Method and system for analyzing line loss and conversion loss of charging station

Abstract

The invention relates to an analysis method and system for line loss and conversion loss of a charging station, and the method comprises the following steps: carrying out the transformation processing of a charging pile of the charging station, employing data collection equipment, such as a charging station general meter, a guide rail meter of a DC integrated and split type charging pile, and a single-phase carrier AC electric energy meter of an AC charging pile, and detailed data of electric energy consumption are collected. Then, a line loss model of the charging station is constructed by using the data, and a conversion loss model of the charging pile is optimized through an error feedback method. Through the two models, the method can accurately analyze the energy loss of the charging station in the two levels of line and conversion, thereby achieving the improvement of the energy efficiency. Compared with a traditional method, the method does not need to depend on a complex topological structure and archive information, data are directly obtained from the equipment level, and the data processing process is simplified.

Description

Technical Field

[0001] The invention relates to a method and a system for analyzing line loss and conversion loss of a charging station, and belongs to the technical field of loss measurement of charging stations. Background Art

[0002] In the current power system, the operation and maintenance of charging stations are mostly unattended, and all charging piles are powered by a dedicated transformer or multiple distribution boxes. There is power loss in the process from the operator taking power from the grid to the final charging pile settlement. These losses include the loss of the charging pile itself, the line loss, and the transformer loss. When the equipment in the charging station is operating normally and there is no power theft, these losses should be maintained in a stable range. However, abnormal losses in the charging station often reflect equipment failure or power theft in the charging station.

[0003] Traditional methods often rely on manual operation and judgment, lacking intelligent and automated means. This makes the analysis process cumbersome and time-consuming, reducing analysis efficiency. At the same time, manual operation also increases the risk of human error.

[0004] Prior art, such as the Chinese patent application with patent number "CN115575884A", discloses a method for aligning the charging amount of charging piles in a charging station and calculating the measurement error.

[0005] The problem with the above-mentioned prior art is that it is necessary to obtain the topology and archive information of the charging station, including the detailed correspondence between the master meter and the charging pile, whether it passes through the transformer, etc. This information may be difficult to obtain in actual operation, especially for some old or poorly managed charging stations. An energy conservation model for measuring the power of the master meter and each charging pile is established. This model may be affected by many factors, such as the loss of the charging pile itself, the line loss, etc., so the accuracy of the model may be challenged to a certain extent. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present invention proposes a method and system for analyzing line loss and conversion loss of a charging station.

[0007] The technical solution of the present invention is as follows:

[0008] In one aspect, the present invention provides a method for analyzing line loss and conversion loss of a charging station, comprising the following steps:

[0009] Reconstruct the charging piles at the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter;

[0010] A line loss model of a charging station is constructed based on data uploaded by the charging station master meter, the rail meters of the DC integrated charging pile and the DC split charging pile, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station;

[0011] Based on the data uploaded from the rail meters of the DC integrated charging pile and the DC split charging pile, as well as the data collected from the charging station master meter, a conversion loss model of the charging pile is constructed, and the conversion loss model is optimized through the error feedback method;

[0012] The line loss and conversion loss of the charging station are analyzed by the conversion loss model and the line loss model.

[0013] As a preferred implementation, for a DC integrated charging pile, a rail meter is installed inside the DC integrated charging pile, and the rail meter is connected to the AC input bus, and the rail meter is connected to the DC meter of the DC integrated charging pile through an RS-485 communication bus.

[0014] As a preferred implementation, for the DC split charging pile, a rail meter is installed at the rectifier cabinet and the DC split charging pile of the charging station respectively;

[0015] The guide rail table set in the rectifier cabinet is connected to the AC input bus;

[0016] The guide rail meter is set on the split charger and connected to the DC meter of the DC split charging pile through the RS-485 communication bus.

[0017] As a preferred embodiment, the rail meter inside the DC integrated charging pile and the charging station rectifier cabinet measures the voltage of the A phase line, B phase line, and C phase line of the three-phase line on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet by puncture power collection, and collects the current on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet through the Rogowski coil;

[0018] The data collected by the rail meter is transmitted to the concentrator through broadband power line carrier communication technology, and the concentrator transmits it to the collection system through the wireless public network.

[0019] As a preferred implementation, the line loss model of the charging station is expressed as:

[0020] P loss-all =P loss-A +P loss-B +P loss-C ;

[0021] Among them, P loss-all Represents the overall line loss of the charging station, P loss-A represents the line loss of phase A of the charging station, Ploss-B represents the line loss of phase B of the charging station, P loss-C Indicates the line loss of phase C of the charging station.

[0022] As a preferred implementation, the conversion loss model of the charging pile is expressed as:

[0023]

[0024] Where α is the correction coefficient of the conversion loss model of the charging station, W 交流 Represents the electric energy value collected by the total meter of the charging station, W 直流 is the total DC power consumed by each charging pile, and η represents the conversion loss of the charging pile.

[0025] As a preferred implementation, the conversion loss model optimization method is:

[0026] Inputting the data of the DC integrated charging pile and the DC split charging pile into the conversion loss model to obtain the first conversion loss of the charging pile;

[0027] Calculate the second conversion loss of the charging pile:

[0028] The second conversion loss of the charging pile = DC side power of the charging pile / AC side power × 100%;

[0029] The correction coefficient α of the conversion loss model is adjusted according to the value of the second conversion loss so that the value of the first conversion loss approaches the value according to the second conversion loss.

[0030] On the other hand, the present invention also provides a system for analyzing line loss and conversion loss of a charging station, comprising:

[0031] Charging pile transformation module: Transform the charging piles of the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter;

[0032] Line loss model building module: builds a line loss model for a charging station based on data uploaded by the charging station master meter, the DC integrated charging pile and the DC split charging pile rail meter, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station;

[0033] Conversion loss model building module: Based on the data uploaded from the rail meter of the DC integrated charging pile and the DC split charging pile, as well as the data collected through the charging station master meter, the conversion loss model of the charging pile is built, and the conversion loss model is optimized through the error feedback method;

[0034] Result analysis module: analyzing the line loss and conversion loss of the charging station through the conversion loss model and the line loss model.

[0035] The present invention has the following beneficial effects:

[0036] The present invention can collect the power data of the charging pile more accurately by installing a rail meter for the DC integrated charging pile and the DC split charging pile, and replacing the AC charging pile with a single-phase carrier AC energy meter. The line loss model of the charging station and the conversion loss model of the charging pile are directly constructed based on the collected data. These models are based on actual data and can intuitively reflect the loss of the charging station; the conversion loss model is optimized by the error feedback method, which can further improve the accuracy of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is a flowchart for implementing the method.

[0038] Figure 2 This is a schematic diagram of the transformation of the DC integrated charging pile of the present invention.

[0039] Figure 3 This is a schematic diagram of the transformation of the DC split charging pile of the present invention. DETAILED DESCRIPTION

[0040] 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.

[0041] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0042] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0043] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0044] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0045] Embodiment 1:

[0046] See also Figure 1 The present invention provides a method for analyzing line loss and conversion loss of a charging station, comprising the following steps:

[0047] Reconstruct the charging piles at the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter;

[0048] A line loss model of a charging station is constructed based on data uploaded by the charging station master meter, the rail meters of the DC integrated charging pile and the DC split charging pile, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station;

[0049] Based on the data uploaded from the rail meters of the DC integrated charging pile and the DC split charging pile, as well as the data collected from the charging station master meter, a conversion loss model of the charging pile is constructed, and the conversion loss model is optimized through the error feedback method;

[0050] The line loss and conversion loss of the charging station are analyzed by the conversion loss model and the line loss model.

[0051] See also Figure 2 As a preferred implementation, for the DC integrated charging pile, a rail meter is installed inside the DC integrated charging pile, and the rail meter is connected to the AC input bus, and the rail meter is connected to the DC meter of the DC integrated charging pile through the RS-485 communication bus.

[0052] See also Figure 3 As a preferred implementation, for the DC split charging pile, a rail meter is installed at the rectifier cabinet and the DC split charging pile of the charging station;

[0053] The guide rail table set in the rectifier cabinet is connected to the AC input bus;

[0054] The guide rail meter is set on the split charger and connected to the DC meter of the DC split charging pile through the RS-485 communication bus.

[0055] As a preferred embodiment, the rail meter inside the DC integrated charging pile and the charging station rectifier cabinet measures the voltage of the A phase line, B phase line, and C phase line of the three-phase line on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet by puncture power collection, and collects the current on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet through the Rogowski coil;

[0056] The data collected by the rail meter is transmitted to the concentrator through broadband power line carrier communication technology, and the concentrator transmits it to the collection system through the wireless public network.

[0057] Table 1 Data collection table

[0058]

[0059]

[0060] Referring to Table 1, as a preferred implementation, the line loss model of the charging station is expressed as:

[0061] First, calculate the instantaneous line loss power of the three-phase lines A, B, and C of the charging station at a certain moment:

[0062]

[0063] Where P loss-a , P loss-b , P loss-c is the instantaneous line loss power of the three-phase lines A, B, and C, U a , U b , U c is the voltage at the end of the three-phase line A, B, and C with higher potential, U a '、U b '、U c ' is the voltage at the end of the three-phase line A, B, and C with lower potential, I a ,I b ,I c is the current value of the three-phase lines A, B, and C, It is the power factor of the three-phase lines A, B, and C. The default power factor of the DC power line is 1.

[0064] According to the calculation method of instantaneous line loss power, the instantaneous line loss power of the three-phase lines A, B, and C at multiple times can be obtained, and the corresponding line loss power curve can be drawn. By integrating the line loss power curve, the line loss of the phase line can be obtained:

[0065]

[0066] Finally, the line loss model of the charging station is expressed as:

[0067] P loss-all =Ploss-A +P loss-B +P loss-C ;

[0068] Among them, P loss-all Represents the overall line loss of the charging station, P loss-A represents the line loss of phase A of the charging station, P loss-B represents the line loss of phase B of the charging station, P loss-C Represents the line loss of phase C of the charging station. The model can accurately calculate the line loss of the charging station, which helps to locate the parts with large losses and find out the links with large energy consumption, providing direction for subsequent transformation and optimization, and also providing guidance and reference for the future construction of charging stations.

[0069] As a preferred implementation, the conversion loss model of the charging pile is expressed as:

[0070]

[0071] Where α is the correction coefficient of the conversion loss model of the charging station, W 交流 Represents the electric energy value collected by the total meter of the charging station, W 直流 is the total DC electric energy consumed by each charging pile, η represents the conversion loss of the charging pile, and the conversion loss model is constructed according to the method disclosed in the application document CN115453242A.

[0072] As a preferred implementation, the conversion loss model optimization method is:

[0073] Inputting the data of the DC integrated charging pile and the DC split charging pile into the conversion loss model to obtain the first conversion loss of the charging pile;

[0074] Calculate the second conversion loss of the charging pile:

[0075] The second conversion loss of the charging pile = DC side power of the charging pile / AC side power × 100%;

[0076] The correction coefficient α of the conversion loss model is adjusted according to the value of the second conversion loss so that the value of the first conversion loss approaches the value according to the second conversion loss.

[0077] Embodiment 2:

[0078] The present invention also provides a charging station line loss and conversion loss analysis system, comprising:

[0079] Charging pile transformation module: Transform the charging piles of the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter;

[0080] Line loss model building module: builds a line loss model for a charging station based on data uploaded by the charging station master meter, the DC integrated charging pile and the DC split charging pile rail meter, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station;

[0081] Conversion loss model building module: Based on the data uploaded from the rail meter of the DC integrated charging pile and the DC split charging pile, as well as the data collected through the charging station master meter, the conversion loss model of the charging pile is built, and the conversion loss model is optimized through the error feedback method;

[0082] Result analysis module: analyzing the line loss and conversion loss of the charging station through the conversion loss model and the line loss model.

[0083] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0084] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, 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.

[0085] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0086] In several embodiments provided in the present application, if any function 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 technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0087] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for analyzing line loss and conversion loss of a charging station, characterized in that: The following steps are involved: Reconstruct the charging piles at the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter; A line loss model of a charging station is constructed based on data uploaded by the charging station master meter, the rail meters of the DC integrated charging pile and the DC split charging pile, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station; Based on the data uploaded from the rail meters of the DC integrated charging pile and the DC split charging pile, as well as the data collected from the charging station master meter, a conversion loss model of the charging pile is constructed, and the conversion loss model is optimized through the error feedback method; The line loss and conversion loss of the charging station are analyzed by the conversion loss model and the line loss model.

2. The method for analyzing line loss and conversion loss of a charging station according to claim 1, characterized in that: For the DC integrated charging pile, a rail meter is installed inside the DC integrated charging pile, and the rail meter is connected to the AC input bus, and the rail meter is connected to the DC meter of the DC integrated charging pile through the RS-485 communication bus.

3. The method for analyzing line loss and conversion loss of a charging station according to claim 1, characterized in that: For DC split charging piles, guide rail meters are installed at the rectifier cabinet and DC split charging pile of the charging station respectively; The guide rail table set in the rectifier cabinet is connected to the AC input bus; The guide rail meter is set on the split charger and connected to the DC meter of the DC split charging pile through the RS-485 communication bus.

4. The method for analyzing line loss and conversion loss of a charging station according to claim 2 or 3, characterized in that: The rail meter inside the DC integrated charging pile and the charging station rectifier cabinet uses the puncture power collection method to measure the voltage of the A phase line, B phase line, and C phase line of the three-phase line on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet, and collects the current on the AC input side of the DC integrated charging pile and the charging station rectifier cabinet through the Rogowski coil; The data collected by the rail meter is transmitted to the concentrator through broadband power line carrier communication technology, and the concentrator transmits it to the collection system through the wireless public network.

5. The method for analyzing line loss and conversion loss of a charging station according to claim 1, characterized in that: The line loss model of the charging station is expressed as: P loss-all =P loss-A +P loss-B +P loss-C ; Among them, P loss-all Represents the overall line loss of the charging station, P loss-A represents the line loss of phase A of the charging station, P loss-B represents the line loss of phase B of the charging station, P loss-C Indicates the line loss of phase C of the charging station.

6. The method for analyzing line loss and conversion loss of a charging station according to claim 1, characterized in that: The conversion loss model of the charging pile is expressed as: Where α is the correction coefficient of the conversion loss model of the charging station, W 交流 Represents the electric energy value collected by the total meter of the charging station, W 直流 is the total DC power consumed by each charging pile, and η represents the conversion loss of the charging pile.

7. The method for analyzing line loss and conversion loss of a charging station according to claim 6, characterized in that: The conversion loss model optimization method is: Inputting the data of the DC integrated charging pile and the DC split charging pile into the conversion loss model to obtain the first conversion loss of the charging pile; Calculate the second conversion loss of the charging pile: The second conversion loss of the charging pile = DC side power of the charging pile / AC side power × 100%; The correction coefficient α of the conversion loss model is adjusted according to the value of the second conversion loss so that the value of the first conversion loss approaches the value according to the second conversion loss.

8. A charging station line loss and conversion loss analysis system, characterized in that: include: Charging pile transformation module: Transform the charging piles of the charging station; for DC integrated charging piles or DC split charging piles, install rail meters; for AC charging piles, replace the AC energy meter of the AC charging pile with a single-phase carrier AC energy meter; Line loss model building module: builds a line loss model for a charging station based on data uploaded by the charging station master meter, the DC integrated charging pile and the DC split charging pile rail meter, and data collected by the single-phase carrier AC energy meter of the AC charging pile; the charging station master meter refers to a device used to measure the power consumed by all charging facilities in the charging station; Conversion loss model building module: Based on the data uploaded from the rail meter of the DC integrated charging pile and the DC split charging pile, as well as the data collected through the charging station master meter, the conversion loss model of the charging pile is built, and the conversion loss model is optimized through the error feedback method; Result analysis module: analyzing the line loss and conversion loss of the charging station through the conversion loss model and the line loss model.

9. The charging station line loss and conversion loss analysis system according to claim 8, characterized in that: The line loss model construction module, the line loss model of the charging station is expressed as: P loss-all =P loss-A +P loss-B +P loss-C ; Among them, P loss-all Represents the overall line loss of the charging station, P loss-A represents the line loss of phase A of the charging station, P loss-B represents the line loss of phase B of the charging station, P loss-C Indicates the line loss of phase C of the charging station.

10. The charging station line loss and conversion loss analysis system according to claim 8, characterized in that: The conversion loss model building module, the conversion loss model of the charging pile is expressed as: Where α is the correction coefficient of the conversion loss model of the charging station, W 交流 Represents the electric energy value collected by the total meter of the charging station, W 直流 is the total DC power consumed by each charging pile, and η represents the conversion loss of the charging pile.

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