Voltage sag treatment energy storage system

Abstract

The utility model provides a voltage sag management energy storage system, which is provided with an energy storage device, a bidirectional converter used for realizing conversion between direct current and alternating current, and a control machine, the bidirectional converter is connected in series with the energy storage device, and the control machine is respectively in communication connection with the energy storage device and the bidirectional converter. The control machine comprises a DI DO module used for controlling on and off of each switch in the sag treatment energy storage system, a communication module used for carrying out data transmission with each component in the voltage sag treatment energy storage system, and a control module used for controlling each component in the voltage sag treatment energy storage system. The control module is in communication connection with the DI DO module and the communication module, so that when voltage sag or power failure of a power grid occurs, the energy storage device can be used for providing a stable power supply for a load, normal operation of the load is ensured, rapid, accurate and flexible treatment of the voltage sag of the power grid is realized, and the voltage quality and stability of the power grid are improved.

Description

Technical Field

[0001] The utility model relates to the field of energy storage, and in particular to a voltage sag management energy storage system. Background Art

[0002] With the transformation of the global energy structure and the rapid development of renewable energy, the scale of power grids has become larger and larger, and their structures have become more and more complex. As a result, occasional line failures or interference in the power grid may cause the voltage of the power grid to temporarily drop or lose power, which may easily cause the power grid load to shut down, restart, or lose data, causing huge economic losses and safety hazards to users.

[0003] In the prior art, commonly used voltage sag or power outage management devices include dynamic voltage restorer (DVR) and uninterruptible power supply (UPS). Among them, the dynamic voltage restorer (DVR) is a series compensation device, and two inverter circuits will appear in the main circuit of the compensation system, thereby increasing the equipment cost and reducing the working efficiency; while the uninterruptible power supply (UPS) cannot efficiently handle the voltage sag compensation process due to its small discharge current and long charging time. Utility Model Content

[0004] The purpose of the utility model is to solve at least one of the technical problems existing in the prior art and to provide a voltage sag control energy storage system, which can use the energy storage device to provide stable power to the load when the voltage sag or power outage occurs in the power grid, thereby ensuring the normal operation of the load, achieving rapid, accurate and flexible control of the voltage sag of the power grid, and improving the voltage quality and stability of the power grid.

[0005] To achieve the above objectives, a first aspect of an embodiment of the present application provides a voltage sag management energy storage system, comprising:

[0006] An energy storage device, which is used to store electric energy input from an external power grid or output electric energy to user equipment. The energy storage device includes a plurality of batteries;

[0007] A bidirectional converter is used to realize the conversion between direct current and alternating current. The bidirectional converter is connected in series with the energy storage device.

[0008] The control machine is used to control various components in the voltage sag management energy storage system. The control machine is communicated with the energy storage device, and is communicated with the bidirectional converter. The control machine includes a DIDO module, a communication module and a control module. The DIDO module is used to receive the working status of various components in the voltage sag management energy storage system and control the opening and closing of various switches in the voltage sag management energy storage system. The communication module is used to transmit data with various components in the voltage sag management energy storage system. The control module is used to control the DIDO module and the communication module. The control module is communicated with the DIDO module, and the control module is communicated with the communication module.

[0009] Furthermore, in some embodiments, the voltage sag management energy storage system also includes an isolation transformer, which is used to protect the circuit of the voltage sag management energy storage system, the isolation transformer is connected in series with the bidirectional converter, and the isolation transformer is communicatively connected with the control module.

[0010] Further, in some embodiments, the isolation transformer includes an all-copper winding, and the line structure of the all-copper winding includes a star line structure and a triangle line structure, and the star line structure is connected to the triangle line structure.

[0011] Furthermore, in some embodiments, the control machine also includes a power detection module, which is used to detect the bus voltage of the external power grid, and the power detection module is communicatively connected to the control module.

[0012] Furthermore, in some embodiments, the control machine also includes a display module, which is used to display operating parameters of the voltage sag management energy storage system, and the display module is communicatively connected to the control module.

[0013] Furthermore, in some embodiments, the voltage sag management energy storage system also includes a fast switch, which is used as a connecting switch between the energy storage device and the external power grid. The fast switch is connected in parallel with the energy storage device, and the fast switch is communicatively connected with the control machine.

[0014] Furthermore, in some embodiments, the voltage sag management energy storage system also includes an output switch, which is used as a connecting switch between the energy storage device and the user equipment, the output switch is connected in parallel with the energy storage device, and the output switch is communicatively connected with the control machine.

[0015] Furthermore, in some embodiments, the voltage sag management energy storage system also includes a bypass switch, which is used to control the start and stop of the bypass function of the voltage sag management energy storage system, the bypass switch is connected in parallel with the energy storage device, and the bypass switch is communicatively connected with the control machine.

[0016] Furthermore, in some embodiments, the voltage sag control energy storage system also includes a voltage sensor, which is used to collect the magnitude and frequency of the grid voltage signal, and the voltage sensor is communicatively connected to the control machine.

[0017] Furthermore, in some embodiments, the voltage sag control energy storage system also includes a current sensor, which is used to collect the magnitude and direction of the grid current signal. The current sensor is communicatively connected to the control machine, and the current sensor is connected in series with the voltage sensor.

[0018] A voltage sag management energy storage system according to an embodiment of the utility model has at least the following beneficial effects: an energy storage device for storing electric energy input from an external power grid or outputting electric energy to user equipment, a bidirectional converter and a control machine for realizing conversion between direct current and alternating current, wherein the bidirectional converter and the energy storage device are connected in series, the control machine is respectively communicated with the energy storage device and the bidirectional converter, the control machine includes a DIDO module for receiving the working status of each component in the voltage sag management energy storage system, a communication module for transmitting data with each component in the voltage sag management energy storage system, and a control module for controlling each component in the voltage sag management energy storage system, the control module is respectively communicated with the DIDO module and the communication module, and thus when a voltage sag or power failure occurs in the power grid, the energy storage device can be used to provide a stable power supply to the load to ensure the normal operation of the load, thereby realizing rapid, accurate and flexible management of the voltage sag of the power grid, and improving the voltage quality and stability of the power grid.

[0019] Other features and advantages of the present invention will be described in the following description and will become apparent in part from the description. The purpose and other advantages of the present invention can be realized and obtained through the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the technical solution of the utility model and constitute a part of the specification. Together with the embodiments of the utility model, they are used to explain the technical solution of the utility model and do not constitute a limitation on the technical solution of the utility model.

[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0022] Figure 1 It is an overall structural diagram of a voltage sag control energy storage system provided by an embodiment of the utility model.

[0023] Figure numerals: voltage sag control energy storage system 100, energy storage device 110, bidirectional converter 120, control machine 130, DIDO module 131, communication module 132, control module 133, power supply detection module 134, isolation transformer 140, all-copper winding 141, star line structure 142, triangle line structure 143. DETAILED DESCRIPTION

[0024] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0025] In the description of the utility model, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0026] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0027] With the transformation of the global energy structure and the rapid development of renewable energy, the scale of power grids has become larger and larger, and their structures have become more and more complex. As a result, occasional line failures or interference in the power grid may cause the voltage of the power grid to temporarily drop or lose power, which may easily cause the power grid load to shut down, restart, or lose data, causing huge economic losses and safety hazards to users.

[0028] In the prior art, commonly used voltage sag or power outage management devices include dynamic voltage restorer (DVR) and uninterruptible power supply (UPS). Among them, the dynamic voltage restorer (DVR) is a series compensation device, and two inverter circuits will appear in the main circuit of the compensation system, thereby increasing the equipment cost and reducing the working efficiency; while the uninterruptible power supply (UPS) cannot efficiently handle the voltage sag compensation process due to its small discharge current and long charging time.

[0029] Based on this, an embodiment of the utility model provides a voltage sag management energy storage system, which is provided with an energy storage device for storing electric energy input from an external power grid or outputting electric energy to user equipment, a bidirectional converter and a control machine for realizing conversion between direct current and alternating current, wherein the bidirectional converter and the energy storage device are connected in series, and the control machine is respectively communicated with the energy storage device and the bidirectional converter, and the control machine includes a DIDO module for receiving the working status of each component in the voltage sag management energy storage system, a communication module for transmitting data with each component in the voltage sag management energy storage system, and a control module for controlling each component in the voltage sag management energy storage system, and the control module is respectively communicated with the DIDO module and the communication module, so that when a voltage sag or power failure occurs in the power grid, the energy storage device can be used to provide a stable power supply to the load to ensure the normal operation of the load, thereby realizing fast, accurate and flexible management of the voltage sag of the power grid, and improving the voltage quality and stability of the power grid.

[0030] Therefore, the embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0031] Reference Figure 1 As shown, Figure 1 1 is an overall structural diagram of a voltage sag management energy storage system provided by an embodiment of the utility model. The voltage sag management energy storage system 100 includes an energy storage device 110, which is used to store electrical energy input from an external power grid or output electrical energy to a user device. The energy storage device 110 includes a plurality of batteries; a bidirectional converter 120, which is used to realize the conversion between direct current and alternating current. The bidirectional converter 120 and the energy storage device 110 are connected in series; a control machine 130, which is used to control various components in the voltage sag management energy storage system 100. The control machine 130 and the energy storage device 110 are connected in communication. The control machine 130 The control machine 130 is communicatively connected with the bidirectional converter 120, and includes a DIDO module 131, a communication module 132 and a control module 133. The DIDO module 131 is used to receive the working status of each component in the voltage sag management energy storage system and control the opening and closing of each switch in the voltage sag management energy storage system 100. The communication module 132 is used to transmit data with each component in the voltage sag management energy storage system 100. The control module 133 is used to control the DIDO module 131 and the communication module 132. The control module 133 is communicatively connected to the DIDO module 131, and the control module 133 is communicatively connected to the communication module 132.

[0032] Among them, each battery in the energy storage device 110 is composed of a positive electrode, a negative electrode and a separator, and the batteries are connected by wires to form a series-parallel battery pack; the positive electrode and the negative electrode of the battery pack are respectively connected to the inverter; the energy storage device 110 also includes a battery management module, which is used to collect parameters such as voltage, current, temperature, etc. of the single battery in real time, and has the functions of balancing, protecting, and fault diagnosis of the single battery.

[0033] At the same time, the data transmission interface between the communication module 132 and the various components in the voltage sag management energy storage system 100 is a CAN2.0 high-speed bus interface, which can improve the efficiency of data transmission.

[0034] It should be noted that the voltage sag control energy storage system 100 also includes an isolation transformer 140, which is used to protect the circuit of the voltage sag control energy storage system 100. The isolation transformer 140 is connected in series with the bidirectional converter 120, and the isolation transformer 140 is communicatively connected with the control module 133.

[0035] Furthermore, the isolation transformer 140 includes an all-copper winding 141, and the line structure of the all-copper winding 141 includes a star line structure 142 and a triangle line structure 143, and the star line structure 142 is connected to the triangle line structure 143. This can prevent interference from the external power grid, suppress surges of the external power grid when it is connected to the grid, reduce the switching ripple of the voltage sag control energy storage system 100 in the output current, improve the short-circuit impedance, and improve the safety and stability of the voltage sag control energy storage system 100.

[0036] It should be noted that the control machine 130 also includes a power detection module 134 , which is used to detect the bus voltage of the external power grid. The power detection module 134 is communicatively connected to the control module 133 , and the power detection module 134 is controlled by the control module 133 .

[0037] In addition, the control machine 130 further includes a display module 135 , which is used to display operating parameters of the voltage sag management energy storage system 100 . The display module 135 is communicatively connected to the control module 133 , and the display module 135 is controlled by the control module 133 .

[0038] At the same time, the voltage sag management energy storage system 100 also includes a fast switch 150, which is used as a connecting switch between the energy storage device 110 and the external power grid. The fast switch 150 is connected in parallel with the energy storage device 110, and the fast switch 150 is communicated with the control machine 130, thereby achieving isolation or parallel connection between the voltage sag management energy storage system 100 and the external power grid. At the same time, the switching time of the fast switch 150 is short, which can make the on-state loss low when the line is turned on.

[0039] The fast switch 150 may be a thyristor, or any one or more switching devices with a fast switching function, such as an IGBT, and the present application does not make any specific limitation thereto.

[0040] Furthermore, the voltage sag management energy storage system 100 also includes an output switch 160, which is used as a connecting switch between the energy storage device 110 and the user equipment. The output switch 160 is connected in parallel with the energy storage device 110, and the output switch 160 is communicated with the control machine 130, thereby enabling the user equipment to be put into or out of operation, and plays a protective role in preventing the bypass switch 170 from reverse power transmission when the voltage sag management energy storage system 100 is maintained.

[0041] The output switch 160 may be a relay, a contactor, a circuit breaker or any one or more switching devices with a circuit breaking function, and this application does not make any specific limitation.

[0042] Furthermore, the voltage sag control energy storage system 100 also includes a bypass switch 170, which is used to control the start and stop of the bypass function of the voltage sag control energy storage system 100. The bypass switch 170 is connected in parallel with the energy storage device 110, and the bypass switch 170 is communicatively connected with the control machine 130.

[0043] It should be noted that the voltage sag management energy storage system 100 is provided with a bypass switch 170, the purpose of which is to facilitate the continued operation of the user equipment during maintenance. Since the energy storage device 110 is connected to the power supply line in parallel, when the energy storage device 110 fails, it only needs to control the bypass switch 170 to be in a closed state to keep the voltage sag management energy storage system 100 unaffected, thereby ensuring the safety of the voltage sag management energy storage system 100.

[0044] In addition, the voltage sag control energy storage system 100 also includes a voltage sensor 180, which is used to collect the size and frequency of the grid voltage signal. The voltage sensor 180 is communicated with the control machine 130, and can collect the voltage signal of the external grid in real time.

[0045] At the same time, the voltage sag control energy storage system 100 also includes a current sensor 190, which is used to collect the size and direction of the grid current signal. The current sensor 190 is communicated with the control machine 130, and the current sensor 190 is connected in series with the voltage sensor 180, so that the current signal of the external grid can be collected in real time.

[0046] Furthermore, the working principle of the voltage sag control energy storage system 100 is described as follows:

[0047] When the voltage and frequency of the external power grid are within the normal range, the voltage sag management energy storage system 100 is in the grid-connected mode; when the external power grid experiences a voltage sag or power outage, the voltage sag management energy storage system 100 is in the off-grid mode.

[0048] Among them, the control machine 130 can determine the working mode of the voltage sag control energy storage system 100 based on the data of the power supply detection module 134. At the same time, the control machine 130 can also control the output voltage and frequency of the bidirectional converter 120 and the charging and discharging current state of the energy storage device 110 according to the working mode of the voltage sag control energy storage system 100, thereby achieving power balance and voltage stability of the system, realizing seamless switching between the energy storage system and the power grid, and ensuring the normal operation of the load.

[0049] When the external power grid is normal, the fast switch 150 and the output switch 160 are in a closed state, the bypass switch 170 is in an open state, the external power grid provides power to the user equipment, and the control machine 130 controls the bidirectional converter 120 to be in a charging mode (i.e., the external power grid charges the energy storage device 110) according to the state of the energy storage device 110, thereby replenishing the power of the energy storage device 110 to balance the power demand of the energy storage system 100 to control the voltage sag. At the same time, the control machine 130 also monitors the voltage and frequency of the external power grid in real time through the power detection module 134.

[0050] When a voltage sag or power outage occurs in the external power grid, the fast switch 150 immediately disconnects itself and sends a signal to the control machine 130 indicating that the fast switch 150 has been disconnected, so that the voltage sag management energy storage system 100 is isolated from the external power grid. Then, when the control machine 130 receives the signal that the fast switch 150 has been disconnected and detects an abnormality in the external power grid through the power detection module 134, the control machine 130 quickly switches the working mode of the voltage sag management energy storage system 100 to the off-grid mode according to a preset control strategy, so that the energy storage device 110 is in a discharging state. At the same time, the bidirectional converter 120 converts the DC power output by the energy storage device 110 into AC power, thereby providing a stable power supply for the user equipment until the power grid returns to normal.

[0051] When the external power grid returns to normal, the control machine 130 detects that the power grid is normal through the power supply detection module 134, obtains the voltage, frequency and other parameters of the corresponding external power grid, and then automatically adjusts the output parameters of the bidirectional converter 120 to be the same as the parameters of the external power grid according to the corresponding parameters, and the control machine 130 controls the fast switch 150 to be in a closed state, thereby switching the working mode of the voltage sag control energy storage system 100 to the grid-connected mode, so that the voltage sag control energy storage system 100 is reconnected in parallel with the external power grid.

[0052] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A voltage sag control energy storage system, characterized in that ,include: An energy storage device, the energy storage device is used to store electric energy input from an external power grid or output electric energy to a user device, the energy storage device includes a plurality of batteries; A bidirectional converter, the bidirectional converter is used to realize the conversion between direct current and alternating current, and the bidirectional converter is connected in series with the energy storage device; A control machine, the control machine is used to control the various components in the voltage sag management energy storage system, the control machine is communicatively connected to the energy storage device, the control machine is communicatively connected to the bidirectional converter, the control machine includes a DIDO module, a communication module and a control module, the DIDO module is used to receive the working status of the various components in the voltage sag management energy storage system and control the opening and closing of various switches in the voltage sag management energy storage system, the communication module is used to transmit data with the various components in the voltage sag management energy storage system, the control module is used to control the DIDO module and the communication module, the control module is communicatively connected to the DIDO module, and the control module is communicatively connected to the communication module.

2. The voltage sag management energy storage system according to claim 1, characterized in that: The voltage sag management energy storage system also includes an isolation transformer, which is used to protect the circuit of the voltage sag management energy storage system. The isolation transformer is connected in series with the bidirectional converter, and the isolation transformer is communicatively connected with the control module.

3. The voltage sag management energy storage system according to claim 2, characterized in that: The isolation transformer includes an all-copper winding, and the line structure of the all-copper winding includes a star line structure and a triangle line structure, and the star line structure is connected to the triangle line structure.

4. The voltage sag management energy storage system according to claim 1, characterized in that: The control machine further comprises a power supply detection module, which is used to detect the bus voltage of the external power grid, and the power supply detection module is communicatively connected with the control module.

5. The voltage sag management energy storage system according to claim 1, characterized in that: The control machine also includes a display module, which is used to display the operating parameters of the voltage sag management energy storage system, and the display module is communicatively connected with the control module.

6. The voltage sag management energy storage system according to claim 1, characterized in that: The voltage sag management energy storage system also includes a fast switch, which is used as a connecting switch between the energy storage device and the external power grid. The fast switch is connected in parallel with the energy storage device, and the fast switch is communicatively connected with the control machine.

7. The voltage sag management energy storage system according to claim 1, characterized in that: The voltage sag management energy storage system also includes an output switch, which is used as a connection switch between the energy storage device and the user equipment. The output switch is connected in parallel with the energy storage device, and the output switch is communicatively connected with the control machine.

8. The voltage sag management energy storage system according to claim 1, characterized in that: The voltage sag management energy storage system also includes a bypass switch, which is used to control the start and stop of the bypass function of the voltage sag management energy storage system. The bypass switch is connected in parallel with the energy storage device, and the bypass switch is communicatively connected with the control machine.

9. The voltage sag management energy storage system according to claim 1, characterized in that: The voltage sag control energy storage system also includes a voltage sensor, which is used to collect the size and frequency of the grid voltage signal, and the voltage sensor is communicatively connected to the control machine.

10. The voltage sag management energy storage system according to claim 9, characterized in that: The voltage sag control energy storage system also includes a current sensor, which is used to collect the size and direction of the grid current signal. The current sensor is communicatively connected to the control machine, and is connected in series with the voltage sensor.

Images