CN104092236B - hybrid renewable energy and energy storage system power supply system and control method thereof - Google Patents

Abstract

A hybrid renewable energy and energy storage system power supply system and its control method integrates electrochemical energy storage devices and mechanical energy storage devices, and then matches with solar photovoltaic and wind power generation systems, and connects to the mains. In the control concept, AC and DC are used to give priority to each other to supply AC and DC loads, thereby reducing conversion losses. This power supply system can make the residence, base station or computer room self-sufficient in electricity. When connected to the mains, it can trade electricity with the power company, avoid power outages during power outages, and ensure a certain power supply.

Description

Hybrid renewable energy and energy storage system power supply system and its control method

technical field

The present invention relates to the application field of micro-grid technology, in particular to a hybrid renewable energy and energy storage system power supply system and its control method, which can be combined with iEN (Intelligent Energy Network) intelligent energy-saving service monitoring system for energy management services, and can be used in Power generation equipment for residences, base stations or computer rooms is one of iEN's future development technologies.

Background technique

In view of the energy storage and energy supply system integrating natural energy in the previous proposal, the previous proposal is applied to the energy storage and supply system for converting wind and solar energy into electric energy, heat energy and cold energy. In addition to storage and supply, heat and cold energy are generated without the need for additional electricity to supply air-conditioning cooling and hot water needs, and make full use of natural energy to replace air-conditioning hosts and boilers and other equipment. However, the previous proposal cannot adjust the power supply sequence of power generation equipment (fuel cells, wind power, solar photovoltaics, flywheel batteries, lithium-iron batteries) according to demand and electricity prices at different time periods (peak, off-peak, and power outages), effectively ensuring power supply reliability and reducing power consumption. Power generation costs; it is impossible to give priority to the corresponding nature of power for loads of different natures, for example, DC power is not given priority to DC loads, etc., and there are problems such as power loss.

It can be seen that the above-mentioned existing methods still have many deficiencies, are not really a good design, and need to be improved urgently.

Contents of the invention

The hybrid renewable energy and energy storage system power supply system and its control method for achieving the above-mentioned purpose of the invention refer to a combination of various energy storage systems (fuel cells, lithium iron phosphate batteries, flywheel batteries) and renewable energy systems (solar photovoltaic and wind power generation) ) have certain shortcomings and limitations. Due to the inherent characteristics of energy storage systems and renewable energy, if you want to improve them, you have to pay the price of research and development and cost. The combination of various energy storage systems and renewable energy It can maximize strengths and circumvent weaknesses, give full play to the advantages of various devices, realize the requirement of self-sufficiency in electricity consumption, and prolong the life of equipment.

This patent proposes a hybrid energy storage system and renewable energy power supply architecture, which integrates electrochemical energy storage devices (lithium iron phosphate batteries and fuel cells) and mechanical energy storage devices (flywheel batteries), and then cooperates with solar photovoltaic and wind power generation systems. It can also be used as a power supply system for residences, base stations or computer rooms by connecting with the mains.

The hybrid renewable energy and energy storage system power supply system of the present invention, wherein the system includes a mechanical energy storage device, which is a flywheel energy storage device, a device that connects to the mains and operates according to the law of inertia, and provides emergency power supply in special situations The device, the hybrid power supply device, is connected to the renewable energy power supply structure and the integrated electrochemical energy storage device, and the AC-DC converter is connected to the hybrid power supply device and connected to the AC-DC load terminal. According to the AC-DC load Provide AC and DC power supply and control unit according to the demand of the end, receive the signal of the hybrid power supply device and the AC and DC load, control and monitor the degree of the AC and DC power supply, wherein the mechanical energy storage device operates and stores energy in a low power mode, and The hybrid power supply device supplies the AC-DC power to the AC-DC load terminal according to the judgment of the control unit through the AC-DC converter.

The above hybrid renewable energy and energy storage system power supply system, wherein the renewable energy power supply architecture is solar photovoltaic, wind power generation, and fuel cells to supply the AC and DC loads, and the integrated electrochemical energy storage device is a flywheel battery and lithium iron phosphate The battery is used to charge the flywheel battery and the lithium-iron-phosphate battery with excess power as a power backup.

Among them, the system is connected to the city power grid, and conducts power testing and monitoring with the power company to avoid power interruptions and maintain stable and continuous power supply.

In case of a power outage, when the wind power generation, the solar photovoltaic and the fuel cell power supply are far less than the load required by the AC and DC load end, the control unit starts the flywheel battery and the lithium iron phosphate battery to supply power, and the unnecessary load Unloading is carried out to prolong the system supply necessary load time.

The system sequentially utilizes the solar photovoltaic, the wind power generation, the fuel cell and the city power to supply power, and charges the flywheel battery and the lithium iron phosphate battery with excess power.

The hybrid renewable energy and energy storage system power supply control method of the present invention includes the following steps:

1. Mains supply electric energy to the mechanical energy storage device, the mechanical energy storage device is a self-operating flywheel energy storage device, and is connected to the hybrid power supply device, through the connected AC-DC converter and control unit, Judging and carrying out the supply and demand power demand of AC and DC load terminals;

2. The mains supply power to the flywheel energy storage device, so that the flywheel energy storage device performs low-power inertial operation;

3. The AC-DC converter judges the supply-demand balance between the hybrid power supply device and the AC-DC load terminal through the control unit;

4. When the power supply is greater than the demand, store the electric energy;

5. The hybrid power supply device continues to supply power when the demand is greater than the power supply; and

6. The control unit judges the required AC and DC power requirements, and outputs it to the AC and DC load terminal through the AC-DC converter.

The power supply control method of the hybrid renewable energy and energy storage system described above, wherein in the control concept of the method, AC power is preferentially supplied to AC loads, and DC power is preferentially supplied to DC loads to reduce conversion losses.

The power supply control method of the hybrid renewable energy and energy storage system of the present invention, wherein in the method during the peak time of power consumption, the power source of the hybrid power supply device sequentially uses solar photovoltaic power generation, wind power generation and the fuel of the integrated electrochemical energy storage device The battery is powered by a lithium iron phosphate battery.

Compared with the prior art or method, the hybrid renewable energy and energy storage system power supply system and mains grid in the present invention can carry out power distribution according to special circumstances, and can sell excess power storage back to the power company. To achieve the purpose of saving energy and being able to control the deployment of electric power.

The power supply control method of the hybrid renewable energy and energy storage system, wherein in the off-peak period of the method, the electric energy source of the hybrid power supply device sequentially uses solar photovoltaic power generation, wind power generation, and the fuel cell and the fuel cell of the integrated electrochemical energy storage device The utility power supplies power, and the excess power is used to charge the battery of the flywheel energy storage device and the lithium iron phosphate battery.

The hybrid renewable energy and energy storage system power supply control method, wherein in the method when there is a power outage or a power outage, the power generated by the flywheel energy storage device and the lithium iron phosphate battery is immediately supplied to the AC and DC loads, providing an interruption electricity.

In the power supply method of the hybrid renewable energy and energy storage system, after the system runs stably, the electric energy source of the hybrid power supply device sequentially uses the solar photovoltaic, wind power generation and fuel cell to supply the load. The hybrid renewable energy and energy storage system power supply system and its control method provided by the present invention, when compared with other existing technologies, integrate electrochemical energy storage systems (lithium iron phosphate batteries, fuel cells), mechanical energy storage systems (flywheel battery), photovoltaic and wind power generation systems, and connected to the mains grid, have the following advantages:

1. AC power is preferentially supplied to AC loads, while DC power is preferentially supplied to DC loads to reduce conversion losses.

2. Electricity charges are more expensive during peak hours of electricity consumption, and the wholesale price of electricity is higher. The system uses solar photovoltaics, wind power, fuel cells, and lithium-iron-phosphate batteries for power supply in sequence. The electricity consumption can be self-sufficient, and the excess electricity can be sold back to the power company, and continuously charge the flywheel energy storage battery as a power backup.

3. The electricity bill is cheaper during the ionization peak period, and the wholesale price of electricity is lower. The system uses solar photovoltaic power, wind power generation, fuel cells and mains power to supply power in sequence, and uses the excess power to charge the flywheel battery and lithium iron phosphate battery .

4. In the event of a sudden power failure, the power generated by the flywheel and the lithium-iron-phosphate battery can be directly supplied to the load, serving as a bridge for power interruption, providing zero-interruption power. After the system is running stably, the system sequentially uses solar photovoltaics, wind power, and fuel cells to supply loads, and uses excess power to charge flywheel batteries and lithium-iron-phosphate batteries as power backup. If the power outage is too long, and the power generated by wind power, photovoltaics, and fuel cells is far less than the load, the flywheel battery and lithium-iron battery will be started to supply power, and unnecessary loads will be removed. The system needs to maintain a state where the power generation is greater than the load , to extend the necessary load time for supply.

Description of drawings

Fig. 1 is a structure diagram of the hybrid renewable energy and energy storage system power supply system of the present invention;

Fig. 2 is a flow chart of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 3 is a control flow chart 1 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 4 is a control flow chart 2 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 5 is a control flow chart 3 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 6 is a control flow chart 4 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 7 is a control flow chart 1 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 8 is a control flow chart 2 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 9 is a control flow chart 3 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 10 is a control flow chart 1 of the power outage period of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 11 is a control flowchart 2 of the power outage period of the hybrid renewable energy and energy storage system power supply control method of the present invention;

Fig. 12 is a control flow chart 3 of the power outage period of the hybrid renewable energy and energy storage system power supply control method of the present invention.

Symbol Description

10 Mains

20 Mechanical energy storage device

21 Flywheel energy storage device

30 hybrid power supply unit

31 Renewable Energy Power Supply Architecture

311 solar photoelectric

312 Wind power generation

313 fuel cells

32 Integrated electrochemical energy storage device

322 lithium iron phosphate battery

40 AC-DC Converter

50 AC and DC load

51 AC load

511 Necessary AC load

52 DC load

521 Necessary DC load

60 control unit

50 AC and DC load

51 exchanges

52 DC

60 control unit

S11～S16 method flow chart

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

Below, the present invention is further described in conjunction with accompanying drawing:

Please refer to Fig. 1, which is a structure diagram of the hybrid renewable energy and energy storage system power supply system of the present invention,

A hybrid renewable energy and energy storage system power supply system, wherein the system includes at least a mechanical energy storage device 20, which can be a flywheel energy storage device 21, a device that is connected to the mains and operates according to the law of inertia, depending on special circumstances The emergency power supply device is adjusted according to actual needs. The hybrid power supply device 30 is connected to the renewable energy power supply structure 31 and the integrated electrochemical energy storage device 32. The AC-DC converter 40 is connected to the hybrid power supply device 30. connected, and connected to the AC/DC load end 40, provide AC/DC power supply and control unit according to the demand of the AC/DC load end, receive the signal of the hybrid power supply device 30 and the AC/DC load, control and monitor the AC/DC power supply level, wherein , the mechanical energy storage device 20 operates and stores energy in a low power mode, and the hybrid power supply device 30 supplies the AC and DC power to the AC and DC load end through the AC/DC converter 40 according to the judgment of the control unit.

Please refer to FIG. 2 , which is a flow chart of the hybrid renewable energy and energy storage system power supply control method of the present invention.

S11 Mains supply electric energy to the mechanical energy storage device, the mechanical energy storage device is a self-operating flywheel energy storage device, and is connected to the hybrid power supply device, through the connected AC-DC converter and control unit, the judgment And carry out the supply and demand power demand of the AC and DC load end;

S12 The mains supply power to the flywheel energy storage device, so that the flywheel energy storage device performs low-power inertial operation;

S13, the AC-DC converter judges the supply-demand balance between the hybrid power supply device and the AC-DC load terminal through the control unit;

S14, when the power supply is greater than the demand, store the electric energy;

S15 When the demand is greater than the power supply, the hybrid power supply device continues to supply power;

S16 The control unit judges the required AC and DC power requirements, and outputs it to the AC and DC load terminal through the AC-DC converter.

AC power is preferentially supplied to AC loads, while DC power is preferentially supplied to DC loads, and different control methods are proposed according to different time periods (peak periods, off-peak periods, and power outage periods):

Please refer to FIG. 3, which is a control flow chart 1 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention, which includes the following steps:

[1] Electricity charges are more expensive during peak hours, and the wholesale price of electricity is higher. The system adopts different control methods according to different conditions:

Control method 1:

When the wind power generation 312 and solar photovoltaic 311 generate more power than the AC load 51 and the DC load 52, the wind power generation 312 gives priority to supplying the AC load 51, while the solar photovoltaic 311 gives priority to supplying the DC load 52, and if there is any shortage, it will pass through the AC-DC converter 40 alternately supplies DC or AC loads. Then the remaining electricity and the electricity generated by the fuel cell 313 and the lithium iron phosphate battery 322 are sold back to the power company.

Please refer to FIG. 4, which is the control flow chart 2 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention, including the following steps:

Control method 2:

When the wind power generation 312, solar photovoltaic 311 and fuel cell 313 generate more electricity than the AC load 51 and the DC load 52, the wind power generation 312 supplies the AC load 51 first, and the solar photovoltaic 311 and fuel cell 313 supply the DC load 52 sequentially. Part of the AC/DC converter 40 is used to alternately supply DC or AC loads. Then the remaining electricity and the electricity generated by the lithium iron phosphate battery 322 are sold back to the power company.

Please refer to FIG. 5, which is a control flow chart 3 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention, including the following steps:

Control method 3:

When wind power generation 312, solar photovoltaic 311, fuel cell 313 and lithium iron phosphate battery 322 generate more electricity than AC load 51 and DC load 52, wind power generation 312 preferentially supplies AC load 51, while solar photovoltaic 311, fuel cell 313, lithium iron The phosphoric acid battery 322 supplies the DC load 52 in sequence, and if there is any shortage, then alternately supplies the DC or AC load through the AC-DC converter 40, and sells the remaining power back to the power company.

Please refer to FIG. 6, which is a control flow chart 4 of the peak period control method of the hybrid renewable energy and energy storage system power supply control method of the present invention, which includes the following steps:

Control method 4:

When wind power generation 312, solar photovoltaic 311, fuel cell 313 and lithium iron phosphate battery 322 generate less electricity than AC load 51 and DC load 52, wind power generation 312 preferentially supplies AC load 51, while solar photovoltaic 311, fuel cell 313, lithium iron The phosphoric acid battery 322 supplies the DC load 52 in sequence, and if there is any shortage, the DC or AC load is alternately supplied through the AC-DC converter 40 , and the insufficient power is provided by the commercial power 10 .

Please refer to FIG. 7, which is a control flow chart 1 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention, including the following steps:

[2] Off-peak hours

Electricity charges are cheaper during off-peak hours, and the wholesale price of electricity is lower. The system adopts different control methods according to different conditions:

Control method 1:

When the wind power generation 312 and solar photovoltaic 311 generate more power than the AC load 51 and the DC load 52, the wind power generation 312 gives priority to supplying the AC load 51, and the solar photovoltaic 311 gives priority to supplying the DC load 52. Alternately supply DC or AC loads, and charge the flywheel battery and the lithium-iron-phosphate battery 322 with excess power for power backup, while the fuel cell 313 does not start.

Please refer to FIG. 8, which is a control flow chart 2 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention, which includes the following steps:

Control method 2:

When the wind power generation 312, solar photovoltaic 311 and fuel cell 313 generate more electricity than the AC load 51 and the DC load 52, the wind power generation 312 supplies the AC load 51 first, and the solar photovoltaic 311 and fuel cell 313 supply the DC load 52 sequentially. The part is then alternately supplied to DC or AC loads through the AC-DC converter 40, and the power is self-sufficient, and the excess power can be used to charge the flywheel battery and the lithium-iron-phosphate battery 322 as power backup.

Please refer to FIG. 9, which is a control flow chart 3 of the off-peak period of the hybrid renewable energy and energy storage system power supply control method of the present invention, including the following steps:

Control method 3:

When the wind power generation 312, solar photovoltaic 311, and fuel cell 313 generate less electricity than the AC load 51 and the DC load 52, the wind power generation 312 supplies the AC load 51 in priority, while the solar photovoltaic 311 and the fuel cell 313 supply the DC load 52 in sequence, and pass The AC-DC converter 40 alternately supplies DC or AC loads, and the part with insufficient power is provided by the mains 10 . The flywheel battery and the lithium-iron-phosphate battery 322 are not activated for power backup.

Please refer to FIG. 10 , which is the control flow chart 1 of the hybrid renewable energy and energy storage system power supply control method of the present invention during the power outage period, which includes the following steps:

[3] Blackout period

In case of sudden power failure, in order to avoid power interruption, the system adopts the following control methods:

Control method 1:

The flywheel battery and the lithium-iron battery 322 act as a bridge for sudden power interruptions, and immediately provide load power to achieve the goal of zero power interruption. Solar photovoltaics 311, wind power generation 312, and fuel cells 313 then supply the loads in sequence, and through AC-DC conversion The converter 40 alternately supplies DC or AC loads.

Please refer to FIG. 11 , which is the control flow chart 2 of the hybrid renewable energy and energy storage system power supply control method of the present invention during the power outage period, which includes the following steps:

After the power outage is stable, the system adopts different control methods according to different conditions:

Control method 2:

When wind power generation 312, solar photovoltaic 311, and fuel cell 313 generate more electricity than AC load 51 and DC load 52, wind power generation 312 gives priority to supplying AC load 51, while solar photovoltaic 311 and fuel cell 313 supply DC load 52 in turn. The part is then alternately supplied to the DC or AC load through the AC-DC converter 40, and the excess power is used to charge the flywheel battery and the lithium-iron-phosphate battery 322 for power backup.

Please refer to FIG. 12, which is a control flow chart 3 of the hybrid renewable energy and energy storage system power supply control method of the present invention during the power outage period, which includes the following steps:

Control method 3:

If the power outage is too long, and the power generated by wind power 312, solar photovoltaic 311, and fuel cell 313 is less than the load, start the flywheel battery and lithium iron phosphate battery 322 to supply power, and unload the non-essential DC load 521 and necessary AC load 511, The system maintains the state that the power generation is greater than the load, so as to prolong the time for the system to supply the necessary load.

The above detailed description is a specific description of the feasible embodiment of the present invention, but the embodiment is not used to limit the patent scope of the present invention, and any equivalent implementation or change that does not depart from the technical spirit of the present invention shall be included in within the patent scope of this case.

Claims (4)

1. A power supply system composed of a hybrid renewable energy source and an energy storage system, characterized in that the power supply system includes: The mechanical energy storage device is a flywheel energy storage device, which is connected to the mains and operates according to the law of inertia to store energy. It is an emergency power supply device for special situations, such as sudden power failure and prolonged power failure; The hybrid power supply device is a connected renewable energy power supply structure and an integrated electrochemical energy storage device. The renewable energy power supply structure is solar photovoltaic and wind power generation, and the integrated electrochemical energy storage device is a fuel cell and a lithium iron phosphate battery; The AC-DC converter is connected to the hybrid power supply device and connected to the AC-DC load terminal, and provides AC-DC power supply according to the demand of the AC-DC load terminal; and A control unit receives signals from the hybrid power supply device and the AC/DC load, and controls and monitors the AC/DC power supply level; Wherein, the mechanical energy storage device operates and stores energy in a low-power mode, and the hybrid power supply device supplies AC and DC power to the AC and DC load end through the AC-DC converter according to the judgment of the control unit; During peak hours of electricity consumption, the power supply system sequentially uses solar photovoltaics, wind power, fuel cells and lithium iron phosphate batteries for power supply; During the ionization peak period, the power supply system sequentially uses the solar photovoltaic, the wind power generation, the fuel cell and the city power to supply power, and charges the flywheel energy storage device and the lithium iron phosphate battery with excess power; When there is a power outage, the power supply system uses the flywheel energy storage device and the lithium iron phosphate battery to provide interrupted power. After the power supply system runs stably, the power supply system uses solar photovoltaic power generation, wind power generation, and fuel cells to supply loads in sequence, and the redundant The electricity charges the flywheel energy storage device and the lithium iron phosphate battery. If the power failure time is too long, and the power supply of the wind power generation, the solar photovoltaic and the fuel cell is far less than the load required by the AC and DC load end, the control unit starts the flywheel The energy storage device supplies power to the lithium iron phosphate battery, and unloads unnecessary loads to prolong the time for the power supply system to supply necessary loads. 2. The power supply system composed of hybrid renewable energy and energy storage system according to claim 1, characterized in that the power supply system is connected to the mains grid and is connected to the power company for power testing and monitoring. 3. A control method for a power supply system composed of a hybrid renewable energy source and an energy storage system, characterized in that the steps include: A. Mains supply electric energy to the mechanical energy storage device. The mechanical energy storage device is a flywheel energy storage device that operates on its own and is connected to a hybrid power supply device. Through the connected AC-DC converter and control unit, Judging and determining the supply and demand power demand at the AC and DC load side; the hybrid power supply device is a connected renewable energy power supply structure and an integrated electrochemical energy storage device. The renewable energy power supply structure is solar photovoltaic and wind power generation, and the integrated electrochemical energy storage device is used as fuel Batteries and lithium iron phosphate batteries; B. The mains supply power to the flywheel energy storage device, so that the flywheel energy storage device performs low-power inertial operation; C. The AC-DC converter judges the supply-demand balance between the hybrid power supply device and the AC-DC load terminal through the control unit; D. When the power supply is greater than the demand, store the electric energy; E. The hybrid power supply continues to supply power when demand exceeds supply; and F. The control unit judges the required AC and DC power supply requirements, and outputs it to the AC and DC load terminal through the AC-DC converter; In the method, during the peak time of power consumption, the electric energy source of the hybrid power supply device sequentially uses solar photovoltaic power generation, wind power generation, fuel cell and lithium iron phosphate battery integrated with electrochemical energy storage device for power supply; In the method, during off-peak hours, the hybrid power supply device uses solar photovoltaic power generation, wind power generation, fuel cells of the integrated electrochemical energy storage device and mains power to supply power in sequence, and uses excess power to the flywheel energy storage device Charge with the lithium iron phosphate battery; In this method, when there is a power failure or a power failure, the power generated by the flywheel energy storage device and the lithium iron phosphate battery is immediately supplied to the AC and DC load to provide interrupted power; after the power supply system runs stably, the hybrid power supply The power source of the device then uses the solar photovoltaic, wind power generation and fuel cell to supply the load in sequence, and charges the flywheel energy storage device and lithium iron phosphate battery with the excess power; When the power generation of the battery is far less than the load, the flywheel energy storage device and the lithium iron phosphate battery will be started to supply power, and the unnecessary load will be removed. 4. The control method of the power supply system composed of hybrid renewable energy and energy storage system according to claim 3, characterized in that, in terms of the control concept of the method, AC power is preferentially supplied to AC loads, and DC power is preferentially supplied to DC loads.