A control method for energy storage system and power system

Abstract

The present invention relates to a control method and power system for an energy storage system. The method monitors the power, load power and energy storage capacity of the energy storage system in each energy storage area in real time, and detects whether the energy storage system has a fault in real time based on the energy storage area. For any energy storage area, if the energy storage system has a fault, the power supply between the faulty energy storage system and the load is disconnected, and an energy storage system from an adjacent energy storage area is introduced to supply power to the load during peak or flat power periods. Whether to introduce mains power is determined according to the energy storage capacity, and mains power is introduced to supply power to the load during valley power periods. If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, an energy storage system from an adjacent energy storage area is introduced to supply power to the load. The method can ensure the normal operation of the load while achieving efficient utilization of the source and load, thereby maximizing benefits.

Description

Technical Field

[0001] The present invention relates to the field of energy storage control technology, and in particular to a control method for an energy storage system and a power system. Background Art

[0002] With the promotion and application of new energy sources such as solar energy and wind energy, energy storage technology has also developed. Lithium batteries have gradually become the mainstream product for energy storage due to their high energy, long service life, high rated voltage, high power tolerance, very low self-discharge rate, light weight, green environmental protection and almost no water consumption in production.

[0003] Currently, most energy storage systems use centralized solutions, which result in irrational energy distribution and make emergency dispatch difficult when there is excess demand or damage, causing the load to stop working. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a control method for an energy storage system and a power system, which can ensure the normal operation of the load when the load demand exceeds or the energy storage device is damaged.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for controlling an energy storage system, comprising the steps of:

[0007] S1. Obtaining energy storage area division information of each energy storage system;

[0008] S2. Real-time monitoring of the power, load power, and energy storage capacity of the energy storage system in each energy storage area, and real-time detection of whether there is a fault in the energy storage system in units of the energy storage area;

[0009] For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods.

[0010] If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load.

[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0012] A power system includes a plurality of energy storage areas, each of which includes an AC bus, at least two energy storage systems, and loads corresponding to the number of energy storage systems;

[0013] In each of the energy storage areas:

[0014] Each of the energy storage systems is connected to the AC bus of the current energy storage area through DC / AC, and is also connected to the AC bus of the adjacent energy storage area.

[0015] The AC bus is connected to the load of the current energy storage area through AC / DC, and is connected to the load of the adjacent energy storage area;

[0016] Each of the energy storage systems is connected to the mains;

[0017] The power system implements the following steps:

[0018] S1. Obtaining energy storage area division information of each energy storage system;

[0019] S2. Real-time monitoring of the power, load power, and energy storage capacity of the energy storage system in each energy storage area, and real-time detection of whether there is a fault in the energy storage system in units of the energy storage area;

[0020] For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods.

[0021] If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load.

[0022] The beneficial effects of the present invention are as follows: when the load demand exceeds or the energy storage equipment is damaged, the control method and power system of the energy storage system of the present invention can introduce the energy storage system power supply and the mains power of the adjacent energy storage area according to the peak and valley power conditions and the energy storage capacity, thereby ensuring the normal operation of the load while achieving efficient utilization of the source and load and maximizing the benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flowchart illustrating a method for controlling an energy storage system according to an embodiment of the present invention;

[0024] Figure 2 This is a structural diagram of an electric power system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0026] Please refer to Figure 1 , a control method for an energy storage system, comprising the steps of:

[0027] S1. Obtaining energy storage area division information of each energy storage system;

[0028] S2. Real-time monitoring of the power, load power, and energy storage capacity of the energy storage system in each energy storage area, and real-time detection of whether there is a fault in the energy storage system in units of the energy storage area;

[0029] For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods.

[0030] If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load.

[0031] As can be seen from the above description, the beneficial effects of the present invention are: a control method for an energy storage system of the present invention can introduce energy storage system power supply and city power from adjacent energy storage areas based on peak and valley power conditions and energy storage capacity when load demand exceeds or energy storage equipment is damaged. This can ensure the normal operation of the load while achieving efficient utilization of the source and load and maximizing benefits.

[0032] Furthermore, if the energy storage system is normal and the power of the energy storage system cannot meet the load power during peak or flat power periods, the judgment is specifically as follows:

[0033] Determine whether all the energy storage systems in the substation exist:

[0034] ;

[0035] If so, the power of the energy storage system cannot meet the load power;

[0036] in, X represents the power of the energy storage system, N Indicates the load power, μ Indicates the DC / AC energy conversion efficiency on the connection line between the energy storage system and the load, θ Indicates the AC / DC energy conversion efficiency on the connection line between the energy storage system and the load.

[0037] The above description provides a quantitative criterion for determining whether the energy storage system's power meets the load power during peak or off-peak periods. Taking into account the energy conversion efficiency of DC / AC and AC / DC, the energy storage system's power supply capacity can be determined more scientifically.

[0038] Furthermore, if the energy storage system is normal and is in peak or flat power period, the following steps are further included:

[0039] If the power of the energy storage system meets the load demand, the energy storage system will supply power to the load, and when the energy storage capacity of the energy storage system is lower than a preset low capacity threshold, the mains power will be introduced to supply power to the load.

[0040] As can be seen from the above description, when the energy storage system can meet the load power, energy storage is used first and energy storage resources are used rationally. When the energy storage capacity is insufficient, the mains power is introduced in a timely manner to avoid load power outages due to energy storage depletion. This ensures that the load continues to operate stably during peak or off-peak periods, improving the user's electricity experience.

[0041] Furthermore, the method further comprises the steps of:

[0042] If the energy storage system is normal and in the off-peak period, the mains power is introduced to power the load and charge the energy storage system. Charging of the energy storage system is stopped when the energy storage capacity of the energy storage system is greater than a preset high capacity threshold.

[0043] As can be seen from the above description, off-peak electricity prices are lower, so charging energy storage during this time can effectively reduce energy storage costs. Furthermore, by setting a high-capacity threshold to stop charging, overcharging of the energy storage is avoided, extending the service life of the energy storage system and improving the overall benefits of the energy storage system from both economic costs and equipment lifespan.

[0044] Furthermore, if the energy storage system fails, the connection between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage station is introduced to power the load during peak or flat power periods. Whether to introduce the mains power is determined based on the energy storage capacity, and the mains power is introduced to power the load during off-peak power periods. Specifically:

[0045] If the energy storage system fails during peak or flat power periods, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system in the adjacent energy storage area is introduced to supply power to the load. When the energy storage capacity of the energy storage system in the adjacent energy storage area is less than a preset low capacity threshold, the mains power is introduced to supply power to the load.

[0046] If the energy storage system fails and it is during off-peak hours, the power supply between the failed energy storage system and the load is disconnected, and the mains power is introduced to supply power to the load.

[0047] As can be seen from the above description, the power from adjacent energy storage stations and the mains is used to guarantee the load operation of the current energy storage station. During peak or flat power periods, the energy storage resources of adjacent energy storage stations are fully utilized to reduce the use of mains power and lower electricity costs. During off-peak power periods, the mains power is directly introduced, which simply and efficiently guarantees the power supply to the load and enhances the reliability and stability of the system.

[0048] A power system includes a plurality of energy storage areas, each of which includes an AC bus, at least two energy storage systems, and loads corresponding to the number of energy storage systems;

[0049] In each of the energy storage areas:

[0050] Each of the energy storage systems is connected to the AC bus of the current energy storage area through DC / AC, and is also connected to the AC bus of the adjacent energy storage area.

[0051] The AC bus is connected to the load of the current energy storage area through AC / DC, and is connected to the load of the adjacent energy storage area;

[0052] Each of the energy storage systems is connected to the mains;

[0053] The power system implements the following steps:

[0054] S1. Obtaining energy storage area division information of each energy storage system;

[0055] S2. Real-time monitoring of the power, load power, and energy storage capacity of the energy storage system in each energy storage area, and real-time detection of whether there is a fault in the energy storage system in units of the energy storage area;

[0056] For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods.

[0057] If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load.

[0058] From the above description, it can be seen that the beneficial effect of the present invention is that: when the load demand exceeds or the energy storage equipment is damaged, the power system of the present invention can introduce the energy storage system power supply and the mains power of the adjacent energy storage area according to the peak and valley power conditions and the energy storage capacity, and can achieve efficient utilization of the source and load while ensuring the normal operation of the load, thereby maximizing the benefits.

[0059] Furthermore, if the energy storage system is normal and the power of the energy storage system cannot meet the load power during peak or flat power periods, the judgment is specifically as follows:

[0060] Determine whether all the energy storage systems in the substation exist:

[0061] ;

[0062] If so, the power of the energy storage system cannot meet the load power;

[0063] in, X represents the power of the energy storage system, N Indicates the load power, μ Indicates the DC / AC energy conversion efficiency on the connection line between the energy storage system and the load, θ Indicates the AC / DC energy conversion efficiency on the connection line between the energy storage system and the load.

[0064] The above description provides a quantitative criterion for determining whether the energy storage system's power meets the load power during peak or off-peak periods. Taking into account the energy conversion efficiency of DC / AC and AC / DC, the energy storage system's power supply capacity can be determined more scientifically.

[0065] Furthermore, if the energy storage system is normal and is in peak or flat power period, the following steps are further included:

[0066] If the power of the energy storage system meets the load demand, the energy storage system will supply power to the load, and when the energy storage capacity of the energy storage system is lower than a preset low capacity threshold, the mains power will be introduced to supply power to the load.

[0067] As can be seen from the above description, when the energy storage system can meet the load power, energy storage is used first and energy storage resources are used rationally. When the energy storage capacity is insufficient, the mains power is introduced in a timely manner to avoid load power outages due to energy storage depletion. This ensures that the load continues to operate stably during peak or off-peak periods, improving the user's electricity experience.

[0068] Furthermore, the method further comprises the steps of:

[0069] If the energy storage system is normal and in the off-peak period, the mains power is introduced to power the load and charge the energy storage system. Charging of the energy storage system is stopped when the energy storage capacity of the energy storage system is greater than a preset high capacity threshold.

[0070] As can be seen from the above description, off-peak electricity prices are lower, so charging energy storage during this time can effectively reduce energy storage costs. Furthermore, by setting a high-capacity threshold to stop charging, overcharging of the energy storage is avoided, extending the service life of the energy storage system and improving the overall benefits of the energy storage system from both economic costs and equipment lifespan.

[0071] Furthermore, if the energy storage system fails, the connection between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage station is introduced to power the load during peak or flat power periods. Whether to introduce the mains power is determined based on the energy storage capacity, and the mains power is introduced to power the load during off-peak power periods. Specifically:

[0072] If the energy storage system fails during peak or flat power periods, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system in the adjacent energy storage area is introduced to supply power to the load. When the energy storage capacity of the energy storage system in the adjacent energy storage area is less than a preset low capacity threshold, the mains power is introduced to supply power to the load.

[0073] If the energy storage system fails and it is during off-peak hours, the power supply between the failed energy storage system and the load is disconnected, and the mains power is introduced to supply power to the load.

[0074] As can be seen from the above description, the power from adjacent energy storage stations and the mains is used to guarantee the load operation of the current energy storage station. During peak or flat power periods, the energy storage resources of adjacent energy storage stations are fully utilized to reduce the use of mains power and lower electricity costs. During off-peak power periods, the mains power is directly introduced, which simply and efficiently guarantees the power supply to the load and enhances the reliability and stability of the system.

[0075] A control method for an energy storage system and a power system of the present invention are applicable to scenarios where there may be excess demand and damage to the energy storage power system, and realize emergency dispatch and backup.

[0076] Please refer to Figure 2 , embodiment 1 of the present invention is:

[0077] A power system includes a plurality of energy storage areas, each of which includes an AC bus, at least two energy storage systems, and loads corresponding to the number of energy storage systems;

[0078] In each of the energy storage areas:

[0079] Each of the energy storage systems is connected to the AC bus of the current energy storage area through DC / AC, and is also connected to the AC bus of the adjacent energy storage area.

[0080] The AC bus is connected to the load of the current energy storage area through AC / DC, and is connected to the load of the adjacent energy storage area;

[0081] Each of the energy storage systems is connected to the mains.

[0082] In this embodiment, each energy storage area consists of an AC bus, two energy storage systems, two loads, and AC / DC and DC / AC. Figure 2 , taking the structures of two substations as examples for explanation and display.

[0083] Energy storage systems 1 and 2, DC / AC systems 1 and 2, and AC / DC systems 1 and 2 form substation 1, matching loads 1 and 2. The AC bus within substation 1 is connected to the energy storage system via switches K11 and K21, and to the loads via switches L11 and L21. The power grid is connected to the AC bus within substation 1 via a transformer, with on / off control controlled by switch M11.

[0084] Energy storage systems 3 and 4, DC / AC systems 3 and 4, and AC / DC systems 3 and 4 form substation 2, matching loads 3 and 4. The AC bus within substation 2 is connected to the energy storage systems via switches K31 and K41, and to the loads via switches L31 and L41. The power grid is connected to the AC bus within substation 2 via a transformer, with on / off control controlled by switch M21.

[0085] At the same time, the energy storage system of substation 1 is connected to the AC bus of substation 2 through the rear switches K12 and K22 of K11 and K21; the load of substation 1 is connected to the AC bus of substation 2 through the front switches L12 and L22 of L11 and L21.

[0086] The energy storage system of substation 2 is connected to the AC bus of substation 1 through the rear switches K13 and K24 of K31 and K41; the load of substation 2 is connected to the AC bus of substation 1 through the front switches L32 and L42 of L31 and L41.

[0087] Please refer to Figure 1 and Figure 2 , the second embodiment of the present invention is:

[0088] A method for controlling an energy storage system, comprising the steps of:

[0089] S1. Obtaining energy storage area division information of each energy storage system;

[0090] S2. Monitor the power, load power, and energy storage capacity of the energy storage system in each energy storage area in real time, and detect in real time whether there is a fault in the energy storage system in units of the energy storage area.

[0091] In this embodiment, refer to Figure 2 The structure of a power system shown is used as an example to illustrate that each energy storage area includes two energy storage systems. The power of energy storage system 1 is X1, the power of load 1 is N 1. The energy conversion efficiency of DC / AC-1 is μ 1. The energy conversion efficiency of AC / DC-1 is θ 1, the corresponding switch is K 11 , L 11 ; The switch on the AC busbar of station area 2 is K 12 , L 12 , mains switch M 11 .

[0092] That is, the power of the energy storage system (2i-1) in energy storage area i is X 2i-1 , the power of the load (2i-1) is N (2i-1) , the energy conversion efficiency of DC / AC-(2i-1) is μ (2i-1) , the energy conversion efficiency of AC / DC-(2i-1) is θ (2i-1) , the corresponding switch is , ; The switches on the AC busbars of the substations 1~j are , , . (i is the station number, j is the total number of stations).

[0093] The power of energy storage system 2i in energy storage area i is , the power of load 2i is , the energy conversion efficiency of DC / AC-2i is μ 2i , the energy conversion efficiency of AC / DC-2i is , the corresponding switch is , ; The switches on the AC busbars of the substations 1~j are , , . (i is the station number, j is the total number of stations, i<j).

[0094] For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods. Specifically:

[0095] If the energy storage system fails during peak or flat power periods, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system in the adjacent energy storage area is introduced to supply power to the load. When the energy storage capacity of the energy storage system in the adjacent energy storage area is less than a preset low capacity threshold, the mains power is introduced to supply power to the load.

[0096] In this embodiment, the scenario where the power grid is in a peak power period or a normal power period and the energy storage system in the corresponding substation fails and cannot operate is described using energy storage substation i as an example.

[0097] When the energy storage system (2i-1) of the station i and the energy storage system 2i of the station i are in a fault state, and hour, When the switch is disconnected and K 2i，1 , close the switch of the adjacent area and ,as well as and ,or and , disconnect the mains switch , close the load switch , L 2i，1 When the capacity of the energy storage system is less than the low capacity threshold of the overall capacity (set to 20% in this embodiment), the closed , introducing the mains electricity to supplement the load. At the same time, if the output power of the adjacent substation cannot meet the load demand of the current substation, the mains electricity will be introduced to supply the load.

[0098] In addition, when the energy storage system (2i-1) of the station i and the energy storage system 2i of the station i are in a fault state, the switch is disconnected. and K 2i，1 , and due to the connection between adjacent energy storage stations, the switch can be closed according to the required number of stations, and as well as and When the capacity of the energy storage system is less than 20% of the total capacity, the closed , introduce AC power to supplement the load.

[0099] If the energy storage system fails and it is during off-peak hours, the power supply between the failed energy storage system and the load is disconnected, and the mains power is introduced to supply power to the load.

[0100] In this embodiment, when the energy storage system (2i-1) of the station area i and the energy storage system 2i of the station area i are in a fault state, the switch is disconnected. andK 2i，1 ,closure , introduce AC power to supplement the load.

[0101] If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load;

[0102] If the power of the energy storage system meets the load demand, the energy storage system will supply power to the load, and when the energy storage capacity of the energy storage system is lower than a preset low capacity threshold, the mains power will be introduced to supply power to the load.

[0103] In this embodiment, the power grid is in the peak power period or the flat power period, and , When the switch is closed , and K 2i，1 , L 2i，1 , and close the switches from far to near according to the required number of stations, and as well as and When the capacity of the energy storage system is less than 20% of the total capacity, the closed , introduce AC power to supplement the load.

[0104] When all equipment in the area is in normal condition, and hour, When the switch is closed , and K 2i，1 , L 2i，1 Then, the energy storage system supplies power to the load, and the other switches are disconnected; when the capacity of the energy storage system is less than 20% of the total capacity, the switches are closed. , introduce AC power to supplement the load.

[0105] If the energy storage system is normal and in the off-peak period, the mains power is introduced to power the load and charge the energy storage system. Charging of the energy storage system is stopped when the energy storage capacity of the energy storage system is greater than a preset high capacity threshold.

[0106] In this embodiment, when all devices are in normal state, and , When, or , When the switch is closed , andK 2i，1 , L 2i，1 , Charge the energy storage system and supply power to the load; when the energy storage system capacity is greater than the preset high capacity threshold (in this embodiment, the high capacity threshold is 95% of the total capacity), stop charging and turn off the switch , K 2i，1 .

[0107] The third embodiment of the present invention is:

[0108] A power system is based on the power system structure shown in the above embodiment 1 and implements the steps in the control method of an energy storage system in the above embodiment 2.

[0109] In summary, the control method and power system of the energy storage system provided by the present invention can introduce energy storage system power supply and city power from adjacent energy storage areas according to peak and valley power conditions and energy storage capacity when load demand exceeds or energy storage equipment is damaged. This can achieve efficient utilization of sources and loads while ensuring the normal operation of the load, thereby maximizing benefits.

[0110] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control method for an energy storage system, characterized in that: Including steps: S1. Obtaining energy storage area division information of each energy storage system; S2. Real-time monitoring of the power, load power, and energy storage capacity of the energy storage system in each energy storage area, and real-time detection of whether there is a fault in the energy storage system in units of the energy storage area; For any of the energy storage areas, if the energy storage system fails, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system of the adjacent energy storage area is introduced to power the load during peak or flat power periods. Whether to introduce mains power is determined based on the energy storage capacity, and mains power is introduced to power the load during off-peak power periods. Specifically: If the energy storage system fails during peak or flat power periods, the power supply between the failed energy storage system and the load is disconnected, and the energy storage system in the adjacent energy storage area is introduced to supply power to the load. When the energy storage capacity of the energy storage system in the adjacent energy storage area is less than a preset low capacity threshold, the mains power is introduced to supply power to the load. If the energy storage system fails and it is during off-peak hours, the power supply between the energy storage system and the load is disconnected, and the mains power is introduced to supply power to the load; If the energy storage system is normal and during peak or flat power periods, when the power of the energy storage system cannot meet the load power, the energy storage system of the adjacent energy storage area is introduced to supply power to the load; If the energy storage system is normal and during peak or flat power periods, the following also applies: If the power of the energy storage system meets the load demand, the energy storage system will supply power to the load, and when the energy storage capacity of the energy storage system is lower than the preset low capacity threshold, the mains power will be introduced to supply power to the load; If the energy storage system is normal and in the off-peak period, the mains power is introduced to power the load and charge the energy storage system. Charging of the energy storage system is stopped when the energy storage capacity of the energy storage system is greater than a preset high capacity threshold.

2. The control method of an energy storage system according to claim 1, characterized in that: If the energy storage system is normal and the power of the energy storage system cannot meet the load power during peak or flat power periods, the judgment is specifically as follows: Determine whether all the energy storage systems in the substation exist: ； If so, the power of the energy storage system meets the load power; in, X represents the power of the energy storage system, N Indicates the load power, μ Indicates the DC / AC energy conversion efficiency on the connection line between the energy storage system and the load, θ Indicates the AC / DC energy conversion efficiency on the connection line between the energy storage system and the load.

3. A power system, characterized in that: It includes several energy storage areas, each of which includes an AC bus, at least two energy storage systems, and loads corresponding to the number of energy storage systems; In each of the energy storage areas: Each of the energy storage systems is connected to the AC bus of the current energy storage area through DC / AC, and is also connected to the AC bus of the adjacent energy storage area. The AC bus is connected to the load of the current energy storage area through AC / DC, and is connected to the load of the adjacent energy storage area; Each of the energy storage systems is connected to the mains; The power system implements the steps in the control method of an energy storage system described in any one of claims 1-2 above.

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