Synchronous Test Platform and Control Method for Multiple Energy Storage Converters

Abstract

This invention relates to the field of energy storage technology and discloses a synchronous testing platform for multiple energy storage converters and its control method. The testing platform of this invention includes: an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller. The power grid is connected to the high-voltage side of the transformer sequentially through the incoming line switch and the pre-charge circuit. One side of the AC circuit breaker is connected to the windings on the low-voltage side of the transformer, and the other side is connected to the AC side of the energy storage converter. The DC side of the first group of energy storage converters is connected to the DC side of the second group of energy storage converters through DC circuit breakers. The first group of energy storage converters is connected to the auxiliary power supply. In this invention, after the first group of PCS (Power Storage Converters) is pre-charged, the pre-charge circuit is bypassed. Then, the first group of PCS is unlocked and controlled in DC voltage mode, and the second group of PCS is started sequentially, thereby achieving synchronous charging and discharging testing of 2N PCS, greatly improving the charging and discharging testing efficiency of the energy storage converter.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, specifically to a synchronous testing platform for multiple energy storage converters and its control method. Background Technology

[0002] A power conversion system (PCS) is the core component of an energy storage system, used to convert DC power from batteries into AC power (discharging) and vice versa (charging). Energy storage systems based on string PCS, due to the direct connection between battery clusters and the PCS, reduce intermediate conversion stages and eliminate the problem of circulating current in multiple parallel clusters. They offer advantages such as higher efficiency, smaller footprint, and higher return on investment, thus gaining increasing attention.

[0003] Each battery cluster in an energy storage system requires a PCS (Power Control System). As the scale of energy storage systems increases, the demand for string PCS is growing daily, placing higher demands on the charging and discharging testing efficiency of the PCS. Conventional PCS testing platforms employ a paired testing method, with one PCS controlling voltage and another controlling power, requiring a DC power source to provide the necessary DC voltage for PCS operation. Only two PCS can be charged and discharged at a time, and the DC power source must be connected before each test and disconnected after the voltage-controlled PCS establishes its DC voltage. When testing a large number of PCS, the testing time is long, requiring frequent wiring and disconnection, and frequent connection and disconnection of the DC power source, resulting in low testing efficiency and a lengthy testing process.

[0004] For example, Chinese patent CN120214457A discloses a test platform and method for an energy storage converter, specifically disclosing that: a 380V power grid is sequentially connected to the AC side of a first circuit breaker, a first contactor, a transformer, and a first power supply unit (PCS); the DC side of the PCS under test is sequentially connected to a second circuit breaker, a second contactor, and the DC terminals of the first and second PCS; the AC side of the PCS under test is sequentially connected to a third circuit breaker, a third contactor, and the AC terminal of the second PCS; a pre-charge module is connected in parallel with the first PCS; and a unit controller is connected to the first contactor, the second contactor, the third contactor, the pre-charge module, the PCS under test, and each module in the AC / DC combined power source. This test platform can only perform charge and discharge tests on one energy storage converter (PCS) at a time, resulting in low testing efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a synchronous testing platform for multiple energy storage converters and its control method to solve the problems mentioned in the background art.

[0006] This invention provides a synchronous testing platform for multiple energy storage converters. The multiple energy storage converters are divided into a first group and a second group, with each group including N units. The testing platform includes: an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller.

[0007] The high-voltage side of the transformer has a single winding, while the low-voltage side has 2N windings.

[0008] The high-voltage side of the transformer, the pre-charge circuit, and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid.

[0009] The number of AC circuit breakers and the number of DC circuit breakers are 2N and N, respectively;

[0010] One side of each of the 2N AC circuit breakers is connected to one of the 2N windings on the low-voltage side of the transformer, and the other side is connected to the AC side of each of the 2N energy storage converters.

[0011] The auxiliary power supply ports of the first group of energy storage converters are connected to the auxiliary power supply through the auxiliary power supply switch after being connected in parallel.

[0012] One side of each of the N DC circuit breakers is connected to the DC side of the first group of energy storage converters, and the other side of each of the N DC circuit breakers is connected to the DC side of the second group of energy storage converters.

[0013] The unit controller is communicatively connected to the incoming line switch, the pre-charge circuit, and the energy storage converter.

[0014] Based on the above scheme, the synchronous testing platform for multiple energy storage converters of the present invention is configured with an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller. The high-voltage side of the transformer, the pre-charge circuit, and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid. One side of each of the 2N AC circuit breakers is connected to one of the 2N windings on the low-voltage side of the transformer, and the other side is connected to the AC side of each of the 2N energy storage converters. The auxiliary power supply ports of the first group of energy storage converters are connected to the auxiliary power supply through the auxiliary power supply switch after being connected in parallel. One side of each of the N DC circuit breakers is connected to the DC side of the first group of energy storage converters, and the other side is connected to the DC side of the second group of energy storage converters. The unit controller is communicatively connected to the incoming line switch, the pre-charge circuit, and the energy storage converters. The present invention provides a synchronous testing platform for multiple energy storage converters. The first group of N voltage-controlled PCS units is externally powered, controlling the internal AC switch to close first. Then, the high-voltage incoming switch closes, and grid power is supplied to the first group of N voltage-controlled PCS units via a pre-charge circuit for uncontrolled rectified pre-charging. Once a certain voltage is reached, the pre-charge circuit is bypassed, and the first group of N voltage-controlled PCS units unlocks the controlled DC voltage. Subsequently, the second group of N power-controlled PCS units start sequentially, and the charging and discharging power is set, thereby achieving synchronous charging and discharging testing of 2N PCS units, greatly improving the charging and discharging testing efficiency of the energy storage converter.

[0015] In one feasible solution, the precharge circuit includes: a precharge resistor and a bypass switch;

[0016] The pre-charge resistor and the bypass switch are connected in parallel, and the bypass switch is communicatively connected to the unit controller.

[0017] In one feasible embodiment, the unit controller includes: a first control device, a second control device, and a coordination controller;

[0018] The first control device is communicatively connected to the incoming line switch, the bypass switch, and the first group of energy storage converters, respectively.

[0019] The second control device is communicatively connected to the energy storage converter of the second group;

[0020] Furthermore, the first control device and the second control device are respectively connected to the coordination controller for communication.

[0021] One feasible solution also includes: a first liquid cooling unit and a second liquid cooling unit;

[0022] The first group of energy storage converters is connected to the first liquid cooling unit through inlet and outlet water pipes, and the second group of energy storage converters is connected to the second liquid cooling unit through inlet and outlet water pipes.

[0023] The first liquid cooling unit and the second liquid cooling unit are respectively communicatively connected to the first control device and the second control device.

[0024] In one feasible approach, the phases of the windings on the low-voltage side of the transformer are the same.

[0025] This invention also provides a control method for a synchronous testing platform for multiple energy storage converters, comprising the following steps:

[0026] S1 Manually closes AC circuit breakers, DC circuit breakers, and auxiliary power supply switches;

[0027] S2 controls the first group of energy storage converters to constant DC voltage mode and controls the AC side switch inside the first group of energy storage converters to close.

[0028] S3 controls the closing of the incoming line switch and the opening of the bypass switch, so that the energy storage converter of the first group is pre-charged.

[0029] After charging to the set voltage, S4 controls the bypass switch to close;

[0030] S5 controls the unlocking of the first group of energy storage converters and closes the DC side switch inside the first group of energy storage converters. At the same time, the first liquid cooling unit starts to control the temperature of the first group of energy storage converters.

[0031] S6 controls the second group of energy storage converters to constant power mode and starts sequentially, while the second liquid cooling unit starts and controls the temperature of the second group of energy storage converters.

[0032] S7 controls the charging or discharging of the second group of energy storage converters, while the corresponding first group of energy storage converters is discharging or charging.

[0033] After the S8 test is completed, control the second set of energy storage converters and the second liquid cooling unit to shut down;

[0034] S9 controls the shutdown of the first group of energy storage converters, the opening of the bypass switch and the incoming line switch, and the shutdown of the first liquid cooling unit;

[0035] S10 Manually disconnects the auxiliary power supply switch, AC circuit breaker, and DC circuit breaker.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. A single test can achieve synchronous charging and discharging of 2N (48) energy storage converters (PCS), which greatly improves the charging and discharging test efficiency of energy storage converters.

[0038] 2. The coordinating controller is connected to two control devices, each of which is connected to N (24) PCS. The coordinating controller enables comprehensive control and management of 2N (48) PCS. All charging and discharging test operations are performed under the control of the coordinating controller, simplifying the operation.

[0039] 3. By configuring a pre-charge circuit on the high-voltage side of the multi-winding transformer, N (24) PCS can be pre-charged synchronously without equipping each PCS with a pre-charge or DC source.

[0040] 4. By equipping all PCS with circuit breakers on both the AC and DC sides, a single or multiple PCS can be disconnected in case of an malfunction without affecting the operation of other PCS. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a synchronous testing platform for multiple energy storage converters in Embodiment 1 of the present invention;

[0043] Figure 2 This is a flowchart illustrating the control method in Embodiment 2 of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0048] As described in the background section of this application, each battery cluster in an energy storage system requires a PCS (Power Control System). With the increasing scale of energy storage systems, the demand for string PCS is growing daily, placing higher demands on the charging and discharging testing efficiency of the PCS. Conventional PCS testing platforms employ a counter-testing method, with one PCS controlling voltage and another controlling power, and require a DC power source to provide the DC voltage needed for PCS operation. Only two PCS can be charged and discharged at a time, and the DC power source must be switched on before each test and switched off after the voltage-controlled PCS establishes DC voltage. When testing a large number of PCS, the testing time is long, requiring frequent wiring and disconnection, and frequent switching on and off of the DC power source, resulting in low testing efficiency and a lengthy testing process.

[0049] To address the aforementioned problems, the inventors of this application have proposed a technical solution, the specific embodiments of which are as follows:

[0050] Example 1: Figure 1 This is a schematic diagram of a synchronous testing platform for multiple energy storage converters in Embodiment 1 of the present invention.

[0051] like Figure 1 As shown, the synchronous test platform for multiple energy storage converters in this embodiment includes: an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker, and a unit controller.

[0052] The multiple energy storage converters (PCS) are divided into two groups, namely Group 1 and Group 2, each containing N energy storage converters, where N is a natural number greater than 1. In this embodiment, N is 24, and there are a total of 48 energy storage converters. The 48 energy storage converters are labeled as PCS 1#, PCS 2#, PCS 3#, and so on up to PCS 48#. Group 1 includes 24 energy storage converters from PCS 1#, PCS 2#, to PCS 24#, and Group 2 includes 24 energy storage converters from PCS 25#, PCS 26#, to PCS 48#.

[0053] The transformer is a multi-winding transformer. The high-voltage side of the transformer has a single winding, while the low-voltage side has 48 (2N) windings. That is, the number of windings on the low-voltage side of the transformer corresponds to the number of energy storage converters being tested simultaneously. Preferably, the windings on the low-voltage side of the transformer are in phase.

[0054] The high-voltage side of the transformer, the pre-charge circuit, and the incoming line switch QF1 are connected in series, and the other side of the incoming line switch QF1 is connected to the power grid, so that the power grid is connected to the high-voltage side of the transformer.

[0055] The number of AC circuit breakers and DC circuit breakers are 2N and N respectively, that is, the number of AC circuit breakers in this embodiment is 48, and the 48 AC circuit breakers are marked as QF4~QF51 respectively; the number of DC circuit breakers is 24, and the 24 DC circuit breakers are marked as QF52~QF75 respectively.

[0056] One side of each of the 48 AC circuit breakers QF4~QF51 is connected to one of the 48 windings on the low-voltage side of the transformer, and the other side of each of the 48 AC circuit breakers QF4~QF51 is connected to the AC side of PCS 1~PCS 48 (48 energy storage converters).

[0057] The auxiliary power supply ports of the first group's 1#PCS~24#PCS (24 energy storage converters) are connected in parallel to one side of the auxiliary power supply switch QF3. The other side of the auxiliary power supply switch QF3 is connected to the AC220V auxiliary power supply, which provides auxiliary power to the 24 energy storage converters in the first group.

[0058] Furthermore, the DC side of the first group's 1#PCS~24#PCS (24 energy storage converters) is connected to one side of QF52~QF75 (24 DC circuit breakers), and the other side of QF52~QF75 (24 DC circuit breakers) is connected to the DC side of the second group's 25#PCS~48#PCS (24 energy storage converters).

[0059] The unit controller is connected to the incoming line switch QF1, the pre-charge circuit, and PCS 1 to PCS 48 (48 energy storage converters) respectively. The unit controller controls the closing and opening of the incoming line switch QF1, the access and bypass of the pre-charge circuit, and the control and management of PCS 1 to PCS 48 (48 energy storage converters).

[0060] As can be seen from the above, the synchronous test platform for multiple energy storage converters in this embodiment is configured with an incoming line switch, a pre-charge circuit, a transformer, an auxiliary power supply switch, AC circuit breakers, DC circuit breakers, and a unit controller. The high-voltage side of the transformer, the pre-charge circuit, and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid. One side of each of the 2N AC circuit breakers is connected to one of the 2N windings on the low-voltage side of the transformer, and the other side is connected to the AC side of each of the 2N energy storage converters. The auxiliary power supply ports of the first group of energy storage converters are connected to the auxiliary power supply through the auxiliary power supply switch after being connected in parallel. One side of each of the N DC circuit breakers is connected to the DC side of the first group of energy storage converters, and the other side is connected to the DC side of the second group of energy storage converters. The unit controller is communicatively connected to the incoming line switch, the pre-charge circuit, and the energy storage converters. In this embodiment, the multi-energy storage converter synchronous test platform has N voltage-controlled PCS in the first group connected to an external auxiliary power supply. The internal AC switch of each PCS is closed first. Then, the high-voltage incoming switch is closed, and the grid power is used to pre-charge the N voltage-controlled PCS in the first group through the pre-charge circuit. When the voltage reaches a certain level, the pre-charge circuit is bypassed, and the DC voltage of the N voltage-controlled PCS in the first group is unlocked. Then, the N power-controlled PCS in the second group are started in sequence, and the charging and discharging power is set, thereby realizing synchronous charging and discharging testing of 2N PCS, which greatly improves the charging and discharging testing efficiency of the energy storage converter.

[0061] Optionally, in this embodiment, the pre-charge circuit of the multi-energy storage converter synchronous test platform includes a pre-charge resistor R and a bypass switch QF2.

[0062] The pre-charge resistor R and the bypass switch QF2 are connected in parallel to form a pre-charge circuit. One side of the pre-charge circuit is connected to the incoming switch QF1, and the other side is connected to the high-voltage side of the transformer.

[0063] The bypass switch QF2 of the precharge circuit is connected to the unit controller. The unit controller controls the closing and opening of the bypass switch QF2 to bypass or connect the precharge resistor R to the circuit.

[0064] Furthermore, in this embodiment, the multi-energy storage converter synchronous test platform includes a unit controller comprising a first control device, a second control device, and a coordination controller.

[0065] The first control device (control device #1) is connected to the incoming line switch QF1, the bypass switch QF2, and the first group of 1#PCS~24#PCS (24 energy storage converters). The first control device controls the operation of the 24 energy storage converters in the first group and controls the closing and opening of the incoming line switch QF1 and the bypass switch QF2.

[0066] The second control device (control device #2) is connected to the second group of 25#PCS~48#PCS (24 energy storage converters) and controls the operation of the 24 energy storage converters in the second group.

[0067] Furthermore, the first control device and the second control device are respectively connected to the coordination controller for integrated management.

[0068] Furthermore, the synchronous test platform for multiple energy storage converters in this embodiment also includes: a first liquid cooling unit and a second liquid cooling unit.

[0069] The first liquid cooling unit (1# liquid cooling unit) and the second liquid cooling unit (2# liquid cooling unit) are respectively connected to the first control device and the second control device.

[0070] The first group of 1#PCS~24#PCS (24 energy storage converters) are connected to the first liquid cooling unit through inlet and outlet water pipes, and the first control device controls the temperature of the energy storage converters in the first group through the first liquid cooling unit.

[0071] The second group of 25#PCS~48#PCS (24 energy storage converters) are connected to the second liquid cooling unit through inlet and outlet water pipes. The second control device controls the temperature of the energy storage converters in the second group through the second liquid cooling unit.

[0072] Example 2: Figure 2 This is a flowchart illustrating the control method in Embodiment 2 of the present invention.

[0073] like Figure 2 As shown, the control method for the synchronous test platform of multiple energy storage converters in this embodiment first ensures normal communication between the components of the test platform. The control method includes the following steps:

[0074] S1 manually closes QF4~QF51 (48 AC circuit breakers), manually closes QF52~QF75 (24 DC circuit breakers), and manually closes QF3 (auxiliary power supply switch). At this time, the AC220V auxiliary power supply supplies power to the first group of 1#PCS~24#PCS (24 energy storage converters).

[0075] S2 The first control device controls the first group of 1#PCS~24#PCS (24 energy storage converters) to constant DC voltage mode. The first control device also controls the AC side switch inside the first group of 1#PCS~24#PCS (24 energy storage converters) to close.

[0076] S3 controls the closing of the incoming line switch and the opening of the bypass switch, enabling the first group of energy storage converters to be precharged.

[0077] Specifically, after the AC side switch in the first group of energy storage converters is closed, the first control device controls the high-voltage incoming switch QF1 to close and controls the bypass switch QF2 to open. At this time, the pre-charging resistor R of the pre-charging circuit is connected to the circuit, and the grid power is used to perform uncontrolled rectification pre-charging of the 24 energy storage converters in the first group through the pre-charging resistor R.

[0078] After charging to the set voltage, S4 controls the bypass switch to close.

[0079] Specifically, after the first energy storage converter is charged to the preset voltage, the first control device controls the bypass switch QF2 to close, so that the pre-charge resistor R of the pre-charge circuit is bypassed.

[0080] S5 controls the unlocking of the first group of energy storage converters and closes the DC side switch inside the energy storage converter. At the same time, the first liquid cooling unit starts to control the temperature of the energy storage converter.

[0081] Specifically, the first control device unlocks the constant DC voltage mode of the first group of 1#PCS~24#PCS (24 energy storage converters) and controls the DC side switch inside the first group of energy storage converters to close. At the same time, the first control device controls the first liquid cooling unit to start and control the temperature of the first group of 1#PCS~24#PCS (24 energy storage converters).

[0082] S6 controls the second group of energy storage converters to constant power mode and starts them sequentially. At the same time, the second liquid cooling unit starts and controls the temperature of the second group of energy storage converters.

[0083] Specifically, after the first group of energy storage converters is unlocked and controlled in DC voltage mode, the second control device controls the second group of 25#PCS~48#PCS (24 energy storage converters) to constant power mode and starts the second group of 25#PCS~48#PCS (24 energy storage converters) in sequence. At the same time, the second control device controls the second liquid cooling unit to start and performs temperature control on the second group of 25#PCS~48#PCS (24 energy storage converters).

[0084] S7 controls the charging or discharging of the second group of energy storage converters, while the corresponding first group of energy storage converters is discharging or charging.

[0085] Specifically, the coordinating controller presets the charging and discharging power, and then controls the charging or discharging test of the second group's 25#PCS~48#PCS (24 energy storage converters), while the corresponding discharge or charging test is carried out on the first group's 1#PCS~24#PCS (24 energy storage converters), thus realizing the synchronous charging and discharging test of 2N (48) energy storage converters.

[0086] After the S8 test is completed, control the shutdown of PCS 25 to PCS 48 (24 energy storage converters) in the second group, and simultaneously control the shutdown of the second liquid cooling unit.

[0087] Specifically, after the charge and discharge test is completed, the second control device first controls the shutdown of PCS 25 to PCS 48 in the second group, and at the same time, the second control device controls the shutdown of the second liquid cooling unit.

[0088] S9 then controls the shutdown of PCS 1 to PCS 24 (24 energy storage converters) in the first group, opens the bypass switch QF2, opens the incoming switch QF1, and simultaneously controls the shutdown of the first liquid cooling unit.

[0089] Specifically, after the second group of energy storage converters shuts down, the first control device then controls the shutdown of 1#PCS~24#PCS (24 energy storage converters) of the first group, controls the bypass switch QF2 to open, controls the incoming line switch QF1 to open, and at the same time, the first control device controls the shutdown of the first liquid cooling unit.

[0090] S10 Finally, manually disconnect auxiliary power supply switch QF3, manually disconnect QF4~QF51 (48 AC circuit breakers), and manually disconnect QF52~QF75 (24 DC circuit breakers).

[0091] In this invention, unless otherwise explicitly specified and limited, the first feature being "on" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium.

[0092] Furthermore, "above," "on top of," and "above" the first feature in relation to the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "under," and "beneath" the first feature in relation to the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0093] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A synchronous testing platform for multiple energy storage converters, wherein the multiple energy storage converters are divided into a first group and a second group, each group comprising N converters, characterized in that... The test platform includes: incoming line switch, pre-charge circuit, transformer, auxiliary power supply switch, AC circuit breaker, DC circuit breaker and unit controller; The high-voltage side of the transformer has a single winding, while the low-voltage side has 2N windings. The high-voltage side of the transformer, the pre-charge circuit, and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid. The number of AC circuit breakers and the number of DC circuit breakers are 2N and N, respectively; One side of each of the 2N AC circuit breakers is connected to one of the 2N windings on the low-voltage side of the transformer, and the other side is connected to the AC side of each of the 2N energy storage converters. The auxiliary power supply ports of the first group of energy storage converters are connected to the auxiliary power supply through the auxiliary power supply switch after being connected in parallel. One side of each of the N DC circuit breakers is connected to the DC side of the first group of energy storage converters, and the other side of each of the N DC circuit breakers is connected to the DC side of the second group of energy storage converters. The unit controller is communicatively connected to the incoming line switch, the pre-charge circuit, and the energy storage converter.

2. The synchronous testing platform for multiple energy storage converters according to claim 1, characterized in that, The pre-charge circuit includes: a pre-charge resistor and a bypass switch; The pre-charge resistor and the bypass switch are connected in parallel, and the bypass switch is communicatively connected to the unit controller.

3. The synchronous testing platform for multiple energy storage converters according to claim 2, characterized in that, The unit controller includes: a first control device, a second control device, and a coordination controller; The first control device is communicatively connected to the incoming line switch, the bypass switch, and the first group of energy storage converters, respectively. The second control device is communicatively connected to the energy storage converter of the second group; Furthermore, the first control device and the second control device are respectively connected to the coordination controller for communication.

4. The synchronous testing platform for multiple energy storage converters according to claim 3, characterized in that, Also includes: First liquid-cooled unit and second liquid-cooled unit; The first group of energy storage converters is connected to the first liquid cooling unit through inlet and outlet water pipes, and the second group of energy storage converters is connected to the second liquid cooling unit through inlet and outlet water pipes. The first liquid cooling unit and the second liquid cooling unit are respectively communicatively connected to the first control device and the second control device.

5. The synchronous testing platform for multiple energy storage converters according to claim 1, characterized in that, The low-voltage side windings of the transformer have the same phase.

6. A control method based on the synchronous test platform for multiple energy storage converters as described in claim 4, characterized in that, Includes the following steps: S1 Manually closes AC circuit breakers, DC circuit breakers, and auxiliary power supply switches; S2 controls the first group of energy storage converters to constant DC voltage mode and controls the AC side switch inside the first group of energy storage converters to close. S3 controls the closing of the incoming line switch and the opening of the bypass switch, so that the energy storage converter of the first group is pre-charged. After charging to the set voltage, S4 controls the bypass switch to close; S5 controls the unlocking of the first group of energy storage converters and closes the DC side switch inside the first group of energy storage converters. At the same time, the first liquid cooling unit starts to control the temperature of the first group of energy storage converters. S6 controls the second group of energy storage converters to constant power mode and starts sequentially, while the second liquid cooling unit starts and controls the temperature of the second group of energy storage converters. S7 controls the charging or discharging of the second group of energy storage converters, while the corresponding first group of energy storage converters is discharging or charging. After the S8 test is completed, control the second set of energy storage converters and the second liquid cooling unit to shut down; S9 controls the shutdown of the first group of energy storage converters, the opening of the bypass switch and the incoming line switch, and the shutdown of the first liquid cooling unit; S10 Manually disconnects the auxiliary power supply switch, AC circuit breaker, and DC circuit breaker.

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