Grid-connected energy storage system

Abstract

The utility model relates to a grid-connected energy storage system, which comprises an energy storage module connected with a power grid and a load and used for storing electric energy provided by the power grid and outputting the electric energy to the load; the data acquisition module is connected with the user-side transformer, the user-side load and the energy storage module and is used for acquiring power data of the user-side transformer, the user-side load and the energy storage module; and the energy storage controller is connected with the data acquisition module and the energy storage module and is used for generating a control signal according to the power data, and the energy storage module is used for storing energy or outputting electric energy according to the control signal. The grid-connected energy storage system can meet urban and industrial power utilization requirements more efficiently.

Description

Technical Field

[0001] The utility model relates to the technical field of grid-connected energy storage systems, in particular to a grid-connected energy storage system. Background Art

[0002] Energy storage is an important component and key supporting technology of smart grids, energy systems with a high proportion of renewable energy, and "Internet +" smart energy. Energy storage can provide peak load regulation, frequency regulation, standby, black start, demand response support and other services for grid operation, and is an important means to improve the flexibility, economy and safety of traditional power systems; energy storage can significantly improve the absorption level of renewable energy such as wind and light, support distributed power and microgrids, and is a key technology to promote the replacement of the main energy from fossil energy to renewable energy.

[0003] Modern cities and industrial electricity consumption usually have large-scale, continuous and high-power demands for power supply, and the electricity demand may change over time. Grid-connected energy storage systems can alleviate short-term fluctuations in the power system and provide backup power. In existing technologies, the energy storage capacity and charge and discharge rate of grid-connected energy storage systems are relatively limited, and the charge and discharge mode is relatively single, which cannot effectively meet the electricity demand of modern cities and industries. Utility Model Content

[0004] Based on this, it is necessary to provide a grid-connected energy storage system that can more efficiently meet urban and industrial electricity needs in response to the above problems.

[0005] A grid-connected energy storage system, comprising:

[0006] The energy storage module is connected to the grid module and the load through the power supply bus, and is used to store the electric energy provided by the grid and output the electric energy to the load;

[0007] A data acquisition module is connected to the power grid module, the load and the energy storage module, and is used to collect power data of the power grid module, the load and the energy storage module;

[0008] The energy storage controller is connected to the data acquisition module and the energy storage module, and is used to generate a control signal according to the power data. The energy storage module is used to store or output electric energy according to the control signal.

[0009] In one embodiment, the energy storage module includes an energy storage inverter and an energy storage unit. The energy storage inverter is connected to the energy storage unit and the power supply bus, respectively, and is used to convert the AC power provided by the power grid module into DC power and store it in the energy storage unit, or to convert the DC power of the energy storage unit into AC power to supply the load.

[0010] In one embodiment, the energy storage inverter is communicatively connected to the energy storage controller, the power data of the power grid module collected by the data acquisition module is greater than the power data of the load, the energy storage controller sends a first control signal to the energy storage inverter, and the energy storage inverter closes the energy storage switch to store energy after receiving the first control signal.

[0011] In one embodiment, the energy storage inverter is communicatively connected to the energy storage controller, the power data of the power grid module collected by the data acquisition module is less than the power data of the load, the energy storage controller sends a second control signal to the energy storage inverter, and the energy storage inverter closes the power output switch to output electric energy after receiving the second control signal.

[0012] In one embodiment, the power grid module includes a power grid and a transformer, the power grid is connected to the transformer, and the data acquisition module is used to collect output power data of the transformer.

[0013] In one embodiment, the energy storage module includes a plurality of energy storage units and a plurality of energy storage converters corresponding to the energy storage units, and each energy storage unit is connected to each energy storage converter in a one-to-one correspondence.

[0014] In one embodiment, the energy storage module, the data acquisition module and the energy storage controller are connected to each other using a CAN bus or an RS485 bus.

[0015] In one of the embodiments, an anti-reverse flow meter is connected between the load and the power grid.

[0016] In one embodiment, the grid-connected energy storage system further includes a data switch for exchanging data among the data acquisition module, the energy storage module and the energy storage controller.

[0017] In one embodiment, the grid-connected energy storage system further includes a wireless communication module, and the wireless communication module is connected to the data switch.

[0018] The above-mentioned grid-connected energy storage system includes: an energy storage module, which is connected to the power grid and the load, and is used to store the electric energy provided by the power grid and output the electric energy to the load; the energy storage module can smooth out power fluctuations, store excess electric energy when the power grid demand is peak, and release electric energy when the demand is low, and can provide continuous power supply to key loads when the power grid fails or the power is cut off, thereby improving the adaptability of the power system to changing load demands and helping to improve the stability and reliability of the power grid; a data acquisition module, which is connected to the user-side transformer, the user-side load and the energy storage module, and is used to collect power data of the user-side transformer, the user-side load and the energy storage module; the data collected by the data acquisition module Power data can be used to analyze the characteristics of user-side loads, including peak loads, load curves, and load fluctuations, which helps to clarify load demand and optimize load distribution. The energy storage controller is connected to the data acquisition module and the energy storage module to generate control signals based on power data. The energy storage module is used to store energy or output electrical energy based on the control signal. It can generate control signals based on real-time power data, adjust the working state of the energy storage module according to system requirements and operating status, and improve the dynamic response capability of the system. It can also be controlled according to the needs of different time periods to improve the flexibility of the system, thereby being able to more efficiently meet urban and industrial electricity needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is an application environment diagram of a grid-connected energy storage system according to an embodiment of the present application;

[0021] Figure 2 This is a schematic block diagram of the structure of a grid-connected energy storage system according to an embodiment of the present application.

[0022] 1. Energy storage module; 2. Power supply bus; 3. Grid module; 4. Load; 5. Data acquisition module; 6. Energy storage controller; 11. Energy storage converter; 12. Energy storage unit; 13. Energy storage switch; 14. Output switch; 31. Grid; 32. Transformer; 7. Anti-reverse current meter; 8. Energy storage switch; 9. Output switch. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0029] See also Figure 1, FIG1 shows a schematic diagram of the application environment of the grid-connected energy storage system in an embodiment of the utility model. An embodiment of the utility model provides a grid-connected energy storage system, which can be connected to a power supply network or different entities in the power supply network, such as a municipal power grid, a user-side transformer and a load in the municipal power grid, wherein the user side refers to the side from the power transmission system to the user equipment and load, including a transformer and the user's electrical equipment, and the user-side transformer is used to convert the electric energy transmitted by the high-voltage power grid into low-voltage electric energy suitable for the user equipment and load. The user-side load may include household appliances, industrial machinery and public facilities. The grid-connected energy storage system can obtain data such as the frequency, voltage, real-time power demand and load curve of the power grid by exchanging data with the power grid and determine the working mode of the grid-connected energy storage system based on the above data. The grid-connected energy storage system may include a monitoring system, an energy management system (EMS) and an energy storage battery unit. Among them, the monitoring system can be connected to each key node of the power grid through the remote terminal unit (RTU) and the sensor network, and is used to collect, transmit and display various data related to the power system in real time, including voltage, current, frequency, power, load, etc. For example, the SCADA system (Supervisory Control and Data Acquisition) is one of the widely used monitoring systems in the power grid. In addition to the sensor network, the monitoring system can also include a communication module and a user interface. The communication module is used to ensure the reliable transmission of the data collected by the sensor, and can include multiple communication methods such as optical fiber, microwave link or satellite communication. The user interface is used for the operators of the power grid to monitor the power grid status in real time, receive alarm information and perform operations, and can include a graphical display interface, a report interface and a real-time data interface. The energy management system is a subsystem used to monitor, control and optimize energy use. It adjusts the operating parameters of the energy system by real-time processing and analyzing information such as power load, energy flow, temperature, humidity, etc., and coordinates and dispatches the work of various energy equipment.

[0030] Figure 1 This is a schematic block diagram of the structure of a grid-connected energy storage system according to an embodiment of the present application. A grid-connected energy storage system provided by an embodiment of the present application includes:

[0031] The energy storage module is connected to the grid module and the load through the power supply bus, and is used to store the electric energy provided by the grid and output the electric energy to the load; wherein the energy storage module may include multiple energy storage units, and the energy storage unit may be an energy storage battery, such as a lithium-ion battery, a lead-acid battery, a sodium-sulfur battery or a lithium-sulfur battery. Different types of energy storage units can determine when to start charging or discharging under the control of the energy management system. When charging, the energy storage unit converts the electric energy received from the grid into an energy storage form corresponding to the energy storage unit through different energy storage methods, such as electrochemical energy storage or mechanical energy storage. When the grid needs additional electric energy, the energy storage unit converts the stored energy into alternating current and injects it into the grid to meet the grid's electric energy needs.

[0032] The data acquisition module is connected to the power grid module, the load and the energy storage module, and is used to collect power data of the power grid module, the load and the energy storage module; the data acquisition module may include sensors, data collectors, memory and communication interfaces, etc., wherein the sensors are used to detect physical quantities and environmental parameters, the data collectors are used to obtain analog signals from the sensors and convert them into digital signals, the communication interfaces are used to realize communication with modules or devices such as energy storage modules and energy storage controllers to transmit the collected data, and the communication interfaces may be Ethernet, Wi-Fi, Bluetooth, RS-232 serial port or RS-485 serial port, etc., and the memory may be used to store the collected data, and may be a solid-state memory, a memory chip or an SD card, etc.

[0033] The energy storage controller is connected to the data acquisition module and the energy storage module, and is used to generate a control signal according to the power data. The energy storage module is used to store or output electrical energy according to the control signal. The energy storage controller can monitor the state of the energy storage module and control the energy storage module to store and release electrical energy.

[0034] The above-mentioned grid-connected energy storage system includes: an energy storage module, which is connected to the grid module and the load through the power supply bus, and is used to store the electric energy provided by the grid and output the electric energy to the load. The grid module includes the grid and the transformer; the energy storage module can smooth out power fluctuations, store excess electric energy when the load demand is low, and release electric energy when the demand is peak. It can also provide continuous power supply to key loads when the grid fails or the power is cut off, thereby improving the adaptability of the power system to changing load demands and helping to improve the stability and reliability of the grid; a data acquisition module, which is connected to the transformer, the load and the energy storage module, and is used to collect power data of the user-side transformer, the user-side load and the energy storage module; data acquisition The power data collected by the data acquisition module can be used to analyze the characteristics of the user-side load, including peak load, load curve and load fluctuation, which is helpful to clarify the load demand and optimize the load distribution; the energy storage controller is connected to the data acquisition module and the energy storage module, and is used to generate a control signal according to the power data. The energy storage module is used to store energy or output electric energy according to the control signal. It can generate a control signal based on real-time power data, adjust the working state of the energy storage module according to system requirements and operating status, and improve the dynamic response capability of the system. It can also be controlled according to the needs of different time periods, thereby improving the flexibility of the system, so as to more efficiently meet the urban and industrial electricity needs.

[0035] In one embodiment, the energy storage module includes an energy storage converter and an energy storage unit, wherein the energy storage converter is respectively connected to the energy storage unit and the power supply bus, and is used to convert the AC power provided by the power grid module into DC power and store it in the energy storage unit, or to convert the DC power of the energy storage unit into AC power and supply it to the load. Among them, the energy storage converter is an electronic device used in a grid-connected energy storage system, which is used to convert the electric energy stored in the energy storage unit into AC power or DC power in a controllable manner, and output it for power supply or interact with the power grid when necessary. It can control the conversion and flow of electric energy. When the power grid fails, the energy storage unit can be quickly switched to the energy storage mode to ensure the power supply of critical loads. The energy storage converter is used to control the charging and discharging of the energy storage unit, and can receive electric energy storage from a power source (such as a power grid, etc.), and can also output the stored electric energy to the load, which is conducive to balancing the peak-to-valley difference of the power grid.

[0036] When the power grid is in a power supply valley and the user side is in working state, the power grid can be used to charge the energy storage module whose power meets certain conditions, that is, the power data of the power grid module collected by the data acquisition module is greater than the power data of the load, for example, when the power P of the transformer ≧ the actual charging power P of the energy storage module 实充 + Actual power used by the user side P 实用 ; Actual charging power P of the energy storage module 实充 ≦Preset charging power P of energy storage module 预充In one embodiment, the input power of the energy storage module is less than the difference between the power of the user-side transformer in the power grid and the user-side load power in the power grid, and the input power of the energy storage module is less than or equal to the preset minimum input power of the energy storage module, and the energy storage controller sends a first control signal to the energy storage converter, and the energy storage converter turns on the energy storage switch to store energy after receiving the first control signal.

[0037] When the municipal power grid is at its peak and the user side is in working state, the energy storage module whose power meets certain conditions can be used to supply power to the user side load, that is, the power data of the power grid module collected by the data acquisition module is less than the power data of the load. For example, when the actual discharge power P of the energy storage system = the actual power used by the user side P 实际 *90% and the actual discharge power of the energy storage module P 实放 ≦Preset discharge power P of energy storage module 预放 The energy storage module can be used to supply power to the user-side load in the power grid. In one embodiment, the output power of the energy storage module is greater than the load power, and the output power of the energy storage module is less than or equal to the preset maximum output power of the energy storage module. The energy storage controller sends a second control signal to the energy storage converter, and the energy storage converter opens the power output switch to output power after receiving the second control signal.

[0038] In one embodiment, the energy storage switch and the output switch both include a switch quantity sensor and a relay. The switch quantity collector is connected to the data acquisition module to obtain the switch quantity, and the relay is connected to the switch quantity collector to control the on-off between the energy storage converter and the load. The switch quantity sensor is a sensor used to detect the state of a physical quantity. The information it outputs is discrete information or binary information, such as on / off, high / low, 1 / 0, etc., which is used to obtain key trigger or status information. The relay is used to amplify, isolate or control electrical signals. The switch quantity collector is connected to the data acquisition module to realize the integrated collection of switch status and other related data. Connecting the relay to the switch quantity collector to control the on-off of the energy storage converter can make the grid-connected energy storage system more flexible and controllable, and have higher reliability.

[0039] In one embodiment, the energy storage module includes a plurality of energy storage units and a plurality of energy storage converters corresponding to the energy storage units, and each energy storage unit is connected to each energy storage converter in a one-to-one correspondence.

[0040] In one embodiment, the energy storage module, the data acquisition module and the energy storage controller are connected to each other by CAN bus or RS485 bus communication. The RS485 bus supports a relatively long communication distance, has strong anti-interference ability and supports multiple devices to be connected to the same bus to form a multi-node network. On the one hand, it can improve the reliability of communication. On the other hand, since multiple energy storage modules and data acquisition modules are dispersedly arranged in the grid-connected energy storage system, the use of RS485 bus is conducive to the flexible deployment of each module. The CAN bus has low hardware cost, high bandwidth and strong real-time performance, and can improve the reliability and flexibility of the coordinated operation of each energy storage unit and the energy storage converter.

[0041] In one embodiment, an anti-backflow meter is connected between the load and the grid module. The anti-backflow meter is used to prevent reverse metering, which can prevent the meter from making errors when detecting the flow of electric energy, so that the amount of electricity collected by the meter can more accurately reflect the actual electricity consumption.

[0042] In one of the embodiments, the grid-connected energy storage system further includes a data switch for realizing data exchange between the data acquisition module, the energy storage module and the energy storage controller. The data switch is a network device used to connect multiple computers or terminal devices and forward data packets from one port to another port according to the destination address of the data packet. The data switch is set to realize data exchange between the modules, so that information can be transmitted in real time between the modules, including the battery status, charge and discharge rate, temperature and other data of the energy storage module, so that the energy storage controller can more accurately monitor and control the operating status of the grid-connected energy storage system, which helps to improve the intelligence, efficiency and manageability of the system.

[0043] In one embodiment, the grid-connected energy storage system also includes a wireless communication module, which is connected to a data switch and is used to provide wireless communication capabilities for the data switch. In this way, the data switch can transmit the collected data to other terminals in the system wirelessly, and receive instructions sent by the energy storage controller or the monitoring subsystem, so that the energy storage controller can remotely monitor and control the energy storage unit or communicate wirelessly with other devices in the power system. Among them, the wireless communication module can include WIFI components, 3G / 4G / 5G components and Bluetooth components, etc. The specific communication method can be determined according to actual needs.

[0044] In some embodiments, the communication method between the components of the grid-connected energy storage system is not limited to Ethernet, serial port, optical fiber and other communication methods, and information and control interaction with the upper system can be carried out through these communication methods. The communication protocol used is not limited to MODBUS-RTU, MODBUS-TCP, IEC104, IEC101, IEC61850 and other protocol types.

[0045] In some embodiments, the grid-connected energy storage system further includes a monitoring system, a video switch, a video access module, and a temperature and humidity acquisition device, wherein the video switch can receive video information collected by each monitoring device in the grid-connected energy storage system, the first end of the data switch is connected to the video switch via Ethernet, and the second end is connected to the video access module via Ethernet, and the video information received by the video switch can be forwarded to the video access module, the video access module is connected to the monitoring subsystem via Ethernet, and the video data can be transmitted to the monitoring subsystem, and the video access module can include functions such as video compression and encoding and decoding to ensure efficient transmission and storage of videos. In some embodiments, the grid-connected energy storage system further includes an environmental data acquisition device, such as a temperature sensor, a humidity sensor, or a gas sensor. The temperature and humidity acquisition device can be connected to the data collector via an RS485 bus, and multiple temperature and humidity acquisition devices can be connected on the same bus to simultaneously measure the temperature and humidity data of different nodes, so that it is more suitable for grid-connected energy storage systems with distributed settings of various components.

[0046] In some embodiments, the grid-connected energy storage system may further include a human-machine interface (HMI), which may be integrated into a terminal such as a monitoring subsystem for remote monitoring and issuing instructions.

[0047] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A grid-connected energy storage system, It is characterized in that include: An energy storage module, connected to the power grid module and the load via a power supply bus, and used to store the electric energy provided by the power grid and output the electric energy to the load; A data acquisition module, connected to the power grid module, the load and the energy storage module, for collecting power data of the power grid module, the load and the energy storage module; An energy storage controller is connected to the data acquisition module and the energy storage module, and is used to generate a control signal according to the power data. The energy storage module is used to store or output electric energy according to the control signal.

2. The grid-connected energy storage system according to claim 1, It is characterized in that The energy storage module includes an energy storage inverter and an energy storage unit. The energy storage inverter is connected to the energy storage unit and the power supply bus respectively, and is used to convert the alternating current provided by the power grid module into direct current and store it in the energy storage unit, or to convert the direct current of the energy storage unit into alternating current and supply it to the load.

3. The grid-connected energy storage system according to claim 2, It is characterized in that The energy storage inverter is communicatively connected to the energy storage controller, the power data of the power grid module collected by the data acquisition module is greater than the power data of the load, the energy storage controller sends a first control signal to the energy storage inverter, and the energy storage inverter closes the energy storage switch to store energy after receiving the first control signal.

4. The grid-connected energy storage system according to claim 2, It is characterized in that The energy storage inverter is communicatively connected to the energy storage controller, the power data of the power grid module collected by the data acquisition module is less than the power data of the load, the energy storage controller sends a second control signal to the energy storage inverter, and the energy storage inverter closes the power output switch to output electric energy after receiving the second control signal.

5. The grid-connected energy storage system according to claim 2, It is characterized in that The power grid module includes a power grid and a transformer, the power grid is connected to the transformer, and the data acquisition module is used to collect output power data of the transformer.

6. The grid-connected energy storage system according to claim 2, It is characterized in that The energy storage module includes a plurality of energy storage units and a plurality of energy storage converters corresponding to the energy storage units, and each energy storage unit is connected to each energy storage converter in a one-to-one correspondence.

7. The grid-connected energy storage system according to claim 1, It is characterized in that The energy storage module, the data acquisition module and the energy storage controller are connected in pairs using a CAN bus or an RS485 bus.

8. The grid-connected energy storage system according to claim 2, It is characterized in that An anti-backflow meter is connected between the load and the power grid module.

9. The grid-connected energy storage system according to claim 1, It is characterized in that The grid-connected energy storage system also includes a data switch for exchanging data among the data acquisition module, the energy storage module and the energy storage controller.

10. The grid-connected energy storage system according to claim 9, It is characterized in that The grid-connected energy storage system further includes a wireless communication module, and the wireless communication module is connected to the data switch.

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