Grid-connected and off-grid cabinet type optical storage system adaptive to rapid power fluctuation load

Abstract

The utility model provides a grid-connected and off-grid cabinet type optical storage system adaptive to a fast power fluctuation load. The grid-connected and off-grid cabinet type optical storage system comprises a DC bus; a plurality of photovoltaic power generation modules, wherein a photovoltaic access module is arranged between each photovoltaic power generation module and the DC bus; the energy storage module is connected with a first energy storage converter, and the first energy storage converter is provided with a first power connection interface; according to the system, the second energy storage converter is configured to be connected with the direct-current bus and connected into the direct-current bus, so that electric energy required by the load is provided by the direct-current bus, and meanwhile, the photovoltaic power generation module and the energy storage module are also connected into the direct-current bus; therefore, the system only needs to detect the conventional protection of the system and is matched with a corresponding control strategy, so that the photovoltaic power generation can be ensured to be completely absorbed, and the utilization rate of the new energy power generation amount is improved.

Description

Technical Field

[0001] The utility model generally relates to the technical field of energy storage power supply, and specifically relates to an on-grid and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads. Background Art

[0002] With the proposal of the dual carbon goals, the demand for reducing carbon emissions and improving the utilization rate of new energy is gradually increasing. Traditional industries are undergoing energy transformation, increasing the utilization rate of new energy and reducing carbon emissions. However, in traditional industries, some power-consuming equipment has large power fluctuations. Conventional new energy has unstable power generation, which makes it impossible to effectively utilize the power generated by new energy. Utility Model Content

[0003] In view of the above problems, the present application provides an off-grid cabinet-type photovoltaic storage system that is adaptable to rapid power fluctuation loads. It can improve the utilization rate of renewable energy power generation by adjusting the adaptation of electrical equipment and renewable energy power generation, thereby achieving the purpose of effective utilization of electrical energy.

[0004] The utility model provides an on-grid and off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads, comprising:

[0005] DC bus;

[0006] A plurality of photovoltaic power generation modules are connected to the DC bus, and a photovoltaic access module is provided between each photovoltaic power generation module and the DC bus;

[0007] An energy storage module connected to the DC bus, wherein the energy storage module is connected to a first energy storage converter, and the first energy storage converter is provided with a first power connection interface;

[0008] A load is connected to the DC bus, and a second energy storage converter is arranged between the load and the DC bus.

[0009] Specifically, this system is connected to the DC bus by configuring the second energy storage converter, so that the DC bus can provide the power required by the load. At the same time, the photovoltaic power generation module and the energy storage module are also connected to the DC bus, so that the power required by photovoltaics, batteries, and loads can flow freely in the DC bus. Therefore, the system only needs to detect the conventional protection of the system and match the corresponding control strategy to ensure that the power generated by photovoltaics is fully absorbed, thereby improving the utilization rate of new energy power generation and achieving the purpose of effective use of electric energy.

[0010] Furthermore, a first circuit breaker is provided between the first power connection interface and the first energy storage converter, a second circuit breaker is provided between each photovoltaic power generation module and the DC bus, and a third circuit breaker is provided between the load and the DC bus.

[0011] Specifically, by setting the first circuit breaker, the second circuit breaker and the third circuit breaker, it is possible to control whether each module is connected to the DC bus through various circuit breakers, thereby achieving the purpose of regulating the photovoltaic system.

[0012] Furthermore, it also includes an energy management module, which is connected to the energy storage module, the first circuit breaker, the first energy storage inverter, the third circuit breaker, the second energy storage inverter and the plurality of photovoltaic access modules.

[0013] Specifically, by setting up an energy management module, the energy management module can automatically control each circuit breaker according to the energy storage status of the energy storage module, thereby achieving the purpose of automatic regulation, making regulation more convenient and achieving better regulation effect.

[0014] Furthermore, the energy management module is connected to the cloud platform.

[0015] Specifically, by connecting the energy management module to the cloud platform, the data of the management module can be uploaded to the cloud platform and the data can be transmitted remotely, so that the remote control terminal can timely obtain and collect the data of the energy management module and realize remote operation and maintenance management, thereby greatly saving operation and maintenance costs.

[0016] Furthermore, the photovoltaic access module is a DC / DC module.

[0017] Specifically, the photovoltaic power generation module adopts DC grid-connected access, and the photovoltaic access module adopts a DC / DC module to directly connect to the DC bus, adapt the DC bus voltage, and power the system through the DC bus.

[0018] Furthermore, the first energy storage converter and the second energy storage converter are both DC / AC off-grid inverters.

[0019] Specifically, the load power supply uses a DC / AC off-grid inverter module for power supply, and the inverter establishes an AC voltage source, which can adapt the power of the power load in real time.

[0020] Beneficial Effects

[0021] The utility model provides an off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads, comprising: a DC bus; a plurality of photovoltaic power generation modules, a photovoltaic access module is arranged between each photovoltaic power generation module and the DC bus; an energy storage module, the energy storage module is connected to a first energy storage inverter, the first energy storage inverter is provided with a first power connection interface; a load, a second energy storage inverter is arranged between the load and the DC bus. The system is connected to the DC bus by configuring the second energy storage inverter to be connected to the DC bus, so that the electric energy required by the load is provided by the DC bus. At the same time, the photovoltaic power generation module and the energy storage module are also connected to the DC bus, so that the electric energy required by the photovoltaic, battery and load can flow freely on the DC bus. Therefore, the system only needs to detect the conventional protection of the system and match the corresponding control strategy to ensure that the electric energy generated by the photovoltaic is completely absorbed, thereby improving the utilization rate of the new energy power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0023] Figure 1 A structural block diagram of an on-grid and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads provided by the utility model.

[0024] Figure 2 The utility model provides a grid-connected control logic diagram of an off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads.

[0025] Figure 3 The utility model provides a control logic diagram when the power grid is out of power in an on-grid and off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings.

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] The utility model provides an off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads. As a specific implementation method, reference is made to Figure 1-Figure 3 , the system comprises:

[0029] DC bus 1;

[0030] A plurality of photovoltaic power generation modules 2 are connected to the DC bus 1, and a photovoltaic access module 21 is provided between each photovoltaic power generation module 2 and the DC bus 1;

[0031] An energy storage module 3 is connected to the DC bus 1, and the energy storage module 3 is connected to a first energy storage converter 31, and the first energy storage converter 31 is provided with a first power connection interface 32;

[0032] The load 4 is connected to the DC bus 1 , and a second energy storage converter 41 is provided between the load and the DC bus 1 .

[0033] Specifically, when working, the first power connection interface 32 is connected to the mains, and is connected to the DC bus 1 through the second energy storage inverter 41, and connected to the DC bus, so that the power required by the load 4 is provided by the DC bus 1. At the same time, the photovoltaic power generation module 2 and the energy storage module 3 are also connected to the DC bus, so that the power required by the photovoltaic, battery, and load can flow freely in the DC bus; therefore, the system only needs to detect the conventional protection of the system and match the corresponding control strategy to ensure that the power generated by the photovoltaic is completely absorbed, thereby improving the utilization rate of the new energy power generation and achieving the purpose of effectively utilizing the power. The specific control strategy is referred to below.

[0034] Furthermore, a first circuit breaker 33 is provided between the first power connection interface 32 and the first energy storage converter 31 , a second circuit breaker 22 is provided between each photovoltaic power generation module 2 and the DC bus 1 , and a third circuit breaker 42 is provided between the load 4 and the DC bus 1 .

[0035] Specifically, by providing the first circuit breaker 33, the second circuit breaker and the third circuit breaker 42, it is possible to control whether each module is connected to the DC bus through various circuit breakers, thereby achieving the purpose of regulating the photovoltaic system.

[0036] Further, refer to Figure 2 , Figure 3 It should be noted that the energy storage module 3 is a BES, which can be composed of a battery pack, the first circuit breaker 33 is QF1, the multiple second circuit breakers 22 are QF2-QFn, the third circuit breaker 42 is QF4, and the load 4 is a fluctuating load, that is, an electrical device; the photovoltaic access module 21WEI is an MPPT, the second energy storage converter 41 is a 2#PCS, and an inverter energy storage converter is used. The photovoltaic power generation module 2 is a 1#-n# photovoltaic system, and the first energy storage converter 31 is a 1#PCS, that is, the grid is connected to the energy storage converter. The grid-connected control strategy and the off-grid control strategy of this system during operation are referenced. Figure 2 , is the control strategy for grid connection, specifically:

[0037] Step 1: When the mains power is normal, confirm whether QF1 is closed. If QF1 is not closed, control QF1 to close, and then proceed to step 2. If it is not closed, close QF1, and then proceed to step 2.

[0038] Step 2: confirm whether 1#PCS is started. If 1#PCS is started, proceed to step 3. If 1#PCS is not started, start 1#PCS and then proceed to step 3.

[0039] Step three, obtain the real-time state of charge SOC of the energy storage module 4. When the real-time state of charge SOC is less than SOCmax, proceed to step four. When the real-time state of charge SOC is not less than SOCmax, proceed to step five, wherein SOCmax is the maximum SOC threshold of the battery system, which refers to the maximum or minimum limit value of the battery's state of charge (SOC). SOC represents the proportion of the remaining capacity of the battery to its total capacity, usually expressed as a percentage, and its value range is 0 to 1. When SOC is 0, it means that the battery has been fully discharged; when SOC is 1, it means that the battery is fully charged. Since SOC cannot be measured directly, but is estimated through parameters such as the battery's terminal voltage, charge and discharge current, and internal resistance, these parameters will be affected by multiple factors such as battery aging, ambient temperature changes, and vehicle driving conditions. Therefore, setting the SOC threshold is to control the battery's charging or discharging process to a certain extent to avoid overcharging or over-discharging of the battery, thereby protecting the battery's safety and extending its service life;

[0040] Step 4: Confirm the relationship between the real-time load power PZ and the photovoltaic inverter power PV. When PZ is less than or equal to PV, 1#PCS charges and charges the energy storage module 3. The power P1 sent by the grid-connected PCS is equal to the battery system's allowed charging and discharging power PB. When PZ is greater than PV, 1#PCS is on standby.

[0041] Step 5: Confirm the relationship between the real-time load power PZ and the photovoltaic inverter power PV. When PZ is less than or equal to PV, 1#PCS charges and charges the energy storage module 3, and P1=PV-PZ; when PZ is greater than PV, limit the MPPT power and PV is less than PZ.

[0042] refer to Figure 3 , is the off-grid control strategy of the system, specifically:

[0043] ①. The mains power is cut off and the system alarms. Confirm the status of QF1. If QF1 is closed, disconnect QF1 and proceed to step ②.

[0044] ②. Confirm the status of 1#PCS. If 1#PCS is in the start state, stop 1#PCS. After 1#PCS stops, proceed to step ③;

[0045] ③. Compare the real-time state of charge SOC and SOCmin. If SOC is greater than SOCmin, proceed to step ④. If SOC is not greater than SOCmin, disconnect QF4 to make the real-time state of charge SOC greater than SOCmin, and then proceed to step ④.

[0046] ④. Confirm the status of QF4. If QF4 is open, close QF4. If QF4 is closed, proceed to step ⑤.

[0047] ⑤. Confirm the relationship between SOCmax and SOC. If SOCmax=SOC, proceed to step ⑥. If SOCmax is not equal to SOC, proceed to step ⑦.

[0048] ⑥. Confirm the relationship between the real-time load power PZ and the photovoltaic inverter power PV. When PZ is less than or equal to PV, charge the energy storage module 3, PB=PV-PZ, PB is the allowable charge and discharge power of the battery system. When PZ is greater than PV, supply power to the energy storage module, PB= PZ-PV, where PB is the allowable charge and discharge power of the battery system.

[0049] ⑦. Confirm the relationship between the real-time load power PZ and the photovoltaic inverter power PV. When PZ is less than or equal to PV, limit the MPPT power to make PV less than or equal to PZ. When PZ is greater than PV, the photovoltaic maximum power is generated.

[0050] Furthermore, as a specific real-time method, it also includes an energy management module 5, which is connected to the energy storage module 3, the first circuit breaker 33, the first energy storage inverter 31, the third circuit breaker 42, the second energy storage inverter 41 and multiple photovoltaic access modules 21.

[0051] Specifically, by setting up the energy management module 5, the energy management module 5 can automatically control each circuit breaker according to the energy storage status of the energy storage module, thereby achieving the purpose of automatic regulation, making the regulation more convenient and achieving better regulation effect.

[0052] Furthermore, the energy management module 5 is connected to the cloud platform.

[0053] Specifically, by connecting the energy management module 5 to the cloud platform, the data of the management module 5 can be uploaded to the cloud platform and the data can be transmitted remotely, so that the remote control terminal can timely obtain and collect the data of the energy management module 5, realize remote operation and maintenance management, and thus save a lot of operation and maintenance costs.

[0054] Furthermore, through the above control strategy, the system control of the present application only needs to control the upper and lower limits of the state of charge of the battery system. The control logic is simple and can also ensure that the load preferentially consumes the power generated by photovoltaics.

[0055] Furthermore, in order to ensure that the photovoltaic power is consumed locally by the equipment as much as possible and avoid the photovoltaic power being fed back to the power grid, this system is equipped with an energy storage system as an energy cache. When the photovoltaic power generation power is greater than the load power consumption, the excess power is used to charge the battery system; when the photovoltaic power generation power is less than the load power consumption, the missing power value can be supplied by the battery system.

[0056] Furthermore, the photovoltaic access module 21 is a DC / DC module.

[0057] Specifically, the photovoltaic power generation module adopts DC grid-connected access, and the photovoltaic access module adopts a DC / DC module to directly connect to the DC bus, adapt the DC bus voltage, and power the system through the DC bus.

[0058] Furthermore, the first energy storage converter 31 and the second energy storage converter 41 are both DC / AC off-grid inverters.

[0059] Specifically, the load power supply uses a DC / AC off-grid inverter module for power supply, and the inverter establishes an AC voltage source, which can adapt the power of the power load in real time.

[0060] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A grid-connected and off-grid cabinet-type photovoltaic storage system adapted to fast power fluctuation loads, characterized in that: include: DC bus (1); A plurality of photovoltaic power generation modules (2), each connected to the DC bus (1), a photovoltaic access module (21) being provided between each photovoltaic power generation module (2) and the DC bus (1); An energy storage module (3) connected to the DC bus (1), the energy storage module (3) being connected to a first energy storage converter (31), the first energy storage converter (31) being provided with a first power connection interface (32); A load (4) connected to the DC bus (1), wherein a second energy storage converter (41) is provided between the load and the DC bus (1); A first circuit breaker (33) is provided between the first power connection interface (32) and the first energy storage converter (31), a second circuit breaker (22) is provided between each photovoltaic power generation module (2) and the DC bus (1), and a third circuit breaker (42) is provided between the load (4) and the DC bus (1).

2. According to claim 1, a grid-connected and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads is characterized in that: It also includes an energy management module (5), wherein the energy management module (5) is connected to the first circuit breaker (33), the first energy storage converter (31), the third circuit breaker (42), and a plurality of second energy storage converters (41).

3. According to claim 2, a grid-connected and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads is characterized in that: The energy management module (5) is connected to the cloud platform.

4. According to claim 1, a grid-connected and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads is characterized in that: The photovoltaic access module (21) is a DC / DC module.

5. According to claim 1, a grid-connected and off-grid cabinet-type photovoltaic storage system adapted to rapid power fluctuation loads is characterized in that: The first energy storage converter (31) and the second energy storage converter (41) are both DC / AC off-grid inverters.

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