CN202218023U - New-energy distributed type energy-storage application control system - Google Patents

Abstract

The utility model relates to a distributed type energy-storage application control system comprising a new-energy generating device, an energy storage unit, a generating/energy storage control unit, an inverter unit and the like, and a system main control unit, wherein the generating/energy storage control unit is connected with the new-energy generating device, the energy storage unit, the inverter unit and a power grid and communicates with the system main control unit and the energy storage unit. Under the control of the system main control unit, the generating/energy storage control unit can convert electricity generated by the new-energy generating device or alternating-current power of a power grid, then the electricity or the alternating-current power is stored in the energy storage unit and also can be directly inverted into the alternating-current power which is supplied to the power grid or alternating-current loads; and the electricity stored in the energy storage unit also can be inverted into alternating-current power which is supplied to the power grid or the alternating-current loads. According to the distributed type energy-storage application control system, the generating efficiency of the new-energy generating device can be furthest improved under the actual practical environment, and the peak and valley adjusting functions also can be realized, so that the electricity of the power grid is reasonably utilized, and the waste of the electricity is reduced.

Description

New energy distributed energy storage application control system

technical field

The utility model relates to the fields of electric energy storage, off-grid and grid-connected inverter power generation, etc., specifically refers to storing solar energy and grid electric energy in energy storage devices (such as battery packs), and then off-grid or grid-connected inverters when needed. A control system for variable power generation.

Background technique

In the field of photovoltaic power generation, currently commonly used solar energy utilization modes mainly include the photovoltaic utilization mode of small off-grid power generation in Figure 1, the photovoltaic utilization mode of large-scale photovoltaic power station grid-connected power generation in Figure 2, and the large-scale energy storage power station in Figure 3 There are several types of photovoltaic utilization modes.

The utilization mode of small-scale photovoltaic off-grid power generation in Figure 1 is suitable for applications such as street lamps, billboards, small-scale photovoltaic building integration, and roof power generation of residences. Because the dispatch of the grid is not accepted, the stored electric energy may be consumed due to no load for a long time However, the solar battery array cannot store energy for the battery pack or supply power to the load, which causes a lot of waste and the system economy is not high.

The grid-connected power generation utilization mode of large-scale photovoltaic power plants in Figure 2 is widely used. At present, the scale of this kind of photovoltaic power station is still relatively small, and the impact of grid-connected power generation on the power grid is still relatively small. When the construction of large-scale photovoltaic power stations reaches a certain scale, it will inevitably cause great trouble to the power grid. Because photovoltaic power generation is extremely unstable, it is available during the day and not at night, and it is extremely unstable even during the day, so it is difficult to dispatch and manage the power supply system. Large-scale photovoltaic power plants need to lay many solar panels. After connecting multiple solar panels in series, they are connected in parallel through a combiner box, and then input to multiple parallel-connected inverters of hundreds of kilowatts or even megawatts. The inverters are connected to the grid. generate electricity. The disadvantage of connecting many solar panels in series and parallel is that the output of the entire solar array is based on the string of solar cells with the worst power generation effect. The solar array is also affected by the cloud cover, building shadows, dust, temperature, The impact of line distribution impedance and so on is serious, and the solar cell array may form multiple constantly changing maximum power points. Generally, the maximum power tracking function of solar cells is integrated in the inverter. Therefore, the inverter may not work at the actual best maximum power point, resulting in low power generation efficiency of photovoltaic power plants and low investment returns of photovoltaic power plants. high.

The large-scale energy storage power station in Figure 3 is formed to alleviate the problem of power supply scheduling. When the grid load is heavy, the electrical energy stored in the large energy storage unit array or the electrical energy generated by the solar cell array can be connected to the grid for power generation through the inverter. When the grid load is light, the excess electrical energy of the grid can be temporarily stored in the Large energy storage unit array in case of emergency. This utilization mode can alleviate the problem of power supply scheduling, but investing in the construction of such a large-scale energy storage power station requires a large piece of land and many large-scale energy storage batteries, which conflicts with the current situation of increasingly tense land resources. Large-scale energy storage batteries The security of centralized configuration also needs to be considered. Moreover, when a solar panel, a certain battery or a certain high-power equipment in the energy storage power station has a problem, a large part of the equipment in the energy storage power station will be shut down for repair, and the grid dispatching command cannot be executed. , resulting in great waste and reduced return on investment.

Therefore, it is necessary to study a new energy storage inverter power generation system to solve the above problems.

Contents of the invention

The technical problem that the utility model needs to solve is:

(1) Solve the problem that the photovoltaic power generation system reduces the utilization rate of solar energy due to the short board effect of solar cells;

(2) Solve the problems of existing energy storage power stations occupying a large amount of land resources, high maintenance costs and low benefits;

(3) Solve the problem that the existing photovoltaic power generation system does not have the function of power grid peak regulation and valley regulation;

(4) Solve the problem of surplus electric energy storage.

In order to solve the above technical problems, the technical solution adopted by the utility model circuit is:

A new energy distributed energy storage application control system is provided, which includes a system master control unit and one or more subsystems controlled by the master control unit. Each subsystem includes one or more of the following functional units with a corresponding number: new energy power generation device, using solar cell array or wind power generator set or a combination of the two, connected to the power generation/energy storage control unit and controlled by the unit; energy storage The unit is composed of energy storage devices such as batteries or supercapacitors connected in series and parallel. It is connected to the power generation/energy storage control unit and controlled by the unit to store electric energy; the power generation/energy storage control unit communicates with the system master control unit and accepts the system master control unit. The unit command realizes the conversion of electric energy in the system; the conversion of electric energy includes two-way electric energy conversion between the power grid and the energy storage unit, the new energy power generation device to the power grid, the new energy power generation device to the AC load, and the new energy power generation device to the energy storage unit , The energy storage unit converts the electric energy to the AC load; and the energy storage unit and its own status information are sent to the system master control unit; the inverter unit adopts a bidirectional inverter circuit, connected with the power generation/energy storage control unit, and is controlled by the system The master control unit completes the two-way power conversion between the grid and the energy storage unit, and the power conversion of the new energy power generation device to the power grid, the new energy power generation device to the AC load, and the energy storage unit to the AC load; off-grid/grid-connected The control unit is connected between the inverter unit and the AC load, and is controlled by the system master control unit to realize the power supply switching between the AC load and the grid. Each subsystem can be configured in an independent building area.

Further, the system master control unit communicates with the power grid monitoring and dispatching system, and is dispatched and coordinated by the power grid monitoring and dispatching system to control the trend of electric energy in the system.

Further, the energy storage unit has a battery management system (BMS) inside; the power generation/energy storage control unit also communicates with the battery management system (BMS) of the energy storage unit to monitor the status of the energy storage unit.

Alternatively, the utility model adopts another approximate solution: the new energy distributed energy storage application control system includes a system master control unit, an inverter unit, an off-grid/grid-connected control unit, and one or more new energy generators, energy storage units corresponding to the number of new energy generators, and power generation/energy storage control units corresponding to the number of new energy generators. The above-mentioned new energy power generation device, energy storage unit, and power generation/energy storage control unit form a group, and each group is arranged in an area. The above-mentioned three functional modules share one inverter unit and one off-grid/grid-connected control unit. The connection lines are brought together to the inverter unit.

The functions of each module are similar to the previous scheme, that is, the new energy power generation device adopts solar cell array or wind power generator set or a combination of the two, and is connected with the power generation/energy storage control unit to be controlled by the unit; the energy storage unit is controlled by the battery or super Capacitors and other energy storage devices are connected in series and parallel, connected with the power generation/energy storage control unit and controlled by the unit to realize the storage of electric energy; the power generation/energy storage control unit communicates with the system master control unit, and accepts the system master control unit to realize the power storage in the system Conversion; the conversion of electric energy includes two-way electric energy conversion between the grid and the energy storage unit, from the new energy power generation device to the power grid, from the new energy power generation device to the AC load, from the new energy power generation device to the energy storage unit, and from the energy storage unit to the AC load power conversion; and send the energy storage unit and its own status information to the system master control unit. The inverter unit adopts a bidirectional inverter circuit, which is connected to each power generation/energy storage control unit, and is controlled by the system master control unit to complete the bidirectional power conversion between the grid and the energy storage unit and the new energy power generation device to the grid and new energy power generation device Electric energy conversion to AC loads, energy storage units to AC loads. The off-grid/grid-connected control unit is connected between the inverter unit and the AC load, and is controlled by the system master control unit to realize the power supply switching between the AC load and the grid. Each subsystem can be configured in an independent building area.

Further, the system master control unit communicates with the power grid monitoring and dispatching system, and is dispatched and coordinated by the power grid monitoring and dispatching system to control the trend of electric energy in the system.

Further, the energy storage unit has a battery management system (BMS) inside; the power generation/energy storage control unit also communicates with the battery management system (BMS) of the energy storage unit to monitor the status of the energy storage unit.

Compared with the prior art, the beneficial effects of the utility model are:

1), the system described in this utility model can realize the storage and utilization of various surplus electric energy, and then realize the function of peak regulation and valley regulation of the power grid; the function design of each module is independent and perfect, and the functions of each module complement each other, and it is applied in large-scale energy storage power stations Among them, when a certain unit equipment fails, only the energy storage and power generation unit directly related to this equipment cannot work normally, which will not have a great impact on the entire system, and the repair and maintenance project and cost are relatively small;

2) Key components such as new energy power generation devices, energy storage units, power generation/energy storage control units, and inverter units in the system described in this utility model can be scattered and arranged on the roofs, curtain walls, and idle areas of buildings in a certain area. On the block, there is no need to open up additional land to install these power generation equipment, saving resources;

3) Adopting the system described in this utility model can cancel the lightning protection combiner box that must be configured in the existing solar power generation inverter system, and can cancel the maximum power point tracking function of the inverter unit, and instead use power generation/energy storage control The unit completes these functions, which can ensure that each new energy power generation device works near its respective maximum power point, and improve the power generation efficiency of the new energy power generation device.

Description of drawings

Fig. 1 is a schematic block diagram of the principle of photovoltaic utilization mode of small and medium-sized off-grid power generation in the prior art;

Fig. 2 is a schematic diagram of the principle of photovoltaic utilization mode of grid-connected power generation of large-scale photovoltaic power plants in the prior art;

Fig. 3 is a schematic diagram of a photovoltaic utilization mode of a large-scale energy storage power station in the prior art;

Fig. 4 is a schematic diagram of the composition principle of the new energy distributed energy storage application control system described in the utility model;

Fig. 5 is a schematic diagram of the composition principle of another embodiment of the new energy distributed energy storage application control system of the utility model.

Detailed ways

In order to facilitate the understanding of those skilled in the art, the utility model will be further described in detail below in conjunction with specific embodiments and accompanying drawings.

As shown in Figure 4, the new energy distributed energy storage application control system described in this embodiment includes a new energy power generation device, a power generation/energy storage control unit, an energy storage unit, an inverter unit, an off-grid/grid-connected control unit, a system master Control unit, power grid monitoring and dispatching system.

It is applied in the application system of large-scale energy storage power stations. The power generation/energy storage control unit is connected with the new energy power generation device, the energy storage unit, the AC power grid, and the system master control unit. The power generation/energy storage control unit communicates with the The battery management system (BMS) communication of the energy storage unit monitors the status of the energy storage unit, and communicates with the system master control unit through the communication line, receives the system master control unit instructions and sends the energy storage unit and new energy power generation device to the system master control unit status information. The new energy power generation device 1, the energy storage unit 1, and the power generation/energy storage control unit 1 are arranged in area 1; the new energy power generation device 2, the energy storage unit 2, and the power generation/energy storage control unit 2 are arranged in area 2; the new Energy generating device n, energy storage unit n, and power generation/energy storage control unit n are arranged in area N, and the outputs of power generation/energy storage control units 1, 2,...n arranged in areas 1, 2, ... N are connected in parallel to Together, as the input of the inverter unit, the inverter unit is connected with the system master control unit, the AC grid and the off-grid/grid-connected control unit. The inverter unit and off-grid/grid-connected control unit receive instructions from the system master control unit. When the load needs it, it works in the off-grid mode that supplies power to the load. In the grid-connected mode of generating power to the grid, when the new energy power generation device fails to generate electricity, the power generation/energy storage control units 1, 2, ... n can receive instructions from the system master control unit, rectify and correct the power factor of the grid power and After high-frequency conversion, the energy storage units 1, 2, ...n store energy, and through the reasonable dispatch of the power grid monitoring and dispatching system, the function of peak regulation and valley regulation of the AC power grid can be realized. The inverter unit no longer integrates the function of maximum power tracking, but adds the function of maximum power tracking to the power generation/energy storage control unit, so that the new energy power generation devices can generate electricity according to their respective maximum power, so that the entire new energy power generation device system Maximize power generation efficiency.

The above-mentioned distributed energy storage and inverter system has at least six working modes, which will be described in detail below with reference to FIG. 4 .

Mode 1: The storage mode of the power generated by the new energy power generation device. Under the conditions of normal power generation of the new energy power generation device, insufficient power of the energy storage unit, no dispatching command issued by the grid monitoring and dispatching system, and no working of the AC load, the power generated by the new energy power generation device is controlled by the power generation/energy storage control unit to the energy storage unit. Energy storage, power generation/energy storage control unit communicates with the BMS system of the energy storage unit, intelligently monitors the status of the energy storage unit in real time to ensure safe and reliable energy storage.

Mode 2: grid electric energy storage mode. When the new energy power generation device cannot generate electricity, the power of the energy storage unit is insufficient, and the grid load is not heavy, the grid monitoring and dispatching system issues an instruction, the internal charging control module of the power generation/energy storage control unit starts to work, and the grid power is stored in the energy storage unit middle.

Mode 3: The mode in which the power generated by the new energy power generation device is stored and simultaneously connected to the grid for inverter power generation. Under the conditions of normal power generation of the new energy power generation device, insufficient power of the energy storage unit, dispatching instructions of the grid monitoring and dispatching system, and the failure of the AC load, the electric energy generated by the new energy power generation device is controlled by the power generation/energy storage control unit to the energy storage unit. At the same time of energy storage, the power generation/energy storage control unit outputs stable direct current through the inverter unit to be connected to the grid for power generation.

Mode 4: The mode in which the power generated by the new energy power generation device is stored while off-grid inverter power generation. The difference between this mode and mode 3 is that the inverter unit is not connected to the grid, but only supplies power to the AC loads in the area.

Mode 5: The mode in which the stored electric energy is connected to the grid for inverter generation. When the new energy power generation device cannot generate power, the energy storage unit has sufficient power, and the grid load is heavy, the grid monitoring and dispatching system issues an instruction, and the stored electric energy is connected to the grid for power generation through the power generation/energy storage control unit and the inverter unit.

Mode 6: The stored electric energy off-grid inverter power generation mode. The difference between this mode and mode five is that the inverter unit is not connected to the grid, and only supplies power to the AC loads in the area.

In the distributed energy storage inverter system, the new energy power generation device 1 distributed in a certain area, the power generation/energy storage control unit 1, the energy storage unit 1 and the new energy power generation device 2 distributed in another area, the power generation/energy storage control unit When unit 2, energy storage unit 2 or new energy power generation device n distributed in other areas, power generation/energy storage control unit n, and energy storage unit n work in the energy storage state and when they work in the power generation state, it is completely determined by the system general manager. The control unit decides according to the collected current status of the new energy power generation device, energy storage unit, AC power grid and other equipment.

Fig. 5 is a block diagram of another embodiment of the system described in the present invention. It is more suitable for application in small new energy power generation systems. The difference between the embodiment shown in Figure 5 and the embodiment shown in Figure 4 is that the DC output of each power generation/energy storage control unit is not connected in parallel, but is connected to a small inverter unit, and the inverter unit is connected to the off-grid/ Grid-connected control unit, then off-grid or grid-connected power generation. A new energy power generation device is equipped with a power generation/energy storage control unit, an energy storage unit, an inverter unit, and an off-grid/grid-connected control unit. These modules are a group and are arranged in the same area. Their working mode and principle Similar to the embodiment shown in FIG. 4 , details are not repeated here.

The functional units not specifically described in the utility model can adopt the mature functional modules in the prior art, and will not be repeated here.

It should be noted that the above-mentioned embodiment is only a preferred embodiment of the utility model, and it cannot be understood as a limitation on the scope of protection of the utility model. Changes and modifications all belong to the protection scope of the present utility model.

Claims (10)

1. A new energy distributed energy storage application control system, characterized in that it includes a system master control unit, and one or more of the following functional units corresponding to the number: New energy power generation devices, using solar cell arrays or wind turbines or a combination of the two, connected to the power generation/energy storage control unit and controlled by the unit; The energy storage unit is composed of energy storage devices such as batteries or supercapacitors connected in series and parallel, connected with the power generation/energy storage control unit and controlled by the unit to realize the storage of electric energy; The power generation/energy storage control unit communicates with the system master control unit, accepts the command of the system master control unit to realize the conversion of electric energy in the system; the conversion of electric energy includes two-way power conversion between the power grid and the energy storage unit, Electric energy conversion from power grid, new energy power generation device to AC load, new energy power generation device to energy storage unit, and energy storage unit to AC load; and send the status information of the energy storage unit and itself to the system master control unit; The inverter unit adopts a bidirectional inverter circuit, connected with the power generation/energy storage control unit, and is controlled by the system master control unit to complete the bidirectional electric energy conversion between the grid and the energy storage unit and the new energy power generation device to the power grid and new energy power generation device Electric energy conversion to AC loads, energy storage units to AC loads; The off-grid/grid-connected control unit is connected between the inverter unit and the AC load, and is controlled by the system master control unit to realize the power supply switching between the AC load and the grid. 2. The new energy distributed energy storage application control system according to claim 1, wherein the system master control unit communicates with the grid monitoring and dispatching system, and is dispatched by the grid monitoring and dispatching system to coordinate and control the direction of electric energy in the system. 3. The new energy distributed energy storage application control system according to claim 2, wherein the energy storage unit has a battery management system (BMS) inside. 4. The new energy distributed energy storage application control system according to claim 3, wherein the power generation/energy storage control unit also communicates with the battery management system (BMS) of the energy storage unit to realize the status of the energy storage unit monitor. 5. The new energy distributed energy storage application control system according to claim 4, characterized in that, the system uses a corresponding set of new energy power generation devices, energy storage units, power generation/energy storage control units, and inverters The switch unit, off-grid/grid-connected control unit and AC load are subsystems, and each subsystem is configured in an independent building area. 6. A new energy distributed energy storage application control system, characterized in that it includes: A system master control unit; One or more new energy power generation devices, using solar cell arrays or wind turbines or a combination of both, connected to the power generation/energy storage control unit and controlled by the unit; The energy storage unit corresponding to the number of new energy power generation devices is composed of energy storage devices such as batteries or super capacitors connected in series and parallel, connected with the power generation/energy storage control unit and controlled by the unit to realize the storage of electric energy; The power generation/energy storage control unit corresponding to the number of new energy power generation devices communicates with the system master control unit, and receives the system master control unit command to realize the conversion of electric energy in the system; the conversion of electric energy includes two-way electric energy between the grid and the energy storage unit Conversion, electric energy conversion from new energy generators to the grid, from new energy generators to AC loads, from new energy generators to energy storage units, and from energy storage units to AC loads; and send the status information of the energy storage units and themselves to the system master control unit; An inverter unit, which uses a bidirectional inverter circuit, is connected to each power generation/energy storage control unit, and is controlled by the system master control unit to complete the two-way power conversion between the grid and the energy storage unit and the new energy power generation device to the grid, new energy Electric energy conversion of power generation device to AC load, energy storage unit to AC load; An off-grid/grid-connected control unit, which is connected between the inverter unit and the AC load, and is controlled by the system master control unit to switch between the AC load and the power grid. 7. The new energy distributed energy storage application control system according to claim 6, wherein the system master control unit communicates with the power grid monitoring and dispatching system, and is dispatched and coordinated by the power grid monitoring and dispatching system to control the direction of electric energy in the system. 8. The new energy distributed energy storage application control system according to claim 7, wherein the energy storage unit has a battery management system (BMS) inside. 9. The new energy distributed energy storage application control system according to claim 8, characterized in that, the power generation/energy storage control unit also communicates with the battery management system (BMS) of the energy storage unit to realize the status of the energy storage unit monitor. 10. The new energy distributed energy storage application control system according to claim 9, characterized in that the system is composed of correspondingly set new energy power generation devices, energy storage units, and power generation/energy storage control units. The groups are arranged in an area and are brought together to the inverter units by connecting lines.

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