Power grid power balancing system and energy storage microgrid

Abstract

This application discloses a power grid power balancing system and an energy storage microgrid. Relating to the field of power grid control technology, the system includes a power monitoring module that acquires voltage parameters on the power grid's common bus and determines the target power grid based on these parameters. The balancing control module dynamically adjusts the power of the composite energy storage module according to the target power grid, thereby achieving real-time power balancing on the power grid's common bus. This application directly collects voltage parameters from the power grid's common bus and determines the target power grid power corresponding to the operation of each device in the grid. Then, it controls the dynamic power of the composite energy storage module based on the target power grid to suppress power fluctuations on the bus, achieving power balancing control of the power grid's common bus. This application eliminates the need for additional complex circuit structures for power regulation, simplifying the energy storage microgrid system, and improves the microgrid's anti-interference capability by combining real-time bus power balancing control.

Description

Technical Field

[0001] This application relates to the field of power grid control technology, and in particular to a power grid power balancing system and an energy storage microgrid. Background Technology

[0002] Against the backdrop of increasingly scarce global energy resources, the development of emerging energy industries is particularly urgent. However, traditional clean energy power generation methods such as wind and solar power are significantly affected by environmental factors, resulting in large fluctuations in power output. This makes it difficult for traditional power grids to fully handle the load, leading to a significant waste of energy. Microgrids, as relatively independent energy storage systems, can provide electricity and heat to loads, effectively solving the integration problem of new energy sources such as wind power, photovoltaic power, and fuel cells, and are therefore attracting increasing attention.

[0003] However, existing energy storage microgrid systems require additional current and voltage sampling circuits or high-speed communication lines to accurately control power. A large number of power electronic devices not only increase the structural complexity of the microgrid, but also easily cause harmonic interference to the microgrid when generating electricity in the grid, affecting the power quality of the grid.

[0004] Therefore, how to effectively improve the anti-interference capability of microgrid energy storage systems has become an urgent problem to be solved. Summary of the Invention

[0005] The main purpose of this application is to provide a power grid power balancing system and an energy storage microgrid, aiming to solve the technical problem of how to effectively improve the anti-interference capability of the microgrid energy storage system.

[0006] To achieve the above objectives, this application proposes a power grid power balancing system, which includes: a power monitoring module and a power balancing control module;

[0007] The power monitoring module is connected to the power grid common bus, the composite energy storage module and the balance control module respectively;

[0008] The power monitoring module is used to acquire voltage parameters on the common bus of the power grid and determine the target power grid power based on the voltage parameters.

[0009] The equalization control module is used to control the power monitoring module to dynamically adjust the power of the composite energy storage module according to the target grid power, so as to achieve real-time power balance of the grid common bus.

[0010] In one embodiment, the composite energy storage module includes: a battery pack and a supercapacitor pack;

[0011] Both the battery pack and the supercapacitor pack are connected to the power monitoring module;

[0012] The equalization control module is also used to control the power monitoring module to dynamically regulate the power of the battery pack and / or the supercapacitor pack according to the current regulation mode and the target grid power, so as to achieve real-time power balance of the grid common bus.

[0013] In one embodiment, the power monitoring module includes a first power converter; the equalization control module includes a first control unit;

[0014] The first power converter is connected to the power grid common bus and the battery pack respectively, and the first control unit is connected to the first power converter and the battery pack respectively;

[0015] The first power converter is used to acquire the voltage parameters on the common bus of the power grid, and determine the energy storage power corresponding to the battery pack, the power generation power corresponding to the power generation system, and the load power corresponding to the load based on the voltage parameters.

[0016] The first control unit is configured to, when the current control mode is the battery control mode, control the first power converter to dynamically regulate the power of the battery pack according to the battery power, the power generation power and the load power.

[0017] In one embodiment, the first control unit is further configured to determine the target battery connection state based on a preset power threshold and the load power when the sum of the stored power and the generated power is equal to the load power;

[0018] The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the connection status of the target battery.

[0019] In one embodiment, the first control unit is connected to the battery pack;

[0020] The first control unit is further configured to determine the target number of batteries based on the load power;

[0021] The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the number of target batteries and the connection status of the target batteries.

[0022] In one embodiment, the first control unit is further configured to control the first power converter to put the battery pack into a charging state when the sum of the stored power and the load power is equal to the generated power.

[0023] In one embodiment, the power monitoring module further includes: a second power converter; the equalization control module further includes: a second control unit;

[0024] The second power converter is connected to the power grid common bus, the supercapacitor bank and the second control unit respectively;

[0025] The second power converter is used to obtain voltage parameters on the common bus of the power grid;

[0026] The second control unit is used to control the second power converter to dynamically regulate the power of the supercapacitor bank according to the voltage parameters and the preset operating voltage range when the current regulation mode is capacitor regulation mode.

[0027] In one embodiment, the second control unit is further configured to determine whether the voltage parameter is within a preset operating voltage range;

[0028] The second control unit is further configured to control the second power converter to dynamically adjust the power of the supercapacitor bank according to the voltage parameter and the preset voltage threshold when the voltage parameter is not within the preset operating voltage range.

[0029] In one embodiment, the system further includes a fault protection module;

[0030] The fault protection module is connected to the equalization control module, the power grid common bus, and the load, respectively.

[0031] The equalization control module is also used to send a cut-off signal to the fault protection module when it detects that the fluctuation index of the voltage parameter is greater than a preset fluctuation threshold.

[0032] The fault protection module is used to disconnect the load from the power grid common bus when the disconnection signal is received.

[0033] In addition, to achieve the above objectives, this application also proposes an energy storage microgrid, which includes: a grid common bus, a power generation system, loads, composite energy storage modules, and a grid power balancing system as described above.

[0034] This application provides a power grid power balancing system and an energy storage microgrid. The system includes a power monitoring module and a balancing control module. The power monitoring module is connected to the power grid common bus, a composite energy storage module, and the balancing control module. The power monitoring module acquires voltage parameters on the power grid common bus and determines the target power grid based on these parameters. The balancing control module dynamically adjusts the power of the composite energy storage module according to the target power grid, thereby achieving real-time power balancing on the power grid common bus. Therefore, compared to existing technologies, this application proposes a power grid power balancing system where the power monitoring module can directly acquire voltage parameters on the power grid's common (DC / AC) bus and determine the operating power of each device in the grid (i.e., the target power) based on these parameters. Then, it controls the composite energy storage module to charge or discharge according to the determined target power, thereby achieving dynamic power adjustment of the composite energy storage module and achieving real-time power balancing control of the power grid's common bus. Therefore, this application eliminates the need for complex additional circuit structures, effectively simplifying the energy storage microgrid system and improving the microgrid's anti-interference capability through real-time balancing control of the bus voltage. Attached Figure Description

[0035] 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.

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a first structural block diagram of a first embodiment of the power grid power balancing system of this application;

[0038] Figure 2 This is a second structural block diagram of the first embodiment of the power grid power balancing system of this application;

[0039] Figure 3 This is a first structural block diagram of the second embodiment of the power grid power balancing system of this application;

[0040] Figure 4 This is a second structural block diagram of the second embodiment of the power grid power balancing system of this application;

[0041] Figure 5 This is a schematic diagram of the battery pack structure of the second embodiment of the power grid power balancing system of this application;

[0042] Figure 6This is a schematic diagram of the hybrid control mode of the second embodiment of the power grid power balancing system of this application;

[0043] Figure 7 This is a schematic diagram of the system framework corresponding to the energy storage system embodiment of this application.

[0044] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0045] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0046] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0047] The main solution of this application is to propose a power grid power balancing system and an energy storage microgrid. The system includes a power monitoring module and a balancing control module. The power monitoring module is connected to the power grid common bus and the composite energy storage module, respectively. The balancing control module is connected to both the power monitoring module and the composite energy storage module. The power monitoring module is used to acquire voltage parameters on the power grid common bus and determine the target power grid based on the voltage parameters. The balancing control module is used to dynamically regulate the power of the composite energy storage module according to the target power grid, so as to achieve real-time power balancing on the power grid common bus.

[0048] Currently, in order to accurately control power in energy storage microgrid systems, additional current and voltage sampling circuits or high-speed communication lines are required. A large number of power electronic devices not only increase the structural complexity of the microgrid, but also easily cause harmonic interference to the microgrid during grid-connected power generation, affecting the power quality of the grid.

[0049] This application proposes a power grid power balancing system. In this system, a power monitoring module can directly collect voltage parameters from the common (DC / AC) bus of the power grid and determine the operating power of each device in the grid, i.e., the target power, based on these voltage parameters. Then, based on the determined target power, the system controls the charging or discharging of a composite energy storage module, thereby achieving dynamic power adjustment of the composite energy storage module and ultimately achieving real-time power balancing control of the common bus of the power grid. Therefore, this application eliminates the need for additional complex circuit structures, effectively simplifying the energy storage microgrid system, and improving the microgrid's anti-interference capability through real-time equalization control of the bus voltage.

[0050] This application provides a power grid power balancing system, referring to... Figure 1 , Figure 1 This is a first structural block diagram of the first embodiment of the power grid power balancing system of this application.

[0051] like Figure 1 As shown, in this embodiment, the power grid power balancing system includes: a power monitoring module and a balancing control module;

[0052] The power monitoring module is connected to the power grid common bus, the composite energy storage module and the balance control module respectively;

[0053] The power monitoring module is used to acquire voltage parameters on the common bus of the power grid and determine the target power grid power based on the voltage parameters.

[0054] The equalization control module is used to control the power monitoring module to dynamically regulate the power of the composite energy storage module according to the target grid power, so as to achieve real-time power balance of the grid common bus.

[0055] It is easy to understand that the power grid power balancing system proposed in this embodiment is used to improve the grid's anti-interference capability and achieve grid power stability. Therefore, in this embodiment, the power monitoring module is connected to the grid's common bus and the composite energy storage module respectively, and collects the real-time voltage values ​​corresponding to the grid's common DC bus or common AC DC bus, i.e., the aforementioned voltage parameters.

[0056] Meanwhile, in this embodiment, the power monitoring module can determine the real-time operating power of the equipment connected to the power grid, i.e., the aforementioned target power grid power, based on voltage parameters. Therefore, the balancing control module can perform charging and discharging control on the composite energy storage module connected to the power grid according to the determined target power grid power, so as to dynamically regulate the power of the composite energy storage module, thereby avoiding interference from the equipment connected to the power grid to the power grid, and thus realizing real-time power balancing control of the power grid's common bus.

[0057] Furthermore, as one possible implementation method, refer to Figure 2 , Figure 2 This is a second structural block diagram of the power grid power balancing system according to the first embodiment of this application. In this embodiment, the system further includes a fault protection module;

[0058] The fault protection module is connected to the equalization control module, the power grid common bus, and the load, respectively.

[0059] The equalization control module is also used to send a cut-off signal to the fault protection module when it detects that the fluctuation index of the voltage parameter is greater than a preset fluctuation threshold.

[0060] The fault protection module is used to disconnect the load from the power grid common bus when the disconnection signal is received.

[0061] It is easy to understand that load fluctuations connected to the power grid are one of the main sources of power grid disturbances. Therefore, in this embodiment, the balancing control module can control the disconnection of the load from the power grid when it detects that the voltage parameter corresponding to the common bus of the power grid fluctuates within a certain period of time or the fluctuation frequency, i.e., the above fluctuation index exceeds the preset fluctuation threshold, so that the load can smoothly switch from the grid-connected operation mode to the islanded operation mode.

[0062] Specifically, in this embodiment, a switching module, namely the aforementioned fault protection module, can be added between the load and the common bus of the power grid. This fault protection module can disconnect the load from the power grid when it receives a disconnection signal sent by the balancing control module, which should detect abnormal power grid fluctuations. Only when the power grid fluctuation index is no longer greater than a preset fluctuation threshold, or when the load re-establishes a stable voltage and frequency and sends a connection request, and both values ​​are within the allowable range, and the power grid power quality meets the standard requirements, will the balancing control module send a conduction signal to the fault protection module to reconnect the load to the power grid.

[0063] In summary, compared to existing technologies, the power monitoring module in this embodiment can directly collect voltage parameters on the common (DC / AC) bus of the power grid and determine the operating power of each device in the grid, i.e., the aforementioned target power, based on these voltage parameters. Then, it controls the charging or discharging of the composite energy storage module according to the determined target power, thereby achieving dynamic power adjustment of the composite energy storage module and balancing the real-time power of the common bus of the power grid. Therefore, this embodiment does not require additional complex circuit structures, effectively simplifying the energy storage microgrid system, and improving the microgrid's anti-interference capability through real-time equalization control of the bus voltage. Furthermore, this embodiment can avoid load interference to the power grid by adding a simple switching module, further improving the system's anti-interference capability.

[0064] This embodiment discloses a power grid power balancing system, comprising a power monitoring module and a balancing control module. The power monitoring module is connected to both the power grid common bus and the composite energy storage module, and the balancing control module is connected to both the power monitoring module and the composite energy storage module. The power monitoring module acquires voltage parameters on the power grid common bus and determines the target power grid based on these parameters. The balancing control module dynamically adjusts the power of the composite energy storage module according to the target power grid, thereby achieving real-time power balancing on the power grid common bus. Compared to existing technologies, in this embodiment, the power monitoring module can directly acquire voltage parameters on the power grid's common (DC / AC) bus and determine the operating power of each device in the power grid, i.e., the target power, based on these parameters. Then, it controls the composite energy storage module to charge or discharge according to the determined target power, thereby achieving dynamic power adjustment of the composite energy storage module and achieving real-time power balancing control on the power grid's common bus. Therefore, this embodiment eliminates the need for additional complex circuit structures, effectively simplifying the energy storage microgrid system and improving the microgrid's anti-interference capability through real-time balancing control of the bus voltage. In addition, the system includes a fault protection module; the fault protection module is connected to the balancing control module, the power grid common bus, and the load; the balancing control module is also used to send a disconnection signal to the fault protection module when it detects that the voltage parameter fluctuation index is greater than a preset fluctuation threshold; the fault protection module is used to disconnect the load from the power grid common bus when it receives the disconnection signal. This embodiment can avoid load interference to the power grid by adding an additional simple switch module, further improving the system's anti-interference capability.

[0065] Reference Figure 3 , Figure 3 This is a first structural block diagram of the second embodiment of the power grid power balancing system of this application, based on the above. Figure 1 The illustrated embodiment presents a second embodiment of the power grid power balancing system of this application.

[0066] like Figure 3 As shown, in this embodiment, the composite energy storage module includes: a battery pack and a supercapacitor pack;

[0067] Both the battery pack and the supercapacitor pack are connected to the power monitoring module;

[0068] The equalization control module is also used to control the power monitoring module to dynamically regulate the power of the battery pack and / or the supercapacitor pack according to the current regulation mode and the target grid power, so as to achieve real-time power balance of the grid common bus.

[0069] It is easy to understand that the composite energy storage module connected to the power grid in this embodiment may include a battery pack and a supercapacitor pack. Moreover, this embodiment can pre-set more than one power balancing control mode to dynamically control the power of the battery pack and / or supercapacitor pack, thereby achieving real-time effective power balancing of the power grid's common bus.

[0070] As one possible implementation method, in this embodiment, reference is made to... Figure 4 , Figure 4 This is a structural block diagram of a second embodiment of the power grid power balancing system of this application. The power monitoring module includes a first power converter; the balancing control module includes a first control unit.

[0071] The first power converter is connected to the power grid common bus and the battery pack respectively, and the first control unit is connected to the first power converter and the battery pack respectively;

[0072] The first power converter is used to acquire the voltage parameters on the common bus of the power grid, and determine the energy storage power corresponding to the battery pack, the power generation power corresponding to the power generation system, and the load power corresponding to the load based on the voltage parameters.

[0073] The first control unit is configured to, when the current control mode is the battery control mode, control the first power converter to dynamically regulate the power of the battery pack according to the battery power, the power generation power and the load power.

[0074] It is easy to understand that existing methods require adding current and voltage sampling circuits or high-speed communication lines between the input source, load, and energy management unit for power monitoring. To avoid degrading the system's anti-interference capability, the power monitoring module in this embodiment may include a first power converter. This first power converter can be a simple DC-AC converter or a bidirectional DC-DC converter. This first power converter can directly determine the battery pack's energy storage power, the generator's power generation power, and the load's power based on the voltage parameters on the grid's common bus, which is the aforementioned target grid power.

[0075] It should be understood that the current control mode is the battery control mode, which means that the system can effectively control the real-time power of the common bus simply by controlling the working state of the battery pack. As one possible implementation, in this embodiment, the first control unit is further configured to determine the target battery connection state based on a preset power threshold and the load power when the sum of the stored power and the generated power equals the load power.

[0076] The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the connection status of the target battery.

[0077] In one possible implementation, in this embodiment, the first control unit is further configured to control the first power converter to enable the battery pack to enter a charging state when the sum of the stored power and the load power is equal to the generated power.

[0078] It is easy to understand that in this embodiment, when the first control unit detects that the sum of the power output from the battery pack to the DC / AC bus determined by the first power converter and the power output from the power generation system to the DC / AC bus is equal to the power consumed by the load, the first control unit can control the first power converter to generate electricity from the battery pack in order to maintain the operation of the load.

[0079] When the sum of the power absorbed by the battery pack from the DC / AC bus and the power consumed by the load is equal to the power output to the bus by the power generation system, the first control unit can control the first power converter to charge the battery pack, so that the power generation system charges the battery pack and supplies power to the load, thereby keeping the voltage parameters on the common DC / AC bus within a normal preset range in the energy storage microgrid system and achieving bus power balance control.

[0080] In one possible implementation, in this embodiment, the first control unit is connected to the battery pack;

[0081] The first control unit is further configured to determine the target number of batteries based on the load power;

[0082] The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the number of target batteries and the connection status of the target batteries.

[0083] It is easy to understand that the battery pack described above in this embodiment can be composed of multiple batteries, and the battery pack contains multiple switching devices, each of which can be controlled by the first power converter. The on or off state of different switching devices will cause the multiple batteries to be connected in series or in parallel, and the series or parallel connection of the batteries in the battery pack can be determined according to the power required by the load.

[0084] Specifically, in this embodiment, when the power required by the load is small, the battery packs can be connected in parallel by switching devices to generate a lower voltage to power the load, thus avoiding damage to the load due to a higher voltage. When the power required by the load is large, the battery packs can be connected in series by switching devices to generate a higher voltage to power the load, thus avoiding the inability to maintain the operation of the load due to a lower voltage.

[0085] Therefore, in this embodiment, a preset power threshold can be set in advance. When the first control unit detects that the sum of the stored power and the generated power equals the load power, thus requiring the battery to supply power to the load, it can determine whether the batteries in the current battery pack should be connected in series or in parallel based on the preset power threshold and the load power, that is, determine the target battery connection state. Furthermore, based on the target battery connection state, the first power converter is controlled to make the battery pack enter a generation state matching the current load condition. At this time, if the load power is greater than the preset power threshold, the target battery connection state can be a series connection; if the load power is less than the preset power threshold, the target battery connection state can be a parallel connection.

[0086] Furthermore, in this embodiment, after determining the battery connection status within the battery pack, the embodiment can further determine the number of batteries within the battery pack that need to be connected to the power grid based on the load power, i.e., the aforementioned target number of batteries. Then, based on the target number of batteries and the target battery connection status, the first power converter is controlled to enable the battery pack to enter the power generation state. At this time, the aforementioned battery pack can also be connected to the first control unit.

[0087] For ease of understanding, Figure 5 Let's take an example to illustrate this. Figure 5 This is a schematic diagram of the battery pack structure of the second embodiment of the power grid power balancing system of this application, as shown below. Figure 5 As shown, the battery pack may include a battery switch array composed of several pairs of battery-switch transistors. The first control unit, given the battery connection status and the target number of batteries, determines the number of switches to be turned on corresponding to the target number of batteries. It is easy to understand that if a switch is turned on, the corresponding battery is short-circuited and cannot be connected to the power grid; conversely, if the switch is turned off, the corresponding battery can be connected to the power grid to supply power to the load. It is understood that, compared to more common switch control methods, this embodiment can be based on... Figure 5 The battery switch array based on MOSFETs shown enables precise power control.

[0088] As another possible implementation method, refer to Figure 4 In this embodiment, the power monitoring module further includes a second power converter; the equalization control module further includes a second control unit.

[0089] The second power converter is connected to the power grid common bus, the supercapacitor bank and the second control unit respectively;

[0090] The second power converter is used to obtain voltage parameters on the common bus of the power grid;

[0091] The second control unit is used to control the second power converter to dynamically regulate the power of the supercapacitor bank according to the voltage parameters and the preset operating voltage range when the current regulation mode is capacitor regulation mode.

[0092] As another possible implementation, in this embodiment, the second control unit is further used to determine whether the voltage parameter is within a preset operating voltage range;

[0093] The second control unit is further configured to control the second power converter to dynamically adjust the power of the supercapacitor bank according to the voltage parameter and the preset voltage threshold when the voltage parameter is not within the preset operating voltage range.

[0094] It is easy to understand that in this embodiment, the power monitoring module may also include a second power converter connected to the power grid common bus and the supercapacitor bank respectively. The second power converter may also be a simple DC-AC converter or a bidirectional DC-DC converter, which can collect voltage parameters on the DC / AC bus. When the current control mode is the capacitor control mode, it indicates that the system can control the bus power through the supercapacitor bank. At this time, the second control unit can determine whether the voltage parameters are within the preset operating voltage range to regulate the power of the supercapacitor bank.

[0095] Specifically, when the second control unit detects that the voltage parameter is not within the preset operating voltage range, the aforementioned preset voltage threshold can be a critical value corresponding to the preset operating voltage range. For example, if the preset voltage operating range is A to B, the second control unit can adjust the capacitor power based on the bus voltage parameter and the preset voltage threshold.

[0096] It is easy to understand that if the voltage parameter is lower than A, the second control unit can control the second power converter to discharge the supercapacitor; if the voltage parameter is higher than B, the second control unit can control the second power converter to charge the supercapacitor in order to maintain the stability of the voltage parameters on the DC / AC bus.

[0097] It should be understood that the current control mode in this embodiment can also be a hybrid control mode. For ease of understanding, it is referred to as... Figure 6 Let's take an example to illustrate this. Figure 6 This is a schematic diagram of the hybrid control mode of the second embodiment of the power grid power balancing system of this application, as shown below. Figure 6As shown, if the power grid's common bus is a DC bus, then in this mode, both the first and second power converters can work collaboratively as bidirectional DC-DC converters to achieve comprehensive management of the bus voltage parameters. In this case, the first power converter controls the battery bank to maintain long-term energy balance—that is, the energy balance between the generation system, load, and battery; while the second power converter uses the supercapacitor bank to handle short-term energy fluctuations and maintain system stability. In this way, the physical parameters on the bus can be kept within a suitable range, thereby ensuring the stable operation of the power system.

[0098] In summary, this embodiment can directly acquire voltage parameters on the DC / AC bus through the first power converter, determine the output power of the power generation system, the power consumed by the load, and the power absorbed or output by the battery pack based on these voltage parameters, and then control the charging and discharging of the battery pack according to the determined power, or directly control the charging and discharging of the supercapacitor pack according to the voltage parameters. Therefore, this embodiment can achieve effective power balance control of the power grid without adding an extra complex structure, effectively suppressing DC bus voltage fluctuations, thereby not only effectively simplifying the structure of the energy storage microgrid system, but also improving the system's anti-interference capability.

[0099] In addition, in this embodiment, the first control unit also realizes rapid load output tracking, thereby reducing the disturbance of load output to the power grid and further stabilizing the power of the power grid bus.

[0100] This embodiment discloses a composite energy storage module including a battery pack and a supercapacitor pack; a power monitoring module including a first power converter; and a balancing control module including a first control unit. The first power converter is connected to both the grid common bus and the battery pack, and the first control unit is connected to both the first power converter and the battery pack. The first power converter is used to acquire voltage parameters on the grid common bus and determine the battery pack's energy storage power, the power generation system's power generation power, and the load power based on the voltage parameters. The first control unit is used to, when the current control mode is battery control mode, determine the target battery connection state based on a preset power threshold and the load power when the sum of the energy storage power and the power generation power equals the load power; determine the target number of batteries based on the load power; and control the first power converter to put the battery pack into a power generation state based on the target number of batteries and the target battery connection state. The first control unit is also used to control the first power converter to put the battery pack into a charging state when the sum of the energy storage power and the load power equals the power generation power. The power monitoring module further includes a second power converter; the balancing control module further includes a second control unit; the second power converter is connected to the grid common bus, the supercapacitor bank, and the second control unit respectively; the second power converter is used to acquire voltage parameters on the grid common bus; the second control unit is used to control the power of the supercapacitor bank dynamically according to the voltage parameters and a preset operating voltage range when the current control mode is capacitor control mode. The second control unit is also used to control the power of the supercapacitor bank dynamically according to the voltage parameters and a preset voltage threshold if the voltage parameters are not within the preset operating voltage range. In this embodiment, the voltage parameters on the DC / AC bus can be directly acquired by the first power converter, and the output power of the power generation system, the power consumed by the load, and the power absorbed or output power of the battery bank can be determined based on the voltage parameters. Then, the charging and discharging of the battery bank can be controlled according to the determined power, or the charging and discharging of the supercapacitor bank can be directly controlled according to the voltage parameters. Therefore, this embodiment can achieve effective power balancing control of the grid without adding a complex structure, effectively suppressing DC bus voltage fluctuations, thereby not only effectively simplifying the structure of the energy storage microgrid system, but also improving the system's anti-interference capability. In addition, in this embodiment, the first control unit also realizes rapid load output tracking, thereby reducing the disturbance of load output to the power grid and further stabilizing the power of the power grid bus.

[0101] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0102] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0103] This application provides an energy storage microgrid, referring to... Figure 7 , Figure 7 This is a schematic diagram of the system framework corresponding to the energy storage system embodiment of this application, as shown below. Figure 7 As shown, the energy storage microgrid in this embodiment includes a grid common bus 1001, a power generation system 1002, a load 1003, a composite energy storage module 1004, and a grid power balancing system 1005 as described in the above embodiment.

[0104] The power grid common bus 1001 is connected to the power generation system 1002, the load 1003, the composite energy storage module 1004, and the power grid power balancing system 1005, respectively; the power grid power balancing system 1005 and the composite energy storage module 1004 are connected.

[0105] In addition, the aforementioned power generation system may include: power grid, backup power source (diesel generator / gas generator, etc.), wind turbine, photovoltaic panel and energy storage equipment (lithium battery, etc.); the aforementioned composite energy storage module may include: battery bank and supercapacitor bank.

[0106] The energy storage microgrid provided in this application can solve the technical problem of how to effectively improve the anti-interference capability of microgrid energy storage systems. Compared with the prior art, the beneficial effects of the energy storage microgrid provided in this application are the same as those of the grid power balancing system provided in the above embodiments, and will not be repeated here.

[0107] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0108] The above are only some embodiments of this application and do not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A power grid power balancing system, characterized in that, The system includes: a power monitoring module and an equalization control module; The power monitoring module is connected to the power grid common bus, the composite energy storage module and the balance control module respectively; The power monitoring module is used to acquire voltage parameters on the common bus of the power grid and determine the target power grid power based on the voltage parameters. The equalization control module is used to control the power monitoring module to dynamically regulate the power of the composite energy storage module according to the target grid power, so as to achieve real-time power balance of the grid common bus.

2. The power grid power balancing system as described in claim 1, characterized in that, The composite energy storage module includes: a battery pack and a supercapacitor pack; Both the battery pack and the supercapacitor pack are connected to the power monitoring module; The equalization control module is also used to control the power monitoring module to dynamically regulate the power of the battery pack and / or the supercapacitor pack according to the current regulation mode and the target grid power, so as to achieve real-time power balance of the grid common bus.

3. The power grid power balancing system as described in claim 2, characterized in that, The power monitoring module includes a first power converter; the equalization control module includes a first control unit; The first power converter is connected to the power grid common bus and the battery pack respectively, and the first control unit is connected to the first power converter and the battery pack respectively; The first power converter is used to acquire the voltage parameters on the common bus of the power grid, and determine the energy storage power corresponding to the battery pack, the power generation power corresponding to the power generation system, and the load power corresponding to the load based on the voltage parameters. The first control unit is configured to, when the current control mode is the battery control mode, control the first power converter to dynamically regulate the power of the battery pack according to the battery power, the power generation power and the load power.

4. The power grid power balancing system as described in claim 3, characterized in that, The first control unit is further configured to determine the target battery connection status based on a preset power threshold and the load power when the sum of the stored power and the generated power is equal to the load power; The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the connection status of the target battery.

5. The power grid power balancing system as described in claim 4, characterized in that, The first control unit is connected to the battery pack; The first control unit is further configured to determine the target number of batteries based on the load power; The first control unit is further configured to control the first power converter to enable the battery pack to enter the power generation state based on the number of target batteries and the connection status of the target batteries.

6. The power grid power balancing system as described in claim 5, characterized in that, The first control unit is further configured to control the first power converter to put the battery pack into a charging state when the sum of the stored power and the load power is equal to the generated power.

7. The power grid power balancing system as described in claim 6, characterized in that, The power monitoring module further includes: a second power converter; the equalization control module further includes: a second control unit; The second power converter is connected to the power grid common bus, the supercapacitor bank and the second control unit respectively; The second power converter is used to obtain voltage parameters on the common bus of the power grid; The second control unit is used to control the second power converter to dynamically regulate the power of the supercapacitor bank according to the voltage parameters and the preset operating voltage range when the current regulation mode is capacitor regulation mode.

8. The power grid power balancing system as described in claim 7, characterized in that, The second control unit is also used to determine whether the voltage parameter is within a preset operating voltage range; The second control unit is further configured to control the second power converter to dynamically adjust the power of the supercapacitor bank according to the voltage parameter and the preset voltage threshold when the voltage parameter is not within the preset operating voltage range.

9. The power grid power balancing system as described in claim 8, characterized in that, The system also includes a fault protection module; The fault protection module is connected to the equalization control module, the power grid common bus, and the load, respectively. The equalization control module is also used to send a cut-off signal to the fault protection module when it detects that the fluctuation index of the voltage parameter is greater than a preset fluctuation threshold. The fault protection module is used to disconnect the load from the power grid common bus when the disconnection signal is received.

10. An energy storage microgrid, characterized in that, The microgrid includes: a common busbar, a power generation system, loads, composite energy storage modules, and a power balancing system as described in any one of claims 1 to 9.

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