Grid-connected and off-grid switching optical storage distributed energy storage cabinet

Abstract

The invention relates to the field of energy storage, in particular to a grid-connected and off-grid switching optical storage distributed energy storage cabinet. Comprising a cabinet body and a battery cluster, the battery cluster is arranged in a battery cabin, the battery cluster is composed of multiple groups of battery plug boxes, and batteries are installed in the battery plug boxes; the high-voltage box is fixedly arranged at the bottom of the cabinet body and is connected with the battery cluster; the energy storage converter is arranged in the cabinet body, and one end of the energy storage converter is connected with the high-voltage box; the static change-over switch is located in the cabinet body, the static change-over switch is arranged at the lower part of the energy storage converter, and the other end of the energy storage converter is connected with the static change-over switch; and the bidirectional inverter group is connected between the energy storage converter and the high-voltage box through a line 1. According to the invention, the internal layout of the distributed energy storage cabinet is adjusted, a photovoltaic access system is added, light storage integration is realized, and the utilization rate of new energy is further improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage, and in particular to a photovoltaic distributed energy storage cabinet that can be switched on and off the grid. Background Art

[0002] With the continuous optimization and adjustment of the global energy structure, the photovoltaic storage integrated system, as an important development direction in the field of new energy, is receiving more and more attention. The present invention aims to provide a comprehensive, efficient and sustainable photovoltaic storage integrated solution to meet the growing demand for new energy "green electricity".

[0003] Most of the existing distributed energy storage cabinets do not have direct DC / DC access to the photovoltaic system, which is insufficient in improving the utilization rate of new energy, especially photovoltaic power generation, reducing the utilization rate of traditional petrochemical energy, and reducing carbon emissions. In addition, the existing distributed energy storage cabinets generally adopt the grid-connected operation mode, and rarely adopt the off-grid operation mode. When the off-grid operation mode is required, most of them adopt the manual off-grid operation mode, which cannot achieve seamless switching between grid-connected and off-grid, and cannot meet the needs in some important uninterruptible power supply systems, microgrid systems and other power consumption scenarios. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention provides a photovoltaic distributed energy storage cabinet with on-grid and off-grid switching. The present invention is designed from several aspects, such as the system design of the photovoltaic distributed energy storage cabinet, photovoltaic access, seamless on-grid and off-grid switching, and fire protection system, and can solve the problems of photovoltaic system DC / DC access and energy storage system seamless on-grid and off-grid switching.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A photovoltaic distributed energy storage cabinet capable of switching between on-grid and off-grid conditions, comprising:

[0007] The cabinet has a power distribution control compartment on the left and a battery compartment on the right;

[0008] A battery cluster is arranged in the battery compartment. The battery cluster is composed of a plurality of battery plug-in boxes, and the batteries are installed in the battery plug-in boxes;

[0009] The high-voltage box is fixedly arranged at the bottom of the cabinet and is connected to the battery cluster;

[0010] The energy storage converter is arranged in the cabinet, and one end of the energy storage converter is connected to the high-voltage box;

[0011] The static transfer switch is located inside the cabinet. The static transfer switch is arranged at the bottom of the energy storage converter. The other end of the energy storage converter is connected to the static transfer switch.

[0012] The bidirectional inverter group is connected to the bidirectional inverter group through line 1 between the energy storage converter and the high-voltage box.

[0013] Furthermore, the static transfer switch is connected to the mains via circuit breaker 1.

[0014] Furthermore, the energy storage converter and the static transfer switch are connected to the load via line 2.

[0015] Furthermore, the static transfer switch and circuit breaker one are connected to line two via line three, and circuit breaker two is arranged on line three.

[0016] Furthermore, a circuit breaker three is arranged on the line two, and one end of the circuit breaker three is connected to the load.

[0017] Further, the bidirectional inverter group includes:

[0018] A bidirectional inverter 1, one end of which is connected to a circuit breaker 4, and the bidirectional inverter 1 is connected to a photovoltaic system 1 through the circuit breaker 4;

[0019] One end of the bidirectional inverter 2 is connected to the circuit breaker 5, and the bidirectional inverter 2 is connected to the photovoltaic system 2 through the circuit breaker 5.

[0020] Compared with the prior art, the beneficial effects of the invention are as follows: the present invention adjusts the internal layout of the distributed energy storage cabinet, adds a photovoltaic access system, realizes the integration of photovoltaic and energy storage, and further improves the utilization rate of new energy; in the event of a city power outage, the static transfer switch cuts off the connection with the power grid, and the battery cluster supplies power to the load, meeting the requirements of seamless switching on and off the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objectives and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the main structure of the cabinet in the present invention.

[0023] Figure 2 It is a schematic diagram of the side structure of the cabinet in the present invention.

[0024] Figure 3 It is a schematic diagram of the rear structure of the cabinet in the present invention.

[0025] Figure 4 It is a schematic diagram of the internal structure of the cabinet in the present invention.

[0026] Figure 5 It is a topological diagram of the present invention.

[0027] Figure 6 It is a communication architecture diagram of the present invention.

[0028] Figure 7 It is an illustration of the control mode of the present invention.

[0029] Among them: 100, cabinet; 101, battery cluster; 1011, smoke detector; 1012, temperature detector; 1013, combustible gas detector; 103, battery compartment; 1031, battery plug box; 102, power distribution control compartment; 200, high-voltage box; 300, energy storage inverter; 400, static transfer switch; 600, line one; 401, circuit breaker one; 700, line two; 701, circuit breaker three; 800, line three; 801, circuit breaker two; 500, bidirectional inverter group; 501, bidirectional inverter one; 502, bidirectional inverter two; 601, circuit breaker four; 602, circuit breaker five; 901, photovoltaic system one; 902, photovoltaic system two; 903, load. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below by examples, which are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0031] A photovoltaic distributed energy storage cabinet capable of switching between on-grid and off-grid conditions, comprising:

[0032] The cabinet 100 adopts an integrated structure of left and right compartments, with the left side being a power distribution control compartment 102 and the right side being a battery compartment 103;

[0033] The battery cluster 101 is arranged in the battery compartment 103. The battery cluster 101 is composed of multiple groups of battery plug-in boxes 1031. The batteries are installed in the battery plug-in boxes 1031. The voltage of the battery cluster 101 is 768V and the power is 215.04kWh. The battery plug-in boxes 1031 are symmetrically arranged in the battery compartment 103 to facilitate the balanced weight arrangement of the battery cluster 101 in the cabinet 100.

[0034] The high-voltage box 200 is fixedly arranged at the bottom of the cabinet 100 and is connected to the battery cluster 101;

[0035] The energy storage converter 300 is arranged in the cabinet 100. One end of the energy storage converter (PCS) 300 is connected to the high-voltage box 200. The rated power of the energy storage converter 300 is 100KW.

[0036] The static transfer switch 400 is located inside the cabinet 100. The static transfer switch 400 is arranged at the lower part of the energy storage converter 300. The other end of the energy storage converter 300 is connected to the static transfer switch 400. The rated power of the static transfer switch (STS) 400 is 200KW.

[0037] The bidirectional inverter group 500 is connected to the bidirectional inverter group 500 through the line 1 600 between the energy storage converter 300 and the high-voltage box 200; the bidirectional inverter group (MPPT) 500 is connected to the photovoltaic system. The photovoltaic system includes a photovoltaic system 1 901 and a photovoltaic system 2 902.

[0038] The static transfer switch 400 is connected to the mains via a circuit breaker 401; the circuit breaker 401 is a 4P circuit breaker with a rated current of 400A;

[0039] The energy storage converter 300 and the static transfer switch 400 are connected to the load 903 via line 2 700;

[0040] The static transfer switch 400 and the circuit breaker 1 401 are connected to the circuit 2 700 through the circuit 3 800. The circuit breaker 2 801 is arranged on the circuit 3 800. The circuit breaker 2 801 is a 3P circuit breaker. The rated current of the circuit breaker 2 801 is 400A.

[0041] A circuit breaker 3 701 is provided on the line 2 700. The circuit breaker 3 701 is a 3P circuit breaker, and the rated current of the circuit breaker 3 701 is 20A. One end of the circuit breaker 3 701 is connected to the load 903.

[0042] The bidirectional inverter group 500 includes:

[0043] A bidirectional inverter 501 has a rated power of 50KW, one end of which is connected to a circuit breaker 601, which is a 4P circuit breaker with a rated current of 100A; the bidirectional inverter 501 is connected to a photovoltaic system 901 through the circuit breaker 601; the bidirectional inverter 501 is a DC / DC module;

[0044] The bidirectional inverter 2 502 has a rated power of 50KW, one end of which is connected to the circuit breaker 5 602, which is a 4P circuit breaker with a rated current of 100A; the bidirectional inverter 2 502 is connected to the photovoltaic system 2 902 through the circuit breaker 5 602; the bidirectional inverter 2 502 is a DC / DC module;

[0045] Circuit breaker four 601 and circuit breaker five 602 are arranged at the front of the power distribution control cabin 102.

[0046] The bidirectional inverter group 500 is located in the cabinet 100, and the bidirectional inverter group 500 is located on the upper part of the energy storage converter 300, and the bidirectional inverter 1 501 is located on the upper part of the bidirectional inverter 2 502;

[0047] The direct current of the photovoltaic system 901 passes through the circuit breaker 601 to the bidirectional inverter 501, and then after voltage conversion by the bidirectional inverter 501, the direct current of the photovoltaic system is directly connected to the DC side of the energy storage converter 300 and the high-voltage box 200. The direct current of the photovoltaic system passes through the DC side of the energy storage converter 300 and the high-voltage box 200, and can supply power to external loads, and can also pass through the high-voltage box 200 to charge the battery cluster 101.

[0048] Different operation control strategies can be set according to different requirements, as follows:

[0049] Self-generation and self-use: When the photovoltaic system 1 901 and the photovoltaic system 2 902 generate insufficient power, the photovoltaic system 1 901 and the photovoltaic system 2 902 and the battery cluster 101 jointly supply power to the load 903. If the power is still insufficient, the remaining power is supplemented by the mains. When the photovoltaic system 1 901 and the photovoltaic system 2 902 have sufficient power, the photovoltaic system 1 901 and the photovoltaic system 2 902 supply power to the load 903. If there is surplus photovoltaic power generation, the photovoltaic system 1 901 and the photovoltaic system 2 902 charge the battery cluster 101. If there is still surplus photovoltaic power generation, the power generation power of the photovoltaic system 1 901 and the photovoltaic system 2 902 is limited to prevent backflow to the mains power grid.

[0050] Surplus power is connected to the grid: When the photovoltaic system 1 901 and the photovoltaic system 2 902 generate insufficient power, the photovoltaic system 1 901 and the photovoltaic system 2 902 generate power together with the battery cluster 101 to supply power to the load 903. If the power is still insufficient, the remaining power is supplemented by the mains. When the photovoltaic system 1 901 and the photovoltaic system 2 902 generate sufficient power, the power generated by the photovoltaic system 1 901 and the photovoltaic system 2 902 supplies power to the load 903. If there is a surplus, the power generated by the photovoltaic system 1 901 and the photovoltaic system 2 902 charges the battery cluster 101. If there is still a surplus, the power generation power of the photovoltaic system 1 901 and the photovoltaic system 2 902 is not restricted and is allowed to flow back to the grid.

[0051] The mains electricity supplies power to the load 903 through the circuit breaker 1 401, the static transfer switch 400, the line 2 700 and the circuit breaker 3 701. If the static transfer switch 400 fails, the mains electricity can supply power to the load 903 through the circuit breaker 2 801 and the circuit breaker 3 701. In the case of a mains power outage, the static transfer switch 400 and the circuit breaker 2 801 are disconnected, cutting off the connection with the mains power grid. The EMS issues a command, and the energy storage converter 300 enters the off-grid operation state. The battery cluster 101 supplies power to the load 903. The switching time is no more than 20ms, meeting the requirements of seamless switching between on-grid and off-grid. According to different needs, the control strategies of "peak shaving and valley filling", "microgrid mode" and "battery backup power" can be set.

[0052] Peak shaving and valley filling: Increase the power limit of the bidirectional inverter group 500 photovoltaic power generation. In addition, due to the existence of photovoltaic power generation, the power of the energy storage inverter 300 will be non-zero even during the static period; according to the user's load curve and the peak and valley time period of the project location, reasonably set the control strategy to achieve the function of peak shaving and valley filling, and at the same time, arbitrage can be carried out based on the peak and valley price difference.

[0053] Microgrid mode: PV system 1 901 and PV system 2 902 supply power to load 903 and charge battery cluster 101. When there is no power generation from PV system 1 901 and PV system 2 902, battery cluster 101 supplies power to load 903 in off-grid operation mode when the power is sufficient. In pure off-grid mode, the power of energy storage converter 300 is not controlled, and the power of bidirectional inverter group 500 is controlled. Specifically, PV system 1 901 and PV system 2 902 are connected to bidirectional inverter group 500 for power control. The power of PV system 1 901 and PV system 2 902 is limited by power storage converter 300, and battery cluster 101 stores energy to perform battery SOC protection logic.

[0054] Battery backup: In grid-connected mode, check whether the battery cluster 101 has a charging opportunity to ensure that the battery cluster 101 is fully charged as much as possible. In off-grid mode, the logic is the same as in microgrid mode, and the battery cluster 101 stores energy to perform battery SOC protection logic.

[0055] The photovoltaic direct current of the present invention passes through a DC circuit breaker to a bidirectional inverter group, and then after voltage conversion by the bidirectional inverter group, the photovoltaic direct current is directly connected to the DC side of the energy storage converter and the high-voltage box. The photovoltaic direct current to the DC side of the energy storage converter and the high-voltage box can power the load, or it can pass through the high-voltage box to charge the battery cluster. According to different needs, the control strategies of "self-generation for self-use" and "surplus power to the grid" can be set.

[0056] The smoke detector 1011, the temperature detector 1012 and the combustible gas detector 1013 are fixedly arranged on the upper part of the battery compartment 103. Specifically, the smoke detector 1011, the temperature detector 1012 and the combustible gas detector 1013 are located on the upper part of the battery plug box;

[0057] When the photovoltaic distributed energy storage cabinet is in working state, when one of the smoke detector 1011, the temperature detector 1012 and the combustible gas detector 1013 sounds an alarm, it reaches the first-level fire alarm. The fire protection system transmits a signal to the energy storage cabinet EMS control system. The EMS control system sends a signal to trip the incoming line and load-side molded case circuit breakers, and the energy storage converter and the photovoltaic access bidirectional inverter group 500 are shut down, and the sound and light alarm (not shown in the figure) turns on the sound and light alarm.

[0058] When two of the smoke detectors 1011, temperature detectors 1012, and combustible gas detectors 1013 sound an alarm, a secondary fire alarm is reached. The smoke detectors 1011, temperature detectors 1012, and combustible gas detectors 1013 transmit signals to the energy storage cabinet EMS control system. At this time, the energy storage cabinet EMS control system sends a signal and the alarm rings. At the same time, although there is no fire in the battery plug box, the temperature continues to rise. At this time, it is necessary to start the external fire water valve of the cabinet. The fire water passes through the water flow switch and the water fire main pipe to reach the highest end of the battery cluster. A fire sprinkler is configured at the end of the water fire pipe at the highest position of the battery cluster. When the temperature of the battery cluster reaches the set threshold, the temperature protection fuse of the fire sprinkler blows, and the fire water reaches the battery cluster. The fire water cools the battery system to avoid re-ignition. Battery cluster-level water fire fighting is achieved to prevent the spread of accidents.

[0059] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships of devices or equipment in normal use, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention in this regard. Although the above describes the specific embodiments of the present invention, those skilled in the art should understand that this is only an example, and the scope of protection of the present invention is defined by the attached claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the scope of protection of the present invention.

Claims

1. A photovoltaic distributed energy storage cabinet capable of switching between on-grid and off-grid operation, characterized in that: include: The cabinet has a power distribution control compartment on the left and a battery compartment on the right; A battery cluster is arranged in the battery compartment. The battery cluster is composed of a plurality of battery plug-in boxes, and the batteries are installed in the battery plug-in boxes; The high-voltage box is fixedly arranged at the bottom of the cabinet and is connected to the battery cluster; The energy storage converter is arranged in the cabinet, and one end of the energy storage converter is connected to the high-voltage box; The static transfer switch is located inside the cabinet. The static transfer switch is arranged at the bottom of the energy storage converter. The other end of the energy storage converter is connected to the static transfer switch. The bidirectional inverter group is connected to the bidirectional inverter group through line 1 between the energy storage converter and the high-voltage box.

2. The photovoltaic distributed energy storage cabinet for on-grid and off-grid switching according to claim 1 is characterized in that: The static transfer switch is connected to the mains via a circuit breaker.

3. The photovoltaic distributed energy storage cabinet for on-grid and off-grid switching according to claim 1 is characterized in that: The energy storage converter and the static transfer switch are connected to the load via line 2.

4. The photovoltaic distributed energy storage cabinet for on-grid and off-grid switching according to claim 3 is characterized in that: The static transfer switch and the circuit breaker 1 are connected to the circuit breaker 2 via the circuit breaker 3, and the circuit breaker 2 is arranged on the circuit breaker 3.

5. The photovoltaic distributed energy storage cabinet for on-grid and off-grid switching according to claim 3 is characterized in that: Circuit breaker three is arranged on line two, and one end of circuit breaker three is connected to the load.

6. The photovoltaic distributed energy storage cabinet for on-grid and off-grid switching according to claim 4 is characterized in that: The bidirectional inverter group comprises: A bidirectional inverter 1, one end of which is connected to a circuit breaker 4, and the bidirectional inverter 1 is connected to a photovoltaic system 1 through the circuit breaker 4; One end of the bidirectional inverter 2 is connected to the circuit breaker 5, and the bidirectional inverter 2 is connected to the photovoltaic system 2 through the circuit breaker 5.

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