Test system and test method of energy storage system

Abstract

The invention provides an energy storage system test system and test method, an AC access device, a simulation device, a station switching device and a load are arranged in the test system, the AC access device is used for realizing grid-connected and off-grid control when a to-be-tested energy storage system is tested, the simulation device is used for supporting access of various AC or DC voltage systems, and the station switching device is used for switching the station switching device and the load. The station switching device is used for matching the access power of the to-be-tested energy storage system, the load is used as an electric energy consumption device during testing, the testing method can set the voltage and power output by the simulation device, and the interface of the station switching device is adaptively adjusted according to the voltage and power output by the simulation device. Therefore, system access of various direct-current voltages and alternating-current voltages can be considered at the same time, modular expansion can be carried out according to power, the test requirements of energy storage systems of different alternating-current and direct-current voltage levels are met, and the system has the advantages of being high in compatibility and good in expansibility.

Description

Technical Field

[0001] The present invention relates to the field of energy storage system testing, and in particular to a testing system and a testing method for an energy storage system. Background Art

[0002] Currently, the proportion of green renewable energy such as solar energy and wind energy in energy supply is increasing. However, due to the instability of green renewable energy, it is easy to lead to overproduction or shortage of energy, so the demand for energy storage systems is also increasing.

[0003] With the rapid development of energy storage technology, energy storage systems, namely energy storage systems, are flourishing in the market. For example, energy storage systems have different forms such as centralized architecture and string architecture, and different types of batteries such as lithium batteries, flow batteries, sodium batteries, etc. However, these new energy storage systems do not have unified technical standards, which makes it difficult to evaluate the performance, stability and safety of energy storage systems.

[0004] Currently, there are some solutions for testing the charging and discharging performance of energy storage systems such as batteries or energy storage inverters, but they are often only targeted at specific types and are difficult to be compatible with energy storage systems of different forms and types. In addition, the testing of energy storage systems is not comprehensive enough.

[0005] Therefore, a compatibility solution is needed that can test energy storage systems of different forms and types. Summary of the invention

[0006] One purpose of the present application is to provide a testing system and a testing method for an energy storage system, so as to solve the problem that it is difficult to test energy storage systems of different forms and types under the prior art.

[0007] To achieve the above objectives, some embodiments of the present application provide a testing system for an energy storage system, the system comprising:

[0008] AC access device, used to access the AC power grid and realize grid-connection and off-grid control when testing the energy storage system to be tested;

[0009] A simulation device, connected to the AC access device, used to support the access of various AC or DC voltage systems;

[0010] A station switching device, connected to the simulation device, for selecting the simulation device to match the access power of the energy storage system to be tested;

[0011] The load is connected to the AC access device and is used as an electric energy consumption device when the energy storage system to be tested is tested.

[0012] Furthermore, the simulation device includes a power grid simulation device and a DC simulation device. The power grid simulation device is used to support access to multiple AC voltage systems and simulate power grid operation conditions under multiple working modes. The DC simulation device is used to support access to multiple DC voltage systems and is used as a power device with different charging and discharging powers in battery testing.

[0013] Furthermore, the workstation switching device includes an AC workstation switching device and a DC workstation switching device. The AC workstation switching device is used to select the input side of the power grid simulation device to match the access power of the AC side of the energy storage system to be tested, and the DC workstation switching device is used to select the input side of the DC simulation device to match the access power of the DC side of the energy storage system to be tested.

[0014] Some embodiments of the present application further provide a method for testing an energy storage system, using the above-mentioned energy storage system testing system, the method comprising:

[0015] Connecting the energy storage system to be tested to the station switching device;

[0016] According to the voltage and power required by the energy storage system to be tested, set the voltage and power output by the simulation device;

[0017] Adapt and adjust the interface of the station switching device according to the voltage and power output by the simulation device;

[0018] Perform charge and discharge tests on the energy storage system to be tested.

[0019] Furthermore, the energy storage system to be tested includes one of the following: an energy storage converter, a DC side energy storage system, a combined DC side energy storage system, an AC side energy storage system, and a combined AC side energy storage system.

[0020] Furthermore, the test system includes an AC access device, a power grid simulation device, a DC simulation device, an AC station switching device, and a DC station switching device. The energy storage system to be tested is an energy storage converter. The method includes:

[0021] Connect the AC side of the energy storage converter to the AC station switching device, and connect the DC side of the energy storage converter to the DC station switching device;

[0022] The output power of the power grid simulation device is set to the maximum value of the active power output on the AC side of the energy storage converter;

[0023] According to the maximum value, the interfaces of the AC station switching device and the DC station switching device are adaptively adjusted;

[0024] Within the preset test time, the average values ​​of the AC side active power, the DC side active power and the external auxiliary power supply active power of the energy storage converter are obtained;

[0025] The charging efficiency of the energy storage converter is determined based on the average value, wherein the charging efficiency of the energy storage converter is calculated by the following formula:

[0026]

[0027] Among them, η 1 is the charging efficiency of the energy storage converter, P DC is the active power on the DC side of the energy storage converter, P AC is the AC side active power of the energy storage converter, P AU is the external auxiliary active power.

[0028] Furthermore, the test system includes an AC access device, a DC simulation device, a load and a DC station switching device, the energy storage system to be tested is a DC side energy storage system, and the method includes:

[0029] Connect the DC side energy storage system to the DC station switching device;

[0030] Set the output power of the DC simulation device to the test power of the DC side energy storage system;

[0031] The DC side energy storage system is subjected to a cycle efficiency test to determine the cycle efficiency of the DC side energy storage system. The cycle efficiency of the DC side energy storage system is calculated by the following formula:

[0032]

[0033] Among them, η 1 is the cycle efficiency of the DC side energy storage system, E d is the DC side discharge energy of the DC side energy storage system, E c is the DC side charging energy of the DC side energy storage system, W d is the auxiliary power consumed by the DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the DC side energy storage system during the charging process.

[0034] Furthermore, the test system includes an AC access device, a DC simulation device, a load and a DC station switching device, the energy storage system to be tested is a combined DC side energy storage system, and the method includes:

[0035] Connecting a combined DC side energy storage system to a DC workstation switching device, wherein the combined DC side energy storage system includes a first DC side energy storage system and a second DC side energy storage system;

[0036] The output power of the DC simulation device is set to the test power of the first DC side energy storage system and the second DC side energy storage system;

[0037] The combined DC side energy storage system is subjected to a cycle efficiency test to determine the cycle efficiency of the first DC side energy storage system, wherein the cycle efficiency of the first DC side energy storage system is calculated by the following formula:

[0038]

[0039] Among them, η 1 is the cycle efficiency of the first DC side energy storage system, E d is the DC side discharge energy of the first DC side energy storage system, E c is the DC side charging energy of the first DC side energy storage system, W d is the auxiliary electric energy consumed by the first DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first DC side energy storage system during the charging process.

[0040] Furthermore, the test system includes an AC access device, a power grid simulation device, a load and an AC station switching device, the energy storage system to be tested is an AC side energy storage system, and the method includes:

[0041] Connect the AC side energy storage system to the AC station switching device;

[0042] The output power of the grid simulation device is set to the test power of the AC side energy storage system;

[0043] Perform a cycle efficiency test on the AC side energy storage system to determine the cycle efficiency of the AC side energy storage system, wherein the cycle efficiency of the AC side energy storage system is calculated by the following formula:

[0044]

[0045] Among them, η 1 is the cycle efficiency of the AC side energy storage system, E d is the AC side discharge energy of the AC side energy storage system, E c is the AC side charging energy of the AC side energy storage system, W d is the auxiliary power consumed by the AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the AC side energy storage system during the charging process.

[0046] Furthermore, the test system includes an AC access device, a power grid simulation device, a load and an AC station switching device, the energy storage system to be tested is a combined AC side energy storage system, and the method includes:

[0047] Connecting the combined AC side energy storage system to the AC workstation switching device, wherein the combined AC side energy storage system includes a first AC side energy storage system and a second AC side energy storage system;

[0048] The output power of the AC simulation device is set to the test power of the first AC side energy storage system and the second AC side energy storage system;

[0049] The combined AC side energy storage system is subjected to a cycle efficiency test to determine the cycle efficiency of the first AC side energy storage system, wherein the cycle efficiency of the first AC side energy storage system is calculated by the following formula:

[0050]

[0051] Among them, η 1 is the cycle efficiency of the first AC side energy storage system, E d is the AC side discharge energy of the first AC side energy storage system, E c is the AC side charging energy of the first AC side energy storage system, W d is the auxiliary power consumed by the first AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first AC side energy storage system during the charging process.

[0052] Compared with the prior art, the solution provided by the present application sets an AC access device, a simulation device, a workstation switching device and a load in the test system of the energy storage system. The AC access device is connected to the AC power grid and realizes grid-connected and off-grid control when testing the energy storage system to be tested. The simulation device is connected to the AC access device to support the access of various AC or DC voltage systems. The workstation switching device is connected to the simulation device to select the simulation device to match the access power of the energy storage system to be tested. The load is connected to the AC access device to serve as an energy consumption device when testing the energy storage system to be tested. The corresponding test method can connect the energy storage system to be tested with the workstation switching device. And according to the voltage and power required by the energy storage system to be tested, the voltage and power output by the simulation device are set. According to the voltage and power output by the simulation device, the interface of the workstation switching device is adapted and adjusted, and then the energy storage system to be tested is subjected to charge and discharge tests, thereby realizing electrical performance tests compatible with a variety of energy storage inverters and different forms of battery energy storage systems. It can simultaneously take into account the access of systems with a variety of DC voltages and AC voltages, and can also be modularly expanded according to power to meet the test requirements of energy storage systems with different AC and DC voltage levels. At the same time, it avoids the problem of backfeeding electricity to the power grid during the discharge process of the battery energy storage system test, and has the characteristics of strong compatibility and good scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0054] Figure 1 A functional block diagram of a testing system for an energy storage system provided in some embodiments of the present application.

[0055] Figure 2 A schematic structural diagram of a testing system for an energy storage system provided in some embodiments of the present application.

[0056] Figure 3 A flowchart of a method for testing an energy storage system provided for some embodiments of the present application.

[0057] Figure 4 A schematic structural diagram of a test system for testing an energy storage converter provided in some embodiments of the present application.

[0058] Figure 5 A schematic diagram of the structure of a test system for testing a DC side energy storage system provided in some embodiments of the present application.

[0059] Figure 6 A schematic structural diagram of a test system for testing a combined DC-side energy storage system provided in some embodiments of the present application.

[0060] Figure 7 A schematic diagram of the structure of a test system for testing an AC side energy storage system provided in some embodiments of the present application.

[0061] Figure 8 A schematic structural diagram of a test system for testing a combined AC side energy storage system provided in some embodiments of the present application. DETAILED DESCRIPTION

[0062] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0063] Here, the energy storage system test system and test method of the embodiment of the present application are suitable for use in test scenarios for verifying and testing the electrical performance, stability and safety of energy storage systems with different system forms and different battery types.

[0064] In this scenario, energy storage systems with different system forms and different battery types have the problem of different voltage access. Existing test solutions can usually only be performed for a certain type of energy storage system product, and it is difficult to take into account all usage scenarios. Using a multi-tap transformer to achieve system access with multiple DC voltages and AC voltages is not only expensive, but also has the problem of only a few gears to choose from and complex wiring. In addition, it is necessary to use battery series selection on the DC side to meet the needs of different voltages. However, due to the attenuation and voltage inconsistency of the battery itself, it is difficult to output accurate voltage, which has a negative impact on the energy storage system test.

[0065] The solution provided in the embodiment of the present application sets an AC access device, a simulation device, a workstation switching device and a load in the test system of the energy storage system. The AC access device is connected to the AC power grid and realizes the grid connection and off-grid control when the energy storage system to be tested is tested. The simulation device is connected to the AC access device to support the access of multiple AC or DC voltage systems. The workstation switching device is connected to the simulation device to select the simulation device to match the access power of the energy storage system to be tested. The load is connected to the AC access device and is used as an energy consumption device when the energy storage system to be tested is tested. The corresponding test method can connect the energy storage system to be tested with the workstation switching device, and according to The voltage and power required by the energy storage system to be tested are set by the voltage and power output by the simulation device. According to the voltage and power output by the simulation device, the interface of the workstation switching device is adjusted to adapt, and then the energy storage system to be tested is tested for charge and discharge. This realizes electrical performance testing compatible with a variety of energy storage inverters and different forms of battery energy storage systems. It can simultaneously take into account the access of multiple DC voltages and AC voltage systems, and can also be modularly expanded according to power to meet the testing requirements of energy storage systems with different AC and DC voltage levels. At the same time, it avoids the problem of backfeeding electricity to the grid during the discharge process of the battery energy storage system test. It has the characteristics of strong compatibility and good scalability.

[0066] Some embodiments of the present application provide a testing system for an energy storage system, such as Figure 1 As shown, the system includes: an AC access device 101, a simulation device 102, a workstation switching device 103 and a load 104.

[0067] The AC access device 101 is used to access the AC power grid and realize the grid-connected and off-grid control when testing the energy storage system to be tested. Different numbers of simulation devices 102 and loads 104 can be connected according to the test requirements to form the corresponding test equipment, and serve as the gateway for grid-connected and off-grid switching.

[0068] The simulation device 102 is connected to the AC access device and is used to support the access of various AC or DC voltage systems.

[0069] The station switching device 103 is connected to the simulation device and is used to select the simulation device to match the access power of the energy storage system to be tested.

[0070] The load 104 is connected to the AC access device and is used as an electric energy consumption device when the energy storage system to be tested is tested, so as to ensure that the entire test system does not reverse power to the grid during off-grid testing and single battery energy storage system discharge testing.

[0071] In some embodiments of the present application, the simulation device 102 may include a power grid simulation device and a DC simulation device. The power grid simulation device is used to support access to multiple AC voltage systems and simulate the operation of the power grid in multiple working modes, including grid-connected operation and off-grid operation. The DC simulation device is used to support access to multiple DC voltage systems and can be used as a power device with different charge and discharge powers in battery testing, which is achieved by setting different charge and discharge powers.

[0072] In some embodiments of the present application, the workstation switching device 103 may include an AC workstation switching device and a DC workstation switching device. The AC workstation switching device is used to select the input side of the power grid simulation device to match the access power of the AC side of the energy storage system to be tested. The DC workstation switching device is used to select the input side of the DC simulation device to match the access power of the DC side of the energy storage system to be tested.

[0073] Figure 2 The structure of the test system of the energy storage system in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional power grid simulator is the power grid simulation device, the bidirectional DC simulator is the DC simulation device, the RLC load is the load 104, the AC station switching cabinet is the AC station switching device, and the DC station switching cabinet is the DC station switching device. Among them, the bidirectional power grid simulator, the bidirectional DC simulator and the RLC load can be expanded into multiple ones according to the test requirements, and the corresponding numbered bidirectional power grid simulators, bidirectional DC simulators and RLC loads constitute a single test system, which can adapt to the testing of energy storage systems with different powers. The expanded test system is matched and used by the AC access cabinet on the power grid side. The AC station switching cabinet can select the access power on the AC side of the energy storage system to be tested, and the DC station switching cabinet can select the access power on the DC side of the energy storage system to be tested. By switching different access powers, multiple sets of energy storage systems to be tested can be tested at the same time. In addition, by selecting different AC / DC voltages for the bidirectional grid simulator or bidirectional DC simulator, the testing requirements of energy storage converters with different AC / DC voltage levels and battery systems of different types and voltages can be met. When testing the energy storage system, the RLC load can be used for power consumption to ensure that no power is fed back to the grid. The RLC load can also be used as a load in off-grid testing.

[0074] Some embodiments of the present application also provide a testing method using the aforementioned energy storage system testing system, which may include the following steps:

[0075] Step S301, connecting the energy storage system to be tested to the workstation switching device.

[0076] In some embodiments of the present application, the energy storage system to be tested may include, but is not limited to, the following energy storage systems: an energy storage converter, a DC side energy storage system, a combined DC side energy storage system, an AC side energy storage system, and a combined AC side energy storage system.

[0077] A power conversion system (PCS) is a device in an electrochemical energy storage system that realizes bidirectional conversion of electric energy between a battery system and a power grid. Different power storage converter products have different AC / DC voltage levels.

[0078] The combined DC side energy storage system may include two DC side energy storage systems, and a pair-drag test may be performed during the test, that is, one DC side energy storage system performs charging / discharging, and the other DC side energy storage system performs discharging / charging.

[0079] Similarly, the combined AC side energy storage system may include two AC side energy storage systems, and a pair-drag test may be performed during testing, that is, one AC side energy storage system performs charging / discharging, and the other AC side energy storage system performs discharging / charging.

[0080] In addition, according to the DC or AC type of the energy storage system to be tested, it is connected to the corresponding station switching device.

[0081] Step S302, setting the voltage and power output by the simulation device according to the voltage and power required by the energy storage system to be tested.

[0082] Here, the simulation device outputs the voltage and power required by the energy storage system to be tested. Similarly, according to the DC or AC type of the energy storage system to be tested, the output voltage and power are set for the corresponding simulation device.

[0083] Step S303: Adaptively adjust the interface of the station switching device according to the voltage and power output by the simulation device.

[0084] Here, the corresponding station switching device is adjusted to the interface of the power grid simulation device or the DC simulation device to be used.

[0085] Step S304: performing a charge and discharge test on the energy storage system to be tested.

[0086] After the settings are completed, the energy storage system to be tested can be charged and discharged, the relevant data during the test process can be recorded, and the test results of the energy storage system to be tested can be determined based on the relevant data.

[0087] In some embodiments of the present application, a test system for testing an energy storage converter may include an AC access device, a power grid simulation device, a DC simulation device, an AC workstation switching device, and a DC workstation switching device.

[0088] Figure 4 The structure of the test system for testing the energy storage current meter in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional power grid simulator is the power grid simulation device, the bidirectional DC simulator is the DC simulation device, the AC station switching cabinet is the AC station switching device, the DC station switching cabinet is the DC station switching device, and the energy storage converter under test is the energy storage converter. Among them, the AC access cabinet is connected to multiple bidirectional power grid simulators and multiple bidirectional DC simulators, multiple bidirectional power grid simulators are connected to the AC station switching cabinet, multiple bidirectional DC simulators are connected to the DC station switching cabinet, and the AC side (AC) and DC side (DC) of the energy storage converter under test are connected to the AC station switching cabinet and the DC station switching cabinet respectively.

[0089] The test method for testing the energy storage converter may include the following steps:

[0090] 1) Connect the AC side of the energy storage converter to the AC station switching device, and connect the DC side of the energy storage converter to the DC station switching device;

[0091] 2) The output power of the power grid simulation device is set to the maximum value of the active power output on the AC side of the energy storage converter, that is, 100% P;

[0092] 3) According to the maximum value, the interfaces of the AC station switching device and the DC station switching device are adaptively adjusted to the interfaces of the power grid simulation device and the DC simulation device to be used respectively;

[0093] 4) Within the preset test time, the average value of the AC side active power, the DC side active power and the external auxiliary power supply active power of the energy storage converter is obtained; here, the test time can be determined as needed, for example, 10 minutes, and the AC side active power, the DC side active power and the external auxiliary power supply active power of the energy storage converter can be synchronously recorded by a data acquisition device according to a certain recording period such as 200ms, and then the average value of the AC side active power, the DC side active power and the external auxiliary power supply active power within the test time is calculated;

[0094] 5) Based on the average value, determine the charging efficiency of the energy storage inverter.

[0095] Here, the charging efficiency of the energy storage converter can be calculated by the following formula:

[0096]

[0097] Among them, η 1 is the charging efficiency of the energy storage converter, P DC is the active power on the DC side of the energy storage converter, P ACis the AC side active power of the energy storage converter, P AU is the external auxiliary active power.

[0098] In some embodiments of the present application, a test system for testing a DC side energy storage system may include an AC access device, a DC simulation device, a load, and a DC workstation switching device.

[0099] Figure 5 The structure of the test system for testing the DC side energy storage system in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional DC simulator is the DC simulation device, the DC station switching cabinet is the DC station switching device, the RLC load is the load, and the DC side energy storage system under test is the DC side energy storage system. Among them, the AC access cabinet is connected to multiple bidirectional DC simulators and multiple RLC loads, multiple bidirectional DC simulators are connected to the DC station switching cabinet, and the DC side energy storage system under test is connected to the DC station switching cabinet.

[0100] The test method for testing the DC side energy storage system may include the following steps:

[0101] 1) Connect the DC side energy storage system to the DC station switching device;

[0102] 2) Set the output power of the DC simulation device to the test power of the DC side energy storage system;

[0103] 3) Conduct a cycle efficiency test on the DC side energy storage system to determine the cycle efficiency of the DC side energy storage system.

[0104] Here, when performing a charging test, the power of the DC simulation device is adjusted for the charging test, and when performing a discharging test, the power of the DC simulation device is adjusted for the discharging test, and at the same time, loads of the same power are put into use to meet the requirement of not feeding electrical energy back to the grid.

[0105] When conducting a cycle efficiency test on a DC side energy storage system, i.e., a battery system, adjust the power of the DC side energy storage system under test connected to the DC simulation device to the test power. When the DC side energy storage system under test is charged, use the AC power grid for charging. When the DC side energy storage system under test is discharged, an RLC load of corresponding power is put into use for energy consumption. The charging energy, discharging energy, and power supply energy of the auxiliary equipment of the DC side energy storage system under test are recorded when the charging and discharging cut-off conditions are reached. The cycle efficiency of the DC side energy storage system under test is calculated based on the charging energy, discharging energy, and power supply energy of the auxiliary equipment.

[0106] Here, the cycle efficiency of the DC side energy storage system can be calculated by the following formula:

[0107]

[0108] Among them, η 1 is the cycle efficiency of the DC side energy storage system, E d is the DC side discharge energy of the DC side energy storage system, E c is the DC side charging energy of the DC side energy storage system, W d is the auxiliary power consumed by the DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the DC side energy storage system during the charging process.

[0109] In some embodiments of the present application, a test system for testing a combined DC side energy storage system may include an AC access device, a DC simulation device, a load and a DC workstation switching device, and the combined DC side energy storage system includes a first DC side energy storage system and a second DC side energy storage system.

[0110] Figure 6 The structure of the test system for testing the combined DC side energy storage system in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional DC simulator is the DC simulation device, the DC station switching cabinet is the DC station switching device, the RLC load is the load, the 1# tested DC side energy storage system is the first DC side energy storage system, and the 2# tested DC side energy storage system is the second DC side energy storage system. Among them, the AC access cabinet is connected to multiple bidirectional DC simulators and multiple RLC loads, multiple bidirectional DC simulators are connected to the DC station switching cabinet, and the 1# tested DC side energy storage system and the 2# tested DC side energy storage system are connected to the DC station switching cabinet.

[0111] The test method for testing the combined DC side energy storage system may include the following steps:

[0112] 1) Connect the combined DC side energy storage system to the DC station switching device;

[0113] Here, the first DC side energy storage system and the second DC side energy storage system are both connected to the DC workstation switching device, and the first DC side energy storage system and the second DC side energy storage system are subjected to a towing test;

[0114] 2) setting the output power of the DC simulation device to the test power of the first DC side energy storage system and the second DC side energy storage system;

[0115] 3) Conduct a cycle efficiency test on the combined DC side energy storage system to determine the cycle efficiency of the first DC side energy storage system.

[0116] Here, the cycle efficiency tests of the first DC side energy storage system and the second DC side energy storage system are respectively performed. When the cycle efficiency test of the first DC side energy storage system is performed, the first DC side energy storage system is first charged, and the second DC side energy storage system is discharged at the same power at the same time, and then the first DC side energy storage system is discharged, and the second DC side energy storage system is charged at the same power at the same time, and the charging energy, discharging energy and auxiliary equipment power supply energy of the first DC side energy storage system when the charging and discharging cut-off conditions are reached are recorded, and the cycle efficiency of the first DC side energy storage system is calculated based on the charging energy, discharging energy and auxiliary equipment power supply energy.

[0117] Here, the cycle efficiency of the first DC side energy storage system can be calculated by the following formula:

[0118]

[0119] Among them, η 1 is the cycle efficiency of the first DC side energy storage system, E d is the DC side discharge energy of the first DC side energy storage system, E c is the DC side charging energy of the first DC side energy storage system, W d is the auxiliary electric energy consumed by the first DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first DC side energy storage system during the charging process.

[0120] The process of determining the cycle efficiency of the second DC side energy storage system is similar to the above process.

[0121] In some embodiments of the present application, a test system for testing an AC-side energy storage system may include an AC access device, a power grid simulation device, a load, and an AC workstation switching device.

[0122] Figure 7 The structure of the test system for testing the AC side energy storage system in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional power grid simulator is the AC simulation device, the AC station switching cabinet is the AC station switching device, the RLC load is the load, and the AC side energy storage system under test is the AC side energy storage system. Among them, the AC access cabinet is connected to multiple bidirectional power grid simulators and multiple RLC loads, multiple bidirectional power grid simulators are connected to the AC station switching cabinet, and the AC side energy storage system under test is connected to the AC station switching cabinet.

[0123] The test method for testing the AC side energy storage system may include the following steps:

[0124] 1) Connect the AC side energy storage system to the AC station switching device;

[0125] 2) Set the output power of the grid simulation device to the test power of the AC side energy storage system;

[0126] 3) Conduct a cycle efficiency test on the AC side energy storage system to determine the cycle efficiency of the AC side energy storage system.

[0127] Here, when performing a charging test, the power of the grid simulation device is adjusted to perform a charging test, and when performing a discharging test, the power of the grid simulation device is adjusted to perform a discharging test, and at the same time, loads of the same power are put into use to meet the requirement of not feeding electrical energy back to the grid.

[0128] When conducting a cycle efficiency test on the AC side energy storage system, i.e., the battery system, the power of the AC side energy storage system under test connected to the grid simulation device is adjusted to the test power. When the AC side energy storage system under test is charged, it is charged using the AC grid. When the AC side energy storage system under test is discharged, an RLC load of corresponding power is put into use for energy consumption. The charging energy, discharging energy, and power supply energy of the auxiliary equipment of the AC side energy storage system under test are recorded when the charging and discharging cut-off conditions are reached. The cycle efficiency of the AC side energy storage system under test is calculated based on the charging energy, discharging energy, and power supply energy of the auxiliary equipment.

[0129] Here, the cycle efficiency of the AC side energy storage system can be calculated by the following formula:

[0130]

[0131] Among them, η 1 is the cycle efficiency of the AC side energy storage system, E d is the AC side discharge energy of the AC side energy storage system, E c is the AC side charging energy of the AC side energy storage system, W d is the auxiliary power consumed by the AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the AC side energy storage system during the charging process.

[0132] In some embodiments of the present application, a test system for testing a combined AC side energy storage system may include an AC access device, a power grid simulation device, a load and an AC workstation switching device, and the combined AC side energy storage system includes a first AC side energy storage system and a second AC side energy storage system.

[0133] Figure 8The structure of the test system for testing the combined AC side energy storage system in some embodiments of the present application is shown, the AC access cabinet in the figure is the AC access device, connected to the AC power grid, the bidirectional power grid simulator is the power grid simulation device, the AC station switching cabinet is the AC station switching device, the RLC load is the load, the 1# tested AC side energy storage system is the first AC side energy storage system, and the 2# tested AC side energy storage system is the second AC side energy storage system. Among them, the AC access cabinet is connected to multiple bidirectional power grid simulators and multiple RLC loads, multiple bidirectional power grid simulators are connected to the AC station switching cabinet, and the 1# tested AC side energy storage system and the 2# tested AC side energy storage system are connected to the AC station switching cabinet.

[0134] The test method for testing the combined AC side energy storage system may include the following steps:

[0135] 1) Connect the combined AC side energy storage system to the AC station switching device;

[0136] Here, the first AC side energy storage system and the second AC side energy storage system are both connected to the AC workstation switching device, and the first AC side energy storage system and the second AC side energy storage system are subjected to a towing test;

[0137] 2) setting the output power of the power grid simulation device to the test power of the first AC side energy storage system and the second AC side energy storage system;

[0138] 3) Perform a cycle efficiency test on the combined AC side energy storage system to determine the cycle efficiency of the first AC side energy storage system.

[0139] Here, the cycle efficiency tests of the first AC side energy storage system and the second AC side energy storage system are respectively performed. When the cycle efficiency test of the first AC side energy storage system is performed, the first AC side energy storage system is first charged, and the second AC side energy storage system is discharged at the same power at the same time, and then the first AC side energy storage system is discharged, and the second AC side energy storage system is charged at the same power at the same time, and the charging energy, discharging energy and auxiliary equipment power supply energy of the first AC side energy storage system when the charging and discharging cut-off conditions are reached are recorded, and the cycle efficiency of the first AC side energy storage system is calculated based on the charging energy, discharging energy and auxiliary equipment power supply energy.

[0140] Here, the cycle efficiency of the first AC side energy storage system can be calculated by the following formula:

[0141]

[0142] Among them, η 1 is the cycle efficiency of the first AC side energy storage system, W d is the DC side discharge energy of the first AC side energy storage system, E cis the DC side charging energy of the first AC side energy storage system, W d is the auxiliary power consumed by the first AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first AC side energy storage system during the charging process.

[0143] The process of determining the cycle efficiency of the second AC side energy storage system is similar to the above process.

[0144] In summary, the solution provided in the present application sets up an AC access device, a simulation device, a workstation switching device and a load in the test system of the energy storage system. The AC access device is connected to the AC power grid and realizes grid-connected and off-grid control when testing the energy storage system to be tested. The simulation device is connected to the AC access device to support the access of various AC or DC voltage systems. The workstation switching device is connected to the simulation device to select the simulation device to match the access power of the energy storage system to be tested. The load is connected to the AC access device and is used as an energy consumption device when testing the energy storage system to be tested. The corresponding test method can connect the energy storage system to be tested with the workstation switching device, and based on According to the voltage and power required by the energy storage system to be tested, the voltage and power output by the simulation device are set. According to the voltage and power output by the simulation device, the interface of the workstation switching device is adjusted, and then the energy storage system to be tested is charged and discharged. This realizes electrical performance testing compatible with a variety of energy storage inverters and different forms of battery energy storage systems. It can take into account the access of multiple DC voltages and AC voltage systems at the same time, and can also be modularly expanded according to power to meet the testing requirements of energy storage systems with different AC and DC voltage levels. At the same time, it avoids the problem of backfeeding electricity to the power grid during the discharge process of the battery energy storage system test. It has the characteristics of strong compatibility and good scalability.

[0145] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices stated in the device claim can also be implemented by one unit or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

Claims

1. A testing system for an energy storage system, characterized in that: The system includes: AC access device, used to access the AC power grid and realize grid-connection and off-grid control when testing the energy storage system to be tested; A simulation device, connected to the AC access device, for supporting access to a variety of AC or DC voltage systems; A station switching device, connected to the simulation device, for selecting the simulation device to match the access power of the energy storage system to be tested; A load is connected to the AC access device and is used as an electric energy consumption device when the energy storage system to be tested is tested.

2. The test system according to claim 1, characterized in that: The simulation device includes a power grid simulation device and a DC simulation device. The power grid simulation device is used to support access to multiple AC voltage systems and simulate power grid operation conditions under multiple working modes. The DC simulation device is used to support access to multiple DC voltage systems and is used as a power device with different charging and discharging powers in battery testing.

3. The test system according to claim 1, characterized in that: The workstation switching device includes an AC workstation switching device and a DC workstation switching device. The AC workstation switching device is used to select the input side of the power grid simulation device to match the access power of the AC side of the energy storage system to be tested. The DC workstation switching device is used to select the input side of the DC simulation device to match the access power of the DC side of the energy storage system to be tested.

4. A method for testing an energy storage system, using the testing system according to any one of claims 1 to 3, characterized in that: The method includes: Connecting the energy storage system to be tested to the station switching device; According to the voltage and power required by the energy storage system to be tested, setting the voltage and power output by the simulation device; Adaptively adjusting the interface of the station switching device according to the voltage and power output by the simulation device; A charge and discharge test is performed on the energy storage system to be tested.

5. The method according to claim 4, characterized in that The energy storage system to be tested includes the following: Energy storage converter, DC side energy storage system, combined DC side energy storage system, AC side energy storage system and combined AC side energy storage system.

6. The method according to claim 5, characterized in that The test system includes an AC access device, a power grid simulation device, a DC simulation device, an AC station switching device, and a DC station switching device. The energy storage system to be tested is an energy storage converter. The method includes: Connecting the AC side of the energy storage converter to an AC station switching device, and connecting the DC side of the energy storage converter to a DC station switching device; The output power of the power grid simulation device is set to the maximum value of the active power output on the AC side of the energy storage converter; According to the maximum value, adaptively adjusting the interfaces of the AC station switching device and the DC station switching device; Within a preset test time, obtaining the average value of the AC side active power, the DC side active power and the external auxiliary power supply active power of the energy storage converter; The charging efficiency of the energy storage converter is determined according to the average value, wherein the charging efficiency of the energy storage converter is calculated by the following formula: Among them, η1 is the charging efficiency of the energy storage converter, P DC is the active power on the DC side of the energy storage converter, P AC is the AC side active power of the energy storage converter, P AU is the external auxiliary active power.

7. The method according to claim 5, characterized in that The test system includes an AC access device, a DC simulation device, a load, and a DC station switching device. The energy storage system to be tested is a DC side energy storage system. The method includes: Connecting the DC side energy storage system to the DC station switching device; Setting the output power of the DC simulation device to the test power of the DC side energy storage system; A cycle efficiency test is performed on the DC side energy storage system to determine the cycle efficiency of the DC side energy storage system, wherein the cycle efficiency of the DC side energy storage system is calculated by the following formula: Among them, η1 is the cycle efficiency of the DC side energy storage system, E d is the DC side discharge energy of the DC side energy storage system, E c is the DC side charging energy of the DC side energy storage system, W d is the auxiliary power consumed by the DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the DC side energy storage system during the charging process.

8. The method according to claim 5, characterized in that The test system includes an AC access device, a DC simulation device, a load and a DC station switching device. The energy storage system to be tested is a combined DC side energy storage system. The method includes: Connecting the combined DC side energy storage system to the DC station switching device, wherein the combined DC side energy storage system includes a first DC side energy storage system and a second DC side energy storage system; Setting the output power of the DC simulation device to the test power of the first DC side energy storage system and the second DC side energy storage system; A cycle efficiency test is performed on the combined DC side energy storage system to determine the cycle efficiency of the first DC side energy storage system, wherein the cycle efficiency of the first DC side energy storage system is calculated by the following formula: Where η1 is the cycle efficiency of the first DC side energy storage system, E d is the DC side discharge energy of the first DC side energy storage system, E c is the DC side charging energy of the first DC side energy storage system, W d is the auxiliary electric energy consumed by the first DC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first DC side energy storage system during the charging process.

9. The method according to claim 5, characterized in that The test system includes an AC access device, a power grid simulation device, a load and an AC workstation switching device, the energy storage system to be tested is an AC side energy storage system, and the method includes: Connecting the AC side energy storage system to the AC station switching device; Setting the output power of the power grid simulation device to the test power of the AC side energy storage system; A cycle efficiency test is performed on the AC side energy storage system to determine the cycle efficiency of the AC side energy storage system, wherein the cycle efficiency of the AC side energy storage system is calculated by the following formula: Among them, η1 is the cycle efficiency of the AC side energy storage system, E d is the AC side discharge energy of the AC side energy storage system, E c is the AC side charging energy of the AC side energy storage system, W d is the auxiliary power consumed by the AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the AC side energy storage system during the charging process.

10. The method according to claim 5, characterized in that The test system includes an AC access device, a power grid simulation device, a load and an AC workstation switching device, the energy storage system to be tested is a combined AC side energy storage system, and the method includes: Connecting the combined AC side energy storage system to the AC workstation switching device, wherein the combined AC side energy storage system includes a first AC side energy storage system and a second AC side energy storage system; Setting the output power of the AC simulation device to the test power of the first AC side energy storage system and the second AC side energy storage system; A cycle efficiency test is performed on the combined AC side energy storage system to determine the cycle efficiency of the first AC side energy storage system, wherein the cycle efficiency of the first AC side energy storage system is calculated by the following formula: Where η1 is the cycle efficiency of the first AC side energy storage system, E d is the AC side discharge energy of the first AC side energy storage system, E c is the AC side charging energy of the first AC side energy storage system, W d is the auxiliary power consumed by the first AC side energy storage system during the discharge process, W c It is the auxiliary electric energy consumed by the first AC side energy storage system during the charging process.

Images