Photovoltaic power station energy storage and adjustment system

Abstract

The utility model provides an energy storage and adjustment system of a photovoltaic power station, which is specially designed for special challenges faced by the photovoltaic power station in a plateau area, such as electric power fluctuation, equipment damage, difficulty in fault processing and the like in extreme weather. The system comprises a battery prefabricated cabin and a boosting all-in-one machine, the battery prefabricated cabin comprises an energy storage battery and a confluence cabinet, the boosting all-in-one machine comprises a bidirectional converter PCS and a transformer, and storage and steady-state conversion of photoelectric energy can be effectively achieved. The system further comprises an energy management system which is connected with the energy storage battery and the bidirectional converter PCS. Besides, the battery cabin is further provided with auxiliary monitoring equipment, such as a video monitoring module, a temperature and humidity monitoring module and a fire-fighting module, which are used for monitoring and ensuring the safety and stability of the environment in the battery prefabricated cabin. The whole system is reasonable in design, stable operation of the power station can be guaranteed, possible equipment faults can be handled in time, the service life of equipment is prolonged, and the operation efficiency of the power station is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric power, and more specifically relates to a photovoltaic power station energy storage and regulation system thereof. Background Art

[0002] In plateau areas, photovoltaic power stations face many challenges. For example, the climate in plateau areas is particularly changeable, and there may be extreme weather such as strong winds, heavy rains, heat, and severe cold, which not only affects the equipment and panels of photovoltaic power stations, but may also have an adverse effect on the operation of the power station. For example, strong winds may damage photovoltaic panels, heavy rains may cause terrain changes and affect the stability of the power station structure, and extreme high and low temperatures may affect the conversion efficiency of photovoltaic panels.

[0003] In addition, human resources in plateau areas are relatively limited, which will cause certain troubles for equipment maintenance and operation management of photovoltaic power stations. Therefore, it is particularly important for photovoltaic power stations to find an energy storage and regulation system that can match the environmental characteristics of plateau areas and achieve stable operation. Considering the above situation, the photovoltaic power station energy storage and regulation system of the utility model came into being.

[0004] This system has a reasonable structure and powerful functions, which can effectively solve all problems of operating photovoltaic power stations in plateau areas. For example, its battery prefabricated cabin and booster integrated machine design can effectively deal with the power fluctuation problem in plateau areas and achieve efficient and stable photoelectric conversion and voltage regulation. In addition, its energy management system, video monitoring module, temperature and humidity monitoring module and fire protection module and other equipment and systems can monitor and manage the operating status of photovoltaic power station equipment in real time, and promptly alarm and handle faults, thereby improving the operating efficiency of photovoltaic power stations, reducing the failure rate, and ensuring the service life of photovoltaic power station equipment. . Summary of the invention

[0005] The utility model aims to solve the special challenges faced by photovoltaic power stations in plateau areas, including power fluctuations under extreme weather conditions, difficulties in handling damaged photovoltaic equipment and faults, and insufficient monitoring and management of power station operations. In response to these problems, the utility model proposes a photovoltaic power station energy storage and regulation system, which not only has good energy storage and stable power conversion capabilities to cope with power fluctuations, but also includes excellent real-time monitoring function equipment to promptly detect and handle equipment failures and ensure stable operation of the power station.

[0006] In order to achieve the above-mentioned purpose, the utility model is implemented by adopting the following technical solutions: the system comprises: a battery prefabricated cabin and a booster integrated machine;

[0007] The battery prefabricated cabin includes an energy storage battery 1 and a combiner cabinet 2;

[0008] The step-up integrated machine comprises a bidirectional converter PCS3 and a transformer 4;

[0009] The energy storage battery 1 is electrically connected to the energy storage bidirectional converter PCS3 through the combiner cabinet 2, the energy storage bidirectional converter PCS3 is electrically connected to the low voltage side of the transformer 4, and the high voltage side of the transformer 4 is connected to the power grid.

[0010] In one solution, the system further comprises: a booster station switch cabinet 5, an energy management system 6, and an auxiliary monitoring device 7;

[0011] The booster station switch cabinet 5 serves as the grid connection point of the energy storage battery 1, and the high-voltage side of the transformer 4 is connected to the grid through the booster station switch cabinet 5;

[0012] The energy management system 6 includes a battery management system 61, a converter monitoring system 62 and an energy storage battery on-site monitoring system 63;

[0013] The battery management system 61 is connected to the energy storage battery 1, the converter monitoring system 62 is connected to the energy storage bidirectional converter PCS3, and the energy storage battery on-site monitoring system 63 is connected to all local electrical equipment of the energy storage battery 1 to monitor the electrical equipment and realize the whole station as the monitoring platform of the energy storage battery 1, including the centralized monitoring of the battery management system 61 converter monitoring system 62;

[0014] The auxiliary monitoring device 7 is installed in the battery prefabricated compartment to monitor the status of the battery prefabricated compartment.

[0015] In one embodiment, the auxiliary monitoring equipment 7 includes a video monitoring module 8, a temperature and humidity monitoring module 9, and a fire protection module 10; the battery prefabricated cabin is equipped with a monitoring camera of the video monitoring module 8, a sensor of the temperature and humidity monitoring module 9, and a smoke alarm detector of the fire protection module 10.

[0016] In one solution, the system uses 8 sets of 5MWh battery prefabricated cabins, and the bidirectional converter PCS3 uses a 5MWPCS3 integrated booster, and each set of battery prefabricated cabins corresponds to a PCS3 integrated booster.

[0017] In one embodiment, the transformer 4 is a 800V / 35kV / 2800kVA double-split transformer 4 .

[0018] Beneficial effects of the utility model:

[0019] The application of the photovoltaic power station energy storage and regulation system of the utility model in plateau areas can effectively solve the problems of power fluctuations, equipment damage, and management and monitoring. The system can not only stably store and convert electrical energy and reduce power fluctuations caused by extreme climate, but also quickly stabilize current, voltage and other parameters through the electrical connection of the bidirectional converter and transformer to ensure the stable operation of the photovoltaic power station. At the same time, it covers a comprehensive energy management system including battery management, converter monitoring and on-site monitoring, emphasizing real-time and accurate monitoring, so that equipment failures can be discovered and handled in a timely manner, reducing equipment maintenance time and cost, and improving the operating efficiency and service life of the photovoltaic power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a connection block diagram of the utility model system;

[0021] Figure 2 This is a block diagram of the battery management system of the utility model.

[0022] In the figure, 1-energy storage battery, 2-combination cabinet, 3-bidirectional converter PCS, 4-transformer, 5-boosting station switch cabinet, 6-energy management system, 61-battery management system, 62-converter monitoring system, 63-on-site monitoring system of energy storage battery, 7-auxiliary monitoring equipment, 8-video monitoring module, 9-temperature and humidity monitoring module, 10-fire protection module. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0024] like Figure 1 As shown, the system also includes: a booster station switch cabinet 5, an energy management system 6, and an auxiliary monitoring device 7; the booster station switch cabinet 5 serves as a grid connection point for the energy storage battery 1, and the high-voltage side of the transformer 4 is connected to the power grid through the booster station switch cabinet 5.

[0025] The energy management system 6 includes a battery management system 61, an inverter monitoring system 62 and an on-site monitoring system 63 for energy storage batteries; the battery management system 61 is connected to the energy storage battery 1, the inverter monitoring system 62 is connected to the energy storage bidirectional inverter PCS3, and the on-site monitoring system 63 for energy storage batteries is connected to all local electrical equipment of the energy storage battery 1 to monitor the electrical equipment and serve as a monitoring platform for the energy storage battery 1 to realize the entire station, including centralized monitoring of the battery management system 61 and the inverter monitoring system 62; the auxiliary monitoring equipment 7 is installed in the battery prefabricated cabin for monitoring the condition of the battery prefabricated cabin.

[0026] The energy storage system consists of a 2.5MW PCS3 integrated booster and a 5MWh "battery prefabricated cabin" (battery system); the 2.5MW integrated booster includes two 1250kW bidirectional converters PCS3, one 800V / 35kV / 2800kVA double-split transformer 4, and a built-in 35kV circuit breaker; the 5MWh battery prefabricated cabin" (battery system) includes a battery system and a DC combiner cabinet 2, which corresponds one-to-one to the integrated booster, and has a built-in array of standard battery clusters.

[0027] The eight 5MWh prefabricated cabin energy storage systems are inverted by eight 2.5MW integrated step-up transformers and then stepped up to 35kV. PCS3 is connected to the 35kV grid through a 0.8kV / 35kV step-up transformer 4.

[0028] The power of each energy storage battery 1 prefabricated cabin is connected to the bidirectional converter PCS3 inside the booster after being converged through the internal junction box 2 of the prefabricated cabin. PCS3 converts the DC of the battery into an AC voltage of 800V. Two bidirectional converters PCS3 are connected in parallel on the AC side, and the voltage is increased to 35kV through a 2800kVA double-split transformer 4. A vacuum circuit breaker is used on the high-voltage side of transformer 4.

[0029] The 35kV booster station switch cabinet 5 is used as the grid connection point of the energy storage system and is equipped with a line protection and measurement and control device. The line protection and measurement and control device protects the energy storage grid connection line and serves as a backup protection for the energy storage booster transformer 4. In order to prevent the energy storage system from reverse power transmission when the power grid is out of power or the power grid is low voltage, the energy storage switch cabinet 5 is protected by low-frequency and low-voltage load shedding protection as the second anti-reverse power transmission measure for the energy storage system.

[0030] Energy management system 6, the energy management system 6 (EMS) of the energy storage power station includes a battery management system 61, a converter monitoring system 62 and an energy storage system on-site monitoring system. Among them, the battery management system 61 monitoring system realizes the monitoring of battery equipment; the converter monitoring system 62 realizes the monitoring of converter equipment; the energy storage system on-site monitoring system realizes the monitoring of electrical equipment in the energy storage power station, and as the monitoring platform of the entire energy storage power station, realizes the centralized monitoring of the entire station (including the battery management system 61 converter monitoring system 62).

[0031] Battery Management System 61 (BMS)

[0032] BMS adopts a three-level management method to manage battery modules, battery strings and battery system units respectively. Figure 2 As shown: The system uses a three-layer modular structure with strong scalability, and can flexibly respond to different battery string voltage requirements and battery system unit capacity requirements. At the same time, the system is equipped with a BCMS (battery string management system) for each battery string, which can complete the access and exit of a single battery string from the battery system operation, greatly improving the availability of the energy storage system.

[0033] The BMS system has high-speed and highly reliable data transmission capabilities. The system's internal data transmission uses the CAN2.0 high-speed bus, and data information feedback is efficient and timely. It also provides a wealth of high-speed communication interfaces to interconnect with peripheral devices, including Ethernet, RS485, CAN, RS232, USB, etc., as well as a variety of protocol conversions. It can be connected to external or third-party systems according to different needs, fully meeting the power grid's requirements for system reliability and high-speed communication.

[0034] The BMS battery management system 61 can realize the following functions: alarm function, protection function, balancing function, event recording function, parameter setting function, display function, authority management and communication function. The alarm function mainly includes overvoltage alarm, undervoltage alarm, overcurrent alarm, overtemperature alarm, abnormal communication of switch status at all levels, battery abnormal alarm, battery management system 61 abnormal alarm, etc. The protection function mainly includes overvoltage protection, discharge undervoltage protection, discharge overcurrent protection, charge overcurrent protection, temperature protection, etc.

[0035] The auxiliary monitoring part of the energy storage power station is equipped with an auxiliary monitoring system to monitor the temperature, humidity, video, and fire protection of the energy storage power station, reduce the workload of operation and maintenance, and realize the intelligent operation and maintenance of the energy storage power station.

[0036] 1. Video surveillance module 8

[0037] A set of video cameras is installed in the battery prefabrication cabin to monitor the information inside the prefabrication cabin in all directions. A rotating camera is placed outside the energy storage power station to monitor the energy storage power station. All video signals are uploaded to the video management unit of the auxiliary monitoring screen, which has the functions of on-site display, storage and upload.

[0038] 2. Temperature and humidity monitoring module 9

[0039] A set of temperature and humidity sensors is placed in the battery prefabrication cabin to monitor the temperature and humidity information inside the prefabrication cabin. A set of temperature and humidity sensors is placed inside the master control prefabrication cabin to monitor the temperature and humidity information.

[0040] 3. Fire module 10

[0041] Two smoke alarm detectors and one manual alarm button are placed in the prefabricated cabin, which have coding function and upload the alarm information to the fire host of the prefabricated cabin. One smoke alarm detector and one manual alarm button are placed in the prefabricated cabin, and one sound and light alarm is set outside the prefabricated cabin.

[0042] The energy storage battery 1 is composed of single cells connected in series and then in parallel. The selected battery module specification is 3.2V-300Ah. The battery module is composed of 373 battery cells connected in series, with a specification of 1193.6V-300Ah and an operating voltage range of 932.5~1361.45V. Then 14 battery modules are connected in parallel, and the nominal capacity reaches 5013.12kWh. Each 5MWh energy storage battery 1 is installed in a 48-foot container.

[0043] The bidirectional converter PCS3 realizes the bidirectional flow of current by controlling the power elements. The charge and discharge conversion time of the existing product is 200ms, and the fastest can reach 30ms. In theory, it can meet the charge and discharge requirements of the battery during peak load shaving.

[0044] The bidirectional converter PCS3 can realize the AC / DC conversion between the battery and the power grid, complete the bidirectional energy flow between the two, and realize the charge and discharge management of the battery system, grid-side load power tracking, and battery energy storage system charge and discharge power control through control strategies. At present, the mainstream specifications of large energy storage converters on the market are 500kW, 630kW and larger specifications of 1250kW, 2000kW, etc. Considering the site, system requirements, maintenance and operation, etc., a 1250kW energy storage converter is selected. A low-voltage (AC800V) single-machine power converter of 1250kW is used, and a lithium iron phosphate battery is connected to the DC side. The total power of two bidirectional converters PCS3 on the AC side is 2500kW after being connected in parallel.

[0045] Working principle of this utility model:

[0046] First, the photovoltaic panels convert the received light energy into DC power, and then this DC power is sent to the energy storage battery through the combiner cabinet for storage. The energy storage battery is electrically connected to the bidirectional converter PCS through the combiner cabinet, so that the power can be converted into AC power through this bidirectional converter and then sent to the transformer.

[0047] The transformer converts the current and voltage to levels suitable for the grid, and then sends them to the grid through the booster station switch cabinet. In the whole process, the booster station switch cabinet serves as the grid connection point of the energy storage system, connecting the equipment to the grid.

[0048] During the whole process, the energy management system conducts real-time monitoring, including the battery management system managing and monitoring the energy storage battery, the converter monitoring system managing and monitoring the bidirectional converter PCS, and the energy storage battery on-site monitoring system monitoring the local electrical equipment. In this way, possible equipment problems can be discovered and handled in a timely manner to ensure the stable operation of the system.

[0049] Auxiliary monitoring equipment is installed in the battery prefabricated cabin. These devices, such as video monitoring modules, temperature and humidity monitoring modules, and fire protection modules, can monitor and ensure the safety and stability of the environment in the battery prefabricated cabin. The monitoring camera of the video monitoring module can monitor the real-time situation of the battery prefabricated cabin at any time, the sensor of the temperature and humidity monitoring module can monitor the temperature and humidity in the battery prefabricated cabin, and the smoke alarm detector of the fire protection module can detect and alarm possible fires in time.

[0050] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A photovoltaic power station energy storage and regulation system, characterized by: The system comprises: a battery prefabricated cabin and a booster integrated machine; The battery prefabricated cabin comprises an energy storage battery (1) and a combiner cabinet (2); The step-up integrated machine comprises a bidirectional converter PCS (3) and a transformer (4); The energy storage battery (1) is electrically connected to the energy storage bidirectional converter PCS (3) through the combiner cabinet (2); the bidirectional converter PCS (3) is electrically connected to the low-voltage side of the transformer (4); and the high-voltage side of the transformer (4) is connected to the power grid; Booster station switch cabinet (5), energy management system (6), auxiliary monitoring equipment (7); The booster station switch cabinet (5) serves as a grid connection point for the energy storage system, and the high-voltage side of the transformer (4) is connected to the grid through the booster station switch cabinet (5); The energy management system (6) comprises a battery management system (61), a converter monitoring system (62) and an energy storage battery on-site monitoring system (63); The battery management system (61) is connected to the energy storage battery (1), the converter monitoring system (62) is connected to the bidirectional converter PCS (3), and the energy storage battery local monitoring system (63) is connected to all local electrical equipment of the energy storage battery (1) to monitor the electrical equipment and serve as a monitoring platform for the energy storage battery (1) to realize the centralized monitoring of the entire station, including the battery management system (61) and the converter monitoring system (62); The auxiliary monitoring device (7) is installed in the battery prefabricated compartment and is used to monitor the status of the battery prefabricated compartment.

2. A photovoltaic power station energy storage and regulation system according to claim 1, characterized in that: The auxiliary monitoring equipment (7) comprises a video monitoring module (8), a temperature and humidity monitoring module (9), and a fire protection module (10); a monitoring camera of the video monitoring module (8), a sensor of the temperature and humidity monitoring module (9), and a smoke alarm detector of the fire protection module (10) are installed in the battery prefabricated cabin.

3. A photovoltaic power station energy storage and regulation system according to claim 2, characterized in that: The system uses 8 sets of 5MWh battery prefabricated cabins, and the bidirectional converter PCS (3) uses a 5MWPCS3 integrated step-up machine, and each set of battery prefabricated cabins corresponds to a PCS3 integrated step-up machine.

4. A photovoltaic power station energy storage and regulation system according to claim 2, characterized in that: The transformer (4) is a 800V / 35kV / 2800kVA double-split transformer.

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