Test method and test system for grid-connected energy storage battery system

Abstract

The application discloses a kind of energy storage battery system grid-connected test method and test system, test method includes opening to the battery system to be measured charging or discharging;Each initial electric quantity W collected from energy storage converter cabin is obtained;Control energy storage converter cabin executes charging or discharging test, wherein charging test is executed in charging test mode, and discharging test is executed in discharging test mode;When the SOC of the battery system to be measured reaches termination preset value, each measured electric quantity Wi collected from energy storage converter cabin is obtained;According to each initial electric quantity W and each measured electric quantity Wi obtained in charging test mode and discharging test mode, the AC side cycle efficiency η s And the DC side cycle efficiency η d Of energy storage converter cabin is obtained.According to the application, the input and output electric quantity of the battery system to be measured and PCS can be obtained in real time, the charging and discharging cycle efficiency is automatically calculated, compared with manual operation, the test data is more accurate and convenient, the charging and discharging test is safer, and the labor cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of energy storage systems, and more specifically to a test method and test system for grid-connected energy storage battery systems. Background Technology

[0002] With the rapid development of the energy storage industry, a large number of pre-installed energy storage systems have been put into use. Since the energy storage capacity, efficiency, and function determine the normal operation of an energy storage power station, grid-connected charge and discharge tests are required for the pre-installed energy storage battery compartments before they leave the factory. This is beneficial for system operation and maintenance, system design and optimization, and energy management.

[0003] Traditional charge and discharge tests rely on manual operation of the energy storage converter to turn it on and off, change its power, and calculate the charge and discharge capacity. This increases labor costs, reduces the accuracy of test data, and compromises the safety of charge and discharge tests.

[0004] Therefore, a testing method and system for grid-connected energy storage battery systems are needed to at least partially solve the above problems. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To at least partially address the aforementioned problems, this application provides a test method for grid-connected energy storage battery systems. The battery system under test is connected to the power grid via an energy storage converter to form a test system. The test method includes the following steps:

[0007] Start charging or discharging the battery system under test, wherein charging is performed in the charging test mode of the test system and discharging is performed in the discharging test mode of the test system.

[0008] Acquire the initial electrical quantities W collected from the energy storage converter chamber;

[0009] The energy storage converter is controlled to perform charging or discharging tests, wherein a charging test is performed in charging test mode and a discharging test is performed in discharging test mode;

[0010] When the SOC of the battery system under test reaches the preset termination value, acquire the measured electrical quantities Wi collected from the energy storage converter chamber; and

[0011] Based on the initial charge W and the measured charge Wi obtained in the charging test mode and the discharging test mode, the AC-side circulation efficiency η of the energy storage converter is obtained. s DC-side circulation efficiency η d .

[0012] According to this solution, the input and output power of the battery system and PCS under different environmental and power conditions can be obtained in real time, and the charge and discharge cycle efficiency can be automatically calculated. Compared with manual operation, the test data is more accurate and convenient, the charge and discharge test is safer, and the labor cost is reduced.

[0013] Optionally, an auxiliary battery system is connected to the energy storage converter compartment, and the test method further includes:

[0014] The auxiliary battery system is controlled to charge or discharge, and then the energy storage converter is controlled to perform charging or discharging tests.

[0015] The auxiliary battery system is discharged in charging test mode and charged in discharging test mode.

[0016] According to this scheme, the test system can control the auxiliary battery system to automatically provide power support, realize the power regulation inside the energy storage battery system, automatically avoid peak and valley electricity consumption, save resources, avoid overload or backfeeding danger to the power grid, and realize the stability and continuity of the charge and discharge test of the energy storage battery system.

[0017] Optionally, the initial power W includes the initial auxiliary power, the measured power Wi includes measuring the auxiliary power, and the test method further includes:

[0018] The power loss W of the auxiliary battery system is obtained based on the initial auxiliary power and the measured auxiliary power obtained in the charging test mode and the discharging test mode. f损 .

[0019] According to this solution, the auxiliary power loss during the charging and discharging process can be obtained in real time under different environmental and power conditions, and the power loss of the auxiliary battery system can be automatically calculated. Compared with manual operation, it is more accurate, convenient and safe, and reduces labor costs.

[0020] Optionally, the test method further includes:

[0021] The test system determines P in charging test mode. L <P max -P e1 If the conditions are met, the system directly controls the energy storage converter to perform a charging test; otherwise, it controls the auxiliary battery system to discharge.

[0022] Where P L P represents the load power of the load connected to the power grid. max P is the maximum power allowed by the power grid. e1 The planned charging power for the battery system under test.

[0023] According to this scheme, when charging tests are conducted, if the power of the factory's internal load increases, the auxiliary battery system will automatically provide a certain amount of discharge power support under the control of the test system.

[0024] Optionally, the test method further includes:

[0025] The test system determines P in discharge test mode. L >P e2 +P min If the conditions are met, the system directly controls the energy storage converter to perform a discharge test; otherwise, it controls the auxiliary battery system to charge.

[0026] Where P L P represents the load power of the load connected to the power grid. min P is the minimum power allowed by the power grid. e2 The planned discharge power of the battery system under test.

[0027] According to this scheme, when conducting discharge tests, if the power of the factory's internal load is relatively small, the auxiliary battery compartment will automatically provide a certain amount of charging power support under the control of the test system to prevent the excess power of the energy storage battery system from being fed back into the grid.

[0028] Optionally, the initial auxiliary power supply capacity obtained in the charging test mode and the discharging test mode is W respectively. hf W df The measured auxiliary source power is W. hfi W dfi ,

[0029] Among them, W f损 =(W dfi -W df )+(W hfi -W hf ).

[0030] Optionally, the initial electrical quantity W includes initial AC electrical quantity and initial DC electrical quantity, and the measured electrical quantity Wi includes measured AC electrical quantity and measured DC electrical quantity.

[0031] The initial AC power obtained in charging test mode and discharging test mode is W respectively. hs W ds The initial DC charge is Whd W dd The measured AC power quantities are W hsi W dsi The measured DC power quantities are W hdi W ddi ,

[0032] Where, η s =(W dsi -W ds ) / (W hsi -W hs )×100%,

[0033] η d =(W ddi -W dd ) / (W hdi -W hd )×100%.

[0034] Optionally, the test method further includes:

[0035] Determine whether the charging time ti of the test system is within a preset time period MP. If it is, charge or discharge the battery system under test; otherwise, the test system is in a waiting state.

[0036] In the charging test mode, the preset time period MP includes at least the off-peak load period and / or the off-peak electricity price period; in the discharging test mode, the preset time period MP includes at least the peak load period and / or the peak electricity price period.

[0037] According to this plan, charging tests can be conducted outside of peak electricity consumption times to avoid overall power overload; charging can be performed during off-peak hours to reduce charging costs. When conducting discharging tests, the risk of backflow into the grid can be avoided; discharging can be performed during peak electricity consumption times to reduce electricity costs.

[0038] Optionally, the test method further includes:

[0039] Determine whether the SOC of the battery system under test is the initial preset value. If yes, charge or discharge the battery system under test. If no, the test system is in a waiting state. In the charging test mode, the initial preset value is 0% to 5%. In the discharging test mode, the initial preset value is 95% to 100%.

[0040] And / or in charging test mode, the termination preset value is 100%; in discharging test mode, the termination preset value is 0%.

[0041] According to this scheme, a suitable test battery system can be selected for charging or discharging tests, and the SOC charge / discharge termination value can be controlled at a high standard level.

[0042] Optionally, the test method further includes:

[0043] The test system can be switched between charging test mode and discharging test mode; thus, charging test or discharging test can be easily selected as needed.

[0044] And / or generate data tables and / or data curves under different operating conditions, wherein the data tables and / or data curves include at least each initial energy W, each measured energy Wi, and AC side cycle efficiency η. s DC-side circulation efficiency η d The different operating conditions include at least different ambient temperatures and different power of the battery system under test.

[0045] According to this plan, test data under different working conditions can be observed more intuitively and systematically.

[0046] According to another aspect of this application, a test system for grid connection of an energy storage battery system is also provided, characterized in that it is used to perform a test method for grid connection of an energy storage battery system as described in any of the preceding aspects, the test system comprising an energy storage converter chamber and a battery system under test, the battery system under test being connected to the power grid through the energy storage converter chamber.

[0047] Optionally, the energy storage converter compartment is equipped with a meter for collecting various electrical quantities;

[0048] And / or the test system may also include an auxiliary battery system connected to the energy storage converter compartment.

[0049] According to this scheme, the input and output power of the battery system and PCS under test can be obtained in real time under different environmental and power conditions by the electricity meter installed in the energy storage converter chamber, and the charge and discharge cycle efficiency can be automatically calculated. Attached Figure Description

[0050] The following drawings, which are incorporated herein by reference and used to understand this application, illustrate embodiments of the application and their descriptions, thereby explaining the principles of the application.

[0051] In the attached image:

[0052] Figure 1 A schematic diagram of the connection structure of a test system for grid connection of an energy storage battery system according to this application;

[0053] Figure 2 for Figure 1The diagram shows a top-view structural schematic of the energy storage converter chamber.

[0054] Figure 3 for Figure 1 The circuit diagram of the energy storage converter shown in the figure;

[0055] Figure 4 for Figure 1 The side view of the integrated inlet and outlet cabinet of the energy storage converter compartment shown in the figure.

[0056] Figure 5 for Figure 1 The flowchart shown is of the test system in charging test mode;

[0057] Figure 6 for Figure 1 The flowchart shown is of the test system in discharge test mode.

[0058] Explanation of reference numerals in the attached figures:

[0059] 10: Power grid; 20: Energy storage battery system; 100: Energy storage converter compartment

[0060] 110: Electrical Room; 111: Power Converter; 112: DC Combiner Cabinet

[0061] 113: AC combiner cabinet; 114: System control cabinet; 120: Transformer room

[0062] 121: Transformer; 130: High Voltage Chamber; 131: Integrated Incoming and Outgoing Line Cabinet

[0063] 132: AC meter; 133: Current transformer; 134: Voltage transformer

[0064] 135: Vacuum circuit breaker; 136: First wiring cable; 137: Cable inlet.

[0065] 138: Second wiring cable; 139: Cable outlet; 101: Box wall.

[0066] 102: Hatch door; 103: First heat exchanger; 104: Second heat exchanger

[0067] 105: Temperature detector; 11: Inter-grid transformer Detailed Implementation

[0068] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.

[0069] To fully understand this application, a detailed description will be provided below. It is obvious that the implementation of embodiments of this application is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of this application are described in detail below; however, other embodiments may also be available in addition to these detailed descriptions.

[0070] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0071] Ordinal numbers such as “first” and “second” used in this application are merely identifiers and have no other meaning, such as a specific order. Moreover, for example, the term “first component” does not imply the existence of a “second component”, and the term “second component” does not imply the existence of a “first component”.

[0072] It should be noted that the terms “up,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” and similar expressions used in this article are for illustrative purposes only and are not intended to be restrictive.

[0073] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0074] This application provides a test method for grid-connected energy storage battery systems, which can be executed by a test system for grid-connected energy storage battery systems. Figure 1 As shown, the test system may include an energy storage converter compartment and a battery system under test. The battery system under test is connected to the power grid via the energy storage converter compartment. Specifically, using... Figure 1 As shown in the example, the power grid includes a first power grid and a second power grid, where the first power grid is the household power grid and the second power grid is the plant power grid. An inter-grid transformer 11 connects the first and second power grids. The energy storage converter compartment is connected to the busbar of the second power grid. Multiple loads are also connected to the busbar of the second power grid.

[0075] The testing system may also include an auxiliary battery system. This auxiliary battery system is connected to the energy storage converter compartment, and its main function is to provide power support for the testing system. When the testing system is undergoing charging tests and the total load is large, it provides some power to the energy storage converter compartment to prevent overloading of the grid. When the testing system is undergoing discharging tests and the total load is small, it absorbs excess power from the energy storage converter compartment to prevent excess power from being fed back into the grid.

[0076] Figures 2 to 4 An energy storage converter 100 according to this application is shown. The energy storage converter 100 is equipped with meters for collecting various electrical quantities. Figures 2 to 4 As shown, the energy storage converter compartment 100 includes an electrical room 110, a transformer room 120, and a high-voltage room 130.

[0077] The electrical room 110 contains at least three power converters 111 connected in parallel, with the DC side of each power converter 111 connected to the energy storage battery system 20. The transformer room 120 contains a transformer 121, with its low-voltage side connected to the AC side of the power converters 111. The high-voltage room 130 contains an integrated incoming / outgoing line cabinet 131, which has a first connecting cable 136 and a second connecting cable 138. The first connecting cable 136 connects to the high-voltage side of the transformer 121, and the second connecting cable 138 connects to the power grid 10. The power converters 111 can be PCS (Power Conversion System).

[0078] In a preferred embodiment, a first connecting cable 136 is connected from a cable inlet 137, which is located on the bottom side of the integrated incoming and outgoing line cabinet 131. A second connecting cable 138 is led out from a cable outlet 139, which is also located on the bottom side of the integrated incoming and outgoing line cabinet 131.

[0079] According to the energy storage converter compartment 100 of this application, an integrated inlet / outlet cabinet 131 is provided, which saves space in the high-voltage room 130 and makes it easy to integrate various devices into the container.

[0080] Preferably, the integrated incoming and outgoing line cabinet 131 also includes a current transformer 133, a voltage transformer 134, an AC meter 132, a vacuum circuit breaker 135, and a relay protection device. This further improves integration, saving space in the high-voltage room 130 while fulfilling the functions of main circuit grid connection and disconnection control, line protection, and energy metering, thus providing space for the installation of three or more power converters 111. Figure 4 An exemplary internal structural arrangement of an integrated incoming and outgoing line cabinet 131 is shown.

[0081] In a preferred embodiment, the high-voltage chamber 130 and the electrical chamber 110 are located at opposite ends of the container, and the transformer chamber 120 is located between the high-voltage chamber 130 and the electrical chamber 110. The volume of the high-voltage chamber 130 is smaller than the volume of the electrical chamber 110. Preferably, the volume of the high-voltage chamber 130 is smaller than the volume of the transformer chamber 120. More preferably, the volume of the transformer chamber 120 is smaller than the volume of the electrical chamber 110.

[0082] Continue to refer to Figure 2 The electrical room 110 is also equipped with a DC combiner cabinet 112, an AC combiner cabinet 113, and a system control cabinet 114. The DC combiner cabinet 112 is connected between the energy storage battery system 20 and the power converter 111, and the AC combiner cabinet 113 is connected between the AC side of the power converter 111 and the low-voltage side of the transformer 121.

[0083] A first meter is installed in the DC combiner cabinet 112. This allows the first meter to measure the DC power input and output of the energy storage battery system 20. A second meter is installed in the AC combiner cabinet 113. This allows the second meter to measure the AC power input and output of the power converter 111.

[0084] The system control cabinet 114 is connected to the DC combiner cabinet 112, AC combiner cabinet 113, power converter 111, transformer 121, and integrated incoming and outgoing line cabinet 131. Furthermore, the system control cabinet 114 is equipped with a third meter. This allows the third meter to measure the amount of electricity generated by the auxiliary battery system (which serves as a secondary power source) during the charging and discharging process of the energy storage battery system 20.

[0085] In a preferred embodiment, the AC combiner cabinet 113 has at least three independent disconnect switches corresponding to at least three power converters 111, and each of the at least three disconnect switches is connected to at least three power converters 111. This allows any one power converter to be disconnected from the DC circuit, improving the safety of wiring and maintenance of the power converters. Furthermore, the parallel connection of at least three power converters 111 can be automatically adjusted according to test conditions to meet the charging and discharging capacity requirements of the energy storage battery.

[0086] To facilitate the maintenance and repair of the equipment in the electrical room 110, transformer room 120 and high-voltage room 130, hatches 102 are provided on the side walls of the container corresponding to the positions of the electrical room 110, transformer room 120 and high-voltage room 130 to allow personnel to enter and exit.

[0087] Please refer to the following. Figure 2At least one first heat exchanger 103 is provided on the top or side of the DC combiner cabinet 112, at least one first heat exchanger 103 is provided on the top or side of the AC combiner cabinet 113, and at least one first heat exchanger 103 is provided on the top or side of the system control cabinet 114.

[0088] At least one second heat exchanger 104 is installed on the bulkhead of the electrical room 110, at least one second heat exchanger 104 is installed on the bulkhead of the transformer room 120, and at least one second heat exchanger 104 is installed on the bulkhead of the high-pressure room 130. For example, in the illustrated embodiment, two second heat exchangers 104 are installed on the bulkhead of the electrical room 110, and two second heat exchangers 104 are installed on the bulkhead of the transformer room 120. The system control cabinet 114 is signal-connected to both the first heat exchanger 103 and the second heat exchanger 104.

[0089] The second heat exchanger 104 is disposed on the side wall of the container, and / or the second heat exchanger 104 is disposed on the hatch 102. Exemplarily, in the embodiment shown in the figure, the second heat exchanger 104 is disposed on the side wall.

[0090] Optionally, the DC combiner cabinet 112, AC combiner cabinet 113, system control cabinet 114, and integrated incoming / outgoing line cabinet 131 are each equipped with at least one temperature detector 105. The transformer 121 is equipped with at least one temperature detector 105. At least one temperature detector 105 is also installed in both the electrical room 110 and the transformer room 120. The system control cabinet 114 is signal-connected to the temperature detector 105. For example, the transformer 121 may be equipped with two temperature detectors 105, and both the electrical room 110 and the transformer room 120 may each be equipped with two temperature detectors 105.

[0091] For example, two temperature detectors 105 inside the transformer chamber 120 are disposed at the chamber wall 101. Two temperature detectors 105 in the electrical room 110 are disposed at the chamber wall 101 and the bulkhead between the transformer chamber 120 and the electrical room 110, respectively.

[0092] Once the upper limit threshold temperature for heat dissipation is reached, the control system issues a command to activate the heat exchangers in the equipment compartments requiring heat dissipation, ensuring the safe and stable operation of the converter chamber. Thus, by equipping the converter chamber with an automatic thermal management control system, the temperature of each piece of equipment is individually controlled, addressing the different cooling needs of different devices. This prevents overheating of components such as the PCS, transformer 121, and high-voltage cabinet from reducing battery system testing efficiency and increasing system operational risks, thereby extending the lifespan of the equipment.

[0093] The testing system can have two modes: charging test mode and discharging test mode. Charging test mode performs charging tests, and discharging test mode performs discharging tests. A start button can be set to switch the testing system between these two modes. Before conducting charge / discharge tests, the testing system can be set to either charging or discharging test mode as needed.

[0094] like Figures 5 to 6 As shown, the testing method of this application includes the following steps:

[0095] S1: Determination of charging time ti

[0096] Determine whether the charging time ti of the test system is within the preset time period MP. If it is, charge or discharge the battery system under test. If not, the test system is in a waiting state.

[0097] In charging test mode, the preset time period (MP) includes at least off-peak load periods and / or off-peak electricity price periods. This avoids peak electricity consumption times, preventing overall power overload; and allows charging during off-peak hours, reducing charging costs.

[0098] In discharge test mode, the preset time period MP includes at least the peak load period and / or peak electricity price period. This avoids the danger of backflow into the grid and allows discharge during peak electricity price periods, reducing electricity costs.

[0099] S2: Initial determination of the SOC (State of charge) of the battery system under test

[0100] Determine if the SOC of the battery system under test is the initial preset value. If it is, charge or discharge the battery system under test. If not, the test system is in a waiting state.

[0101] In charging test mode, the initial preset value is 0% to 5%. Furthermore, for the battery system under test to be charged, its SOC should be sufficiently low, preferably between 0% and 5%. In discharging test mode, the initial preset value is 95% to 100%; further, for the battery system under test to be discharged, its SOC should be sufficiently high, preferably between 95% and 100%.

[0102] S3: Start charging or discharging

[0103] The test system initiates charging or discharging of the battery system under test. Charging is performed in charging test mode, and discharging is performed in discharging test mode.

[0104] S4: Obtain initial battery level (W)

[0105] When the test system starts charging or discharging, it acquires the initial electrical quantities (W) collected from the energy storage converter chamber.

[0106] The initial energy level W includes the initial AC energy level, the initial DC energy level, and the initial auxiliary power level. The initial AC energy level obtained in charging and discharging test modes is W respectively. hs W ds The initial DC charge is W hd W dd The initial auxiliary power supply capacity is W. hf W df .

[0107] S5: Determine if the power meets the preset conditions.

[0108] In charging test mode, the test system determines P. L <P max -P e1 If the conditions are met, the energy storage converter is directly controlled to perform a charging test; otherwise, the auxiliary battery system is controlled to discharge. It can be understood that if P... L =P max -P e1 At that time, the energy storage converter can be directly controlled to perform charging tests, and the auxiliary battery system can also be controlled to discharge.

[0109] Where P L P represents the load power of the load connected to the power grid. max P is the maximum power allowed by the power grid. e1 The planned charging power for the battery system under test.

[0110] In discharge test mode, the test system determines P. L >P e2 +P min If the conditions are met, the energy storage converter is directly controlled to perform a discharge test; otherwise, the auxiliary battery system is controlled to charge. It can be understood that if P... L =P e2 +P min At that time, the energy storage converter can be directly controlled to perform discharge tests, and the auxiliary battery system can also be controlled to charge.

[0111] Where P L P represents the load power of the load connected to the power grid. min P is the minimum power allowed by the power grid. e2 The planned discharge power of the battery system under test.

[0112] During the charge and discharge testing of the energy storage battery system, various operating conditions may occur. For example, during the charging test, if the power of the factory's internal load increases, the total power load of the energy storage battery system and the factory's internal load will exceed the rated capacity of the factory's grid connection, which will damage the grid connection. During the discharging test, if the power of the factory's internal load is small, the excess power of the energy storage battery system will be fed back into the grid, causing interference to the grid.

[0113] To avoid these situations, this embodiment includes an auxiliary battery system connected in parallel with the battery system under test. During testing, the load power of the factory load needs to be determined. Based on the determination result, it is determined whether to enable the auxiliary battery system.

[0114] Specifically, during charging tests, if the power of the factory's on-site load increases, the auxiliary battery system will automatically provide a certain amount of discharge power support under the control of the testing system. During discharging tests, if the power of the factory's on-site load is low, the auxiliary battery compartment will automatically provide a certain amount of charging power support under the control of the testing system to prevent excess power from the energy storage battery system from being fed back into the grid.

[0115] Therefore, the test system can automatically control the auxiliary battery system to provide power support according to the power of the load, realize the power regulation inside the energy storage battery system, automatically avoid peak and valley electricity consumption, save resources, avoid overload or backfeeding danger to the power grid, and realize the stability and continuity of the charge and discharge test of the energy storage battery system.

[0116] S6: Perform charging or discharging tests

[0117] When the power is determined to meet preset conditions, the energy storage converter is controlled to perform a charging or discharging test. In charging test mode, a charging test is performed, and the power relationship can be P. c =P e1 , where P c The actual charging power of the battery system under test; perform a discharge test in discharge test mode, and the power relationship can be P. d =P e2 , where P d This represents the actual discharge power of the battery system under test.

[0118] S7: Auxiliary Battery System Activated

[0119] When the power is determined not to meet the preset conditions, the auxiliary battery system is activated for charging or discharging, and then the energy storage converter chamber is controlled to perform charging or discharging tests. The auxiliary battery system discharges in charging test mode, providing a certain amount of discharge power support for the charging test, and the power relationship can be P.f =P L +P c -P max , where P fd To assist the auxiliary power of the battery system, P c This represents the actual charging power of the battery system under test. Charging is performed in discharge test mode to provide a certain amount of charging power support for the discharge test, and the power relationship can be expressed as P. f =P d +P min -P L , where P d This represents the actual discharge power of the battery system under test.

[0120] S8: Termination judgment of the SOC of the battery system under test

[0121] Determine whether the SOC of the battery system under test is the preset termination value. If it is, stop charging or discharging the battery system under test and the test ends; otherwise, return to step S3.

[0122] In charging test mode, the termination preset value is 100%; in discharging test mode, the termination preset value is 0%.

[0123] S9: Acquire measured power Wi

[0124] When the SOC of the battery system under test reaches the preset termination value, the measured quantities Wi collected from the energy storage converter chamber are acquired.

[0125] The measurement of electrical capacity Wi includes measuring AC electrical capacity, DC electrical capacity, and auxiliary power supply capacity. The AC electrical capacity measured in charging and discharging test modes is W respectively. hsi W dsi The measured DC power was W. hdi W ddi The auxiliary power source was measured to be W. hfi W dfi .

[0126] S10: Obtain performance characterization data

[0127] Based on the initial charge W and measured charge Wi obtained in the charging and discharging test modes, the AC-side cycle efficiency η of the energy storage converter is obtained. s DC-side circulation efficiency η d η s and η d It can be calculated using the following formula:

[0128] η s =(W dsi -W ds) / (W hsi -W hs )×100%, η d =(W ddi -W dd ) / (W hdi -W hd )×100%.

[0129] Based on the initial auxiliary power supply and the measured auxiliary power supply obtained in the charging test mode and the discharging test mode, the power loss W of the auxiliary battery system is obtained. f损 W f损 It can be calculated using the following formula:

[0130] W f损 =(W dfi -W df )+(W hfi -W hf ).

[0131] This embodiment uses meters installed on the DC and AC sides of the energy storage converter to obtain the input and output power of the battery system and PCS under different environmental and power conditions in real time, as well as the auxiliary power loss during the charging and discharging process. It automatically calculates the charge and discharge cycle efficiency and the power loss of the auxiliary battery system. Compared with manual operation, it is more accurate, convenient and safe, and reduces labor costs.

[0132] S11: Generate data tables and / or data curves

[0133] Generate data tables and curves for different operating conditions. The data tables and curves should at least include the initial charge W, the measured charge Wi, and the AC-side cycle efficiency η. s DC-side circulation efficiency η d and W f损 Different operating conditions include at least different ambient temperatures and different power outputs of the battery system under test. Data on these different ambient temperatures and power outputs of the battery system under test can be acquired, and then data tables and curves can be generated based on this data and the calculated results. This allows for a more intuitive and systematic observation of the test data under different operating conditions.

[0134] The charging and discharging tests are described in detail below.

[0135] The charging test process is as follows Figure 5As shown. When conducting charging tests on an energy storage battery system, the first step is to determine whether the charging time and the State of Charge (SOC) of the battery system under test meet the test conditions. Specifically, it is determined whether the charging time *ti* falls within a low-load period and / or a low-price period; and whether the SOC is between 0% and 5%. If the test conditions are met, i.e., within a low-load period and with an SOC between 0% and 5%, the test system will begin charging the battery system under test; otherwise, the system will not begin charging and will remain in a waiting state. After the system begins charging, it automatically determines the load power *P* of the load. L With the maximum power P allowed by the power grid max Does it meet the charging requirements? If P L <P max -P e1 If the charging test function is activated, the energy storage converter will perform a charging test and acquire and record the initial AC power W. hs Initial DC charge W hd Initial auxiliary power W hf If P L >P max -P e1 If this occurs, the auxiliary battery system will be activated to discharge, providing power support for the charging test. At this time, P... f =P L +P c -P max When the battery system under test is charged to 100% SOC, charging stops, and the measured AC power W is acquired and recorded. hsi Measurement of DC power W hdi Measurement of auxiliary power supply W hfi The charging test task has ended.

[0136] After the charging test is completed, the system automatically calculates the DC-side charge W of the battery system under test. h1 =W hdi -W hd AC side charging capacity of the power converter (W) h2 =W hsi -W hs The power loss of the auxiliary power supply (W) f损1 =W hfi -W hf .

[0137] The discharge test process is as follows Figure 6As shown. When conducting discharge tests on an energy storage battery system, the first step is to determine whether the discharge time and the State of Charge (SOC) of the battery system under test meet the test conditions. Specifically, it is determined whether the discharge time *ti* falls within the peak load period and / or peak electricity price period; and whether the SOC is between 95% and 100%. If the test conditions are met, i.e., within the peak load period and with an SOC of 95% to 100%, the test system will begin discharging the battery system under test; otherwise, the system will not begin discharging and will remain in a waiting state. After the system begins discharging, it automatically determines the load power *P* of the load. L With the minimum power P allowed by the power grid min Does it meet the discharge requirements? If P L >P e2 +P min If the discharge test function is activated, the energy storage converter chamber will perform a discharge test and acquire and record the initial AC power W. ds Initial DC charge W dd Initial auxiliary power W df If P L <P e2 +P min If this is the case, the auxiliary battery system will be activated to charge it, providing power support for the discharge test. At this time, P f =P d +P min -P L When the battery system under test discharges to 0% SOC, the discharge stops, and the measured AC power W is acquired and recorded. dsi Measurement of DC power W ddi Measurement of auxiliary power supply W dfi The discharge test task is now complete.

[0138] After the discharge test is completed, the system automatically calculates the DC-side discharge quantity W of the battery system under test. d1 =W ddi -W dd AC side discharge quantity W of the power converter d2 =W dsi -W ds The power loss of the auxiliary power supply (W) f损2 =W dfi -W df .

[0139] After a charge-discharge cycle test is completed, the system collects and saves the various quantities of electricity generated during the charging and discharging processes, generates reports, and automatically calculates the AC-side cycle efficiency (W) of the power converter. dsi -W ds ) / (W hsi -W hs)×100%, DC-side cycle efficiency η of the battery system under test d =(W ddi -W dd ) / (W hdi -W hd )×100%, and the power loss W of the auxiliary power supply during one charge-discharge cycle. f损 =(W dfi -W df )+(W hfi -W hf Furthermore, these calculated data, along with data on different ambient temperatures and the power of different battery systems under test, are used to generate data tables and curves for different operating conditions.

[0140] The test methods and test system provided in this application are as follows:

[0141] By installing meters on the DC and AC sides of the energy storage converter, the calculation of the charging and discharging power of the battery system's DC side and the PCS's AC side, the calculation of the power loss of the auxiliary power supply during charging and discharging, and the automatic generation of test data can be realized. Compared with manual operation, it is more accurate, convenient, and safe, and reduces labor costs.

[0142] When the energy storage battery system is undergoing charge and discharge testing, the testing system will automatically control the auxiliary battery system to provide power support according to the changes in the factory load power, so as to avoid overloading the power grid or the danger of backfeeding, and realize the stability and continuity of the charge and discharge testing of the energy storage battery system.

[0143] The order of steps in this embodiment can be adjusted, combined, or omitted as needed. The processes described in all the preferred embodiments above are merely examples. Unless adverse effects occur, various processing operations can be performed in a different order than described above. The order of steps in the above process can also be added, combined, or omitted as needed.

[0144] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application. Features described in one embodiment may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.

[0145] This application has been described through the above embodiments. However, it should be understood that the above embodiments are only for illustrative purposes. This application is not limited to the above embodiments. Many variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. A method for testing grid-tie of an energy storage battery system, the method comprising: The battery system to be tested is connected to a power grid through a storage converter cabin to form a test system; the test method comprises the following steps: charging or discharging the battery system to be tested, wherein charging is performed in a charging test mode of the test system, and discharging is performed in a discharging test mode of the test system; acquiring initial electric quantity W collected from the storage converter cabin; controlling the storage converter cabin to perform charging or discharging test, wherein charging test is performed in the charging test mode, and discharging test is performed in the discharging test mode; acquiring measured electric quantity Wi collected from the storage converter cabin when the SOC of the battery system to be tested reaches a termination preset value; and According to each initial electric quantity W and each measured electric quantity Wi acquired in the charging test mode and the discharging test mode, the AC side cycle efficiency η of the energy storage converter cabin is obtained s and the DC side cycle efficiency η d .

2. The test method of claim 1, wherein, The auxiliary battery system is connected to the storage converter cabin, and the test method further comprises: controlling the auxiliary battery system to charge or discharge, and then controlling the storage converter cabin to perform charging or discharging test, wherein the auxiliary battery system discharges in the charging test mode and charges in the discharging test mode.

3. The test method of claim 2, wherein, The initial electric quantity W comprises initial auxiliary source electric quantity, and the measured electric quantity Wi comprises measured auxiliary source electric quantity, and the test method further comprises: According to the initial auxiliary power and the measured auxiliary power obtained in the charging test mode and the discharging test mode, the loss power W of the auxiliary battery system is obtained f损 .

4. The test method of claim 2, wherein, Further comprising: The test system judges P L <P max -P e1 whether the condition is established, if yes, directly controls the energy storage converter cabin to perform charging test, if not, controls the auxiliary battery system to discharge, where P L is the load power of a load connected to the power grid, P max is the maximum power allowed by the power grid, P e1 is the planned charging power of the battery system under test.

5. The test method of claim 2, wherein, Further comprising: The test system judges P L > P e2 + P min whether the condition is true, if yes, directly controls the energy storage converter cabin to perform discharge test, if not, controls the auxiliary battery system to charge, P L is the load power of a load connected to the power grid, P min is the minimum power allowed by the power grid, P e2 is the planned discharge power of the battery system to be tested.

6. The test method of claim 3, wherein, The initial auxiliary power is W hf , W df , and the measured auxiliary power is W hfi , W dfi , respectively, which are obtained in the charging test mode and the discharging test mode. where W f损 = (W dfi -W df ) + (W hfi -W hf ).

7. The test method according to claim 1, wherein The initial electric quantity W comprises initial alternating current electric quantity and initial direct current electric quantity, and the measured electric quantity Wi comprises measured alternating current electric quantity and measured direct current electric quantity, The initial AC power obtained in the charging test mode and the discharging test mode is W hs , W ds , respectively, the initial DC power is W hd , W dd , respectively, the measured AC power is W hsi , W dsi , respectively, and the measured DC power is W hdi , W ddi , respectively, wherein η s = (W dsi -W ds ) / (W hsi -W hs ) x 100%, η d = (W ddi -W dd ) / (W hdi -W hd ) x 100%.

8. The test method of claim 1, wherein, Further comprising: judging whether the charging time ti of the test system is within a preset time period MP, if yes, charging or discharging the battery system to be tested, and if no, the test system is in a waiting state, wherein in the charging test mode, the preset time period MP at least comprises a load low valley time period and / or a price low valley time period; and in the discharging test mode, the preset time period MP at least comprises a load peak time period and / or a price peak time period.

9. The test method of claim 1, wherein, Further comprising: judging whether the SOC of the battery system to be tested is an initial preset value, if yes, charging or discharging the battery system to be tested, and if no, the test system is in a waiting state; wherein in the charging test mode, the initial preset value is 0% to 5%; and in the discharging test mode, the initial preset value is 95% to 100%; and / or in the charging test mode, the termination preset value is 100%; and in the discharging test mode, the termination preset value is 0%.

10. The test method of claim 1, wherein, Further comprising: switching the mode of the test system between the charging test mode and the discharging test mode; And / or generate data table and / or data curve under different working conditions, the data table and / or data curve at least include each initial electric quantity W, each measured electric quantity Wi, AC side cycle efficiency η s and DC side cycle efficiency η d , the different working conditions at least include different ambient temperature, different power of the battery system to be measured.

11. A test system for grid-tie of an energy storage battery system, characterized by, The test method for grid connection of a storage battery system according to any one of claims 1 to 10, the test system comprising a storage converter cabin and a battery system to be tested, the battery system to be tested being connected to a power grid through the storage converter cabin.

12. The test system according to claim 11, wherein The storage converter cabin is provided with an electric meter for collecting electric quantity; and / or the test system further comprises an auxiliary battery system, the auxiliary battery system being connected to the storage converter cabin.

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