Energy storage system, black start method, device, equipment and medium of energy storage system

Abstract

The present application relates to the field of power technologies, and provides an energy storage system, a black start method, device, computer equipment, storage medium and computer program product for the energy storage system. The present application can improve the success rate and stability of black start. The method includes: generating a black start signal, and sending the black start signal to a low-voltage energy storage unit and a high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, a first output voltage is generated, the first output voltage is input to a low-voltage bus, the low-voltage bus supplies power to low-voltage devices, and when the high-voltage energy storage unit receives the black start signal, a second output voltage is generated, the second output voltage is input to a high-voltage bus, and the high-voltage bus supplies power to high-voltage devices.

Description

Technical Field

[0001] The present application relates to the technical field of electric power, and particularly to an energy storage system, a black start method, device, computer equipment, storage medium and computer program product for the energy storage system. Background Art

[0002] With the expansion of the power grid scale and the access of renewable power sources such as photovoltaic and wind power, factors such as natural disasters, human operation errors or malfunction of automatic control equipment increase the potential hazards of power grid disconnection and even collapse accidents. Although the probability of large-scale and long-term power outages is not high, it cannot be completely avoided or eliminated. Once it occurs, it will not only cause huge losses to power enterprises and the national economy, but also have a serious impact on people's production and life. Therefore, after a major power outage accident occurs, formulating an effective and reliable recovery plan to quickly restore system power supply is of great significance for reducing power outage losses. Black start refers to the process in which the power grid drives the units without self-starting ability to generate electricity through the generator sets with self-starting ability inside, and finally realizes the power recovery of the entire system.

[0003] Traditional technologies usually use hydro-generator sets and pumped-storage units to achieve black start. However, because the seasonal climate and geographical environment have a relatively large impact on both of them, in areas with water resource shortages or during dry seasons, there will be a lack of sufficient water volume to complete the black start process, resulting in a low success rate of black start. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide an energy storage system, a black start method, device, computer equipment, storage medium and computer program product for the energy storage system.

[0005] In a first aspect, the present application provides a black start method for an energy storage system. The method includes:

[0006] Generating a black start signal;

[0007] Sending the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage equipment, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment.

[0008] In a second aspect, the present application also provides an energy storage system. The system includes: a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit group, a high-voltage energy storage unit group, and a controller; the low-voltage bus is respectively connected to a low-voltage device and the low-voltage energy storage unit group, the controller is respectively connected to the low-voltage energy storage unit group and the high-voltage energy storage unit group, and the high-voltage bus is respectively connected to the high-voltage energy storage unit group and a high-voltage device;

[0009] The controller is configured to send a black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group;

[0010] The low-voltage energy storage unit group is configured to generate a first output voltage when receiving the black start signal, input the first output voltage to the low-voltage bus, and enable the low-voltage bus to supply power to the low-voltage device;

[0011] The high-voltage energy storage unit group is configured to generate a second output voltage when receiving the black start signal, input the second output voltage to the high-voltage bus, and enable the high-voltage bus to supply power to the high-voltage device.

[0012] In one embodiment, the low-voltage energy storage unit group includes a first low-voltage subgroup energy storage unit and a second low-voltage subgroup energy storage unit;

[0013] The system further includes: a first bus, a second bus, a third bus, a first switch, a second switch, and a first transformer; the first transformer is respectively connected to the low-voltage bus and the third bus, the first switch is respectively connected to the third bus and the first bus, the second switch is respectively connected to the third bus and the second bus, the first low-voltage subgroup energy storage unit is respectively connected to the first bus and the controller, and the second low-voltage subgroup energy storage unit is respectively connected to the second bus and the controller;

[0014] The controller is further configured to close the first switch or the second switch when the demand of the low-voltage device is less than or equal to the first capacity or the second capacity; the first capacity is the capacity of the first low-voltage subgroup energy storage unit, and the second capacity is the capacity of the second low-voltage subgroup energy storage unit;

[0015] The first low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus sequentially through the first bus, the third bus, and the first transformer when the first switch is closed,

[0016] Or, the second low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus sequentially through the second bus, the third bus, and the first transformer when the second switch is closed.

[0017] In one embodiment, the controller is further configured to close the first switch and the second switch when the demand of the low-voltage device is greater than the first capacity and the second capacity and less than or equal to the total capacity; the total capacity is the sum of the first capacity and the second capacity;

[0018] The first low-voltage subgroup energy storage unit is used to supply power to the low-voltage busbar sequentially through the first busbar, the third busbar, and the first transformer;

[0019] The second low-voltage subgroup energy storage unit is used to supply power to the low-voltage busbar sequentially through the second busbar, the third busbar, and the first transformer.

[0020] In one embodiment, the system further includes: a third transformer, a fourth switch, and a fifth switch; the third transformer is respectively connected to the high-voltage busbar, the fourth switch, and the fifth switch, the fourth switch is further connected to the first busbar, and the fifth switch is further connected to the second busbar;

[0021] The controller is further configured to close the first switch, the second switch, the fourth switch, and the fifth switch when the demand of the low-voltage device is greater than the total capacity;

[0022] The high-voltage busbar is used to supply power to the low-voltage busbar through the third transformer, the first busbar, the second busbar, the third busbar, and the first transformer.

[0023] In one embodiment, the system further includes: a second transformer, a third switch, and a fourth busbar; the fourth busbar is respectively connected to the high-voltage group energy storage unit and the third switch, and the second transformer is respectively connected to the third switch and the high-voltage busbar;

[0024] The controller is further configured to close the third switch;

[0025] The high-voltage group energy storage unit is used to supply power to the high-voltage busbar sequentially through the fourth busbar and the second transformer when the third switch is closed.

[0026] In a third aspect, the present application further provides a black start device for an energy storage system. The device includes:

[0027] A signal generation module for generating a black start signal;

[0028] A signal transmission module for transmitting the black start signal to the low-voltage group energy storage unit and the high-voltage group energy storage unit, so that when the low-voltage group energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage busbar, and enables the low-voltage busbar to supply power to the low-voltage device, and when the high-voltage group energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage busbar, and enables the high-voltage busbar to supply power to the high-voltage device.

[0029] In a fourth aspect, the present application further provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0030] Generate a black start signal; send the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to low-voltage equipment, and so that when the high-voltage energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment.

[0031] In a fifth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, and when the computer program is executed by a processor, the following steps are implemented:

[0032] Generate a black start signal; send the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to low-voltage equipment, and so that when the high-voltage energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment.

[0033] In a sixth aspect, the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0034] Generate a black start signal; send the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to low-voltage equipment, and so that when the high-voltage energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment.

[0035] The above energy storage system, black start method, device, computer equipment, storage medium and computer program product of the energy storage system generate a black start signal and send the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that the low-voltage energy storage unit generates a first output voltage when receiving the black start signal, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage equipment, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment. The system of this solution includes a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit, a high-voltage energy storage unit and a controller. The low-voltage bus is respectively connected to the low-voltage equipment and the low-voltage energy storage unit, the controller is respectively connected to the low-voltage energy storage unit and the high-voltage energy storage unit, the high-voltage bus is respectively connected to the high-voltage energy storage unit and the high-voltage equipment, the controller sends the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, the low-voltage energy storage unit generates a first output voltage when receiving the black start signal, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage equipment, and the high-voltage energy storage unit generates a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage equipment, thereby improving the success rate and stability of black start. Description of the Drawings

[0036] Figure 1 It is an application environment diagram of the energy storage system in an embodiment;

[0037] Figure 2 It is an application environment diagram of the energy storage system in another embodiment;

[0038] Figure 3 It is a schematic flowchart of the black start method of the energy storage system in an embodiment;

[0039] Figure 4 It is a structural block diagram of the black start device of the energy storage system in an embodiment;

[0040] Figure 5 It is an internal structure diagram of the computer equipment in an embodiment. Detailed Description of the Invention

[0041] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0042] The black start method of the energy storage system provided by the present application can be applied to, for example Figure 1In the application environment shown. This application scenario may include: a controller, a low-voltage energy storage unit group, and a high-voltage energy storage unit group. The controller and the low-voltage energy storage unit group can be communicatively connected, and the controller and the high-voltage energy storage unit group can be communicatively connected. Specifically, the controller sends a black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group. When the low-voltage energy storage unit group receives the black start signal, it generates a first output voltage and inputs the first output voltage to the low-voltage bus, enabling the low-voltage bus to supply power to low-voltage devices. When the high-voltage energy storage unit group receives the black start signal, it generates a second output voltage and inputs the second output voltage to the high-voltage bus, enabling the high-voltage bus to supply power to high-voltage devices. Among them, the controller can be, but is not limited to, a network-forming controller. The low-voltage energy storage unit group can be, but is not limited to, one or more power conversion systems (PCS for short). The high-voltage energy storage unit group can be, but is not limited to, one or more power conversion systems (PCS for short).

[0043] In one embodiment, an energy storage system is provided. Refer to Figure 1 , this energy storage system includes: a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit group, a high-voltage energy storage unit group, and a controller; the low-voltage bus is respectively connected to low-voltage devices and the low-voltage energy storage unit group, the controller is respectively connected to the low-voltage energy storage unit group and the high-voltage energy storage unit group, and the high-voltage bus is respectively connected to the high-voltage energy storage unit group and high-voltage devices;

[0044] The controller is configured to send a black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group; the low-voltage energy storage unit group is configured to generate a first output voltage when receiving the black start signal, input the first output voltage to the low-voltage bus, and enable the low-voltage bus to supply power to low-voltage devices; the high-voltage energy storage unit group is configured to generate a second output voltage when receiving the black start signal, input the second output voltage to the high-voltage bus, and enable the high-voltage bus to supply power to high-voltage devices.

[0045] Among them, as Figure 1 and Figure 2 shown, the black start signal can be a signal used to start a power generation source to achieve the power restoration of the entire system when the target object (such as a power plant) is in a complete blackout state. When the voltage of the low-voltage bus and / or the high-voltage bus becomes 0 volts, it can be determined that it is in a complete blackout state; the low-voltage energy storage unit group can be PCS1, PCS2, PCS3, and PCS4 in Figure 2 (PCS can be a power conversion system); the high-voltage energy storage unit group can be as in Figure 2PCS5, PCS6... PCSn therein; the first output voltage can be the voltage generated by PCS1, PCS2, PCS3, and / or PCS4; the second output voltage can be the voltage generated by PCS5, PCS6, and / or PCSn; the low-voltage bus can be the 380V plant-use bus of the energy storage system; the high-voltage bus can be the 6kV bus; the low-voltage equipment can be the equipment connected to the low-voltage bus, such as a controller, an air conditioner, an energy storage system, etc.; the high-voltage equipment can be the equipment connected to the high-voltage bus, such as auxiliary equipment in the plant.

[0046] Specifically, when the controller detects or obtains that the target object is in a completely black state, it sends a black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group. When the low-voltage energy storage unit group receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to the low-voltage equipment. At the same time, when the high-voltage energy storage unit group receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to the high-voltage equipment.

[0047] In the above energy storage system, the controller generates a black start signal and sends the black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group, enabling the low-voltage energy storage unit group to generate a first output voltage when receiving the black start signal, inputting the first output voltage to the low-voltage bus, and enabling the low-voltage bus to supply power to the low-voltage equipment, and enabling the high-voltage energy storage unit group to generate a second output voltage when receiving the black start signal, inputting the second output voltage to the high-voltage bus, and enabling the high-voltage bus to supply power to the high-voltage equipment. The system of this solution includes a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit group, a high-voltage energy storage unit group, and a controller. The low-voltage bus is respectively connected to the low-voltage equipment and the low-voltage energy storage unit group. The controller is respectively connected to the low-voltage energy storage unit group and the high-voltage energy storage unit group. The high-voltage bus is respectively connected to the high-voltage energy storage unit group and the high-voltage equipment. The controller sends a black start signal to the low-voltage energy storage unit group and the high-voltage energy storage unit group. When the low-voltage energy storage unit group receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to the low-voltage equipment. When the high-voltage energy storage unit group receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to the high-voltage equipment, thereby improving the success rate and stability of black start.

[0048] In one embodiment, as Figure 2As shown in the figure, the system further includes: a first bus, a second bus, a third bus, a first switch, a second switch, and a first transformer; the first transformer is respectively connected to the low-voltage bus and the third bus, the first switch is respectively connected to the third bus and the first bus, the second switch is respectively connected to the third bus and the second bus, the first low-voltage sub-group energy storage unit is respectively connected to the first bus and the controller, and the second low-voltage sub-group energy storage unit is respectively connected to the second bus and the controller;

[0049] The controller is further configured to close the first switch or the second switch when the demand of the low-voltage device is less than or equal to the first capacity or the second capacity; the first low-voltage sub-group energy storage unit is configured to supply power to the low-voltage bus sequentially through the first bus, the third bus, and the first transformer when the first switch is closed, or the second low-voltage sub-group energy storage unit is configured to supply power to the low-voltage bus sequentially through the second bus, the third bus, and the first transformer when the second switch is closed.

[0050] Among them, as Figure 2 shown, the low-voltage group energy storage unit includes a first low-voltage sub-group energy storage unit and a second low-voltage sub-group energy storage unit. For example, the low-voltage group energy storage unit is split into a first low-voltage sub-group energy storage unit and a second low-voltage sub-group energy storage unit, where the first low-voltage sub-group energy storage unit can be, for example, Figure 2 PCS1 and PCS2 in Figure 2 and the second low-voltage sub-group energy storage unit can be, for example,

[0051] Specifically, when the controller detects or obtains that the target object is in a completely dark state, it judges the demand of the low-voltage device. When the demand of the low-voltage device is less than or equal to the first capacity or the second capacity, it closes the first switch or the second switch. When the first switch is closed, it enables the first low-voltage sub-group energy storage unit to supply power to the low-voltage bus sequentially through the first bus, the third bus, and the first transformer, or when the second switch is closed, it enables the second low-voltage sub-group energy storage unit to supply power to the low-voltage bus sequentially through the second bus, the third bus, and the first transformer.

[0052] In the technical solution of this embodiment, when the demand of the low-voltage equipment is less than or equal to the first capacity or the second capacity, the first switch or the second switch is closed, so that the first low-voltage subgroup energy storage unit or the second low-voltage subgroup energy storage unit supplies power to the low-voltage busbar alone, which is beneficial to improving the success rate and stability of black start and reducing resource waste.

[0053] In one embodiment, as Figure 2 shown, the controller is further configured to close the first switch and the second switch when the demand of the low-voltage equipment is greater than the first capacity and the second capacity and less than or equal to the total capacity; the first low-voltage subgroup energy storage unit is configured to supply power to the low-voltage busbar sequentially through the first busbar, the third busbar and the first transformer; the second low-voltage subgroup energy storage unit is configured to supply power to the low-voltage busbar sequentially through the second busbar, the third busbar and the first transformer.

[0054] Wherein, as Figure 2 shown, the total capacity is the sum of the first capacity and the second capacity.

[0055] Specifically, when the demand of the low-voltage equipment is greater than the first capacity and the second capacity and less than or equal to the total capacity, the controller closes the first switch and the second switch, so that the first low-voltage subgroup energy storage unit supplies power to the low-voltage busbar sequentially through the first busbar, the third busbar and the first transformer, and at the same time, the second low-voltage subgroup energy storage unit supplies power to the low-voltage busbar sequentially through the second busbar, the third busbar and the first transformer.

[0056] In the technical solution of this embodiment, when the demand of the low-voltage equipment is greater than the first capacity and the second capacity and less than or equal to the total capacity, the first switch and the second switch are closed, so that the first low-voltage subgroup energy storage unit and the second low-voltage subgroup energy storage unit supply power to the low-voltage busbar at the same time, which is beneficial to improving the success rate, stability and efficiency of black start.

[0057] In one embodiment, as Figure 2 shown, the system further includes: a third transformer, a fourth switch and a fifth switch; the third transformer is respectively connected to the high-voltage busbar, the fourth switch and the fifth switch, the fourth switch is further connected to the first busbar, and the fifth switch is further connected to the second busbar;

[0058] The controller is further configured to close the first switch, the second switch, the fourth switch and the fifth switch when the demand of the low-voltage equipment is greater than the total capacity; the high-voltage busbar is configured to supply power to the low-voltage busbar through the third transformer, the first busbar, the second busbar, the third busbar and the first transformer.

[0059] Wherein, as Figure 2As shown, the third transformer can be a box-type transformer (such as a box-type transformer of 6.3kV / 0.338kV / 0.38kV); the fourth switch can be a synchronization switch.

[0060] Specifically, when the demand of the low-voltage equipment is greater than the total capacity, the controller closes the first switch, the second switch, the fourth switch, and the fifth switch, so that the high-voltage bus supplies power to the low-voltage bus through the third transformer, the first bus and the second bus, the third bus, and the first transformer in sequence.

[0061] The technical solution of this embodiment, by closing the first switch, the second switch, the fourth switch, and the fifth switch when the demand of the low-voltage equipment is greater than the total capacity, enables the power provided by the high-voltage energy storage unit to the high-voltage bus to be provided to the low-voltage bus when the low-voltage energy storage unit is not sufficient to provide enough power to the low-voltage bus (low-voltage equipment connected to the low-voltage bus), which is beneficial to providing enough power to the low-voltage equipment connected to the low-voltage bus, facilitating the low-voltage equipment to complete the black start process faster, and thus improving the success rate and stability of the black start.

[0062] In one embodiment, as Figure 2 shown, the system further includes: a second transformer, a third switch, and a fourth bus; the fourth bus is respectively connected to the high-voltage energy storage unit and the third switch, and the second transformer is respectively connected to the third switch and the high-voltage bus;

[0063] The controller is further configured to close the third switch; the high-voltage energy storage unit is configured to supply power to the high-voltage bus through the fourth bus and the second transformer in sequence when the third switch is closed.

[0064] Among them, as Figure 2 shown, the second transformer can be a box-type transformer; the fourth bus can be a 380V bus 4.

[0065] Specifically, when the controller detects or obtains that the target object is in a full black state, it closes the third switch, so that the high-voltage energy storage unit supplies power to the high-voltage bus through the fourth bus and the second transformer in sequence.

[0066] The technical solution of this embodiment, by the high-voltage energy storage unit supplying power to the high-voltage bus through the fourth bus and the second transformer in sequence when the third switch is closed, is beneficial to improving the success rate and stability of the black start of the high-voltage equipment connected to the high-voltage bus, and thus improving the success rate and stability of the black start.

[0067] In one embodiment, as Figure 3 shown, a black start method for an energy storage system is provided. Taking the method applied to the Figure 1 controller as an example for illustration, it includes the following steps:

[0068] Step S301, generate a black start signal.

[0069] Step S302, send the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage devices, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage devices.

[0070] Specifically, when the controller detects or obtains that the target object is in a complete blackout state, it generates a black start signal, sends the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage devices, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage devices.

[0071] In the black start method of the above energy storage system, a black start signal is generated, the black start signal is sent to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage devices, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage devices. The system of this solution includes a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit, a high-voltage energy storage unit and a controller. The low-voltage bus is respectively connected to low-voltage devices and the low-voltage energy storage unit, the controller is respectively connected to the low-voltage energy storage unit and the high-voltage energy storage unit, the high-voltage bus is respectively connected to the high-voltage energy storage unit and high-voltage devices, the controller sends a black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit. When the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage devices, and when the high-voltage energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage devices, thereby improving the success rate and stability of black start.

[0072] The following uses an embodiment to illustrate the black start method of the energy storage system provided by the present application. This embodiment takes the application of this method to a controller as an example, as Figure 2 shown, the main steps include:

[0073] In the first step, the controller generates a black start signal.

[0074] In the second step, the controller sends the black start signal to the first low-voltage subgroup energy storage unit, the second low-voltage subgroup energy storage unit, and the high-voltage group energy storage unit.

[0075] In the third step, when the demand of the low-voltage equipment is less than or equal to the first capacity or the second capacity, the controller closes the first switch or the second switch. When the first low-voltage subgroup energy storage unit receives the black start signal, it generates a partial first output voltage. When the first switch is closed, the partial first output voltage is supplied to the low-voltage bus through the first bus, the third bus, and the first transformer in sequence. Or when the second low-voltage subgroup energy storage unit receives the black start signal, it generates a partial first output voltage. When the second switch is closed, the partial first output voltage is supplied to the low-voltage bus through the second bus, the third bus, and the first transformer in sequence, so that the low-voltage bus supplies power to the low-voltage equipment.

[0076] Alternatively, when the demand of the low-voltage equipment is greater than the first capacity and the second capacity and less than or equal to the total capacity, the controller closes the first switch and the second switch. When the first low-voltage subgroup energy storage unit receives the black start signal, it generates a partial first output voltage and supplies the partial first output voltage to the low-voltage bus through the first bus, the third bus, and the first transformer in sequence. And when the second low-voltage subgroup energy storage unit receives the black start signal, it generates a partial first output voltage and supplies the partial first output voltage to the low-voltage bus through the second bus, the third bus, and the first transformer in sequence, so that the low-voltage bus supplies power to the low-voltage equipment.

[0077] Alternatively, when the demand of the low-voltage equipment is greater than the total capacity, the controller closes the first switch, the second switch, the fourth switch, and the fifth switch, so that the high-voltage bus supplies power to the low-voltage bus through the third transformer, the first bus, the second bus, the third bus, and the first transformer, and the low-voltage bus supplies power to the low-voltage equipment.

[0078] In the fourth step, the controller closes the third switch. When the high-voltage group energy storage unit receives the black start signal, it generates a second output voltage. When the third switch is closed, the second output voltage is supplied to the high-voltage bus through the fourth bus and the second transformer in sequence, so that the high-voltage bus supplies power to the high-voltage equipment.

[0079] For the technical solution of this embodiment, the system of this solution includes a low-voltage bus, a high-voltage bus, a low-voltage energy storage unit, a high-voltage energy storage unit, and a controller. The low-voltage bus is respectively connected to low-voltage equipment and the low-voltage energy storage unit. The controller is respectively connected to the low-voltage energy storage unit and the high-voltage energy storage unit. The high-voltage bus is respectively connected to the high-voltage energy storage unit and high-voltage equipment. The controller sends a black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit. When the low-voltage energy storage unit receives the black start signal, it generates a first output voltage and inputs the first output voltage to the low-voltage bus, enabling the low-voltage bus to supply power to the low-voltage equipment. When the high-voltage energy storage unit receives the black start signal, it generates a second output voltage and inputs the second output voltage to the high-voltage bus, enabling the high-voltage bus to supply power to the high-voltage equipment, thereby improving the success rate and stability of black start.

[0080] The following uses an application example to illustrate the energy storage system (energy storage black start system) provided by this application. As Figure 2 shown, this system mainly includes: a PCS group (including PCS and a battery pack), a network-forming controller, switches (including synchronization switches), a transformer, and a bus.

[0081] Among them, the PCS connection method follows the low-voltage parallel connection method and is connected to the low-voltage bus and the high-voltage bus for black start. The network-forming controller supports the P / Q control mode (constant power control mode), the V / F control mode (control mode to ensure that the output voltage is proportional to the frequency), and droop regulation control. The network-forming controller is connected to the PCS group through optical fiber or network cable. The network-forming controller is used to switch the working mode of the PCS, track the low-voltage side voltage of the box transformer and the bus voltage connected to the PCS group, and adjust the frequency, voltage, and phase of the PCS group so that the bus connected to the PCS group tracks the low-voltage side voltage of the box transformer and realizes fast synchronization. The network-forming controller coordinates and controls all PCSs to realize the secondary control of the output voltage and frequency of the entire energy storage system, so that the output external characteristics of the entire energy storage system show network-forming characteristics. The network-forming controller is connected to the synchronization switch through hard wiring to control the synchronization switch to perform synchronization detection. When it detects that the low-voltage side voltage of the box transformer and the bus voltage connected to the PCS group meet the synchronization conditions, it closes the bus incoming switch between the low-voltage side of the box transformer and the bus connected to the PCS group to complete synchronization closing. The switch is in the off state before grid connection synchronization. The adjustment of the frequency, voltage, and phase of the system can be realized by the network-forming controller adjusting the PCS group.

[0082] Exemplarily, one set of PCS units is selected for special design to serve as the power source for the self-use power of the energy storage system, such as PCS1 - PCS4. Meanwhile, a 380V bus, such as 380V bus 3, is designed for the specially designed PCS units to switch and connect the PCS units. After passing through the isolation transformer, 380V bus 3 is connected to the 380V self-use bus of the energy storage system, and finally used to supply power to the self-use power of the energy storage system. PCS1 - PCS4 are special units, connected under the same box transformer. PCS1 and PCS2 are connected in parallel and output to 380V bus 1. Two switches, the fourth switch and the first switch, are added to 380V bus 1. Among them, the fourth switch is a synchronization switch, which is used to connect to the low-voltage side of the box transformer, and the first switch is used to connect to 380V bus 3. PCS3 and PCS4 are connected in parallel and output to 380V bus 2. Two switches, the fifth switch and the second switch, are added to 380V bus 2. The fifth switch is used to connect to the low-voltage side of the box transformer, and the second switch is used to connect to 380V bus 3. 380V bus 3 is connected to the 380V self-use bus of the energy storage system through the isolation transformer. The fourth switch, the fifth switch, the first switch, and the second switch are all uniformly controlled by the grid-forming controller. PCS5 - PCSn are conventional units, whose structure is similar to that of the PCS special units but without switches similar to the fourth switch, the fifth switch, the first switch, and the second switch. PCS5 - PCSn are connected in parallel and output to 380V bus 4, and are connected to the 6kV bus through the third switch and the box transformer.

[0083] Optionally, the grid-forming controller switches the control mode of the PCS special units, and flexibly controls the switches within the PCS special units according to the capacity of the self-use power of the energy storage system (the capacity of low-voltage equipment) to realize the power supply for the self-use power of the energy storage system (the power supply for low-voltage equipment). The PCS conventional units solve the transformer inrush current problem through zero-start voltage boosting and do not affect the normal power supply of the self-use power of the energy storage system. The entire zero-start voltage boosting time is less than 1 minute. The grid-forming controller tracks the voltage of the low-voltage side of the box transformer and the voltage of the bus connected to the PCS units, and adjusts the frequency, voltage, and phase of the PCS units so that the self-use bus connected to the PCS units tracks the voltage of the low-voltage side of the box transformer and realizes synchronization. The grid-forming controller controls the synchronization switch to perform synchronization detection. When it detects that the voltage of the low-voltage side of the box transformer and the voltage of the bus connected to the PCS units meet the synchronization conditions, it closes the incoming line switch of the self-use bus between the low-voltage side of the box transformer and the bus connected to the PCS units to complete the fast synchronization closing. After the synchronization closing is completed, the self-use power of the energy storage system is electrically connected to the PCS of the entire energy storage system, and the self-use power of the energy storage system is jointly borne by the energy storage units of the entire energy storage system, which is used to solve the long-time scale start-up requirements during the black start process of the unit and improve the time scale of the energy storage system for black starting the generator set.

[0084] For example, the condition for the system to operate is that the system capacity should be greater than the maximum load demand of auxiliary power equipment in the plant (the maximum load demand of high-voltage equipment) and the power supply capacity of the energy storage plant's own power consumption (the demand of low-voltage equipment), p sys ≥p se +p lmx , where p sys represents the system capacity, in kWh, p se represents the power supply capacity of the energy storage plant's own power consumption, in kWh, p lmx represents the maximum load demand of auxiliary power equipment in the plant, in kWh, and the system capacity is equal to the sum of the capacities of the PCS special group (low-voltage group energy storage units) and the PCS regular group (high-voltage group energy storage units).

[0085]

[0086] where p sg represents the capacity of the PCS special group, in kWh, p i represents the capacity of a single PCS within the PCS special group, in kWh, and the total capacity of the PCS special group is equal to the sum of the capacities of PCS1 - PCS4, p cg represents the capacity of the PCS regular group, p n represents the capacity of a single PCS within the PCS regular group, and the total capacity of the PCS regular group is equal to the sum of the capacities of PCS5 - PCSn (or PCSm, where n and m represent quantities). The system has the following three working states based on short-term start-up requirements and long-term start-up requirements: When p sys ≥p se +p lmx , p se ≤0.5*p sg and p lmx ≤p cg , the system is in working state 1, that is, when the demand of the low-voltage equipment is less than or equal to the first capacity or the second capacity, the controller switches the control mode of the PCS special group to the V / F control mode, closes the first switch or the second switch, opens the fourth switch and the fifth switch, and the energy storage plant's own power consumption is borne by some PCSs within the PCS special group, that is, PCS1 - PCS2 or PCS3 - PCS4 provides power for the energy storage system's own power consumption (low-voltage equipment) through isolation, and the PCS regular group completes the black start process of the unit; When p sys ≥p se +p lmx , p se ≤p sg and p lmx ≤p cg, the system is in operating state 2, that is, when the demand of the low-voltage equipment is greater than the first capacity and the second capacity and less than or equal to the total capacity, the controller switches the PCS special group control mode to the V / F control mode, closes the first switch and the second switch, opens the fourth switch and the fifth switch, and the energy storage plant power is borne by the entire PCS special group, that is, PCS1-PCS4 are isolated to provide power for the energy storage system's own plant power, and the PCS normal group completes the black start process of the unit; when p sys ≥p se +p lmx , p se ≥p sg but p se ≤p sg +p cg , p lmx ≤p cg , the system is in operating state 3, that is, when the demand of the low-voltage equipment is greater than the total capacity, the controller switches the PCS special group control mode to the V / F control mode, closes the first switch and the second switch, and the energy storage plant power is borne by the PCS special group in a short time. After the PCS normal group drives the power plant's large transformer to zero-start boost, the fourth switch closes synchronously, and the fifth switch closes directly. The energy storage system's own plant power is jointly borne by the PCS special group and the PCS normal group, and the black start process of the unit continues. Among them, the system also has the following two flexible operation modes: when the system participates in frequency regulation or normal charge and discharge conditions, the plant power bus of the energy storage system can be switched to the 380V bus of the power plant's plant power to take power; or, when the system participates in frequency regulation or normal charge and discharge conditions, the plant power bus (low-voltage bus) of the energy storage system can be connected to the energy storage system's 6kV bus (high-voltage bus) by closing the first switch, the second switch, the fourth switch and the fifth switch, and then reverse power supply to take power.

[0087] In the energy storage system of this application example, the PCS special group establishes an independent auxiliary power supply bus by flexibly switching the closing of switches to realize the power supply of the auxiliary power of the energy storage system itself. In the full black state of the power plant, it ensures that the battery box, air conditioner, all energy storage secondary systems and key equipment quickly resume the auxiliary power supply, ensuring the safe and stable normal operation of the energy storage system; since the PCS special group solves the problem of the auxiliary power supply of the energy storage system itself, the PCS conventional group can solve the inrush current problem of the transformer through zero-start voltage rise without affecting the normal power supply of the auxiliary power of the energy storage system; by configuring a synchronization switch, the system can quickly synchronize and connect to the grid under the cooperation of the grid-forming controller. The synchronization and connection to the grid are not affected by the voltage amplitude, voltage phase, frequency and the dispersion of the switch closing time. The entire synchronization and connection process realizes intelligence; after the synchronization closing is completed, the auxiliary power of the energy storage system itself is electrically connected to the PCS of the entire energy storage system, and the auxiliary power of the energy storage system itself is jointly borne by the energy storage units of the entire energy storage system, solving the long-time scale start-up demand during the unit black start process and improving the time scale of the energy storage system to black start the generator set.

[0088] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0089] Based on the same inventive concept, the embodiment of the present application also provides a black start device for an energy storage system for implementing the black start method of the energy storage system involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the black start device for the energy storage system provided below can refer to the limitations on the black start method of the energy storage system in the above text, and will not be repeated here.

[0090] In one embodiment, as Figure 4 shown, a black start device for an energy storage system is provided. The device 400 may include:

[0091] A signal generation module 401, configured to generate a black start signal;

[0092] The signal transmission module 402 is configured to transmit the black start signal to the low-voltage energy storage unit and the high-voltage energy storage unit, so that when the low-voltage energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, enables the low-voltage bus to supply power to low-voltage devices, and enables the high-voltage energy storage unit to generate a second output voltage when receiving the black start signal, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to high-voltage devices.

[0093] Each module in the black start device of the above energy storage system can be implemented in whole or in part by software, hardware, and their combination. Each of the above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0094] In one embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 5 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store black start signal data. The input / output interface of the computer device is used for the processor to exchange information with external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a black start method for an energy storage system.

[0095] Those skilled in the art can understand that Figure 5 the structure shown in

[0096] is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0097] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0098] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0099] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with the relevant laws, regulations, and standards of relevant countries and regions.

[0100] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.

[0101] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0102] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. An energy storage system, characterized in that, The system includes: a low-voltage bus, a high-voltage bus, a low-voltage group energy storage unit, a high-voltage group energy storage unit, and a controller; the low-voltage bus is respectively connected to low-voltage devices and the low-voltage group energy storage unit, the controller is respectively connected to the low-voltage group energy storage unit and the high-voltage group energy storage unit, and the high-voltage bus is respectively connected to the high-voltage group energy storage unit and high-voltage devices; the low-voltage group energy storage unit includes a first low-voltage subgroup energy storage unit and a second low-voltage subgroup energy storage unit; The system further includes: a first bus, a second bus, a third bus, a first switch, a second switch, and a first transformer; the first transformer is respectively connected to the low-voltage bus and the third bus, the first switch is respectively connected to the third bus and the first bus, the second switch is respectively connected to the third bus and the second bus, the first low-voltage subgroup energy storage unit is respectively connected to the first bus and the controller, and the second low-voltage subgroup energy storage unit is respectively connected to the second bus and the controller; The system further includes: a third transformer, a fourth switch, and a fifth switch; the third transformer is respectively connected to the high-voltage bus, the fourth switch, and the fifth switch, the fourth switch is further connected to the first bus, and the fifth switch is further connected to the second bus; The system further includes: a second transformer, a third switch, and a fourth bus; the fourth bus is respectively connected to the high-voltage group energy storage unit and the third switch, and the second transformer is respectively connected to the third switch and the high-voltage bus; The controller is configured to send a black start signal to the low-voltage group energy storage unit and the high-voltage group energy storage unit; The low-voltage group energy storage unit is configured to generate a first output voltage when receiving the black start signal, input the first output voltage to the low-voltage bus, and enable the low-voltage bus to supply power to the low-voltage devices; The high-voltage group energy storage unit is configured to generate a second output voltage when receiving the black start signal, input the second output voltage to the high-voltage bus, and enable the high-voltage bus to supply power to the high-voltage devices.

2. The system according to claim 1, wherein, The controller is further configured to close the first switch or the second switch when the demand of the low-voltage devices is less than or equal to a first capacity or a second capacity; the first capacity is the capacity of the first low-voltage subgroup energy storage unit, and the second capacity is the capacity of the second low-voltage subgroup energy storage unit; The first low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus sequentially through the first bus, the third bus, and the first transformer when the first switch is closed, Or, the second low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus sequentially through the second bus, the third bus, and the first transformer when the second switch is closed.

3. The system according to claim 2, wherein, The controller is further configured to close the first switch and the second switch when the demand of the low-voltage device is greater than the first capacity and the second capacity and less than or equal to the total capacity; the total capacity is the sum of the first capacity and the second capacity. The first low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus through the first bus, the third bus, and the first transformer in sequence. The second low-voltage subgroup energy storage unit is configured to supply power to the low-voltage bus through the second bus, the third bus, and the first transformer in sequence.

4. The system according to claim 3, wherein The controller is further configured to close the first switch, the second switch, the fourth switch, and the fifth switch when the demand of the low-voltage device is greater than the total capacity. The high-voltage bus is configured to supply power to the low-voltage bus through the third transformer, the first bus, the second bus, the third bus, and the first transformer.

5. The system according to claim 2, wherein The controller is further configured to close the third switch. The high-voltage group energy storage unit is configured to supply power to the high-voltage bus through the fourth bus and the second transformer in sequence when the third switch is closed.

6. A black start method for an energy storage system, characterized in that, Applied to the energy storage system according to any one of claims 1 to 5, the method includes: Generating a black start signal. Sending the black start signal to the low-voltage group energy storage unit and the high-voltage group energy storage unit, so that when the low-voltage group energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to the low-voltage device, and when the high-voltage group energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to the high-voltage device.

7. A black start device for an energy storage system, characterized in that, Applied to the energy storage system according to any one of claims 1 to 5, the device includes: A signal generation module, configured to generate a black start signal. A signal transmission module, configured to send the black start signal to the low-voltage group energy storage unit and the high-voltage group energy storage unit, so that when the low-voltage group energy storage unit receives the black start signal, it generates a first output voltage, inputs the first output voltage to the low-voltage bus, and enables the low-voltage bus to supply power to the low-voltage device, and when the high-voltage group energy storage unit receives the black start signal, it generates a second output voltage, inputs the second output voltage to the high-voltage bus, and enables the high-voltage bus to supply power to the high-voltage device.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method described in claim 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method described in claim 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method described in claim 6 are implemented.

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