CN110061515A - A kind of energy storage monitoring device of the zinc-iron flow battery applied to photovoltaic power generation field - Google Patents

Abstract

The invention provides an energy storage monitoring device applied to a zinc-iron liquid flow battery in a photovoltaic power plant. The device can use SCADA data to realize a remote control mode, and can predict the photovoltaic power generation power collected by an optical power prediction and acquisition system. The data and the load curve are weighted and superimposed to implement different control strategies for the energy storage system. The communication part of the system adopts the separate networking form of conventional monitoring and high-speed control, and the energy management system monitors and manages the entire energy storage system to realize the steady-state control function. , to ensure the safe and reliable operation of the system, the first coordination controller and the second coordination controller realize the transient control function, and according to different application scenarios, formulate corresponding control strategies to reasonably control the coordinated operation of the energy storage converters to achieve energy In the two-way flow in the zinc-iron flow battery and the power grid, the battery management system can realize the effective management and control of the zinc-iron flow battery.

Description

An energy storage monitoring device for zinc-iron flow batteries applied to photovoltaic power plants

technical field

The invention relates to an energy storage monitoring device for a zinc-iron liquid flow battery applied to a photovoltaic power plant, in particular to an energy storage monitoring device, which belongs to the technical field of power electronics.

Background technique

With the development of my country's power grid, the problems of increasing peak-to-valley difference in power consumption, power grid security and stability, higher power quality requirements, and large-scale grid-connected renewable energy appear. , frequency and peak regulation, new energy access and other functions are more prominent, how to apply the energy storage system to practical engineering applications in a safer and higher quality, and ultimately, monitoring devices.

The cost per kilowatt hour of energy storage is much higher than that of photovoltaic power generation. The cost of pure energy storage system used for peak shaving and valley filling of the power grid, as well as frequency regulation and peak regulation is high. It is difficult to be used for peak shaving and valley filling, frequency and peak regulation of the power grid. At present, the existing energy storage control system does not introduce a photovoltaic power generation system for control, so it is very important to invent a photovoltaic plus energy storage system control system.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art, with complete functions, convenient use and good reliability.

To achieve the above object, the technical scheme adopted in the present invention is:

According to the technical solution provided by the present invention: an energy storage monitoring device for a zinc-iron flow battery applied to a photovoltaic power plant, comprising a power grid, a secondary equipment compartment, a battery container and an energy storage converter container, the power grid is electrically A first transformer, a second transformer and a PT sensor are connected, and the three first transformers, the second transformer and the PT sensor are connected in parallel, and one end of the first transformer is electrically connected with an energy storage system, so One end of the second transformer is electrically connected to a photovoltaic power generation system, one end of the PT sensor is electrically connected to an energy management system, and the energy storage converter container is electrically connected to the secondary equipment compartment and the battery container respectively. , the energy storage converter container is equipped with a DC/AC booster module, a DC/AC converter module, and an energy storage communication control cabinet, and the DC/AC booster module is integrated with a DC/DC monitoring device, so The DC/AC converter module is integrated with a DC/AC monitoring device, the energy storage communication control cabinet is integrated with a second coordination controller, a switch and a protocol conversion device, and a monitoring background and a monitoring background are arranged in the secondary equipment compartment. An energy management system, a battery management system is installed in the battery container, and the switch is electrically connected to the protocol conversion device, the battery management system, the energy management system, the DC/DC monitoring device, the DC/AC monitoring device and the second coordination controller respectively. The other side of the DC/AC monitoring device is electrically connected with the second coordination controller and the DC/DC monitoring device respectively, the other side of the protocol conversion device is connected with a battery management system, the energy management The other side of the system is connected to a monitoring background.

As a further improvement of the present invention, the energy storage system is provided with an energy storage converter, a zinc-iron flow battery and a battery management system. , The battery management system and the energy management system are electrically connected, and the battery management system is electrically connected with the energy management system.

As a further improvement of the present invention, the photovoltaic power generation system is provided with a photovoltaic inverter, photovoltaic components and a light power prediction and collection system, and one side of the photovoltaic inverter is electrically connected to the second transformer and the energy management system respectively. The other side of the photovoltaic inverter is connected with the photovoltaic assembly, and the optical power prediction and collection system is electrically connected with the energy management system.

As a further improvement of the present invention, the energy management system is provided with a server, a user interface, a motion device and a first coordinated controller, and one side of the first coordinated controller is electrically connected to the PT sensor and the energy storage converter respectively. The other side of the first coordination controller is connected in parallel with the server, the user interface and the motion device respectively through the wire harness. There are two servers in total, and one end of the motion device is connected to the dispatch center.

As a further improvement of the present invention, three sets of the energy storage systems are installed in total, and the three sets of the energy storage systems are connected in parallel.

Compared with the prior art, the present invention has the following advantages:

1), the present invention solves the problem of peak shaving and valley filling and frequency modulation of the energy storage system used in the power grid by setting up an energy storage monitoring device for a zinc-iron flow battery applied to a photovoltaic power plant, and by introducing a photovoltaic power generation system for control. Problems such as the high cost of peak shaving, and in the process of simple photovoltaic power generation, the instability of power affects the peak shaving and valley filling, frequency and peak shaving of the power grid.

2) The device can use SCADA data to realize the remote control mode, and at the same time, it can implement different control strategies for the energy storage system by means of weighted superposition of the photovoltaic power generation power prediction data collected by the optical power prediction and acquisition system and the load curve. The communication part adopts the conventional monitoring and high-speed control separate networking form, the energy management system monitors and manages the entire energy storage system, realizes the steady-state control function, and ensures the safe and reliable operation of the system. The first coordination controller and the second coordination controller realize the transient state Control function, and formulate corresponding control strategies according to different application scenarios, reasonably control the coordinated operation of energy storage converters, and realize the bidirectional flow of energy in the zinc-iron flow battery and the power grid. Effective management and control of iron flow batteries.

Description of drawings

FIG. 1 is a schematic diagram of a main wiring diagram and a monitoring device of an energy storage system according to the present invention.

FIG. 2 is a schematic diagram of a main wiring diagram and a monitoring device of the optical storage system of the present invention.

FIG. 3 is a schematic diagram of the network communication of the energy storage monitoring device of the present invention.

FIG. 4 is a schematic diagram of peak shaving and valley filling according to the present invention.

FIG. 5 is a schematic diagram of the planning curve of the present invention.

FIG. 6 is a schematic diagram of the auxiliary frequency modulation of the present invention.

FIG. 7 is a schematic diagram of the auxiliary voltage regulation of the present invention.

FIG. 8 is a schematic diagram of power distribution according to the present invention.

FIG. 9 is a schematic diagram of power distribution of the present invention

FIG. 10 is a schematic diagram of the SOC adjustment control of the present invention.

In the figure: 1. Power grid; 2. Energy management system; 3. Server; 4. User interface; 5. Movement device; 6. First coordination controller; 7. First transformer; 8. PT sensor; 9. Energy storage Converter; 10. Battery Management System; 11. Dispatching Center; 12. Second Transformer; 13. Photovoltaic Inverter; 14. Photovoltaic Module; 15. Photovoltaic Power Generation System; 16. Optical Power Prediction and Acquisition System; 17. Zinc-iron flow battery; 18. Energy storage system; 19. Secondary equipment compartment; 20. Monitoring background; 21. Battery container; 22. DC/DC monitoring device; 23. DC/AC booster module; 24. DC/ AC monitoring device; 25, DC/AC converter module; 26, energy storage converter container; 27, protocol conversion device; 28, switch; 29, second coordination controller; 30, energy storage communication control cabinet.

Detailed ways

In order to make the technical means, creative features, achievement goals and effects realized by the present invention easy to understand, the present invention will be further described below with reference to the specific embodiments.

As shown in Figure 1-10, an energy storage monitoring device for a zinc-iron flow battery applied to a photovoltaic power plant includes a power grid 1, a secondary equipment compartment 19, a battery container 21 and an energy storage converter container 26. The power grid 1 is electrically connected with a first transformer 7, a second transformer 12 and a PT sensor 8, and the three first transformers 7, the second transformer 12 and the PT sensors 8 are connected in parallel in pairs, and the first transformer is connected in parallel. One end of the PT sensor 8 is electrically connected to the energy storage system 18, one end of the second transformer 12 is electrically connected to the photovoltaic power generation system 15, and one end of the PT sensor 8 is electrically connected to the energy management system 2. The converter container 26 is electrically connected with the secondary equipment compartment 19 and the battery container 21 respectively. The energy storage converter container 26 is equipped with a DC/AC booster module 23 , a DC/AC converter module 25 , and a storage battery. A communication control cabinet 30, a DC/DC monitoring device 22 is integrated in the DC/AC boost module 23, a DC/AC monitoring device 24 is integrated in the DC/AC converter module 25, and the energy storage communication control A second coordination controller 29 , a switch 28 and a protocol conversion device 27 are integrated in the cabinet 30 , a monitoring background 20 and an energy management system 2 are arranged in the secondary equipment compartment 19 , and a battery management system is installed in the battery container 21 10. The switch 28 is electrically connected to the protocol conversion device 27, the battery management system 10, the energy management system 2, the DC/DC monitoring device 22, the DC/AC monitoring device 24 and the second coordination controller 29, respectively. The other side of the /AC monitoring device 24 is electrically connected to the second coordination controller 29 and the DC/DC monitoring device 22 respectively, the other side of the protocol conversion device 27 is connected to the battery management system 10, the energy management system The other side of 2 is connected with a monitoring background 20 .

As shown in FIGS. 1 and 2 , the energy storage system 18 is provided with an energy storage converter 9 , a zinc-iron flow battery 17 and a battery management system 10 . A transformer 7 , a zinc-iron flow battery 17 , a battery management system 10 and an energy management system 2 are electrically connected, and the battery management system 10 is electrically connected to the energy management system 2 .

As shown in FIG. 2 , the photovoltaic power generation system 15 is provided with a photovoltaic inverter 13 , a photovoltaic module 14 and an optical power prediction and collection system 16 , and one side of the photovoltaic inverter 13 is connected to the second transformer respectively. 12 is electrically connected to the energy management system 2, the other side of the photovoltaic inverter 13 is connected to the photovoltaic module 14, the optical power prediction and acquisition system 16 is electrically connected to the energy management system 2, and the photovoltaic power generation system 15 is electrically connected. The settings allow maximum utilization of photovoltaic power generation for economical optimization.

As shown in FIG. 1, wherein, the energy management system 2 is provided with a server 3, a user interface 4, a motion device 5 and a first coordinated controller 6, and one side of the first coordinated controller 6 is respectively connected to the PT sensor. 8 and the energy storage converter 9 are electrically connected, and the other side of the first coordination controller 6 is connected in parallel with the server 3, the user interface 4 and the motion device 5 respectively through the wire harness, and the server 3 is provided with two , one end of the motion device 5 is connected to the dispatching center 11, the first coordination controller 6 and the second coordination controller 29 are used to receive dispatching instructions from the energy management system 2 or the dispatching center 11, and complete the energy storage converter Coordinated control of the DC/DC monitoring device 22 and the DC/AC monitoring device 24 in the container 26 .

As shown in FIG. 1 , there are three sets of energy storage systems 18 installed in total, and the three sets of energy storage systems 18 are connected in parallel. The three sets of energy storage systems 18 can store more electrical energy and can play a role in peak shaving The role of valley filling.

It should be noted that the present invention is an energy storage monitoring device applied to a zinc-iron flow battery of a photovoltaic power plant, which can be used in the following aspects:

1) Active power tracking, the energy storage system 18 can quickly respond to the dispatching instructions of the dispatching center 11 to realize the role of auxiliary power regulation. The power tracking control of the controller can be selected through the fixed value control word, and supports remote mode or local mode. The controller 6 converts the data and transmits it to the DC/AC monitoring device 24, so as to achieve the purpose of controlling the charging and discharging power of the energy storage. The local mode means that the active command value is sent to the first coordination controller 6 through the user interface 4, and the first coordination The controller 6 converts the data and transmits it to the DC/AC monitoring device 24 in the device to control the charging and discharging power of the energy storage. The energy storage converter 9 controls the current output active power and the received power command by real-time detection. The active power output of the energy storage system can quickly and accurately respond to dispatch instructions.

2) Generally, peaks are cut to fill valleys, and the energy storage system 18 has excellent peak-shaving performance due to its fast response characteristics. The system can be used as a power source to release electricity during peak periods of electricity consumption, and absorb electricity as a load during valley periods of electricity consumption, thereby improving the economy and safety of power grid operation. The advantage of the smooth charge-discharge curve of the zinc-iron flow battery 17 is that, in addition to taking into account the peak discharge of electricity consumption and the use of low-valley charging, it also collects the predicted power generation information of the photovoltaic power generation system 15 and adjusts the charging and discharging time to use photovoltaic power generation as much as possible. achieve economic optimality.

The controller's peak-shaving and valley-filling control can be selected through the fixed value control word, and supports remote mode or local mode. The remote mode means that the controller sends the power grid peak and valley power load curve according to SCADA data (the load curve is shown in Figure 4) and Based on the weighted superposition (set value) of the predicted photovoltaic power generation curve under meteorological conditions, a charge and discharge control strategy is made for the energy storage system 18. The local control refers to the control according to the peak and valley values set by the local controller through the fixed value The energy storage charging and discharging power, when the weighted superposition of the output of the photovoltaic power generation system 15 and the demand power of the load curve is a negative value, the energy storage system 18 discharges; The energy system 18 is charged with the remaining photovoltaic power generation, and when the load is at a low power consumption point, the energy storage system 18 is charged.

3) Planning curve, the planning curve function is to control the output of the energy storage system 18, so that it arranges the charging and discharging plan according to the predetermined planning curve, so as to realize the economic value of the energy storage system 18, that is, charging when the electricity price is low, and the electricity price is high. when discharging. The remote mode means that the controller performs weighted superposition of the planned curve control value sent by SCADA data and the predicted photovoltaic power generation curve based on meteorological conditions, and makes a charge and discharge control strategy for the energy storage system 18. Local control refers to the local control. The controller sets the planned curve control value by a fixed value and performs weighted superposition of the photovoltaic power generation predicted power generation curve based on meteorological conditions, and makes a charge and discharge control strategy for the energy storage system 18. When the output of the photovoltaic power generation system 15 matches the planned curve (daytime) When the weighted superposition of the load power during the period) is negative, the energy storage system 18 discharges, and when the output of the photovoltaic system and the planned curve (daytime period) the weighted superposition of the load power is a positive value, the energy storage system 18 uses the remaining photovoltaic power generation for charging , when the load is in the valley of electricity consumption, the energy storage system 18 supplements the insufficient charging during the day, so as to realize the charging and discharging of the energy storage system 18 according to the planned curve setting, and at the same time maximize the use of the photovoltaic power generation system 15 to generate electricity to achieve The economic benefits are the best (see Figure 5).

4), frequency regulation and voltage regulation, the energy storage system 18 can be used as an auxiliary for frequency regulation of the power grid, and the fast response characteristics of the zinc-iron flow battery 17 are used to improve the frequency regulation effect. At the same time, the energy storage system 18 can also output reactive power to assist in voltage regulation. The frequency of grid 1 depends on the balance between the active power of the generation and the active power of the load. When the active power of the generation is greater than the active power of the load, the system frequency increases, and when the active power of the generation is less than the load active power, the system frequency decreases, The control system determines the working state of the solar energy storage system by detecting the difference between the grid frequency and the set high value and low value. When the active power provided by the photovoltaic power generation for the grid is insufficient, the control system starts the energy storage system 18 to supplement the active power output. When the grid does not need the assistance of the photovoltaic power generation system 15, the energy storage system 18 is charged, and finally realizes the real-time balance between photovoltaic power generation and the load active power, thereby stabilizing the frequency of the system, and the second coordination controller 29 communicates through the energy storage system in the system. The equipment in the locker 30 collects the frequency of the bus (the frequency of the power grid) and compares the set high and low values in real time. The DC/AC monitoring module 24 controls the energy storage through the instructions issued by the second coordination controller 29 In system 18, when the system frequency drops, the optical storage system discharges, increasing the active output, and when the system frequency rises, the optical storage system charges and reduces the active output, as shown in the schematic diagram of frequency modulation (see Figure 6).

The voltage of grid 1 depends on the balance between the generation reactive power and the load reactive power. When the generated reactive power is greater than the load reactive power, the system voltage rises, and when the generated reactive power is less than the load reactive power, the system When the voltage drops, the control system determines the working state of the optical storage system by detecting the grid voltage and the set high and low values, so as to balance it with the load reactive power in real time, thereby stabilizing the system voltage. The working principle of the device is consistent with the working principle of frequency modulation. , when the system voltage drops, the optical energy storage system emits reactive power, and when the system voltage rises, the optical storage system absorbs reactive power, and the schematic diagram of voltage regulation is shown in Figure 7.

5) Power distribution and SOC adjustment. For energy storage units 18 with larger capacity, the charging and discharging characteristics of each battery pack are not the same, and their SOC values are not completely the same. In order to ensure balanced charging and discharging of each battery pack, To prolong battery life, the second coordination controller 29 sets a power balance distribution strategy and an SOC adjustment control strategy. In this control system, the second coordination controller 29 obtains the SOC status of each battery pack by interconnecting with the battery management system 10. The secondary charging and discharging power, according to the SOC state of each battery pack, sends information proportionally to the DC/AC monitoring device 24 through the energy storage converter 9, and the DC/DC monitoring device 24 controls the working mode of the energy storage converter 9 It is assigned to each battery pack. When charging, the battery pack with a small SOC is charged first, and the charging power is high. When discharging, the battery pack with a large SOC is preferentially discharged, and the discharge power is large. The schematic diagram of power distribution (see Figure 8 and Figure 9).

In order to make each battery group in the energy storage system 18 have an appropriate SOC value, each charge and discharge command can be responded to, and the SOC adjustment control is performed on the premise of not affecting the operation of other functional modules. The control strategy controls the SOC within a reasonable range, and the control principle is shown in Figure 10.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and modifications fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (5)

1. a kind of energy storage monitoring device of the zinc-iron flow battery applied to photovoltaic power generation field, including power grid (1), secondary device cabin (19), battery container (21) and energy accumulation current converter container (26), it is characterised in that: the power grid (1) is electrically connected with One transformer (7), the second transformer (12) and PT sensor (8), three first transformers (7), the second transformers (12) And PT sensor (8) is connected in parallel between any two, one end of first transformer (7) is electrically connected with energy-storage system (18), one end of second transformer (12) is electrically connected with photovoltaic generating system (15), one end of the PT sensor (8) Be electrically connected with Energy Management System (2), the energy accumulation current converter container (26) respectively with secondary device cabin (19) and battery Container is electrically connected between (21), is equipped with DC/AC boost module (23), DC/ in the energy accumulation current converter container (26) AC unsteady flow module (25), energy storage Communication Control cabinet (30), the DC/AC boost module (23) is interior to be integrated with DC/DC monitoring device (22), it is integrated with DC/AC monitoring device (24) in the DC/AC unsteady flow module (25), in the energy storage Communication Control cabinet (30) It is integrated with the second tuning controller (29), interchanger (28) and protocol conversion device (27), is set in the secondary device cabin (19) It is equipped with monitoring backstage (20) and Energy Management System (2), battery management system (10) are installed in the battery container (21), The interchanger (28) is supervised with protocol conversion device (27), battery management system (10), Energy Management System (2), DC/DC respectively It controls device (22), DC/AC monitoring device (24) and the second tuning controller (29) to be electrically connected, the DC/AC monitoring device (24) the other side is electrically connected with the second tuning controller (29) and DC/DC monitoring device (22) respectively, the specification conversion The other side of device (27) is connected with battery management system (10), and the other side of the Energy Management System (2) is connected with monitoring (20) from the background.

2. a kind of energy storage monitoring device of zinc-iron flow battery applied to photovoltaic power generation field according to claim 1, It is characterized in that: being provided with energy accumulation current converter (9), zinc-iron flow battery (17) and battery management system in the energy-storage system (18) (10), the energy accumulation current converter (9) respectively with the first transformer (7), zinc-iron flow battery (17), battery management system (10) and Energy Management System is electrically connected between (2), and the battery management system (10) and Energy Management System (2) are electrically connected.

3. a kind of energy storage monitoring device of zinc-iron flow battery applied to photovoltaic power generation field according to claim 1, It is characterized in that: being provided with photovoltaic DC-to-AC converter (13), photovoltaic module (14) and pre- to optical power in the photovoltaic generating system (15) Survey acquisition system (16), the side of the photovoltaic DC-to-AC converter (13) respectively with the second transformer (12) and Energy Management System (2) It is electrically connected, the other side of the photovoltaic DC-to-AC converter (13) is connected with photovoltaic module (14), described to optical power Prediction and Acquisition system System (16) and Energy Management System (2) are electrically connected.

4. a kind of energy storage monitoring device of zinc-iron flow battery applied to photovoltaic power generation field according to claim 1, It is characterized in that: being provided with server (3), user interface (4), telecontrol equipment (5) and the first association in the Energy Management System (2) It adjusts controller (6), the side of first tuning controller (6) electrically connects with PT sensor (8) and energy accumulation current converter (9) respectively Connect, the other side of first tuning controller (6) by harness respectively with server (3), user interface (4) and telecontrol equipment (5) it is connected in parallel, for the server (3) altogether there are two settings, one end of the telecontrol equipment (5) is connected with control centre (11)。

5. a kind of energy storage monitoring device of zinc-iron flow battery applied to photovoltaic power generation field according to claim 1, Be characterized in that: the energy-storage system (18) is equipped with three sets altogether, is connected in parallel between three sets of energy-storage systems (18).