Energy storage power supply switching system and control method thereof

Abstract

The invention belongs to the technical field of energy storage and power utilization, and particularly discloses an energy storage and power utilization power supply switching system and a control method thereof, and the system comprises a commercial power supply line, a commercial power supply switch cabinet, a transformer, a power distribution cabinet, a power supply switching cabinet, an isolator, an energy storage inverter, an energy storage battery, an energy storage power station integrated management system and a connection relation thereof. The method comprises the following steps: when one group of batteries is used up, the system transfers the original electrical load of the corresponding group of batteries to the battery pack with sufficient electric quantity for power supply by controlling the on and off of the change-over switch in the power supply switching cabinet. According to the invention, the change-over switch in the power supply switching cabinet is controlled through the power supply switching system, the problem that the energy storage electric quantity cannot be fully utilized due to unbalanced power utilization load of the power distribution cabinet is solved, power utilization switching can be carried out under different power utilization conditions, the electric energy utilization rate of the energy storage system is fully improved, the economic benefit is improved, and the power supply reliability is ensured.

Description

Technical Field

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

[0002] The energy storage power system charges the energy storage power station through the municipal grid during off-peak or normal electricity prices, and discharges the energy storage power station to supply power to the power load during peak electricity prices, thereby using the difference between peak and off-peak electricity prices to bring economic benefits.

[0003] At present, industrial and commercial energy storage is used to supply power to office buildings, commercial buildings, etc., and there are multiple groups of distribution cabinets in these places. Traditional energy storage power stations are usually one-to-one, that is, each group of energy storage batteries only supplies power to one group of distribution cabinets. When multiple groups of energy storage batteries are used to supply power to multiple groups of distribution cabinets, due to the different power consumption of each group of distribution cabinets, and the differences in the use time periods and usage frequencies of different power loads, the speed of power consumption of each group of batteries is also different. It may happen that during the peak electricity price period, a group of energy storage batteries has been exhausted while other energy storage batteries still have a large amount of remaining power. At this time, the power load carried by the exhausted battery group can only be supplied by the city power with a high electricity price, while the low-priced electricity stored in other battery groups is not fully utilized, which will lead to a reduction in the power utilization rate of the energy storage power station, thereby reducing the economic benefits of the energy storage system. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a power supply switching system for energy storage and a control method thereof are provided.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An energy storage power supply switching system comprises a city grid power supply component, a first power distribution cabinet, a second power distribution cabinet, a power supply switching cabinet, a first energy storage component and a second energy storage component;

[0007] The two output ends of the mains power supply component are electrically connected to the first power distribution cabinet and the second power distribution cabinet respectively;

[0008] The power switching cabinet includes a switch group, which are switches QF1, QF2, QF3, QF4, and QF5;

[0009] Switches QF1 and QF2 are electrically connected between the first power distribution cabinet and the first energy storage assembly, and the switches QF1 and QF2 are connected in series;

[0010] Switches QF3 and QF4 are electrically connected between the second power distribution cabinet and the second energy storage assembly, and switches QF3 and QF4 are connected in series;

[0011] One end of the switch QF5 is connected to the line between the switches QF1 and QF2 , and the other end is connected to the line between the switches QF3 and QF4 .

[0012] The following is a technical solution further defined by the system in the present invention, wherein the mains power supply assembly includes a mains power supply line, a mains switch cabinet, a first transformer and a second transformer, the mains power supply line is electrically connected to the mains switch cabinet, the mains switch cabinet is electrically connected to the first transformer, and the mains switch cabinet is electrically connected to the second transformer.

[0013] The following is a technical solution further defined by the system in the present invention: a switch is provided on the mains incoming line, a switch is connected between the mains switch cabinet and the input end of the first transformer, and a switch is connected between the mains switch cabinet and the input end of the second transformer.

[0014] The following is a technical solution further defined by the system in the present invention: a switch is connected between the output end of the first transformer and the first distribution cabinet, and a switch is connected between the output end of the second transformer and the second distribution cabinet.

[0015] The following is a technical solution further defined by the system in the present invention, wherein the first energy storage component includes a first isolator, a first energy storage inverter and a first energy storage battery, the first isolator is electrically connected to the first energy storage inverter, and the first energy storage inverter is electrically connected to the first energy storage battery.

[0016] The following is a technical solution further defined by the system in the present invention: the first isolator is electrically connected to the switch QF2, and a switch is connected between the first isolator and the first energy storage inverter.

[0017] The following is a technical solution further defined by the system in the present invention, wherein the second energy storage component includes a second isolator, a second energy storage inverter and a second energy storage battery, the second isolator is electrically connected to the second energy storage inverter, and the second energy storage inverter is electrically connected to the second energy storage battery.

[0018] The following is a technical solution further defined by the system in the present invention: the second isolator is electrically connected to the switch QF4, and a switch is connected between the second isolator and the second energy storage inverter.

[0019] The following is a technical solution further defined by the system in the present invention, wherein the power switching cabinet is electrically connected to the integrated management system of the energy storage power station via a signal line.

[0020] A control method based on the above-mentioned energy storage power supply switching system includes: real-time monitoring of the working status and power data of each group of batteries in the energy storage power station. When the battery is working in a discharge state, under normal circumstances, a group of batteries is used to supply power to a group of power loads. When one group of batteries is exhausted, the system controls the opening and closing of the conversion switch in the power switching cabinet to transfer the original power load of the corresponding group of batteries to the battery group with sufficient power for power supply.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] The present invention controls the switching switch in the power switching cabinet through the power switching system, thereby solving the problem that the energy storage power cannot be fully utilized due to the unbalanced power load of the distribution cabinet. Power switching can be performed under different power consumption conditions, fully improving the power utilization rate of the energy storage system, improving economic benefits, and ensuring power supply reliability.

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 is a system connection relationship diagram of the present invention;

[0026] Figure 2 It is a flow chart of the control method of the present invention.

[0027] Figure numerals: 1. first power distribution cabinet; 2. second power distribution cabinet; 3. power switching cabinet; 4. mains power incoming line; 5. mains power switch cabinet; 6. first transformer; 7. second transformer; 8. first isolator; 9. first energy storage inverter; 10. first energy storage battery; 11. second isolator; 12. second energy storage inverter; 13. second energy storage battery; 14. integrated management system of energy storage power station. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention 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 present invention. However, the present invention 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 present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0029] In the description of the present invention, it should be understood that 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 technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0030] like Figure 1 As shown, this embodiment provides an energy storage power supply switching system. It mainly consists of a 10kV city grid incoming line 4, a 10kV city grid switch cabinet 5, a 10kV / 400V first transformer 6, a 10kV / 400V second transformer 7, a 400V first distribution cabinet 1, a 400V second distribution cabinet 2, a power switching cabinet 3 (switches QF1, QF2, QF3, QF4, QF5), a first isolator 8, a first energy storage inverter 9, a first energy storage battery 10, a second isolator 11, a second energy storage inverter 12, a second energy storage battery 13, and an energy storage power station integrated management system 14, etc.

[0031] The mains power supply line 4 is electrically connected to the mains power switch cabinet 5, and a switch is provided on the mains power supply line 4. A switch is connected between the mains power switch cabinet 5 and the input end of the first transformer 6, a switch is connected between the mains power switch cabinet 5 and the input end of the second transformer 7, a switch is connected between the output end of the first transformer 6 and the first power distribution cabinet 1, and a switch is connected between the output end of the second transformer 7 and the second power distribution cabinet 2. Switches QF1 and QF2 are electrically connected between the first power distribution cabinet 1 and the first energy storage component, and switches QF1 and QF2 are connected in series; switches QF3 and QF4 are electrically connected between the second power distribution cabinet 2 and the second energy storage component, and switches QF3 and QF4 are connected in series; one end of switch QF5 is connected to the line between switches QF1 and QF2, and the other end is connected to the line between switches QF3 and QF4. The first isolator 8 is electrically connected to the switch QF2, a switch is connected between the first isolator 8 and the first energy storage inverter 9, and the first energy storage inverter 9 is electrically connected to the first energy storage battery 10. The second isolator 11 is electrically connected to the switch QF4, a switch is connected between the second isolator 11 and the second energy storage inverter 12, and the second energy storage inverter 12 is electrically connected to the second energy storage battery 13. The power switching cabinet 3 is electrically connected to the energy storage power station integrated management system 14 through a signal line.

[0032] This embodiment provides a control method for an energy storage power supply switching system. A power supply switching system and a corresponding control system are set up on the basis of a traditional energy storage power station. The system can monitor the working status and power data of each group of batteries in the energy storage power station in real time. When the battery is working in a discharge state, under normal circumstances, a group of batteries is used to supply power to a group of power loads. When a group of batteries is exhausted, the system will control the opening and closing of the conversion switch to transfer the original power load of the group of batteries to the battery group with sufficient power for power supply. In this way, the electric energy in the energy storage power station can be utilized to the greatest extent, and the economic benefits of the energy storage system can be maximized.

[0033] In addition, when the city power is cut off, the energy storage power station can serve as an emergency power source to continue to supply power to important loads. The battery groups in the power station can achieve the effect of mutual backup through the power switching control system. That is, when one group of batteries is exhausted, its load is immediately switched to other battery groups through the power switching system to continue powering, thereby improving the power supply reliability of important loads.

[0034] A power switch cabinet 3 is set in the inverter compartment of the energy storage system. The power switch cabinet 3 has a built-in power switch control system. The control system consists of 1 PLC and 5 control switches. This system communicates with the integrated control system of the energy storage power station, and automatically switches the control switch and monitors related information according to the information feedback of the integrated control system. This system analyzes the monitored battery pack working status and remaining power information, and automatically controls each switch to perform opening and closing actions according to the analysis results. The specific control method is as follows:

[0035] like Figure 2 As shown, during the off-peak electricity price period, the battery pack works in a charging state, at this time, the switch QF5 is open, the switches QF1, QF2, QF3, and QF4 are closed, the first energy storage battery 10 is charged by the first power distribution cabinet 1, and the second energy storage battery 13 is charged by the second power distribution cabinet 2. When the first energy storage battery 10 is fully charged, the switches QF1 and QF2 are open, and when the second energy storage battery 13 is fully charged, the switches QF3 and QF4 are open;

[0036] During the peak electricity price period, the battery pack works in a discharge state. At this time, the switch QF5 is open, and the switches QF1, QF2, QF3, and QF4 are closed. The first energy storage battery 10 supplies power to the load carried by the first distribution cabinet 1 through the switches QF2 and QF1, and the second energy storage battery 13 supplies power to the load carried by the second distribution cabinet 2 through the switches QF4 and QF3.

[0037] When the battery pack is working in the discharge state, when the second energy storage battery 13 is exhausted and the first energy storage battery 10 has residual power, the second energy storage battery 13 is shut down, and the first energy storage battery 10 supplies power to the first distribution cabinet 1 and the second distribution cabinet 2 at the same time. At this time, the switch QF4 is opened, and the switches QF1, QF2, QF3, and QF5 are closed;

[0038] When the battery pack is working in a discharge state, when the first energy storage battery 10 is exhausted and the second energy storage battery 13 has residual power, the first energy storage battery 10 is shut down, and the second energy storage battery 13 supplies power to the first distribution cabinet 1 and the second distribution cabinet 2 at the same time. At this time, the switch QF2 is opened, and the switches QF1, QF3, QF4, and QF5 are closed;

[0039] When all batteries are exhausted and it is still during the peak electricity price period, switches QF1, QF2, QF3, QF4, and QF5 are all opened, and the power load is supplied by the mains.

[0040] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply switching system for energy storage, characterized in that: It comprises a city grid power supply component, a first power distribution cabinet (1), a second power distribution cabinet (2), a power supply switching cabinet (3), a first energy storage component and a second energy storage component; The two output ends of the mains power supply component are electrically connected to the first power distribution cabinet (1) and the second power distribution cabinet (2) respectively; The power switching cabinet (3) comprises a switch group, namely switches QF1, QF2, QF3, QF4, and QF5; Switches QF1 and QF2 are electrically connected between the first power distribution cabinet (1) and the first energy storage component, and the switches QF1 and QF2 are connected in series; Switches QF3 and QF4 are electrically connected between the second power distribution cabinet (2) and the second energy storage component, and the switches QF3 and QF4 are connected in series; One end of the switch QF5 is connected to the line between the switches QF1 and QF2 , and the other end is connected to the line between the switches QF3 and QF4 .

2. The energy storage power source switching system according to claim 1, characterized in that: The mains power supply assembly comprises a mains power supply line (4), a mains switch cabinet (5), a first transformer (6) and a second transformer (7); the mains power supply line (4) is electrically connected to the mains switch cabinet (5), the mains switch cabinet (5) is electrically connected to the first transformer (6), and the mains switch cabinet (5) is electrically connected to the second transformer (7).

3. The energy storage power source switching system according to claim 2, characterized in that: A switch is provided on the mains power supply line (4), a switch is connected between the mains power switch cabinet (5) and the input end of the first transformer (6), and a switch is connected between the mains power switch cabinet (5) and the input end of the second transformer (7).

4. The energy storage power source switching system according to claim 3, characterized in that: A switch is connected between the output end of the first transformer (6) and the first distribution cabinet (1), and a switch is connected between the output end of the second transformer (7) and the second distribution cabinet (2).

5. The energy storage power source switching system according to claim 1, characterized in that: The first energy storage component comprises a first isolator (8), a first energy storage inverter (9) and a first energy storage battery (10); the first isolator (8) is electrically connected to the first energy storage inverter (9), and the first energy storage inverter (9) is electrically connected to the first energy storage battery (10).

6. The energy storage power source switching system according to claim 5, characterized in that: The first isolator (8) is electrically connected to the switch QF2, and a switch is connected between the first isolator (8) and the first energy storage inverter (9).

7. The energy storage power source switching system according to claim 1, characterized in that: The second energy storage component comprises a second isolator (11), a second energy storage inverter (12) and a second energy storage battery (13); the second isolator (11) is electrically connected to the second energy storage inverter (12), and the second energy storage inverter (12) is electrically connected to the second energy storage battery (13).

8. The energy storage power source switching system according to claim 7, characterized in that: The second isolator (11) is electrically connected to the switch QF4, and a switch is connected between the second isolator (11) and the second energy storage inverter (12).

9. The energy storage power source switching system according to claim 1, characterized in that: The power switching cabinet (3) is electrically connected to the energy storage power station integrated management system (14) via a signal line.

10. A control method for an energy storage power source switching system according to any one of claims 1 to 9, characterized in that: include: The working state and power data of each battery group in the energy storage power station are monitored in real time. When the battery is in a discharging state, under normal circumstances, one group of batteries supplies power to one group of power loads. When the power of one group of batteries is exhausted, the system controls the opening and closing of the conversion switch in the power switching cabinet (3) to transfer the original power load of the corresponding group of batteries to the battery group with sufficient power for power supply.

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