CN210927503U

CN210927503U - Photovoltaic power generation and energy storage integrated power supply system

Info

Publication number: CN210927503U
Application number: CN201922191260.2U
Authority: CN
Inventors: 王媛; 沈冰; 张勇
Original assignee: Beijing Capital International Airport Co ltd
Current assignee: Beijing Capital International Airport Co ltd
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-07-03
Anticipated expiration: 2029-12-06

Abstract

The utility model discloses a photovoltaic power generation and energy storage integration power supply system, include: the system comprises a photovoltaic power generation subsystem, a box type energy storage subsystem, a box type power distribution station and a load end opening and closing station; the box type power distribution station is provided with a bus conforming to the preset voltage; photovoltaic electricity generated by the photovoltaic power generation subsystem is boosted to a preset voltage through at least one first transformer and then is connected to a bus of the box-type power distribution station; the box type energy storage subsystem is connected with the photovoltaic power generation subsystem and is used for storing photovoltaic electricity generated by the photovoltaic power generation subsystem; the box type energy storage subsystem is used for increasing the stored photovoltaic electricity to a preset voltage through at least one second transformer and then connecting the photovoltaic electricity to a bus of the box type power distribution station; and the bus of the box-type power distribution station is connected with the bus of the load end switching station and is used for transmitting the photovoltaic electricity generated by the photovoltaic power generation subsystem or the photovoltaic electricity stored by the box-type energy storage subsystem to the load end switching station. The project construction of the photovoltaic power generation system is simplified, and the power supply scene of a large-scale public transportation place or an intelligent building is met.

Description

Photovoltaic power generation and energy storage integrated power supply system

Technical Field

The utility model relates to a photovoltaic power generation technical field, more specifically relates to a photovoltaic power generation and energy storage integration power supply system.

Background

Photovoltaic power generation is a technology of directly converting light energy into electric energy by using the photovoltaic effect of a semiconductor interface. The solar energy power generation system mainly comprises a solar panel (assembly), a controller and an inverter, and the main components are electronic components. The solar cells are connected in series and then are packaged and protected to form a large-area solar cell module, and then the photovoltaic power generation device is formed by matching with components such as a power controller and the like. Photovoltaic power generation is widely used at home and abroad as a mature clean energy power generation technology.

The photovoltaic power generation system has huge change due to environmental factors such as weather, seasons, disasters and the like, and has low stability and point quality, so that the technology can only be applied to production and life as auxiliary energy for years, is less separated from a local power grid and operates independently. The application of energy storage fundamentally becomes possible with this clean energy of solar energy as main energy, and energy storage system not only can be with electric energy storage to the battery in for non-electricity generation period, more can promote electric quality and electric power system stability.

The energy storage device is applied to a photovoltaic power generation system at an early stage of global development, and no large public transportation place or intelligent building adopts a light storage and charging integrated form as a wide energy source at present.

Therefore, a photovoltaic power generation and energy storage integrated power supply system capable of meeting the power supply requirements of large public transportation or intelligent buildings is needed.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a photovoltaic power generation and energy storage integration power supply system realizes satisfying large-scale public transport place or intelligent building's power supply.

In order to achieve the above object, the utility model provides a photovoltaic power generation and energy storage integration power supply system, include: the system comprises a photovoltaic power generation subsystem, a box type energy storage subsystem, a box type power distribution station and a load end opening and closing station;

the box type power distribution station is provided with a bus conforming to preset voltage;

photovoltaic electricity generated by the photovoltaic power generation subsystem is boosted to the preset voltage through at least one first transformer and then is connected to the bus of the box-type power distribution station;

the box-type energy storage subsystem is connected with the photovoltaic power generation subsystem and is used for storing photovoltaic electricity generated by the photovoltaic power generation subsystem;

the box type energy storage subsystem raises the stored photovoltaic electricity to the preset voltage through at least one second transformer and then accesses the bus of the box type power distribution station;

the bus of the box-type power distribution station is connected with the bus of the load end switching station and used for transmitting the photovoltaic electricity generated by the photovoltaic power generation subsystem or the photovoltaic electricity stored by the box-type energy storage subsystem to the load end switching station.

Optionally, the photovoltaic power generation subsystem comprises a plurality of strings of photovoltaic modules, a plurality of string inverters, and at least one ac combiner box;

each string of photovoltaic modules comprises a plurality of photovoltaic modules which are connected in series, each string type inverter is connected with a plurality of strings of photovoltaic modules, and each alternating current header box is connected with a plurality of string type inverters;

the alternating current combiner box is connected with the first transformer.

Optionally, the box-type energy storage subsystem includes a first box, and a plurality of storage batteries arranged in a distributed manner are arranged in the first box.

Optionally, the battery is a lithium iron phosphate battery.

Optionally, the box-type power distribution station includes a second box, and a high-voltage operating room, a box transformer substation cabinet and a high-voltage switch cabinet which are isolated from each other are disposed in the second box.

Optionally, a step-up transformer, a transformer high-voltage switch, a high-voltage fuse, a grounding switch and a low-voltage circuit breaker are arranged in the box transformer substation cabinet.

Optionally, the step-up transformer is a dry-type transformer, the transformer high-voltage switch is a load switch, and the low-voltage circuit breaker is an air circuit breaker;

the high-voltage fuse is a plurality of and all set up in high-pressure side in the box power distribution station.

Optionally, the high-voltage switch cabinet is a metal armored movable high-voltage switch cabinet, and a circuit breaker, a current transformer, a voltage transformer and a lightning arrester are arranged in the high-voltage switch cabinet.

Optionally, the system further comprises a microgrid energy management subsystem, and the microgrid energy management subsystem is used for collecting data of the photovoltaic power generation subsystem, the box-type energy storage subsystem, the box-type power distribution station and the load end switching station, and performing centralized monitoring and real-time control according to the collected data.

The utility model provides a photovoltaic power generation and energy storage integration power supply method utilizes foretell photovoltaic power generation and energy storage integration power supply system, the method includes:

under the condition that the photovoltaic power generation subsystem generates power, the box-type energy storage subsystem stores photovoltaic power generated by the photovoltaic power generation subsystem;

if the photovoltaic electric quantity stored by the box-type energy storage subsystem reaches the maximum energy storage value of the box-type energy storage subsystem, transmitting surplus photovoltaic electricity generated by the photovoltaic power generation subsystem to a load end through the box-type power distribution station and the load end opening and closing station for power supply;

and under the condition that the photovoltaic power generation of the photovoltaic power generation subsystem is not met, the photovoltaic power stored by the box type energy storage subsystem is transmitted to a load end through the box type power distribution station and the load end opening and closing station to supply power.

The beneficial effects of the utility model reside in that:

through box energy storage subsystem and box distribution station that highly integrates, be applicable to various indoor outer photovoltaic power generation application scenes, and can simplify photovoltaic power generation system's project organization, can satisfy large-scale public transport place or intelligent building's power supply scene, box distribution station adopts single bus wiring mode, and the wiring is simple clear, convenient operation, equipment are few, be convenient for expand and adopt complete set distribution device.

The apparatus of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings and the following detailed description, which are incorporated herein, and which together serve to explain certain principles of the invention.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments of the present invention with reference to the attached drawings, in which like reference numerals generally represent like parts.

Fig. 1 shows a schematic diagram of a photovoltaic power generation and energy storage integrated power supply system according to an embodiment of the present invention.

Description of reference numerals:

1. a photovoltaic power generation subsystem; 2. a box-type energy storage subsystem; 3. a box-type power distribution station; 4. a load end switching station; 5. a bus bar; 6. a first transformer; 7. a second transformer; 8. a photovoltaic module; 9. a string inverter; 10. an AC combiner box; 11. and a microgrid energy management subsystem.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention have been illustrated in the accompanying drawings, it is to be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

As shown in fig. 1, according to the utility model discloses a photovoltaic power generation and energy storage integration power supply system, include: the system comprises a photovoltaic power generation subsystem 1, a box type energy storage subsystem 2, a box type power distribution station 3 and a load end opening and closing station 4;

the box type power distribution station 3 is provided with a bus 5 which accords with preset voltage;

photovoltaic electricity generated by the photovoltaic power generation subsystem 1 is boosted to a preset voltage through at least one first transformer 6 and then is connected to a bus 5 of the box-type power distribution station 3;

the box-type energy storage subsystem 2 is connected with the photovoltaic power generation subsystem 1 and is used for storing photovoltaic electricity generated by the photovoltaic power generation subsystem 1;

the box-type energy storage subsystem 2 raises the stored photovoltaic electricity to a preset voltage through at least one second transformer 7 and then accesses a bus 5 of the box-type power distribution station 3;

and a bus 5 of the box-type distribution station 3 is connected with a bus 5 of the load end opening and closing station 4 and is used for transmitting the photovoltaic electricity generated by the photovoltaic power generation subsystem 1 or the photovoltaic electricity stored by the box-type energy storage subsystem 2 to the load end opening and closing station 4.

Specifically, through box energy storage subsystem 2 and box distribution station 3 of high integration, be applicable to various indoor outer photovoltaic power generation application scenes, and can simplify photovoltaic power generation system's project group and build, can satisfy large-scale public transport place or intelligent building's power supply scene, box distribution station 3 adopts single bus 5 mode of connection, and the wiring is simple clear, convenient operation, equipment are few, be convenient for expand and adopt complete set distribution device. Wherein, energy storage system can also play the effect of stabilizing electric quality for the user of low reaches (being equivalent to the transformer case).

In the present embodiment, the photovoltaic power generation subsystem 1 includes a plurality of strings of photovoltaic modules 8, a plurality of string inverters 9, and at least one ac combiner box 10;

each string of photovoltaic modules 8 comprises a plurality of photovoltaic modules 8 connected in series, each string-type inverter 9 is connected with a plurality of strings of photovoltaic modules 8, and each alternating current combiner box 10 is connected with a plurality of string-type inverters 9;

the ac combiner box 10 is connected to the first transformer 6.

Specifically, a plurality of photovoltaic modules 8 can form 1 string, the plurality of strings of photovoltaic modules 8 are connected into one string type inverter 9, outgoing lines of a plurality of inverters are connected into one alternating current header box 10, the alternating current header box is sent into the first transformer 6 after being merged, and the alternating current header box is sent into the box type distribution station 3 in a pi connection mode after being boosted to a preset voltage.

In this embodiment, the box-type energy storage subsystem 2 includes a first box, and a plurality of storage batteries arranged in a distributed manner are arranged in the first box, and the storage battery is a lithium iron phosphate storage battery.

Specifically, box energy storage subsystem 2 wholly adopts container formula group battery, and according to specifically energy storage demand distribution arranges a plurality of batteries in the box, the preferred lithium iron phosphate battery of battery adopts container formula group battery can keep apart storage battery and external environment completely, does not receive external environment's interference, and easily equipment and maintenance.

In this embodiment, the box-type distribution station 3 includes a second box, and a high-voltage operating room, a box transformer substation cabinet and a high-voltage switch cabinet which are isolated from each other are provided in the second box. And a step-up transformer, a transformer high-voltage switch, a high-voltage fuse, a grounding switch and a low-voltage circuit breaker are arranged in the box transformer substation cabinet. The step-up transformer is a dry type transformer, the high-voltage switch of the transformer is a load switch, and the low-voltage circuit breaker is an air circuit breaker; the high-voltage fuse is a plurality of and all sets up the high-pressure side in box power distribution station 3. The high-voltage switch cabinet is a metal armored movable high-voltage switch cabinet, and a circuit breaker, a current transformer, a voltage transformer and a lightning arrester are arranged in the high-voltage switch cabinet.

Specifically, the box-type power distribution station 3 has the characteristics of reliable operation, convenient operation and high cost performance, is favorable for safe and reliable operation of an outdoor transformer and convenient installation and construction, and can completely isolate equipment such as a dry-type transformer and a fuse from the external environment in the same box transformer cabinet without being influenced by the external environment, and the operation part is carried out in a high-voltage chamber. The transformer high-voltage switch adopts a load switch, and the load switch adopts an electric operation mode; a plurality of high-voltage fuses are arranged on the high-voltage side of the box-type power distribution station 3 and used as protection elements for overload and short-circuit faults of the box-type power distribution station 3; the circuit breaker is an air circuit breaker and has the characteristic of resisting the operation overvoltage, namely, when the circuit breaker is operated to open and close a carried load, any overvoltage harmful to electric shock and a station transformer is not generated. The electrical part of the box-type power distribution station 3 adopts a metal armored movable high-voltage switch cabinet, and primary elements mainly comprise a vacuum circuit breaker, a current transformer, a voltage transformer, a lightning arrester and the like, so that the power distribution station has the advantages of flexible operation and safe and reliable power supply.

In this embodiment, the micro-grid energy management subsystem 11 is further included, and is configured to perform data acquisition on the photovoltaic power generation subsystem 1, the box energy storage subsystem 2, the box power distribution station 3, and the load end switching station 4, and perform centralized monitoring and real-time control according to the acquired data.

Specifically, the microgrid Energy Management System (EMS) can perform data acquisition and analysis, centralized monitoring, real-time control, intelligent operation and maintenance and the like on the whole system, and is a guarantee for safe, stable and efficient operation of the system.

The embodiment of the utility model provides a still provide a photovoltaic power generation and energy storage integration power supply method, utilize foretell photovoltaic power generation and energy storage integration power supply system, the method includes:

under the condition that the photovoltaic power generation subsystem 1 generates power, the photovoltaic power generated by the photovoltaic power generation subsystem 1 is stored through the box-type energy storage subsystem 2;

if the photovoltaic electric quantity stored by the box-type energy storage subsystem 2 reaches the maximum energy storage value of the box-type energy storage subsystem 2, surplus photovoltaic electricity generated by the photovoltaic power generation subsystem 1 is transmitted to a load end through the box-type power distribution station 3 and the load end opening and closing station 4 for power supply;

under the condition that the photovoltaic power generation of the photovoltaic power generation subsystem 1 is not satisfied, the photovoltaic power stored by the box type energy storage subsystem 2 is transmitted to a load end through the box type power distribution station 3 and the load end opening and closing station 4 to supply power.

Specifically, the energy storage system can prolong the time of the generated energy of the photovoltaic system after load absorption, thereby fully utilizing renewable energy and avoiding the 'light abandonment' condition. For example, in the daytime, the photovoltaic power generation subsystem 1 preferentially charges the energy storage system, the charging time is the same as the running time of the photovoltaic power generation system, the surplus electric quantity of charging is boosted and then transmitted to the box-type distribution station 3, and power is supplied to the load end through the load end switching station 4; at night or in rainy days, when the power generation capacity of the photovoltaic system is insufficient or the photovoltaic system stops running, the energy storage system is controlled by an energy management system EMS and is transmitted to the box-type power distribution station 3 through voltage boosting transformation, and the power is supplied to a load end through the load end opening and closing station 4 and is discharged for a certain time. The power supply in the non-power generation period is realized, and the power quality and the stability of a power system can be improved.

The following is the utility model discloses a photovoltaic power generation and energy storage integration power supply system is at the specific application example of capital airport T1 parking area power supply project:

through site survey, tall buildings do not exist around the T1 parking lot, no obvious obstacles exist on the surrounding terrain, the illumination of the plant area is good, and the development and utilization potential of solar energy resources is good. The photovoltaic power generation and energy storage integrated power supply system has good software and hardware construction conditions.

In the project, a photovoltaic system and an energy storage system are built in a T1 parking lot and are managed through an energy management system, and the schematic diagram of the system structure is shown in figure 1.

The overall design index requirements of the T1 parking lot are shown in Table 1;

TABLE 1

The project is designed to install a 0.5MW/2.22MWh energy storage system in a T1 parking lot, and the energy storage system is accessed to a T2 parking building for consumption.

The system access scheme is as follows:

t1 parking area photovoltaic energy storage system sets up 1 container formula 10kV power distribution station, establishes 1 section 10kV generating line in, and 1.52MW photovoltaic power generation system steps up to 10kV through 2 transformers, and 1 set of energy storage system steps up to 10kV through the transformer, all inserts this section generating line, send to the switching station in the T2 parking building after converging, newly increases 1 platform 10kV cubical switchboard and 1 generating line protection measurement cabinet at T2 switching station.

The wiring design of the photovoltaic power station is as follows:

the engineering arranges photovoltaic modules on the shed roof of a T1 parking lot, 1 string is formed by 22 or 20 photovoltaic modules, one group of string-type inverters is connected to each 12 strings, outgoing lines of 4 inverters are connected to a 1-surface AC combiner box, the outgoing lines are sent to a newly-built transformer after being combined, the voltage is increased to 10.5kV, the outgoing lines are sent to a newly-built container-type 10kV power distribution station in a pi connection mode, and each block is finally sent to a 10kV 277 line bus section of a power distribution room of a T2 parking building through 1 path of 10kV outgoing lines and is connected to the grid. The 10kV side of the project adopts a low-resistance grounding mode to improve the protection sensitivity. According to the requirement of an access system scheme, the short-circuit current of the 10kV equipment is selected according to 25kA, and the low-voltage equipment is temporarily selected according to the 35kA level.

First, main equipment selection

(1) Box-type power distribution station: in order to ensure that the outdoor transformer can safely and reliably operate and is simple and convenient to install and construct, the power station selects and uses a box-type power distribution station which has the advantages of reliable operation, convenient operation and superior price performance. The voltage class of the step-up transformer is 10.5 +/-2 x 2.5% kV/0.5kV, and the wiring group is D, yn 11. The box-type power distribution station can install dry-type transformers, fuses and other equipment in the same box-type power distribution station to be completely isolated from the external environment, is not influenced by the external environment, and is operated in a high-voltage chamber. The self-using capacity requirement of the box-type power distribution station is 80kVA, and the rated voltage ratio is as follows: 10.5/0.5kV, a TN-S system is adopted, and a three-phase five-wire system is adopted. And the connection group is Dyn11, and the power utilization is responsible for supplying power to circuits such as illumination, heating, maintenance and the like in the box transformer substation.

A step-up transformer: the step-up transformer adopts a dry type transformer, and the main parameters are as follows:

the model is as follows: SCB13 —. 10; rated capacity: 800 kVA; rated voltage: 10.5kV (high side), 0.5kV (low side); short-circuit impedance: 6 percent; voltage regulation range: 10.5 +/-2 x 2.5%; connection group number: d, yn 11; a cooling mode: AN.

10kV load switch: a transformer high-voltage switch of the box-type power distribution station adopts a load switch, the load switch adopts an electric operation mode, and the main parameters are as follows:

rated voltage: 12 kV; rated current: 630A; rated frequency: 50 HZ.

10kV fuse: the high-voltage side of each box-type power distribution station is provided with 3 high-voltage fuses which are used as protection elements for overload and short-circuit faults of the box-type power distribution station, and the main parameters are as follows:

rated voltage: 12 kV; rated current: 630A

The main parameters of the grounding switch are as follows;

rated voltage: 12 kV; rated thermal stabilization current and time: 20kA/2 s; rated dynamic stability current (peak): 63 kA.

Low-voltage circuit breaker: the circuit breaker is an air circuit breaker and has the characteristic of resisting the operation overvoltage, namely, when the circuit breaker is operated to open and close a carried load, no overvoltage harmful to electric shock and a station transformer is generated, and the main parameters are as follows;

rated voltage: 0.69 kV; rated current: selecting according to the capacity of the transformer; rated frequency: 50 Hz; limiting the segmentation capability: 50 kA.

(2)10kV box type power distribution station electric part

A three-phase alternating-current indoor complete device KYN28A-12 metal armored movable high-voltage switch cabinet is selected, and primary elements mainly comprise a circuit breaker, a current transformer, a voltage transformer, a lightning arrester and the like. And has the function of five prevention, flexible operation and safe and reliable power supply. The single bus wiring mode is adopted, the wiring is simple and clear, the operation is convenient, the equipment is few, the extension is convenient, and a complete set of power distribution device is adopted. The vacuum circuit breaker is internally matched, rated current is 630-1600A, and cut-off current is 25 kA. The newly-built 10kV box-type power distribution station of this project is container formula, and the station power consumption draws 2 way 0.4kV power end mutual throws by former low voltage system to set up the strapping table in the case.

Lightning protection grounding

In order to ensure the safety and reliability of the photovoltaic grid-connected power generation system of the project and prevent the system devices from being damaged due to external factors such as lightning stroke, surge and the like, the project is provided with the lightning protection grounding device.

(1) The photovoltaic array area (photovoltaic power generation subsystem) adopts an aluminum alloy outer frame of the outer contour of a power generation unit as an overvoltage protection lightning receptor for preventing direct lightning. After the aluminum alloy outer frame for fixing the power generation unit and all components thereof are reliably connected, the aluminum alloy outer frame is reliably welded with the steel bracket at least at two points; the galvanized round steel with phi 12 is connected with an underground main grounding grid to form a three-dimensional lightning protection system. Meanwhile, in consideration of the personal safety of operators when lightning occurs, the field operation managers should prohibit anyone from entering the photovoltaic array area when the local meteorological department forecasts that lightning activities occur and direct lightning occurs.

(2) The multistage SPD surge protection devices are arranged in the combiner box and the power distribution cabinet, so that equipment damage caused by lightning stroke and power grid surge can be effectively avoided, and all cabinets are well grounded.

Third, grounding

The same grounding net is used for protection grounding, working grounding and overvoltage protection grounding. The existing grounding device of a factory is considered to be utilized, the grounding resistance meets the requirements of a component manufacturer and is not more than 4 omega, and when the existing grounding device cannot meet the requirements, a grounding body needs to be repaired until the requirements are met.

All electrical equipment should be grounded according to the regulations, the electrical equipment is connected with a grounding grid on site, each grounding part of the electrical equipment should be connected with a grounding trunk line through an independent grounding branch line, and two ends of each basic channel steel of the high-voltage power distribution cabinet and the low-voltage power distribution cabinet are reliably connected with an indoor grounding trunk line.

The main equipment materials are shown in table 2;

TABLE 2

Fourth, computer monitoring system

Data information of grid-connected inverters of the photovoltaic power generation field distributed in the parking lot is accessed to a box-type distribution station measurement and control unit in the box-type distribution station, and then is transmitted to a computer monitoring system of a photovoltaic power generation field control center through an Ethernet optical transceiver for remote monitoring of the photovoltaic power generation field.

(1) Control, protection, measurement and signaling of grid-connected inverter

The protection and monitoring equipment of the grid-connected inverter is provided by an inverter manufacturer in a matching way.

The inverters normally adopt a centralized monitoring mode, and operators in the photovoltaic power generation field perform centralized remote monitoring and control on all the inverters in the photovoltaic power generation field through a human-computer interface of a computer monitoring system of the inverters. On the local cabinet of each inverter, operators can monitor and control the inverters on the site through the LCD panel on the control cabinet; meanwhile, the cabinet contains a power supply synchronization unit, and the main function of the cabinet is to enable the inverter to be synchronously merged into a power grid.

The inverter is configured with the following protection functions: current quick-break protection, over/under frequency protection, over/under voltage protection, overload protection, reverse power protection, anti-islanding protection, and the like. The protection device acts to trip the inverter output breaker and sends a protection action signal.

The inverter is provided with various detection devices and transmitters, and reflects the real-time state of the inverter. The photovoltaic power plant computer can automatically and continuously monitor each inverter and can display the following contents on the display: the current date and time, the maximum photovoltaic array power, the maximum photovoltaic array open-circuit voltage, the direct current power, the alternating current voltage, the alternating current, the temperature in the inverter, the clock, the frequency, the current generated power, the daily generated energy, the accumulated CO2 emission reduction capacity, the daily generated power curve graph, the power grid voltage is too high, the power grid voltage is too low, the power grid frequency is too high and too low and other fault information.

The monitoring software of the inverter monitoring system has an integrated environment monitoring function and mainly comprises parameters such as sunlight intensity, wind speed, wind direction, outdoor and indoor ambient temperatures, battery board temperature and the like.

(2) Control, protection, measurement and signalling of transformers in a box substation

The method is used for monitoring the conditions of emergencies or people and the like, such as the position of a 10kV load switch of the box type power distribution station, a low-voltage circuit breaker signal, a box type power distribution station temperature signal, a box door opening warning signal of the box type power distribution station and the like, and remotely monitoring the low-voltage circuit breaker of the box type power distribution station. The three-phase voltage and the three-phase current of the low-voltage side of the box type power distribution station are measured to realize an unattended operation mode of the box type power distribution station, and the signals are all connected into a secondary terminal strip of the box type power distribution station so that the box type power distribution station monitoring equipment can be conveniently connected in a leading mode.

Communication of a box-type power distribution station monitoring system: the double optical ports are adopted to support ring network communication; and at least 2 paths of Ethernet interfaces and 8 independent RS485 serial ports are adopted to access other intelligent equipment. The communication protocol supports communication protocols and standards of MODBUS, IEC 61850 and IEC 60870-103/104. The remote control system has the functions of photoelectric conversion, data exchange, remote control, remote signaling and the like, and can upload field signals to a switching station monitoring system and receive control signals.

Each box type power distribution station monitoring device adopts a redundant uninterrupted UPS power supply to supply power, self-powered power supply devices inside the box type power distribution station can provide 1 path of AC220V power supply for the UPS, the UPS power supply is installed in a box type power distribution station monitoring device box, and box type power distribution station LCU monitoring devices are installed in a box type power distribution station body.

(3) Control, measurement and signalling of devices such as switch cabinets

The photovoltaic power generation field is provided with a set of comprehensive automatic system which is a comprehensive automatic communication hub and is an information comprehensive point of a whole station, and the system is responsible for acquiring measured data and state signals from main equipment, summarizing, analyzing, storing and reporting the obtained information and outputting the information, and is also responsible for the connection with remote power dispatching to realize the transmission of data and state quantity and the transmission of control commands; in addition, the system is also connected with other intelligent modules or equipment such as an electronic ammeter, a direct-current power supply system and the like, so as to jointly complete the comprehensive management function of the whole station.

The control mode of each main device is as follows:

local/remote control of 10kV breakers;

local control of the individual ac low-voltage circuit breakers.

The measuring meter is configured as follows:

10kV line: voltage, current, positive and negative active and reactive power, and power factors;

10kV bus: voltage, frequency, power factor;

a transformer: current, active and reactive power, temperature;

an alternating-current low-voltage line: voltage, current;

in addition, the method also comprises the measurement of the direct current bus voltage of the direct current power supply system.

All accident and fault signals are input into the photovoltaic power generation field integrated automatic system, are displayed by a display of the integrated automatic system, give a voice alarm, and print records, and the method specifically comprises the following steps:

tripping and closing of each circuit breaker and disconnection signals of a circuit breaker control circuit;

the states of the investment and test positions of each breaker trolley;

actions of a relay protection and automatic device and a device abnormal signal;

dc system and ac power failure signals.

Fifth, relay protection

10kV circuit, 10kV cubical switchboard's relay protection selects for use microcomputer type protection device, specifically as follows:

(1)10kV line: the output line T is connected to a system side 10kV line and is provided with a microcomputer type quick break, time delay overcurrent protection, low voltage protection, zero sequence overcurrent protection, overload protection and reclosing; the final configuration scheme is subject to the review of the access system.

(2)10kV incoming line: the direct-buried scheme of the current collecting line cable is provided with a microcomputer type quick break, time delay overcurrent protection, low voltage protection, zero sequence overcurrent protection and overload protection; a microcomputer device is adopted, and the functions of protection, control, measurement and remote transmission are integrated.

(3) Dynamic reactive power compensation device protection

A10 kV bus is provided with a group of dynamic reactive power compensation devices, and at least the following protection is provided according to the configuration condition of primary equipment:

the transformer is provided with differential protection and non-electric quantity protection according to the capacity;

the power unit is provided with protection such as drive faults, overvoltage, undervoltage, voltage loss, short circuit, overtemperature faults and the like;

the whole reactive compensation system has the functions of overcurrent output current, overvoltage power supply, undervoltage protection, voltage loss protection and the like;

the protection and control between the SVG loop switch cabinet and the SVG equipment are realized by a measurement and control protection device arranged in a 10kV dynamic reactive power compensation loop switch cabinet (SVG manufacturers are responsible for the protection and measurement and control of the whole set of dynamic reactive power compensation device and provide corresponding protection and measurement and control equipment).

(4)10kV bus: the 10kV bus in the period is provided with 1 bus protection device, and has the functions of bus differential protection, charging protection and the like.

(5) The safety automatic device comprises: a grid disconnection device (comprising a low-cycle low-voltage disconnection device, a high-cycle high-voltage disconnection device and a shock disconnection device) and an anti-islanding protection device (having the capacity of quickly detecting islanding and immediately disconnecting the grid after the islanding is detected) are arranged on the 10kV outgoing line side of a grid-connected power generation project.

(6) Fault recording device

In order to analyze the electric power system accident and the action condition of the relay protection device, the switch station is considered to be provided with a fault recording device to record the current and the voltage of a point from 10s before the fault to 60s after the fault, the action of the protection device, the operation condition of a protection channel and the like. The fault wave recording device has the functions of GPS time synchronization and wave recording information remote transmission scheduling terminal. The equipment has the advantages of high starting speed, reliable action, memory, remote data transmission, recording switching value action sequence and communication capacity. In the engineering, a fault oscillograph screen is configured, and the fault information of the whole station is connected into the oscillograph of the fault oscillograph screen.

Six, AC, DC power supply system

(1) Direct current system

The voltage of a direct current system is 220V, an intelligent high-frequency switch direct current power supply is selected, a rectifying module N +1 is in hot backup, high-frequency switch stepless bidirectional voltage regulation is carried out, and monitoring elements realize local and remote monitoring on alternating current power distribution, the rectifying module, a voltage reduction module and direct current feed. A group of 65Ah valve-controlled sealed fixed lead-acid storage battery is provided for power supplies of protection, control, anti-theft alarm, comprehensive automation equipment and the like. The system adopts single bus connection, and is provided with a silicon voltage regulating device, so that the voltage of the direct current bus is ensured to be within a normal range.

(2) Uninterruptible power supply system

The UPS system consists of rectifier, inverter, static switch, manual maintenance bypass switch, voltage regulating transformer, local LCD monitor and local diagnosis system. When the input power supply is in failure or disappears, the device automatically turns to the inversion power supply of the direct-current power supply so as to realize the uninterrupted output of alternating current 220V.

The capacity of the uninterrupted power supply is configured to be 1x3kVA, and the group 1-plane UPS inverter power supply screen is placed in the secondary equipment room.

Seventh, dispatching automation

(1) Telemechanical system

The photovoltaic power generation field is provided with a computer monitoring system to realize automatic management, a telecontrol function is integrated into the computer monitoring system, telecontrol information acquisition is completed by a data acquisition unit of the computer monitoring system, the running states and parameters of equipment such as an inverter, a bus, a circuit breaker and the like can be acquired, and remote measurement acquisition is performed by adopting alternating current sampling; in order to ensure the reliability of the telemechanical information transmission, a telemechanical workstation is configured, the telemechanical workstation can be considered with a computer monitoring system in a unified way, and direct acquisition and direct transmission of telemechanical information are completed by the telemechanical workstation. Telecontrol workstation, scheduling data network access function, etc. The relevant telecontrol information is sent to the opposite side scheduling post through the scheduling data network and the point-to-point channel simultaneously.

A set of power control system is configured in the photovoltaic power station, has the capability of continuously and smoothly adjusting power and can participate in system power control. The control instruction of the active power and the active power change issued by the power grid dispatching mechanism can be received and automatically executed.

And configuring a reactive voltage control system in the photovoltaic power station. The objects of reactive power and voltage regulation control include inverter reactive power, switching station reactive power compensation devices and the like, and the inverter and the reactive power compensation devices are preferably adopted for regulation. The photovoltaic power station automatically adjusts the reactive power of the photovoltaic power station according to the instruction of a power dispatching department, the voltage of a grid-connected point is controlled within a normal operation range, and the control precision of an adjusting speedometer of the photovoltaic power station meets the requirement of voltage adjustment of a power system.

A light power prediction system is configured in a photovoltaic power station, and the system has the functions of short-term photovoltaic power generation power prediction of 0h-72h and ultra-short-term photovoltaic power generation power prediction of 15min-4 h.

This application example still includes supporting billing system, video monitoring and security protection system, fire alarm and fire control system, communication system and the photovoltaic remote monitering system who designs, and the relevant system of technical personnel can be designed according to the concrete condition and the actual demand of project oneself in this field, and it is no longer repeated here.

The operation strategy of the photovoltaic power generation and energy storage integrated power supply system of the application example is as follows:

strategy 1:

according to the obtained electricity data of the parking building, the charging pile system which is expected to be implemented is added, the photovoltaic electric quantity cannot be completely consumed, but the generated energy of the photovoltaic power generation system can only be consumed by the loads, and the construction of the photovoltaic power generation system of the T1 parking lot cannot be implemented in stages in consideration of the requirement of the construction capacity of the photovoltaic power generation system on a bottom limit, so that the energy storage system is arranged, the time of the generated energy of the photovoltaic power generation system being consumed by the loads is prolonged, the renewable energy is fully utilized, and the condition of 'light abandon' is avoided.

In the daytime, the photovoltaic power generation system preferentially charges the energy storage system, and the charging time is 6 hours and is the same as the running time of the photovoltaic power generation system. The surplus charge is transmitted to a 10kV system through voltage boosting and transformation to supply power to a load and a charging pile;

at night or in rainy days, when the power generation capacity of the photovoltaic power generation system is insufficient or the photovoltaic power generation system stops running, the load and the charging pile are mainly supplied with power by a power grid, the energy storage system is controlled by an Energy Management System (EMS) and is transmitted to a 10kV system through voltage boosting, the discharging time is 6 hours, and the power is supplied to the load and the charging pile;

the micro-grid Energy Management System (EMS) performs data acquisition and analysis, centralized monitoring, real-time control, intelligent operation and maintenance and the like on the system.

Strategy 2:

when a power grid fault or the electric energy quality does not meet the requirement is detected, the photovoltaic power generation and energy storage integrated system (micro-grid system) is timely disconnected from the power grid and operates off-grid, and when the photovoltaic power generation system operates, the energy storage system is in a charging state; and (3) grid-connected power supply is carried out on the energy storage system in the load peak period (about 18-24 hours) at night. When the PCS detects that the power grid is in voltage loss, the PCS controls the quick change-over switch to be switched to an off-grid state, executes a V/F operation mode, and supplies power to important loads.

The micro-grid Energy Management System (EMS) coordinates the micro-grid system and the commercial power to jointly supply power to the load and the charging pile, and the commercial power supply proportion is about 5-15% in order to ensure safe operation.

Through the connection of a 10kVA bus, the CT is installed on a mains supply line to monitor electric energy in the line at any time, certain forward electric energy (accounting for 5-15% of load, empirical data and adjustable) in the line is guaranteed, and photovoltaic and energy storage output is reduced when the forward electric energy is lower than a set value. The rest part is normally powered by an energy storage and photovoltaic guarantee system.

At present, the first airport photovoltaic power generation and energy storage integrated project is already built, and tests show that the photovoltaic power generation and energy storage integrated power supply system can meet design requirements in the aspects of electric balance, battery service life of a box type energy storage system, environmental temperature of regions such as the box type energy storage system and a box type power distribution station and the like.

The establishment of the integrated project of photovoltaic power generation and energy storage of the capital airport becomes the first domestic example of applying the technology to large-scale international airports, has civil aviation demonstration effect, can promote the development of scientific technology and reduce the research and development cost, and has important contribution to the popularization and the economy of energy storage.

While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. The utility model provides a photovoltaic power generation and energy storage integration power supply system which characterized in that includes: the system comprises a photovoltaic power generation subsystem, a box type energy storage subsystem, a box type power distribution station and a load end opening and closing station;

2. The integrated photovoltaic power generation and energy storage power supply system according to claim 1, wherein the photovoltaic power generation subsystem comprises a plurality of strings of photovoltaic modules, a plurality of string inverters, and at least one ac combiner box;

the alternating current combiner box is connected with the first transformer.

3. The integrated photovoltaic power generation and energy storage power supply system according to claim 1, wherein the box-type energy storage subsystem comprises a first box body, and a plurality of storage batteries are arranged in the first box body in a distributed mode.

4. The integrated photovoltaic power generation and energy storage power supply system according to claim 3, wherein the storage battery is a lithium iron phosphate storage battery.

5. The integrated photovoltaic power generation and energy storage power supply system according to claim 1, wherein the box-type distribution station comprises a second box body, and a high-voltage operation room, a box transformer cabinet and a high-voltage switch cabinet which are isolated from each other are arranged in the second box body.

6. The integrated power supply system for photovoltaic power generation and energy storage as claimed in claim 5, wherein a step-up transformer, a transformer high-voltage switch, a high-voltage fuse, a grounding switch and a low-voltage circuit breaker are arranged in the box transformer substation cabinet.

7. The integrated photovoltaic power generation and energy storage power supply system according to claim 6, wherein the step-up transformer is a dry-type transformer, the transformer high-voltage switch is a load switch, and the low-voltage circuit breaker is an air circuit breaker;

8. The integrated power supply system for photovoltaic power generation and energy storage according to claim 5, wherein the high-voltage switch cabinet is a metal-clad removable high-voltage switch cabinet, and a circuit breaker, a current transformer, a voltage transformer and a lightning arrester are arranged in the high-voltage switch cabinet.

9. The integrated photovoltaic power generation and energy storage power supply system according to claim 1, further comprising a microgrid energy management subsystem for collecting data of the photovoltaic power generation subsystem, the box energy storage subsystem, the box-type distribution station and the load end switching station, and performing centralized monitoring and real-time control according to the collected data.