Synchronous test platform for multiple energy storage converters and control method thereof

Abstract

The invention relates to the technical field of energy storage, and discloses a synchronous test platform for multiple energy storage converters and a control method of the synchronous test platform. The test platform comprises a wire inlet switch, a pre-charging loop, a transformer, an auxiliary power supply switch, an alternating-current circuit breaker, a direct-current circuit breaker and a unit controller, a power grid is connected to the high-voltage side of the transformer through the wire inlet switch and the pre-charging loop in sequence, and one side of the alternating-current circuit breaker is connected with a winding on the low-voltage side of the transformer. The direct current side of the first group of energy storage converters is connected with the direct current side of the second group of energy storage converters through the direct current circuit breaker, and the first group of energy storage converters is connected with the auxiliary power supply. According to the test platform, the pre-charging loop is bypassed after the first group of PCS is pre-charged, then the first group of PCS unlocks the direct current voltage control mode, and the second group of PCS starts in sequence control, so that the synchronous charging and discharging test of 2N PCSs is realized, and the charging and discharging test efficiency of the energy storage converter is greatly improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of energy storage technology, and in particular to a synchronous testing platform for multiple energy storage converters and a control method thereof. Background Art

[0002] The power conversion system (PCS) is a core component of energy storage systems, used to convert battery DC power into AC power (discharge) and AC power into DC power (charge). Energy storage systems based on string PCSs, which directly connect battery clusters to the PCS, eliminate intermediate power conversion steps and eliminate the problem of circulating current in parallel with multiple clusters. These systems offer advantages such as higher efficiency, smaller footprint, and higher investment returns, and are gaining increasing attention.

[0003] Each battery cluster in an energy storage system requires a PCS. As the scale of energy storage systems increases, the demand for string-type PCSs is also increasing, placing higher demands on the efficiency of PCS charge and discharge testing. Conventional PCS test platforms utilize a pair-drag test method, with one PCS controlling voltage and another controlling power. A DC source is required to provide the DC voltage required for PCS operation. Only two PCSs can be tested at a time. The DC source must be activated before each test and then deactivated after the voltage-controlling PCS establishes the DC voltage. When testing a large number of PCSs, testing takes a long time and requires frequent wiring and disconnection, as well as frequent activation and deactivation of the DC source. This results in low test efficiency and a lengthy testing process.

[0004] For example, Chinese patent publication number CN120214457A discloses a testing platform and method for energy storage converters. Specifically, the following steps are described: A first circuit breaker, a first contactor, a transformer, and the AC side of a first power supply (PCS) are sequentially connected to a 380V power grid; the DC side of the PCS to be tested is sequentially connected to a second circuit breaker, a second contactor, and the DC side of the first and second PCSs; the AC side of the PCS to be tested is sequentially connected to a third circuit breaker, a third contactor, and the AC side 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 to be tested, and each module in the combined AC / DC power supply. This testing 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 object of the present invention is to provide a synchronous testing platform for multiple energy storage converters and a control method thereof, so as to solve the problems in the above-mentioned background technology.

[0006] An embodiment of the present 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, each group including N converters. 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. The high-voltage side of the transformer is a single winding, and the low-voltage side is provided with 2N windings; The high-voltage side of the transformer, the pre-charging circuit and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid; The number of the AC circuit breakers and the number of the DC circuit breakers are 2N and N respectively; One side of the 2N AC circuit breakers is respectively connected to the 2N windings on the low-voltage side of the transformer, and the other side is respectively connected to the AC side 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 the N DC circuit breakers is respectively connected to the DC side of the energy storage converter of the first group, and the other side of the N DC circuit breakers is respectively connected to the DC side of the energy storage converter of the second group; The unit controller is communicatively connected to the incoming line switch, the pre-charging circuit, and the energy storage converter respectively.

[0007] Based on the above scheme, it can be seen that the synchronous testing platform for multiple energy storage converters of the present invention is equipped with an incoming line switch, a pre-charging loop, 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-charging loop and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid. One side of the 2N AC circuit breakers is respectively connected to the 2N windings on the low-voltage side of the transformer, and the other side is respectively connected to the AC side of the 2N energy storage converters. After being connected in parallel, 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. One side of the N DC circuit breakers is respectively connected to the DC side of the first group of energy storage converters, and the other side is respectively connected to the DC side of the second group of energy storage converters. The unit controller is respectively communicated with the incoming line switch, the pre-charging loop, and the energy storage converter. In the synchronous testing platform for multiple energy storage converters of the present invention, N voltage-controlled PCSs in the first group are connected to an external auxiliary power supply to control their internal AC switches to close first; then the high-voltage incoming line switch is closed, and the grid power passes through the pre-charging circuit to perform uncontrolled rectification pre-charging on the N voltage-controlled PCSs in the first group; when charged to a certain voltage, the pre-charging circuit is bypassed, and the N voltage-controlled PCSs in the first group are unlocked to control the DC voltage; then the N power-controlled PCSs in the second group are started in sequence to set the charging and discharging power, thereby realizing synchronous charging and discharging testing of 2N PCSs, greatly improving the charging and discharging test efficiency of the energy storage converter.

[0008] In a feasible solution, the pre-charge circuit includes: a pre-charge resistor and a bypass switch; The pre-charging resistor and the bypass switch are connected in parallel, and the bypass switch is communicatively connected to the unit controller.

[0009] In a feasible solution, 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 switch, the bypass switch, and the energy storage converter of the first group respectively; The second control device is communicatively connected to the energy storage converter of the second group; The first control device and the second control device are respectively connected to the coordination controller for communication.

[0010] In a feasible solution, it further includes: a first liquid cooling unit and a second liquid cooling unit; The energy storage converter of the first group is connected to the first liquid cooling unit via the inlet and outlet water pipelines, and the energy storage converter of the second group is connected to the second liquid cooling unit via the inlet and outlet water pipelines; The first liquid cooling unit and the second liquid cooling unit are communicatively connected to the first control device and the second control device respectively.

[0011] In a feasible solution, the phases of the windings on the low-voltage side of the transformer are the same.

[0012] An embodiment of the present invention further provides a control method for a synchronous test platform for multiple energy storage converters, comprising the following steps: S1 manually closes the AC circuit breaker, DC circuit breaker and auxiliary power switch; S2 controls the energy storage converter of the first group to be in constant DC voltage mode, and controls the AC side switch in the energy storage converter of the first group to be closed; S3 controls the incoming line switch to close and the bypass switch to open, 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 switches in the first group of energy storage converters. At the same time, the first liquid cooling unit is started 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 them sequentially. At the same time, the second liquid cooling unit starts and controls the temperature of the second group of energy storage converters. S7 controls the second group of energy storage converters to charge or discharge, and the corresponding first group of energy storage converters to discharge or charge; After the S8 test is completed, the second group of energy storage converters and the second liquid cooling unit are controlled to shut down; S9 controls the shutdown of the first energy storage converter, the opening of the bypass switch and the incoming line switch, and the shutdown of the first liquid cooling unit; S10 Manually disconnect the auxiliary power switch, AC circuit breaker, and DC circuit breaker.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. It can realize synchronous charge and discharge test of 2N (48) energy storage converters (PCS) at a time, which greatly improves the charge and discharge test efficiency of energy storage converters.

[0014] 2. The coordination controller is connected to two control devices, and each of the two control devices is connected to N (24) PCSs. The coordination controller is used to achieve comprehensive control and management of 2N (48) PCSs. All charging and discharging test operations are carried out under the control of the coordination controller, which simplifies the operation.

[0015] 3. By configuring a pre-charging circuit on the high voltage side of the multi-winding transformer, N (24) PCSs can be pre-charged synchronously without equipping the PCSs with pre-charging or DC sources separately.

[0016] 4. By equipping all PCSs with circuit breakers on the AC and DC sides, when a single or multiple PCSs are abnormal, they can be disconnected without affecting the operation of other PCSs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 Schematic diagram of a synchronous testing platform for multiple energy storage converters in Example 1 of the present invention; Figure 2 This is a flow chart of the control method in the second embodiment of the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise expressly specified or limited. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0022] The following specific embodiments are used to describe the technical solution of the present invention in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0023] As described in the background technology of this application, each cluster of batteries in the energy storage system must be equipped with a PCS. As the scale of the energy storage system increases, the demand for string-type PCSs is increasing day by day, which puts higher requirements on the efficiency of the PCS charge and discharge test. Conventional PCS test platforms adopt a pair-drag test method in which one PCS controls the voltage and one PCS controls the power, and a DC source is required to provide the DC voltage required for PCS operation. Only two PCS charge and discharge tests can be completed at a time, and the DC source must be turned on before each test, and the DC source must be turned off after the voltage-controlled PCS establishes the DC voltage. When a large number of PCSs need to be tested, the test time is long, and frequent wiring and disconnection, as well as frequent input and output of the DC source, are required. The test efficiency is low and the test process is lengthy.

[0024] In order to solve the above problems, the inventors of this application have proposed the technical solution of this application, and the specific embodiments are as follows: Example 1: Figure 1 Schematic diagram of a synchronous testing platform for multiple energy storage converters in Example 1 of the present invention.

[0025] like Figure 1As shown, the synchronous testing platform for multiple energy storage converters of this embodiment includes: an incoming line switch, a pre-charging circuit, a transformer, an auxiliary power supply switch, an AC circuit breaker, a DC circuit breaker and a unit controller.

[0026] Multiple power storage converters (PCSs) are divided into two groups, namely a first group and a second group. Each group includes N power storage converters, where N is a natural number greater than 1. In this embodiment, N is 24, and there are 48 power storage converters in total. The 48 power storage converters are labeled 1#PCS, 2#PCS, 3#PCS, to 48#PCS, respectively. The first group includes 24 power storage converters, namely 1#PCS, 2#PCS, to 24#PCS, and the second group includes 24 power storage converters, namely 25#PCS, 26#PCS, to 48#PCS.

[0027] The transformer is a multi-winding transformer with a single winding on the high-voltage side and 48 (2N) windings on the low-voltage side. This number corresponds to the number of energy storage converters being tested. Preferably, the windings on the low-voltage side of the transformer are in phase.

[0028] The high-voltage side of the transformer, the pre-charging circuit and the incoming switch QF1 are connected in series in sequence, and the other side of the incoming switch QF1 is connected to the grid, so that the grid is connected to the high-voltage side of the transformer.

[0029] The numbers of AC circuit breakers and DC circuit breakers are 2N and N respectively, that is, in this embodiment, the number of AC circuit breakers is 48, and the 48 AC circuit breakers are marked as QF4 to QF51 respectively; the number of DC circuit breakers is 24, and the 24 DC circuit breakers are marked as QF52 to QF75 respectively.

[0030] One side of the 48 AC circuit breakers QF4~QF51 is connected to the 48 windings on the low-voltage side of the transformer, and the other side of the 48 AC circuit breakers QF4~QF51 is connected to the AC side of 1#PCS~48#PCS (48 energy storage converters).

[0031] The auxiliary power supply ports of the first group of 1#PCS to 24#PCS (24 energy storage converters) are connected in parallel to one side of the auxiliary power supply switch QF3, and the other side of the auxiliary power supply switch QF3 is connected to the AC220V auxiliary power supply. The AC220V auxiliary power supply provides auxiliary power to the 24 energy storage converters in the first group.

[0032] The DC sides of 1#PCS~24#PCS (24 energy storage converters) of the first group are respectively connected to one side of QF52~QF75 (24 DC circuit breakers), and the other side of QF52~QF75 (24 DC circuit breakers) are respectively connected to the DC sides of 25#PCS~48#PCS (24 energy storage converters) of the second group.

[0033] The unit controller is connected to the incoming line switch QF1, the pre-charge circuit, and 1#PCS to 48#PCS (48 energy storage converters) respectively. The unit controller controls the closing and opening of the incoming line switch QF1, the connection and bypass of the pre-charge circuit, and the control and management of 1#PCS to 48#PCS (48 energy storage converters).

[0034] It is not difficult to find out from the above content that the synchronous testing platform for multiple energy storage converters in this embodiment is provided with an incoming line switch, a pre-charging loop, 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-charging loop and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid. One side of the 2N AC circuit breakers is respectively connected to the 2N windings on the low-voltage side of the transformer, and the other side is respectively connected to the AC side of the 2N energy storage converters. After being connected in parallel, 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. One side of the N DC circuit breakers is respectively connected to the DC side of the first group of energy storage converters, and the other side is respectively connected to the DC side of the second group of energy storage converters. The unit controller is respectively communicated with the incoming line switch, the pre-charging loop, and the energy storage converter. In the synchronous testing platform for multiple energy storage converters of this embodiment, the first group of N voltage-controlled PCSs are connected to an external auxiliary power supply to control their internal AC switches to close first; then the high-voltage incoming line switch is closed, and the grid power passes through the pre-charging circuit to perform uncontrolled rectification pre-charging on the N voltage-controlled PCSs of the first group; when the charge reaches a certain voltage, the pre-charging circuit is bypassed, and the N voltage-controlled PCSs of the first group are unlocked to control the DC voltage; then the N power-controlled PCSs of the second group are started in sequence and the charge and discharge power is set, thereby realizing synchronous charge and discharge testing of 2N PCSs, greatly improving the charge and discharge test efficiency of the energy storage converter.

[0035] Optionally, in the synchronous testing platform for multiple energy storage converters in this embodiment, the pre-charging circuit includes: a pre-charging resistor R and a bypass switch QF2.

[0036] The pre-charging resistor R and the bypass switch QF2 are connected in parallel to form a pre-charging loop. One side of the pre-charging loop is connected to the incoming switch QF1, and the other side is connected to the high-voltage side of the transformer.

[0037] The bypass switch QF2 of the pre-charge loop is in communication with the unit controller, and the unit controller controls the closing and opening of the bypass switch QF2 to bypass or connect the pre-charge resistor R to the circuit.

[0038] Furthermore, in the synchronous testing platform for multiple energy storage converters in this embodiment, the unit controller includes: a first control device, a second control device and a coordination controller.

[0039] The first control device (1# control device) is respectively connected to the incoming switch QF1, the bypass switch QF2, and the first group of 1# to 24# PCS (24 energy storage converters). The first control device controls the operation of the first group of 24 energy storage converters and controls the closing and opening of the incoming switch QF1 and the bypass switch QF2.

[0040] The second control device (2# control device) is in communication connection with 25#PCS~48#PCS (24 energy storage converters) of the second group, and the second control device controls the operation of the 24 energy storage converters of the second group.

[0041] The first control device and the second control device are respectively connected to the coordination controller for communication, and the coordination controller performs comprehensive management on the first control device and the second control device.

[0042] Furthermore, the synchronous testing platform for multiple energy storage converters in this embodiment further includes: a first liquid cooling unit and a second liquid cooling unit.

[0043] The first liquid cooling unit (1# liquid cooling unit) and the second liquid cooling unit (2# liquid cooling unit) are communicatively connected to the first control device and the second control device respectively.

[0044] 1#PCS~24#PCS (24 energy storage converters) of the first group are connected to the first liquid cooling unit through water inlet and outlet pipes respectively, and the first control device controls the temperature of the energy storage converter of the first group through the first liquid cooling unit.

[0045] 25#PCS~48#PCS (24 energy storage converters) of the second group are connected to the second liquid cooling unit through the inlet and outlet water pipelines respectively, and the second control device controls the temperature of the energy storage converter of the second group through the second liquid cooling unit.

[0046] Example 2: Figure 2 This is a flow chart of the control method in the second embodiment of the present invention.

[0047] like Figure 2 As shown, the control method of the synchronous test platform of multiple energy storage converters of this embodiment first ensures that the communication between the components of the test platform remains normal. The control method includes the following steps: S1 manually closes QF4 to QF51 (48 AC circuit breakers), QF52 to QF75 (24 DC circuit breakers), and QF3 (auxiliary power supply switch). At this time, the AC220V auxiliary power supply supplies power to the first group of 1#PCS to 24#PCS (24 energy storage converters).

[0048] S2 The first control device controls the first group of 1#PCS~24#PCS (24 energy storage converters) to the constant DC voltage mode. The first control device also controls the AC side switches inside the first group of 1#PCS~24#PCS (24 energy storage converters) to close.

[0049] S3 controls the incoming line switch to close and the bypass switch to open, so that the energy storage converter of the first group can be pre-charged.

[0050] Specifically, after the AC side switches in the first group of energy storage converters are closed, the first control device controls the high-voltage incoming line 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 passes through the pre-charging resistor R to perform uncontrolled rectification pre-charging on the 24 energy storage converters in the first group.

[0051] After charging to the set voltage, S4 controls the bypass switch to close.

[0052] Specifically, after the energy storage converter of the first group is charged to a preset voltage, the first control device controls the bypass switch QF2 to be closed, so that the pre-charging resistor R of the pre-charging circuit is bypassed.

[0053] S5 controls the unlocking of the energy storage converter of the first group and closes the DC side switch in the energy storage converter. At the same time, the first liquid cooling unit starts to control the temperature of the energy storage converter.

[0054] Specifically, the first control device unlocks the constant DC voltage mode of the first group of 1#PCS to 24#PCS (24 energy storage converters) and controls the DC side switches inside the first group of energy storage converters to close. At the same time, the first control device controls the start-up of the first liquid cooling unit to control the temperature of the first group of 1#PCS to 24#PCS (24 energy storage converters).

[0055] S6 controls the second group of energy storage converters to constant power mode and starts the machine in sequence. At the same time, the second liquid cooling unit starts to control the temperature of the second group of energy storage converters.

[0056] Specifically, after the first group of energy storage converters unlocks the DC voltage control mode, the second control device controls the second group's 25#PCS~48#PCS (24 energy storage converters) to the constant power mode, and starts the second group's 25#PCS~48#PCS (24 energy storage converters) in sequence. At the same time, the second control device controls the start-up of the second liquid cooling unit to perform temperature control on the second group's 25#PCS~48#PCS (24 energy storage converters).

[0057] S7 controls the second group of energy storage converters to charge or discharge, and the corresponding first group of energy storage converters to discharge or charge.

[0058] Specifically, the coordination controller presets the charge and discharge power, and then controls the charging or discharging test of the second group of 25#PCS~48#PCS (24 energy storage converters), and correspondingly controls the discharge or charging test of the first group of 1#PCS~24#PCS (24 energy storage converters), thereby realizing the synchronous charge and discharge test of 2N (48) energy storage converters.

[0059] After the S8 test is completed, the second group of 25#PCS~48#PCS (24 energy storage converters) are controlled to shut down, and the second liquid cooling unit is also controlled to shut down.

[0060] Specifically, after the charge and discharge test is completed, the second control device first controls 25#PCS~48#PCS of the second group to shut down, and at the same time the second control device controls the second liquid cooling unit to shut down.

[0061] S9 then controls the first group of 1#PCS~24#PCS (24 energy storage converters) to shut down, the bypass switch QF2 to open, the incoming line switch QF1 to open, and at the same time controls the first liquid cooling unit to shut down.

[0062] Specifically, after the energy storage converter of the second group is shut down, the first control device controls the shutdown of 1#PCS~24#PCS (24 energy storage converters) of the first group, controls the bypass switch QF2 to be opened and disconnected, controls the incoming line switch QF1 to be opened and disconnected, and at the same time, the first control device controls the shutdown of the first liquid cooling unit.

[0063] S10 Finally, manually disconnect the auxiliary power supply switch QF3, manually disconnect QF4~QF51 (48 AC circuit breakers), and manually disconnect QF52~QF75 (24 DC circuit breakers).

[0064] In the present invention, unless otherwise clearly specified and limited, a first feature being “on” or “under” a second feature may mean that the first feature and the second feature are in direct contact, or the first feature and the second feature are in indirect contact through an intermediate medium.

[0065] Furthermore, when a first feature is “above,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the description of this specification, reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0067] 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 including N converters, characterized in that: The test 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; The high-voltage side of the transformer is a single winding, and the low-voltage side is provided with 2N windings; The high-voltage side of the transformer, the pre-charging circuit and the incoming line switch are connected in sequence, and the incoming line switch is connected to the power grid; The number of the AC circuit breakers and the number of the DC circuit breakers are 2N and N respectively; One side of the 2N AC circuit breakers is respectively connected to the 2N windings on the low-voltage side of the transformer, and the other side is respectively connected to the AC side 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 the N DC circuit breakers is respectively connected to the DC side of the energy storage converter of the first group, and the other side of the N DC circuit breakers is respectively connected to the DC side of the energy storage converter of the second group; The unit controller is communicatively connected to the incoming line switch, the pre-charging circuit, and the energy storage converter respectively.

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-charging 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 switch, the bypass switch, and the energy storage converter of the first group respectively; The second control device is communicatively connected to the energy storage converter of the second group; 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: a first liquid cooling unit and a second liquid cooling unit; The energy storage converter of the first group is connected to the first liquid cooling unit via the inlet and outlet water pipelines, and the energy storage converter of the second group is connected to the second liquid cooling unit via the inlet and outlet water pipelines; The first liquid cooling unit and the second liquid cooling unit are communicatively connected to the first control device and the second control device respectively.

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

6. A control method based on the synchronous test platform for multiple energy storage converters according to claim 4, characterized in that: The following steps are involved: S1 manually closes the AC circuit breaker, DC circuit breaker and auxiliary power switch; S2 controls the energy storage converter of the first group to be in constant DC voltage mode, and controls the AC side switch in the energy storage converter of the first group to be closed; S3 controls the incoming line switch to close and the bypass switch to open, 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 switches in the first group of energy storage converters. At the same time, the first liquid cooling unit is started 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 them sequentially. At the same time, the second liquid cooling unit starts and controls the temperature of the second group of energy storage converters. S7 controls the second group of energy storage converters to charge or discharge, and the corresponding first group of energy storage converters to discharge or charge; After the S8 test is completed, the second group of energy storage converters and the second liquid cooling unit are controlled to shut down; S9 controls the shutdown of the first energy storage converter, the opening of the bypass switch and the incoming line switch, and the shutdown of the first liquid cooling unit; S10 Manually disconnect the auxiliary power switch, AC circuit breaker, and DC circuit breaker.

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