Method, device, equipment and program product for commissioning an energy storage system

Abstract

The application provides a debugging method, device, equipment and program product of an energy storage system. The energy storage system comprises an energy storage unit, the energy storage unit comprises a grid-forming converter group and a grid-following converter group, the grid-forming converter group is used for providing an alternating voltage, the grid-following converter group is used for receiving the alternating voltage, the grid-forming converter group is connected with an alternating current bus through a first circuit breaker, and the grid-following converter group is connected with the alternating current bus through a second circuit breaker. The debugging method controls the first circuit breaker and the second circuit breaker to be turned on, so that the grid-forming converter group provides the alternating voltage for the grid-following converter group through the alternating current bus. When the alternating voltage reaches a rated voltage, the grid-following converter group is controlled to perform a debugging operation. The black start capability of the grid-forming converter is used to adaptively provide a stable voltage, and the debugging cost and complexity are reduced without relying on power grid power supply or a high-power alternating current power supply.

Description

Technical Field

[0001] This application relates to the field of electrical engineering technology, and in particular to a commissioning method, apparatus, equipment and program product for an energy storage system. Background Technology

[0002] In the construction of new power systems, energy storage systems, as core supporting equipment for realizing the consumption of new energy sources and ensuring the stable operation of the power grid, are constantly being optimized and upgraded in terms of technology and application forms. Among them, string energy storage systems, with their outstanding advantages such as modular design, high safety, flexible expansion, and strong adaptability to new energy power generation scenarios, have been widely used in the construction of large-scale energy storage power stations. However, before the commissioning of string energy storage systems, the installation and commissioning of thousands of power conversion systems (PCS), battery packs, and supporting equipment must be completed. Even if so many devices have completed factory testing, during the transportation and installation process on site, a large number of problems are inevitable, such as equipment damage and wiring errors. Moreover, since the equipment comes from different manufacturers, the probability of problems occurring if the grid is directly fed back after wiring is very high. Therefore, sufficient on-site pre-commissioning is required before the grid feeds back (during the construction phase) to eliminate problems in the energy storage system. However, before the power station is put into operation, the site usually does not have the power supply conditions of the primary line, and the grid cannot provide the rated AC voltage to the PCS, so only on-site internal testing can be carried out.

[0003] Currently, existing on-site testing solutions include the Voltage-Frequency Off-Grid Control Strategy (VF) and the use of high-power AC power supplies. The VF off-grid strategy allows for commissioning without grid back-feeding voltage; however, while it can provide a fixed voltage amplitude and frequency and AC voltage via a DC inverter, it lacks a power frequency synchronization mechanism. This prevents parallel operation of multiple converters, making full-power parallel testing difficult and hindering the full exposure of potential hidden problems in core equipment such as liquid-cooled units and power devices. The high-power AC power supply solution, limited by the large size and weight of 5MW and above AC power supplies, is ill-suited to the limited space of energy storage power station sites. Furthermore, this solution requires extensive wiring and disconnection work, which is not only complex and time-consuming but also significantly increases commissioning costs.

[0004] Therefore, there is an urgent need for a commissioning scheme for energy storage systems that do not rely on grid power supply and have high adaptability, in order to reduce commissioning costs, improve power plant commissioning efficiency, and at the same time ensure equipment performance and system stability. Summary of the Invention

[0005] The energy storage system commissioning method, apparatus, equipment, and program products provided in this application are intended to reduce commissioning costs, improve power plant commissioning efficiency, and ensure equipment performance and system stability.

[0006] In a first aspect, embodiments of this application provide a commissioning method for an energy storage system. The energy storage system includes an energy storage unit, which includes a grid-connected converter group and a grid-connected converter group. The grid-connected converter group is used to provide AC voltage, and the grid-connected converter group is used to receive AC voltage. The grid-connected converter group is connected to an AC busbar through a first circuit breaker, and the grid-connected converter group is connected to the AC busbar through a second circuit breaker.

[0007] The methods include:

[0008] Control the first circuit breaker and the second circuit breaker to conduct; so that the grid-connected converter group can provide AC voltage to the grid-connected converter group through the AC busbar;

[0009] When the AC voltage reaches the rated voltage, the grid-connected converter group is controlled for commissioning.

[0010] In one possible implementation, the grid converter group consists of multiple grid converters connected in parallel;

[0011] The methods include:

[0012] Each grid converter is controlled to gradually build up its initial AC voltage from zero voltage.

[0013] Adjust the voltage amplitude and / or frequency of multiple grid converters to smoothly raise the voltage of the AC busbar to the rated voltage.

[0014] In one possible implementation, adjusting the voltage amplitude and / or frequency of multiple grid-connected converters to smoothly raise the voltage of the AC busbar to the rated voltage includes:

[0015] Based on the active power droop characteristic and the initial AC voltage corresponding to the grid converter, the frequency of the grid converter is adjusted to balance the active power.

[0016] Based on the reactive power droop characteristics and the initial AC voltage corresponding to the grid converter, the voltage amplitude of the grid converter is adjusted to balance the reactive power.

[0017] By adjusting the frequency and voltage amplitude, the output voltage of multiple grid converters is increased synchronously until the voltage of the AC bus reaches the rated voltage.

[0018] In one possible implementation, the grid-connected converter group consists of multiple grid-connected converters connected in parallel;

[0019] When the AC voltage reaches the rated voltage, the control unit of the grid-connected converter is used for commissioning operations, including:

[0020] Based on the first number of grid-connected converters in the grid-connected converter group and the second number of grid-connected converters in the grid-connected converter group, the drag test mode is determined.

[0021] According to the reverse-drive test mode, a power command is issued to the grid-connected converter group so that the grid-connected converter group can obtain voltage from the AC busbar to perform the power reverse-drive test.

[0022] In one possible implementation, the drag test mode is determined based on a first number of grid-connected converters in the grid-connected converter group and a second number of grid-connected converters in the grid-connected converter group, including:

[0023] If the first quantity is less than the second quantity, then the test mode is determined to be the grid-connected converter start-up test.

[0024] If the first quantity equals the second quantity, then the test mode is determined to be a full-load test of the grid converter.

[0025] If the first quantity is greater than the second quantity, then the test mode is determined to be the grid-connected converter overload test.

[0026] In one possible implementation, the method further includes:

[0027] Determine the number of PCS cabinets corresponding to the energy storage system, and combine any two adjacent PCS cabinets into an energy storage unit; set the PCS cabinets in the energy storage unit as either grid-type PCS cabinets or grid-connected PCS cabinets respectively.

[0028] Among them, the grid-type PCS cabinet serves as a grid-type converter group, and the grid-connected PCS cabinet serves as a grid-connected converter group; each PCS cabinet consists of multiple converters connected in parallel.

[0029] In one possible implementation, the number of energy storage units is multiple, and the method further includes:

[0030] After the grid converter group of the current energy storage unit is commissioned, disconnect the circuit breaker corresponding to the current energy storage unit and turn on the circuit breaker corresponding to the next energy storage unit until all energy storage units have been commissioned.

[0031] Secondly, the present application provides a debugging device for an energy storage system, comprising:

[0032] Energy storage system, which includes energy storage units and controllers. The energy storage units include grid-connected converter groups and grid-connected converter groups.

[0033] The first circuit breaker connects the grid converter group and the AC busbar;

[0034] The second circuit breaker connects the grid-connected converter group and the AC busbar;

[0035] A controller is used to control the state of the circuit breaker and the voltage of the converter to perform the first aspect and / or various possible commissioning methods described above.

[0036] Thirdly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0037] The memory stores the instructions that the computer executes;

[0038] The processor executes computer execution instructions stored in memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0039] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0040] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0041] The energy storage system commissioning method, apparatus, equipment, and program products provided in this application include an energy storage unit, which comprises a grid-connected converter group and a grid-connected converter group. The grid-connected converter group provides AC voltage, and the grid-connected converter group receives AC voltage. The grid-connected converter group is connected to the AC busbar via a first circuit breaker, and the grid-connected converter group is connected to the AC busbar via a second circuit breaker. The commissioning method controls the first and second circuit breakers to conduct, allowing the grid-connected converter group to provide AC voltage to the grid-connected converter group via the AC busbar. When the voltage of the AC busbar reaches the rated voltage, the grid-connected converter group performs commissioning operations. This application utilizes the black-start capability of the grid-connected converter group to adaptively provide stable voltage without relying on grid power or high-power AC power sources, reducing commissioning costs and complexity. Furthermore, the PCS grouping design enables parallel operation of multiple converters. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0043] Figure 1 This application provides a schematic diagram of an energy storage system;

[0044] Figure 2 A flowchart illustrating a commissioning method for an energy storage system provided in this application;

[0045] Figure 3 A schematic diagram illustrating voltage amplitude and frequency adjustment provided in this application;

[0046] Figure 4 A schematic diagram of a commissioning device for an energy storage system provided in this application;

[0047] Figure 5 This is a schematic diagram of the structure of an electronic device provided in this application.

[0048] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0049] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0050] First, let me explain the terms used in this application:

[0051] A converter is a power device that uses power electronic devices to convert the voltage, frequency, phase, or topology of electrical energy.

[0052] String energy storage converter: refers to a medium-power converter that adopts a modular design, with each unit corresponding to a battery cluster, and supports distributed access and independent control.

[0053] In the construction of new power systems, energy storage systems, as core supporting equipment for realizing the consumption of new energy sources and ensuring the stable operation of the power grid, are constantly being optimized and upgraded in terms of technology and application forms. Among them, string energy storage systems, with their outstanding advantages such as modular design, high safety, flexible expansion, and strong adaptability to new energy power generation scenarios, have been widely used in the construction of large-scale energy storage power stations. However, before the commissioning of string energy storage systems, the installation and commissioning of thousands of converters (PCS), battery packs, and supporting equipment must be completed. Even if so many devices have completed factory testing, during the transportation and installation process on site, a large number of problems are inevitable, such as equipment damage and wiring errors. Moreover, since the equipment comes from different manufacturers, the probability of problems occurring if the system is directly put into operation after wiring and waiting for the grid to feed back power is very high. Therefore, it is necessary to conduct sufficient on-site pre-commissioning before the grid feeds back power (during the construction phase) to eliminate problems in the energy storage system. However, before the power station is put into operation, the site usually does not have the power supply conditions of the primary line, and the grid cannot provide the rated AC voltage to the PCS, so only on-site internal testing can be carried out.

[0054] Currently, existing on-site testing solutions include off-grid VF strategy and high-power AC power supply. The off-grid VF strategy allows for commissioning without grid back-feeding voltage; however, while it can provide a fixed voltage amplitude and frequency and AC voltage via a DC inverter, it lacks a power frequency synchronization mechanism. This prevents parallel operation of multiple converters, hindering full-power parallel testing and failing to fully expose potential hidden problems in core equipment such as liquid-cooled units and power devices. The high-power AC power supply solution, limited by the bulky and heavy nature of 5MW and above AC power supplies, is difficult to adapt to the limited space of energy storage power station sites. Furthermore, this solution requires extensive wiring and disconnection work, which is not only complex and time-consuming but also significantly increases commissioning costs.

[0055] Therefore, there is an urgent need for a commissioning scheme for energy storage systems that do not rely on grid power supply and have high adaptability, in order to reduce commissioning costs, improve power plant commissioning efficiency, and at the same time ensure equipment performance and system stability.

[0056] This application provides a commissioning method, apparatus, equipment, and program product for an energy storage system. The energy storage system includes energy storage units, each comprising a grid-connected converter group and a grid-connected converter group. The grid-connected converter group provides AC voltage, while the grid-connected converter group receives AC voltage. The grid-connected converter group is connected to the AC busbar via a first circuit breaker, and the grid-connected converter group is connected to the AC busbar via a second circuit breaker. The commissioning method controls the first and second circuit breakers to conduct, allowing the grid-connected converter group to provide AC voltage to the grid-connected converter group via the AC busbar. When the voltage of the AC busbar reaches the rated voltage, the grid-connected converter group controls itself to perform commissioning operations. This application utilizes the black-start capability of the grid-connected converter to adaptively provide stable voltage, eliminating reliance on grid power or high-power AC power sources, thus reducing commissioning costs and complexity. Furthermore, the PCS grouping design enables parallel operation of multiple converters.

[0057] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with 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. The embodiments of this application will now be described with reference to the accompanying drawings.

[0058] Figure 1 This application provides a schematic diagram of an energy storage system, such as... Figure 1 As shown, a 250MW / 1000MWh string energy storage system is illustrated, comprising 50 5MW transformers, 100 2.5MW circuit breakers, 50 disconnect switches for the 5MW transformers, 1200 208kW converters, and 80 battery compartments consisting of 20,000 50kWh battery packs and 1 million 1kWh lithium iron phosphate cells. Furthermore, the energy storage system includes a large number of BMS systems, EMS systems, cooling equipment, and secondary equipment. The BMS systems, EMS systems, cooling equipment, and secondary equipment are system configurations well-known to those skilled in the art and are not shown here. Figure 1 As shown, in Figure 1 Only one energy storage unit is shown in detail in the document. The other energy storage units are the same as those shown, and will not be repeated here.

[0059] For example, a single converter can be divided into PCS cabinets. Those skilled in the art can make this division based on historical experience and the actual energy storage system setup requirements. This application does not limit the composition of the PCS cabinets. For instance, 12 PCS units can be combined into a grid-type PCS cabinet, or 12 PCS units can be combined into a follow-up-grid PCS cabinet. All PCS units in each PCS cabinet are connected in parallel and connected to a circuit breaker.

[0060] Specifically, such as Figure 1 As shown, for energy storage unit 1, the grid-connected converter group is connected to the AC busbar via a first circuit breaker, and the grid-connected converter group is connected to the AC busbar via a second circuit breaker. The AC busbar is connected to the first side of the transformer, the second side of the transformer is connected to the first side of the transformer disconnect switch, the second side of the transformer disconnect switch is connected to the transformer bus, and the transformer bus and the collector bus are connected to the collector disconnect switch. The collector bus is connected to the common grid connection point. This application can be applied to on-site commissioning scenarios and on-site production testing scenarios of string energy storage systems before commissioning.

[0061] Figure 2 A flowchart illustrating a commissioning method for an energy storage system provided in this application is shown below. Figure 2 As shown in the embodiments of this application, the commissioning method for an energy storage system includes:

[0062] S201, control the first circuit breaker and the second circuit breaker to be turned on; so that the grid-connected converter group can provide AC voltage to the grid-connected converter group through the AC busbar.

[0063] In this context, the AC busbar refers to the AC busbar in an energy storage system used to collect the output of the converter, and can serve as a voltage source for power-to-voltage testing. For example, in a string energy storage system, the AC busbar can be a 690V 50Hz three-phase AC busbar.

[0064] In one possible implementation, prior to performing the commissioning method for the energy storage system, the method further includes:

[0065] Determine the number of PCS cabinets corresponding to the energy storage system, and combine any two adjacent PCS cabinets into an energy storage unit; set the PCS cabinets in the energy storage unit as either grid-type PCS cabinets or grid-connected PCS cabinets respectively.

[0066] Among them, the grid-type PCS cabinet serves as a grid-type converter group, and the grid-connected PCS cabinet serves as a grid-connected converter group; each PCS cabinet consists of multiple converters connected in parallel.

[0067] Among them, the grid-type PCS cabinet refers to the PCS cabinet that operates in black-start mode and establishes AC voltage; the grid-following PCS cabinet refers to the PCS cabinet that performs power-to-voltage testing based on the established AC voltage. For example, before commissioning the energy storage system, two adjacent PCS cabinets are combined into a converter unit, and one cabinet is configured as grid-type and the other as grid-following through software configuration; wherein the configuration controls the on / off state of the isolating switch through the secondary power supply line (380V) to ensure that each converter unit independently completes the black-start voltage establishment and power-to-voltage testing.

[0068] For example, the energy storage system 'a' corresponds to 10 PCS cabinets, namely: PCS cabinet 1, PCS cabinet 2, PCS cabinet 3, PCS cabinet 4, PCS cabinet 5, PCS cabinet 6, PCS cabinet 7, PCS cabinet 8, PCS cabinet 9, and PCS cabinet 10. In this example, the numbers of the PCS cabinets indicate their order. Furthermore, two adjacent PCS cabinets are combined to form an energy storage unit, namely: Energy storage unit 1 - PCS cabinet 1, PCS cabinet 2; Energy storage unit 2 - PCS cabinet 3, PCS cabinet 4; Energy storage unit 3 - PCS cabinet 5, PCS cabinet 6; Energy storage unit 4 - PCS cabinet 7, PCS cabinet 8; Energy storage unit 5 - PCS cabinet 9, PCS cabinet 10. For each energy storage unit, the PCS cabinet in the energy storage unit is configured by software to be either a grid-type PCS cabinet or a grid-connected PCS cabinet. For example, if PCS cabinet 1 is set as a grid-type converter and PCS cabinet 2 is set as a grid-connected converter, then PCS cabinet 1 is used as a grid-type converter group and PCS cabinet 2 is used as a grid-connected converter group.

[0069] By grouping and configuring modular energy storage units, the commissioning process is made parallel and efficient. Furthermore, this mechanism supports simultaneous commissioning of multiple converters, significantly shortening the overall commissioning cycle and reducing the risk of commissioning interruptions due to single-point failures.

[0070] In accordance with the foregoing, when commissioning the energy storage system, each energy storage unit contained in the energy storage system is commissioned one by one; for example, for the commissioning of energy storage unit 1, firstly, the first circuit breaker and the second circuit breaker are turned on; then, the grid converter group is controlled to gradually build up the AC voltage from zero voltage and provide the rated voltage to the AC bus.

[0071] In one possible implementation, the grid converter group consists of multiple grid converters connected in parallel;

[0072] The grid-connected converter group provides AC voltage, and the specific process is as follows:

[0073] Each grid converter is controlled to gradually build up its initial AC voltage from zero voltage.

[0074] Adjust the voltage amplitude and / or frequency of multiple grid converters to smoothly raise the voltage of the AC busbar to the rated voltage.

[0075] Based on the foregoing, for example, if each PCS cabinet consists of 12 converters, then the grid converter group can be determined to consist of 12 grid converters connected in parallel. Each grid converter is controlled to operate in black-start mode, simulating the characteristics of a synchronous generator through Virtual Synchronous Generator (VSG) and Virtual Excitation / Frequency Control (VFC), gradually establishing the initial AC voltage of each grid converter from zero voltage. This process can be achieved through a soft-start mechanism to avoid voltage abrupt changes. Furthermore, using a dual droop control strategy, the voltage amplitude and / or frequency of multiple grid converters are adjusted, so that the voltage of the AC bus smoothly rises and stabilizes at the rated voltage, such as 690V.

[0076] The grid-connected converter group simulates the characteristics of a synchronous generator through virtual synchronization control and virtual excitation control, and autonomously establishes a virtual voltage source. This allows the energy storage system to operate without relying on grid power or high-power AC power during commissioning, reducing commissioning costs and complexity. Through a dual droop control strategy, multiple converters can achieve voltage synchronization and power balance without communication, forming a stable overall voltage source. This solves the circulating current and out-of-synchronization problems when multiple units are connected in parallel, ensuring the accuracy of commissioning results.

[0077] In one possible implementation, the voltage amplitude and / or frequency of multiple grid-connected converters are adjusted to smoothly raise the voltage of the AC bus to the rated voltage. The specific process is as follows:

[0078] Based on the active power droop characteristic and the initial AC voltage corresponding to the grid converter, the frequency of the grid converter is adjusted to balance the active power.

[0079] Based on the reactive power droop characteristics and the initial AC voltage corresponding to the grid converter, the voltage amplitude of the grid converter is adjusted to balance the reactive power.

[0080] By adjusting the frequency and voltage amplitude, the output voltage of multiple grid converters is increased synchronously until the voltage of the AC bus reaches the rated voltage.

[0081] Among them, the active power droop characteristic refers to the control strategy of the converter to dynamically adjust the output frequency according to the output active power, simulating the inertial characteristics of a synchronous generator; the reactive power droop characteristic refers to the control strategy of the converter to dynamically adjust the output voltage amplitude according to the output reactive power, simulating the excitation regulation characteristics of a synchronous generator.

[0082] Figure 3 A schematic diagram of voltage amplitude and frequency adjustment provided in this application is shown below. Figure 3As shown, the active power droop function of the grid is used to characterize the correlation between grid frequency and the active power output of equipment; for example... Figure 3 As shown in the left figure, with the standard power frequency of 50Hz as the reference, when the active power output of any grid converter in the grid converter group is greater than the active power command "Pcmd=100kW", the frequency of that grid converter is reduced, prompting the other grid converters to increase their active power output to balance the output active power. Conversely, similarly, when the active power output of any grid converter is less than the active power command "Pcmd=-100kW", the frequency of that grid converter is increased, prompting the other grid converters to reduce their active power output to balance the output active power.

[0083] The active power command refers to the active power output reference command; this active power command can be set according to the experience of those skilled in the art, and this application does not impose any restrictions here. By setting the active power command, the converter can autonomously fine-tune with frequency changes based on the reference, thereby maintaining frequency stability.

[0084] The grid reactive power droop function is used to characterize the correlation between grid voltage amplitude and equipment reactive power output; for example... Figure 3 As shown in the right figure, with the rated voltage (690V) as the reference, when the voltage is lower than 0.9 times the rated voltage (621V), the converter actively increases reactive power to support and raise the voltage; when the voltage is higher than 0.9 times the rated voltage (759V), the converter reduces reactive power output or even absorbs reactive power to suppress excessive voltage and achieve autonomous balance control of voltage amplitude.

[0085] For example, during a black start of a grid-connected converter group, multiple grid-connected converters establish an initial AC voltage. The slope of the reactive power droop characteristic is 0.1, thus possessing a grid strength of approximately SCR=10.0. When carrying a current not exceeding the rated current, the voltage amplitude experiences a transient deviation of no more than 10%. After establishing the initial voltage, converters outputting higher voltages will generate reactive current, and the grid will control to reduce the voltage, and vice versa. Therefore, the lengths of the voltage vectors between different PCSs tend to be equal, eventually reaching a stable state of "equal voltage, zero reactive power." Conversely, based on the active power droop characteristic, if the voltage vector of a grid-connected converter leads the others, it generates reactive power, and the grid control will reduce the frequency, and vice versa. Therefore, the rotational speeds of the voltage vectors between different PCSs tend to be synchronized, eventually reaching a stable state of "synchronized voltage, zero active power."

[0086] This step achieves autonomous power distribution and voltage synchronization among multiple converters through coordinated control of active and reactive power droop; it eliminates circulating current and out-of-synchronization issues among multiple PCS without communication, ensuring a stable voltage source and the smoothness and reliability of the black start voltage build-up process.

[0087] S202. When the voltage of the AC busbar reaches the rated voltage, control the grid converter group to perform commissioning operations.

[0088] In summary, when the grid-connected converter group establishes a stable virtual voltage source and the voltage of the AC bus reaches the rated voltage, a power command can be issued to the grid-connected converter group so that the grid-connected converter group can perform power throughput according to the power command, thereby realizing the commissioning of the grid-connected converter group.

[0089] In one possible implementation, the grid-connected converter group includes multiple grid-connected converters connected in parallel;

[0090] When the AC voltage reaches the rated voltage, the grid-connected converter group is subjected to commissioning operations. The specific process is as follows:

[0091] Based on the first number of grid-connected converters in the grid-connected converter group and the second number of grid-connected converters in the grid-connected converter group, the drag test mode is determined.

[0092] According to the power-to-grid test mode, a power command is issued to the grid-connected converter group so that the grid-connected converter can obtain voltage from the AC busbar to perform the power-to-grid test.

[0093] Similarly, as described above, a grid-connected converter group can consist of 12 grid-connected converters connected in parallel. The number of converters comprising the grid-connected and grid-supported converter groups is set during the establishment of the energy storage system. This application only groups the PCS cabinets in the energy storage system into pairs and defines the type (i.e., grid-connected converters and grid-supported converters) of each PCS cabinet within each group.

[0094] Among them, the power-to-power test refers to the test that simulates the power throughput under real grid-connected conditions by issuing power commands (such as full-power commands) to verify the performance of key components such as liquid cooling systems and power devices. During the execution of the power-to-power test, the stability of the energy storage unit under the corresponding power-to-power test mode is evaluated by detecting the temperature, current fluctuations and power response time of the converter.

[0095] For example, the software logic can automatically determine the counter-driving test mode based on the number of grid-connected converter groups and grid-connected converter groups, without manual intervention. After determining the counter-driving test mode, the power command corresponding to the counter-driving test mode is issued to the grid-connected converter group so that the grid-connected converter can obtain voltage from the AC busbar to perform the power counter-driving operation test.

[0096] This step determines the parallel testing mode by determining the number of grid-connected converter groups and grid-connected converter groups. This mode can be adapted to energy storage systems of different sizes, ensuring that the test covers the load conditions of real grid-connected scenarios. At the same time, it can avoid the risk of insufficient testing or system overload caused by a fixed parallel testing mode.

[0097] In one possible implementation, the drag test mode is determined based on a first number of grid-connected converters in the grid-connected converter group and a second number of grid-connected converters in the grid-connected converter group. The specific process is as follows:

[0098] If the first quantity is less than the second quantity, then the test mode is determined to be the grid-connected converter start-up test.

[0099] If the first quantity equals the second quantity, then the test mode is determined to be a full-load test of the grid converter.

[0100] If the first quantity is greater than the second quantity, then the test mode is determined to be the grid-connected converter overload test.

[0101] Grid-connected converter start-up test: This refers to the basic test for the commissioning and testing of energy storage systems. It involves insulation testing, control power-on, whole machine self-test, communication interlock verification, and no-load start-up test of the grid-connected converter to verify whether the equipment hardware, sampling circuit and start-stop control logic are normal.

[0102] Full-load parallel operation test of grid-connected converters: Multiple grid-connected converters are used to form a power parallel operation closed loop. The converters are operated at rated full-load conditions through internal power circulation without relying on external high-power grids or test power supplies. This verifies the full-power steady-state operation of the converters, device temperature rise, liquid cooling heat dissipation, and the stability of multiple units in parallel.

[0103] Overload test of grid-connected converter: Based on the normal operating conditions of the converter, the operating conditions are adjusted to make the operating power of the grid-connected converter exceed the rated value. The test is continuously conducted under the overload ratio to verify the disturbance tolerance capability, safety protection redundancy and fault self-healing interlocking reliability of the grid-connected converter, and to ensure the safety and stability of the grid-connected operation of the energy storage system.

[0104] For example, the first number of grid-connected converters in the grid-connected converter group is 12, and the second number of grid-connected converters in the grid-connected converter group is 12. By comparison, the first number and the second number are equal, indicating that the reference power provided by the grid-connected converter matches the total rated power of the grid, which can realize power-to-current circulation and allow each converter to run at full rated power. Therefore, the power-to-current test mode can be determined as "grid-connected converter full-load power-to-current test" to verify the full-power steady-state operation of the converter, device temperature rise, liquid cooling heat dissipation and multi-machine parallel stability.

[0105] When the first quantity is less than the second quantity, it indicates that the power provided by the grid-connected converter can only support a limited reference power, making it difficult to achieve full-load operation of all grid-connected converters. Therefore, the power-to-load test mode can be determined as "grid-connected converter start-up test", which completes the operation and debugging of the grid-connected converter, including control power-on, whole machine self-test, and no-load low power.

[0106] When the first quantity is greater than the second quantity, it indicates that the grid-connected converter provides excess power, and the grid-connected converter can be pushed to overload conditions. Without the need for additional external load equipment, the reliability of overload current limiting, overcurrent, overtemperature, and fault blocking protection can be accurately tested. Therefore, the power-to-load test mode can be determined as "grid-connected converter overload test".

[0107] This step determines the drag test mode based on the first and second quantities, which can adapt to different scale test requirements and meet the commissioning needs of different energy storage systems while ensuring the accuracy of the commissioning results.

[0108] This application provides a commissioning method, apparatus, equipment, and program product for an energy storage system. The energy storage system includes an energy storage unit, which comprises a grid-connected converter group and a grid-connected converter group. The grid-connected converter group provides AC voltage, and the grid-connected converter group receives AC voltage. The grid-connected converter group is connected to an AC busbar via a first circuit breaker, and the grid-connected converter group is connected to the AC busbar via a second circuit breaker. The commissioning method controls the first and second circuit breakers to conduct, allowing the grid-connected converter group to provide AC voltage to the grid-connected converter group via the AC busbar. When the AC voltage reaches the rated voltage, the grid-connected converter group is controlled to perform commissioning operations. This application utilizes the black-start capability of the grid-connected converter to adaptively provide stable voltage without relying on grid power or high-power AC power sources, reducing commissioning costs and complexity. Furthermore, the PCS grouping design enables parallel operation of multiple converters.

[0109] In one possible implementation, the number of energy storage units is multiple, and the method further includes:

[0110] After the grid converter group of the current energy storage unit is commissioned, disconnect the circuit breaker corresponding to the current energy storage unit and turn on the circuit breaker corresponding to the next energy storage unit until all energy storage units have been commissioned.

[0111] For example, such as Figure 1 As shown, after the grid-connected converter group of energy storage unit 1 is debugged, the first and second circuit breakers in energy storage unit 1 are disconnected. Then, the circuit breakers corresponding to the grid-connected converter group and the grid-connected converter group in the next energy storage unit (energy storage unit 2) are turned on, and the AC voltage establishment and debugging steps mentioned above are executed. After the debugging is completed, it is necessary to switch to the next energy storage unit until all energy storage units in the energy storage system have completed the debugging.

[0112] Through modular grouping and cyclic commissioning mechanisms, full-coverage verification of the energy storage system was achieved. This mechanism avoids the risk of equipment damage caused by a single high-power test, while supporting parallel commissioning to improve efficiency and ensure comprehensive pre-commissioning before the power plant is put into operation.

[0113] In conjunction with the foregoing, for example, for a 250MW / 1000MWh energy storage system, compared to the commissioning of a single PCS in the prior art, this application groups the PCS and commissions the energy storage system in a group format. Only 50 commissioning tests are required to complete the commissioning of the entire energy storage system, which greatly saves the cost of pre-commissioning of string energy storage sites and improves pre-commissioning efficiency.

[0114] In conjunction with the foregoing, in practical applications, before connecting an energy storage system (such as energy storage system b) to a power station, the energy storage system b can be commissioned using the commissioning method provided in this application. Specifically: First, determine the number of PCS cabinets in energy storage system b and group all PCS cabinets (that is, group any two adjacent PCS cabinets into one energy storage unit, wherein one PCS cabinet is set as a grid-connected converter group and the other is set as a grid-connected converter group; wherein each PCS cabinet is connected to the corresponding battery compartment).

[0115] Furthermore, the energy storage units of the energy storage system are debugged one by one. For example, the specific steps for debugging energy storage unit b1 (including grid-connected converter group b11 and grid-connected converter group b21) include: first, turning on the circuit breaker b12 connected to the grid-connected converter group b11 and the circuit breaker b22 connected to the grid-connected converter group b21 (at this time, turning off all circuit breakers except those connected to the converter units of energy storage unit b1); then, controlling the grid-connected converter group b11 to gradually build up the AC voltage from zero until it provides the rated voltage to the AC busbar; when the voltage of the AC busbar reaches the rated voltage, a power command is issued to the grid-connected converter group b21 so that the grid-connected converter group b21 can perform power throughput according to the power command, thereby realizing the debugging of the grid-connected converter group b21.

[0116] After the commissioning of energy storage unit b1 is completed, switch to the next energy storage unit: turn off circuit breakers b12 and b21, and turn on the circuit breaker connected to the converter unit of the next energy storage unit. Then, after performing the above-mentioned commissioning steps, switch to the next energy storage unit again, until all energy storage units have completed the aforementioned commissioning steps.

[0117] After the energy storage system is commissioned, when it needs to be connected to the power station, connect the energy storage system to the public grid connection point and turn on the transformer disconnect switch, collector disconnect switch and circuit breaker in the energy storage system.

[0118] For example, such as Figure 1 As shown, the energy storage system is connected to a common grid connection point. Then, the transformer disconnect switches #01, #02, ..., #05 can be controlled via the secondary power supply line (380V); simultaneously, the collector disconnect switches #01, ..., #10 and all circuit breakers in the energy storage system are also controlled to be turned on. It is important to note that during the commissioning of the energy storage system, all transformer disconnect switches and collector disconnect switches in the system are in the open state. Commissioning of each energy storage unit is achieved individually by controlling the on / off state of the circuit breakers connected to each energy storage unit.

[0119] Figure 4 A schematic diagram of a commissioning device for an energy storage system provided in this application is shown below. Figure 4 As shown, it includes:

[0120] Energy storage system 100, the energy storage system includes energy storage unit 101 and controller 102, the energy storage unit 101 includes grid-connected converter group 1011 and grid-connected converter group 1012;

[0121] The first circuit breaker 201 connects the grid converter group 1011 and the AC busbar 300;

[0122] The second circuit breaker 202 is connected to the grid converter group 1012 and the AC busbar 300;

[0123] The controller 102 is used to control the state of the circuit breaker and the voltage of the converter group to perform the above method embodiment.

[0124] For example, when commissioning the energy storage system is required, the controller 102 sends status signals to the circuit breakers connected to each energy storage unit in the energy storage system; for example, when commissioning energy storage unit 1, "a circuit breaker on signal is sent to the circuit breaker connected to energy storage unit 1, and a circuit breaker off signal is sent to the circuit breakers connected to the other energy storage units". The circuit breakers connected to each energy storage unit perform the on / off operation corresponding to the received status signal.

[0125] Specifically, the controller controls the converter voltage as follows: If the stable voltage to be established by the grid-connected converter group is 690V, after executing the black-start mode, the controller 102 sends a voltage slow-start command to the grid-connected converter group in the energy storage unit. Each grid-connected converter in the group achieves pre-frequency self-synchronization through active power droop characteristics and voltage self-balancing through reactive power droop characteristics until the voltage reaches the rated voltage. Then, the controller 102 sends a grid connection command to the grid-connected converter group in the energy storage unit, forming a system of "grid-connected battery compartment, grid-connected converter group, grid-connected converter group, and grid-connected battery compartment". The controller sends an active power command to the grid-connected converter group, which enables the mutual conversion of energy between the two battery compartments, thereby verifying whether the electrical, cooling, control, and communication equipment of the energy storage unit 1 is operating well.

[0126] The energy storage system debugging device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0127] Figure 5 This is a schematic diagram of the structure of an electronic device provided in this application. Figure 5 As shown, the electronic device 50 provided in this embodiment includes at least one processor 501 and a memory 502. Optionally, the device 50 further includes a communication component 503. The processor 501, memory 502, and communication component 503 are connected via a bus 505.

[0128] In a specific implementation, at least one processor 501 executes computer execution instructions stored in memory 502, causing at least one processor 501 to perform the above-described method.

[0129] The specific implementation process of processor 501 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0130] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0131] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0132] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0133] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0134] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0135] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0136] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0137] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0138] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0139] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0140] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0141] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0142] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method of commissioning an energy storage system, the method comprising: The energy storage system includes an energy storage unit, which includes a grid-connected converter group and a grid-connected converter group. The grid-connected converter group is used to provide AC voltage, and the grid-connected converter group is used to receive the AC voltage. The grid-connected converter group is connected to the AC busbar through a first circuit breaker, and the grid-connected converter group is connected to the AC busbar through a second circuit breaker. The method includes: Control the first circuit breaker and the second circuit breaker to be turned on; so that the grid-connected converter group provides the AC voltage to the grid-connected converter group through the AC busbar; When the AC voltage reaches the rated voltage, the grid-connected converter group is controlled to perform commissioning operations.

2. The method of claim 1, wherein, The grid converter group consists of multiple grid converters connected in parallel; The method includes: Each grid converter is controlled to gradually build up its initial AC voltage from zero voltage; The voltage amplitude and / or frequency of the multiple grid converters are adjusted so that the voltage of the AC busbar rises smoothly to the rated voltage.

3. The method according to claim 2, characterized in that, The adjustment of the voltage amplitude and / or frequency of the plurality of grid converters to smoothly raise the voltage of the AC bus to the rated voltage includes: Based on the active power droop characteristic and the initial AC voltage corresponding to the grid converter, the frequency of the grid converter is adjusted to balance the active power. Based on the reactive power droop characteristics and the initial AC voltage corresponding to the grid converter, the voltage amplitude of the grid converter is adjusted to balance the reactive power. By adjusting the frequency and voltage amplitude, the output voltages of the multiple grid converters are synchronously increased until the voltage of the AC busbar reaches the rated voltage.

4. The method according to claim 1, characterized in that, The grid-connected converter group consists of multiple grid-connected converters connected in parallel; When the AC voltage reaches the rated voltage, controlling the grid-connected converter group to perform commissioning operations includes: Based on the first number of grid-connected converters in the grid-connected converter group and the second number of grid-connected converters in the grid-connected converter group, the drag test mode is determined; According to the aforementioned power-to-voltage test mode, a power command is issued to the grid-connected converter group so that the grid-connected converter group can obtain voltage from the AC busbar to perform the power-to-voltage test.

5. The method according to claim 4, characterized in that, The determination of the drag test mode based on the first number of grid-connected converters in the grid-connected converter group and the second number of grid-connected converters in the grid-connected converter group includes: If the first quantity is less than the second quantity, then the test mode is determined to be the grid-connected converter start-up test. If the first quantity is equal to the second quantity, then the drag test mode is determined to be a full-load drag test of the grid converter; If the first quantity is greater than the second quantity, then the test mode is determined to be a grid-connected converter overload test.

6. The method according to any one of claims 1-5, characterized in that, The method further includes: Determine the number of PCS cabinets corresponding to the energy storage system, and form an energy storage unit by combining any two adjacent PCS cabinets; set the PCS cabinets in the energy storage unit as grid-type PCS cabinets and grid-following PCS cabinets respectively. The grid-type PCS cabinet serves as the grid-type converter group, and the grid-connected PCS cabinet serves as the grid-connected converter group; each PCS cabinet consists of multiple converters connected in parallel.

7. The method according to any one of claims 1-5, characterized in that, The number of energy storage units is multiple, and the method further includes: After the grid converter group of the current energy storage unit is commissioned, disconnect the circuit breaker corresponding to the current energy storage unit and turn on the circuit breaker corresponding to the next energy storage unit until all energy storage units have been commissioned.

8. A commissioning device for an energy storage system, characterized in that, include: An energy storage system, the energy storage system including an energy storage unit and a controller, the energy storage unit including a grid-connected converter group and a grid-connected converter group; The first circuit breaker connects the grid converter group and the AC busbar; The second circuit breaker connects the grid-connected converter group and the AC busbar; A controller for controlling the state of the circuit breaker and the voltage of the converter to perform the commissioning method according to any one of claims 1-7.

9. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-7.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-7.

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