device transmits current to the outside. In order to simplify the analysis, the single-phase DC remote supply equivalent topology is as follows Figure 3 As shown, the voltage at the substation head is relatively stable and is equivalent to a voltage source. The DC remote supply device is equivalent to a single-phase current source, and the end user is represented by an equivalent impedance.

[0060] S01: Obtaining the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device;

[0061] S02: Calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram;

[0062] As a preferred embodiment of the first embodiment, the equipment capacity expression of each DC remote power supply parallel device is calculated according to the equivalent topology diagram, specifically:

[0063] Writing KVL and KCL equations for the single-phase equivalent topology of the DC remote parallel supply device yields:

[0064]

[0065] Among them, V1 is the phase voltage at the substation head, in V; V2 is the output phase voltage on the inverter side of the DC remote supply device, in V; V3 is the phase voltage at the end user, in V; Z1 is the single-phase equivalent impedance of the AC line from the substation head to the rectifier side of the DC remote supply device, in Ω; Z2 is the single-phase equivalent impedance of the AC line in parallel with the DC remote supply device, in Ω; Z3 is the single-phase equivalent impedance of the AC line from the inverter side of the DC remote supply device to the end user, in Ω; Z L is the equivalent impedance of the end user, in Ω; i1 is the phase current flowing through Z1, in A; i2 is the phase current flowing through Z3, in A; i0 is the phase current flowing through Z2, in A; i3 is the single-phase output current of the DC remote supply device, in A.

[0066] Low-voltage distribution lines generally use more economical wires. The wires can be equivalent to a resistive load that is proportional to the length. The equivalent resistance per kilometer can be obtained by looking up the table based on the wire diameter. The impedance of each line can be expressed as the equivalent resistance per kilometer multiplied by the length.

[0067]

[0068] Among them, x1 is the length of the AC line from the substation to the rectifier side of the DC remote supply device, in kM, R d1 is the equivalent impedance per kilometer of the line, in Ω / kM; x2 is the length of the AC line in parallel with the DC remote supply device, in kM, R d2 is the equivalent impedance per kilometer of the line, in Ω / kM; x3 is the length of the AC line from the inverter side of the DC remote supply device to the end user, in kM, R d3 It is the equivalent impedance of the line per kilometer, in Ω / kM.

[0069] In this preferred embodiment, the present application can accurately capture the electrical characteristics of key nodes in the power system by using an equivalent topological diagram to obtain the station head voltage, expected output current and equivalent impedance value of the end user of each DC remote supply parallel device. Provides necessary input parameters for subsequent calculations. Then, based on these parameters, the present application uses Kirchhoff's law voltage equation group and Kirchhoff's current law equation group to solve. These two equation groups are basic tools in circuit analysis and can describe the distribution law of voltage and current in the circuit. Through this process, the present application can obtain the equipment capacity expression of each DC remote supply parallel device, which not only includes the power demand of the device, but also reflects its actual role in the power grid. Such an equipment capacity expression is crucial for optimizing the design and operation of the power system because it can predict and adjust the operating state of the device to meet the dynamic needs of the power grid and improve the efficiency of power transmission. The present application can improve the stability and reliability of the power system, while reducing energy consumption and operating costs, and realizing efficient management and utilization of power resources.

[0070] S03: according to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, solve and obtain each equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length;

[0071] Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user;

[0072] According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

[0073] As a preferred embodiment of the first embodiment, according to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length are solved, specifically:

[0074] According to the nonlinear programming solver, the equipment capacity expressions of each DC remote supply parallel device and the first constraint condition, the first equipment capacity of each device is obtained by solving;

[0075] Obtaining a first installation address according to each first device capacity, each first AC line length, each second AC line length, and each third AC line length;

[0076] The first constraint condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user.

[0077] More specifically, when there are no specific requirements for the equipment installation address on site and the equipment specifications can be selected by the user, the capacity selection requirements for the DC remote parallel supply device are mainly based on economic efficiency. The equipment cost is positively correlated with the equipment capacity, and the capacity selection problem of the device can be transformed into how to select a site to minimize the equipment capacity.

[0078] According to formulas (1)-(2), the expression of current i3 can be obtained as shown in formula (3).

[0079]

[0080] The equipment capacity is determined by the voltage at the substation head, the impedance and length of each section of the AC line, the load impedance, and the target voltage of the end user. The voltage at the substation head is relatively stable and can be regarded as a constant; the impedance of each section of the AC line can be obtained by looking up the table according to the wire model, and the total length of the AC line from the substation head to the end user is a fixed value; the power factor of the end residential user is relatively high, and the load impedance can be equivalent to a resistive load; the target voltage of the end user is a set value. How to select a site to minimize the equipment capacity can be organized as a nonlinear programming problem, as shown in formula (4). At present, nonlinear programming solving tools are relatively mature and can solve this nonlinear programming problem.

[0081]

[0082] Among them, x total is the total length of the AC line from the substation to the end user, in kM; R L is the end-user equivalent load, in Ω.

[0083] The nonlinear programming solver starts from the set initial value and searches for the minimum value of the objective function and its corresponding independent variable value under the equality / inequality constraints. In this planning problem, the solver can be used to obtain the minimum value of the device capacity (P) and the corresponding values ​​of each segment length (x1, x2, x3), so as to determine the location of the device (there are two installation locations for the DC remote supply device, one is the location of the inverter and the other is the location of the rectifier).

[0084] In this preferred embodiment, the present application, in the case of not presetting the installation address and equipment capacity, can effectively reduce the initial investment and operating cost of the DC remote supply parallel device by setting the fixed capacity site selection problem as minimizing the equipment capacity. Using a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and specific constraints, the present application can accurately calculate the minimum equipment capacity required under the premise of meeting the power grid performance requirements. This process not only optimizes resource allocation, but also improves the economy of the system. Subsequently, based on the calculated minimum equipment capacity, together with the specific length parameters of the AC line, the optimal installation location of the device, i.e., the first installation address, can be determined. The determination of this position takes into account the total length of the AC line from the station head to the rectifier side of the DC remote supply device, the AC line parallel to the DC remote supply device, and the AC line from the inverter side of the DC remote supply device to the end user, ensuring the rationality of the line configuration and the efficiency of power transmission. Through mathematical modeling and optimization algorithms, the present application not only ensures the reliability and efficiency of power supply, but also provides a scientific and systematic decision support for power grid planning and the site selection of DC devices, thereby reducing construction and operation costs while improving power quality, and achieving a dual improvement in economic and social benefits.

[0085] As a preferred embodiment of the first embodiment, according to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length are solved, specifically:

[0086] According to the nonlinear programming solver, the equipment capacity expression of each DC remote supply parallel device and the second constraint condition, the target voltage value of each first largest end user is obtained;

[0087] According to the first maximum user target voltage values, one or more addresses are selected from the preset second installation addresses;

[0088] Wherein, the first sub-condition of the second constraint condition is to solve the target voltage value of each first maximum end user under the condition that the capacity of each preset second device remains unchanged;

[0089] The second sub-condition of the second constraint condition is that each first maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

[0090] More specifically, when the on-site installation location is limited and there are existing stock equipment, the installation address and equipment capacity are already determined, and the voltage regulation capacity of the solution needs to be evaluated. The solution can only be put into use after the maximum voltage regulation capacity meets the needs of end users. When the installation address and equipment capacity are determined, the maximum voltage regulation capacity of the equipment can be formulated as a nonlinear programming problem, as shown in Equation (5).

[0091]

[0092] Where V min It is the lowest voltage that the end user can use normally. When there is no solution to this planning problem, it means that the maximum voltage regulation capacity of the scheme cannot meet the normal power demand of the end user.

[0093] The nonlinear programming solver starts from the set initial value and finds the minimum value of the objective function and its corresponding independent variable value under the equality / inequality constraints. In this planning problem, the solver can be used to obtain the maximum value of the adjustable voltage (V3), so that the maximum voltage regulation capacity of the equipment can be calculated.

[0094] In this preferred embodiment, the present application sets the goal of the fixed capacity site selection problem as verifying whether the target voltage value of the first largest end user can reach the preset target voltage value of the end user, so as to ensure that the power supply meets the specific needs of the user. By using a nonlinear programming solver, combined with the equipment capacity expression and the second constraint of the DC remote supply parallel device, the maximum end user voltage that can be achieved under a given equipment capacity can be accurately calculated. This step is the key to ensuring the quality of power supply. Subsequently, based on the calculated target voltage value of the first largest user, the present application can be screened in the preset second installation address, and those addresses that can achieve or exceed the preset voltage value can be selected, thereby ensuring that the selected address can provide users with stable and expected power services. Through precise mathematical modeling and optimization algorithms, the present application not only improves the reliability of power supply and user satisfaction, but also optimizes resource allocation, reduces unnecessary equipment investment and energy waste, and achieves a dual improvement in economic benefits and service quality.

[0095] As a preferred embodiment of the first embodiment, according to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length are solved, specifically:

[0096] According to the nonlinear programming solver, the equipment capacity expression of each DC remote supply parallel device and the third constraint condition, the target voltage value of each second largest end user is obtained;

[0097] Each third installation address is obtained based on the target voltage value of each second maximum end user, the AC line length from the substation head to the rectifier side of the DC remote power supply device, each first AC line length, each second AC line length and each third AC line length.

[0098] The third constraint condition includes a first sub-condition, a second sub-condition and a third sub-condition;

[0099] The first sub-condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user;

[0100] The second sub-condition is that each second maximum end-user target voltage value is greater than or equal to the target voltage value of each end user;

[0101] The third sub-condition is to solve the target voltage value of each second largest end user under the condition that the preset capacity of each third device remains unchanged.

[0102] More specifically, when there is existing equipment, the equipment capacity is determined, and the installation location can be selected, the optimal location needs to be selected so that the equipment can achieve the maximum voltage regulation capacity. This can be organized into a nonlinear programming problem, as shown in formula (6).

[0103]

[0104] The nonlinear programming solver starts from the set initial value and searches for the minimum value of the objective function and the corresponding independent variable value under the equality / inequality constraints. In this planning problem, the solver can be used to obtain the maximum value of the adjustable voltage (when the solver calculates, it can be converted to the minimum value by adding a negative sign) and the corresponding values ​​of each segment length (x1, x2, x3), so as to determine the location of the device (there are two installation locations for the DC remote supply device, one is the location of the inverter and the other is the location of the rectifier).

[0105] In this preferred embodiment, the present application can optimize the layout of the DC remote supply parallel device and ensure the efficiency and quality of power supply by solving the fixed capacity site selection problem to find the third installation address that can achieve the target voltage value of the second largest end user. Using a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and the third constraint, the present application can calculate the maximum end-user voltage that can be achieved under the specific equipment capacity limit. This step is crucial to improving the efficiency of the power system. By considering the length of the AC line from the station head to the rectifier side of the DC remote supply device, the parallel AC line of the DC remote supply device, and the AC line length from the inverter side of the DC remote supply device to the end user, the present application can accurately determine the best installation location, that is, the third installation address, which not only meets the constraint of the total length of the line, but also ensures that the voltage value reaches or exceeds the preset target. In addition, by ensuring that the target voltage value of the second largest end user is greater than or equal to the preset target voltage value of the end user, the present application can guarantee the quality of power supply at the user end. Through precise mathematical modeling and optimization algorithms, this application not only improves the reliability of power supply and user satisfaction, but also optimizes resource allocation, ensures the economy and efficiency of the power system, and achieves a dual improvement in technical performance and economic benefits.

[0106] As a preferred embodiment of the first embodiment, according to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or each first AC line length, each second AC line length and each third AC line length are solved, specifically:

[0107] According to the nonlinear programming solver, the equipment capacity expressions of each DC remote supply parallel device and the fourth constraint condition, the capacity of each fourth equipment is obtained by solving;

[0108] The fourth constraint condition is that each third maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

[0109] More specifically, when the on-site installation location is limited, the equipment capacity can be selected. If the equipment capacity is selected more economically while ensuring the normal power consumption of the end user, it can be transformed into a nonlinear programming problem, as shown in Equation (7).

[0110]

[0111] The nonlinear programming solver starts from the set initial value and finds the minimum value of the objective function and its corresponding independent variable value under the equality / inequality constraints. In this planning problem, the solver can be used to obtain the minimum capacity that is greater than the minimum value of the user's power voltage.

[0112] In this preferred embodiment, the present application can achieve cost-effectiveness optimization by setting the goal of the fixed capacity site selection problem to minimize the fourth equipment capacity, while ensuring that the power supply meets the specific needs of users. The present application uses a nonlinear programming solver, combined with the equipment capacity expression of the DC remote supply parallel device and the fourth constraint, to accurately calculate the minimum equipment capacity required at a given installation address. This step is crucial for controlling project costs and improving system efficiency. The present application ensures that the operation of the device at the fourth installation address not only meets the basic power supply requirements, but also provides stable and reliable power services by ensuring that the third maximum end-user target voltage value is greater than or equal to the preset end-user target voltage value. Through precise mathematical modeling and optimization algorithms, the present application not only ensures the quality and reliability of power supply, but also optimizes the configuration and use of equipment, reduces unnecessary over-configuration of equipment, and thus achieves a dual improvement in economic benefits and service quality.

[0113] This application can understand the needs and structure of the power system in detail by obtaining the target voltage value of each end user and the equivalent topological diagram of each DC remote supply parallel device. Secondly, using these topological diagrams, this application can calculate the equipment capacity expression of each DC remote supply parallel device. Then, by applying a nonlinear programming solver and combining the target voltage value and equipment capacity expression of the end user, this application can systematically solve the equipment capacity required for each DC remote supply parallel device under different circumstances, as well as the corresponding AC line length, including each first AC line length (from the station head to the rectifier side of the DC remote supply device), each second AC line length (AC line in parallel with the DC remote supply device), and each third AC line length (from the inverter side of the DC remote supply device to the end user). The data of these line lengths are crucial for determining the optimal installation location of the DC remote supply parallel device. Finally, based on these line lengths, this application can determine the optimal installation address of each DC remote supply parallel device under various circumstances. The present application provides a comprehensive and systematic optimization strategy, which not only ensures that the power supply meets the needs of end users, but also improves the efficiency and reliability of the power system, so as to solve the problem of the inability to accurately determine the capacity and site selection of DC remote supply parallel devices in the prior art.

[0114] Example 2

[0115] Please refer to Figure 4 , which is a constant capacity site selection device for the parallel device provided in an embodiment of the present application.

[0116] In this embodiment, the constant capacity site selection device for the parallel device includes an acquisition module 10, a calculation module 20 and a solution module 30.

[0117] The acquisition module 10 is used to acquire the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device;

[0118] The calculation module 20 is used to calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram;

[0119] The solving module 30 is used to solve and obtain each equipment capacity of each DC remote supply parallel device or each first AC line length, each second AC line length and each third AC line length according to the target voltage value of the end user and the equipment capacity expression of each DC remote supply parallel device;

[0120] Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user;

[0121] According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

[0122] This device uses three modules to divide the work and coordinate the work to better determine the capacity and site selection of the parallel device of the DC remote supply. This application can understand the needs and structure of the power system in detail by obtaining the target voltage value of each end user and the equivalent topological diagram of each DC remote supply parallel device. Secondly, using these topological diagrams, this application can calculate the equipment capacity expression of each DC remote supply parallel device. Then, by applying a nonlinear programming solver and combining the target voltage value and equipment capacity expression of the end user, this application can systematically solve the equipment capacity required for each DC remote supply parallel device under different circumstances, as well as the corresponding AC line length, including each first AC line length (from the station area head to the rectifier side of the DC remote supply device), each second AC line length (AC line in parallel with the DC remote supply device), and each third AC line length (DC remote supply device inverter side to the end user). The data of these line lengths are crucial to determining the optimal installation location of the DC remote supply parallel device. Finally, based on these line lengths, this application can determine the optimal installation address of each DC remote supply parallel device under various circumstances. The present application provides a comprehensive and systematic optimization strategy, which not only ensures that the power supply meets the needs of end users, but also improves the efficiency and reliability of the power system, so as to solve the problem of the inability to accurately determine the capacity and site selection of DC remote supply parallel devices in the prior art.

[0123] Embodiment three:

[0124] An embodiment of the present application provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the method for constant capacity site selection of a parallel device.

[0125] Wherein, the method for fixed capacity site selection of a parallel device, if implemented in the form of a software functional unit and used as an independent product, can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, 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, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, 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, etc.

[0126] Embodiment 4

[0127] The present application provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for fixed-capacity site selection of any parallel device as described in Example 1 is implemented.

[0128] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for selecting a fixed capacity site for a parallel device, characterized in that: include: Obtain the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device; Calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram; According to the target voltage value of the end user and the equipment capacity expression of each DC remote power supply parallel device, the equipment capacity of each DC remote power supply parallel device or the length of each first AC line, the length of each second AC line and the length of each third AC line are obtained by solving; Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user; According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

2. The method for selecting a fixed capacity site for a parallel device according to claim 1, characterized in that: The equipment capacity expression of each DC remote supply parallel device is calculated according to the equivalent topology diagram, specifically: Obtaining each station head voltage, each expected output current and the equivalent impedance value of each end user in each topological diagram; According to each substation head voltage, each expected output current and the equivalent impedance value of each end user in each topological diagram, Kirchhoff's law voltage equation group and Kirchhoff's current law equation group are solved to obtain the equipment capacity expression of each DC remote supply parallel device.

3. The method for selecting a fixed capacity site for a parallel device according to claim 1, characterized in that: The installation addresses of the DC remote power supply parallel devices are obtained according to the lengths of the first AC lines, the second AC lines and the third AC lines, specifically: According to the equipment capacity expressions of each DC remote supply parallel device and the first constraint condition, each first equipment capacity is obtained by solving; Obtaining a first installation address according to each first device capacity, each first AC line length, each second AC line length, and each third AC line length; The first constraint condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user.

4. The method for selecting a fixed capacity site for a parallel device according to claim 1, characterized in that: The device capacity of each DC remote supply parallel device or each first AC line length, each second AC line length and each third AC line length are obtained by solving the target voltage value of the end user and the device capacity expression of each DC remote supply parallel device, specifically: According to the equipment capacity expression of each DC remote supply parallel device and the second constraint condition, the target voltage value of each first largest end user is obtained by solving; According to the first maximum user target voltage values, one or more addresses are selected from the preset second installation addresses; Wherein, the first sub-condition of the second constraint condition is to solve the target voltage value of each first maximum end user under the condition that the capacity of each preset second device remains unchanged; The second sub-condition of the second constraint condition is that each first maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

5. The method for selecting a fixed capacity site for a parallel device according to claim 1, characterized in that: The installation addresses of the DC remote power supply parallel devices are obtained according to the lengths of the first AC lines, the second AC lines and the third AC lines, specifically: According to the equipment capacity expression of each DC remote supply parallel device and the third constraint condition, the target voltage value of each second largest end user is obtained by solving; Each third installation address is obtained based on the target voltage value of each second maximum end user, the AC line length from the substation head to the rectifier side of the DC remote power supply device, each first AC line length, each second AC line length and each third AC line length.

6. The method for constant capacity site selection of parallel devices according to claim 5, characterized in that: The third constraint condition includes a first sub-condition, a second sub-condition and a third sub-condition; The first sub-condition is that the sum of the lengths of the first AC lines, the second AC lines and the third AC lines is equal to the total length of the AC lines from the head of each substation to the end user; The second sub-condition is that each second maximum end-user target voltage value is greater than or equal to the target voltage value of each end user; The third sub-condition is to solve the target voltage value of each second largest end user under the condition that the preset capacity of each third device remains unchanged.

7. The method for constant capacity site selection of a parallel device according to any one of claims 3 to 6, characterized in that: Also includes: According to the equipment capacity expressions of each DC remote supply parallel device and the fourth constraint condition, the fourth equipment capacities corresponding to each DC remote supply parallel device are obtained by solving; The fourth constraint condition is that each third maximum end-user target voltage value is greater than or equal to a target voltage value of each end user.

8. A constant volume site selection device for a parallel device, characterized in that: It includes an acquisition module, a calculation module and a solution module; The acquisition module is used to obtain the target voltage value of each end user and the equivalent topology diagram of each DC remote supply parallel device; The calculation module is used to calculate the equipment capacity expression of each DC remote supply parallel device according to the equivalent topology diagram; The solving module is used to solve and obtain each equipment capacity of each DC remote supply parallel device or each first AC line length, each second AC line length and each third AC line length according to the target voltage value of the end user and the equipment capacity expression of each DC remote supply parallel device; Wherein, each first AC line length is the length of the AC line from the substation head to the rectifier side of each DC remote supply device, each second AC line length is the length of the AC line in parallel of each DC remote supply device, and each third AC line length is the length of the AC line from the inverter side of each DC remote supply device to the end user; According to the first AC line lengths, the second AC line lengths and the third AC line lengths, the installation addresses of the DC remote power supply parallel devices are obtained.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method for constant capacity site selection of parallel devices according to any one of claims 1 to 7.

10. A terminal device, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements the constant capacity site selection method for the parallel device as described in any one of claims 1 to 7.

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