CN117856328A - Energy conversion circuit, control method and terminal of energy storage inverter - Google Patents
Energy conversion circuit, control method and terminal of energy storage inverter Download PDFInfo
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- CN117856328A CN117856328A CN202311723821.3A CN202311723821A CN117856328A CN 117856328 A CN117856328 A CN 117856328A CN 202311723821 A CN202311723821 A CN 202311723821A CN 117856328 A CN117856328 A CN 117856328A
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- 238000004146 energy storage Methods 0.000 title claims abstract description 124
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims abstract description 26
- 230000002457 bidirectional effect Effects 0.000 claims abstract description 53
- 238000001514 detection method Methods 0.000 claims abstract description 31
- 238000004364 calculation method Methods 0.000 claims description 27
- 238000004590 computer program Methods 0.000 claims description 18
- 238000010248 power generation Methods 0.000 claims description 17
- 238000007600 charging Methods 0.000 claims description 14
- 238000002955 isolation Methods 0.000 claims description 8
- 230000002035 prolonged effect Effects 0.000 abstract description 5
- 230000006870 function Effects 0.000 description 6
- 238000010280 constant potential charging Methods 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
- H02J2300/26—The renewable source being solar energy of photovoltaic origin involving maximum power point tracking control for photovoltaic sources
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention relates to an energy conversion circuit, a control method and a terminal of an energy storage inverter, wherein the circuit comprises a control module, an MPPT module, a detection module, a switch circuit, a bidirectional DC/DC module and a bidirectional DC/AC module, the control module is respectively connected with the MPPT module, the detection module, the switch circuit, the bidirectional DC/DC module and the bidirectional DC/AC module, a high-voltage direct current bus end is simultaneously connected to the MPPT module, the bidirectional DC/DC module and the bidirectional DC/AC module, the other end of the MPPT module is connected to a solar end, the other end of the bidirectional DC/DC module is connected to an energy storage battery end, the other end of the bidirectional DC/AC module is connected to a power grid end and a load end through the switch circuit, the detection module is used for detecting electric parameters of the solar end, the battery end, the power grid end, the high-voltage direct current bus end and the load end, and the control module calculates and compares the power of each end according to the detection result of the detection module, and determines a working mode, when the power of the solar end is larger than the power required by the load, the battery is charged, the battery is reduced, and the service life of the battery is prolonged.
Description
Technical Field
The invention relates to the technical field of inverter energy conversion, in particular to an energy storage inverter energy conversion circuit, a control method and a terminal.
Background
At present, the development of clean energy is bigger and bigger, more solar energy enters into a power grid, but the solar energy is more influenced by weather, and in order to better utilize the solar energy, an energy storage battery is arranged for storing when the solar energy is more.
The power grid system with the solar energy and the energy storage battery is added, and meanwhile voltage conversion and inversion are included, direct current at the solar energy end is converted into direct current with different voltages, the energy storage battery is charged, direct current at the solar energy end is converted into alternating current, and the alternating current is provided for a power grid or a load. In order to ensure that the power supply of the load is normal, the power of the energy storage battery needs to be converted and then supplied to the load when the solar energy is insufficient.
The energy of the solar end charges the energy storage battery frequently, and the energy storage battery discharges frequently, so that the service life of the energy storage battery is seriously shortened, and meanwhile, the economic efficiency generated by the solar end is lower.
Therefore, how to improve the economic efficiency of the solar end and prolong the service life of the energy storage battery is a problem to be solved at present.
Disclosure of Invention
The invention aims to provide an energy conversion circuit, a control method and a terminal of an energy storage inverter, which are used for detecting the voltage and the current of each energy supply end and each load end, calculating the power of each end, comparing the power, and starting the charging of a battery only when the energy of a solar end is sufficient, namely the power of the solar end is larger than the power required by the load, so that the charging times of the battery are reduced, and the service life of the battery is prolonged.
In a first aspect, the present invention provides an energy conversion circuit of an energy storage inverter, which is implemented by the following technical scheme:
the utility model provides an energy storage inverter energy conversion circuit, including control module, MPPT module, detection module, switch circuit, two-way DC/DC module and two-way DC/AC module, control module is connected with MPPT module respectively, detection module, switch circuit, two-way DC/DC module and two-way DC/AC module, high voltage direct current busbar end is connected to MPPT module simultaneously, two-way DC/DC module and two-way DC/AC module, the other end of MPPT module is connected to solar energy end, the other end of two-way DC/DC module is connected to the energy storage battery end, the other end of two-way DC/AC module is connected to electric wire netting end and load end through switch circuit, detection module is used for detecting solar energy end, the battery end, the electric netting end, high voltage direct current busbar end and load end's electrical parameter, control module calculates and compares each end power size according to detection module's testing result, according to the comparison result, decide energy storage inverter's mode of operation.
The invention is further provided with: the control module comprises a power calculation module and a comparison module, wherein the power calculation module comprises a battery end power calculation module, a solar end power calculation module, a grid-connected end power calculation module, a load end power calculation module and a power grid end power calculation module, which are respectively used for calculating the power of each end, and the comparison module is used for comparing the power of each end.
The invention is further provided with: the device also comprises an isolation driver, one end of the isolation driver is connected with the bidirectional DC/AC module and the bidirectional DC/DC module, and the other end of the isolation driver is connected with the controller and is used for isolating the controller power supply from the bidirectional DC/AC module power supply and the controller power supply from the bidirectional DC/DC module power supply.
The invention is further provided with: the switching circuit comprises a first switching circuit and a second switching circuit, wherein the first switching circuit is arranged between the grid end and is used for controlling the connection or disconnection of the grid end and the load end; the second switching circuit is arranged between the load end and the grid-connected end and used for controlling the connection or disconnection of the grid-connected end and the load end.
In a second aspect, the present invention provides a control method for an energy conversion circuit of an energy storage inverter, which is implemented by the following technical scheme:
the control method of the energy conversion circuit of the energy storage inverter detects the voltage of the power grid end, judges whether the power grid is connected or not, and determines the working states of the solar end and the battery end in each power generation mode according to the power of each end; and in the grid-connected mode, controlling the energy storage inverter to work in a current type power generation mode, and in the off-grid mode, controlling the energy storage inverter to work in a voltage type power generation mode.
The invention is further provided with: comparing the power of the solar end with the load power in a grid-connected mode, and determining the charging mode of the solar end to the energy storage battery according to the electric quantity of the battery when the power of the solar end is larger than the load power; when the power of the solar energy end is smaller than or equal to the load power, determining whether the energy storage battery end is charged or discharged according to the electric quantity of the battery; and in the off-grid mode, comparing the power of the solar end with the power of the load, when the power of the solar end is larger than the power of the load, supplying power to the load end by the solar end and charging the energy storage battery, and when the power of the solar end is smaller than or equal to the power of the load, supplying power to the load by the solar end and the energy storage battery end together.
The invention is further provided with: and in the grid-connected mode, judging the power of the solar end and the power of the load end according to the current direction of the grid end, judging that the power of the solar end is smaller than or equal to the power of the load end when the current of the grid end flows to the load end, and judging that the power of the solar end is larger than the power of the load end when the current of the grid end flows to the grid end from the grid end.
The invention is further provided with: when the power of the solar energy end is larger than the load power, if the electric quantity of the battery is smaller than or equal to a first electric quantity set value, the solar energy end supplies power to the load end and charges the energy storage battery; if the electric quantity of the battery is larger than the first electric quantity set value, the solar end supplies power to the load end, charges the energy storage battery in a constant voltage mode and generates power to the power grid; when the power of the solar end is smaller than or equal to the load power, if the electric quantity of the battery is larger than a second electric quantity set value, the solar energy and the energy storage battery supply power to the load together; if the electric quantity of the battery is smaller than or equal to the second electric quantity set value, the solar end and the power grid end supply power to the load at the same time, and the energy storage battery is charged.
The invention is further provided with: the method comprises the following steps:
s1, starting up;
s2, detecting whether a power grid exists, if so, entering the next step, and if not, turning to S12;
s3, closing a first switch circuit, closing a second switch circuit, and switching to a grid-connected mode;
s4, the running state of the bidirectional DC/AC module is a current type power generation mode;
s5, judging whether the power of the solar end is larger than the load power, if so, entering the next step, and if not, turning to S9;
s6, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is smaller than or equal to a first electric quantity set value, if so, entering the next step, and if not, turning to S8;
s7, the bidirectional DC/DC module works, the solar end provides energy for the load, and meanwhile the energy storage battery is charged, and S2 is switched;
s8, the solar energy end provides energy for the load, meanwhile, the energy storage battery is charged in a constant voltage mode, and redundant energy is sent to the power grid end and is converted into S2;
s9, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is larger than a second electric quantity set value, if so, entering the next step, and if not, turning to S11;
s10, the solar end and the energy storage battery end jointly provide energy for a load, and S2 is switched;
s11, the solar end and the power grid end jointly provide energy for a load, and meanwhile, the energy storage battery is charged, and S2 is switched;
s12, the first switch circuit is disconnected, the second switch circuit is disconnected, and the off-grid mode is switched;
s13, the running state of the bidirectional DC/AC module is a voltage type power generation mode;
s14, judging whether the power of the solar end is larger than that of the load end, if so, entering the next step, and if not, turning to S16;
s15, the solar end provides energy for the load, and simultaneously charges the energy storage battery, and S2 is switched;
s16, the solar end and the energy storage battery end simultaneously provide energy for the load, and S2 is achieved.
In a third aspect, the present invention provides an energy conversion terminal of an energy storage inverter, which is implemented by the following technical scheme:
an energy storage inverter energy conversion terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the method described herein when executing the computer program.
Compared with the prior art, the beneficial technical effects of this application are:
1. according to the method, whether the power of each energy supply end can meet the power of the load end is judged by detecting the power of each end, and according to the judging result, solar energy is controlled to supply power to the load at first, and the battery is charged under the condition that the solar energy is sufficient, so that the charging frequency of the battery end is reduced, and the service life of the battery is prolonged;
2. further, the method and the device judge whether the power grid is on line or not by detecting the voltage of the power grid end, and control the energy storage inverter to work in a current type power generation mode when the power grid is on line, at the moment, the relative magnitude of electric energy of each end can be obtained by detecting the current flow direction of the power grid end, a judging result of whether the solar energy is charged or not is obtained, a judging process is simplified, and the charging times of the battery are reduced;
3. further, when the power grid is offline, the energy storage inverter is controlled to work in a voltage type power generation mode, whether the battery is charged is determined according to a comparison result of the solar end power and the load power, and the charging times of the battery are reduced;
4. further, when the power grid is on line, the energy of the solar energy end can be judged whether to charge or not only by judging the current direction of the power grid end, so that the judging process is simplified, and the judging accuracy is improved.
Drawings
FIG. 1 is a schematic diagram of an energy conversion circuit of an energy storage inverter according to an embodiment of the present application;
fig. 2 is a schematic flow chart of a control method of an energy conversion circuit of an energy storage inverter according to an embodiment of the present application.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
The utility model provides an energy storage inverter energy conversion circuit, as shown in figure 1, including solar energy end PV, energy storage battery end BAT, electric wire netting AC end, control module, MPPT module, two-way DC/DC module, two-way DC/AC module and control module, maximum power point tracking (MPPT, maximum Power Point Tracking) module is connected between solar energy end and high voltage direct current bus, two-way DC/DC module connects between energy storage battery end and high voltage direct current bus, two-way DC/AC module connects between high voltage direct current bus and the end that is incorporated into the power networks, set up first switch circuit between the end that is incorporated into the power networks and the electric wire netting, set up second switch circuit between the end that is incorporated into the power networks and the load end, decide the switch-on or the disconnection of first switch circuit and/or second switch circuit according to each end energy size.
The solar energy power grid comprises a solar energy end, an energy storage battery end, a load end and a power grid end, and is characterized by further comprising a detection circuit, wherein the detection circuit comprises a current detection circuit and a voltage detection circuit, the current detection circuit and the voltage detection circuit are respectively arranged at the solar energy end, the energy storage battery end, the load end and the power grid end and used for detecting the current magnitude and/or the current flow direction and the voltage magnitude of each end, and the voltage detection circuit is not shown.
The control module is respectively connected with each current detection circuit and is used for calculating the power of the solar end, the energy storage battery end, the grid-connected end, the load end and the grid end according to the detection result of each current detection circuit, so as to control the conversion of the bidirectional DC/DC module and the bidirectional DC/AC module and simultaneously control the connection or disconnection of the first switch circuit and the second switch circuit.
The bidirectional DC/AC module is used for the mutual conversion between alternating current and direct current, and the bidirectional DC/DC module is used for the mutual conversion between direct current and direct current.
And a first isolation driver is arranged between the control module and the bidirectional DC/DC module and used for isolating the control module power supply from the bidirectional DC/DC module power supply. And a second isolation driver is arranged between the control module and the bidirectional DC/AC module and used for isolating the control module power supply from the bidirectional DC/AC module power supply.
The control module is also connected with the first switch circuit and the second switch circuit and used for outputting control signals and controlling the on or off of the first switch circuit and the second switch circuit.
The current detection circuit and the voltage detection circuit are arranged at each end, so that the current and the voltage of each end are detected in real time, the power energy of each end is calculated, the power energy of each end is compared, the relation between the power energy required by a load and the energy of each end for providing energy is judged, and whether the load end is provided with energy by a solar end, the solar end and an energy storage battery end or the solar end, the energy storage battery end and a power grid end is provided with energy together is determined; the energy storage battery is judged to provide energy and supplement energy for the energy storage battery, so that the charge and discharge times of the battery are reduced, the service life of the energy storage battery is prolonged, and the economic benefit of a solar end is improved.
In a specific embodiment of the present application, the first switch circuit adopts a relay circuit RLY1, the second switch circuit adopts a relay circuit RLY2, the control module controls the relay to be turned on or off according to the energy comparison result, and the low voltage of the control module is used for controlling the high voltage of the load end and the power grid end.
Each current detection circuit adopts a current transformer, each voltage detection circuit adopts a voltage sensor, and each current transformer and each voltage sensor are connected with the control module and are used for transmitting detection results to the control module.
The control module comprises a power calculation module and a comparison module, wherein the power calculation module comprises a solar power calculation module, a battery end power calculation module, a grid-connected end power calculation module, a load end power calculation module and a power grid end power calculation module, the solar power calculation module is used for calculating the power of the solar end according to the voltage and the current of the solar end, and correspondingly, the battery end power calculation module is used for calculating the power of the battery end according to the voltage and the current of the battery end; the grid-connected end power calculation module is used for calculating the power of the grid-connected end according to the voltage and the current of the grid-connected end; the load end power calculation module is used for calculating the power of the load end according to the voltage and the current of the load end; the power calculation module of the power grid end is used for calculating the power of the power grid end according to the voltage and the current of the power grid end. The comparison module is used for comparing the power of each end and determining a power supply mode according to the comparison result.
Further, the power grid end calculates whether the power of the power grid end flows into the grid-connected end or flows out of the grid-connected end according to the current direction. The power at the battery terminal also determines whether to charge or energize the battery based on the current direction.
The power grid end current transformer is marked as CT1 and is used for calculating grid-connected power, charging power and the like with a power grid voltage detection value, and the load current sensor is marked as CT2 and is used for calculating load power and overload protection with a load voltage detection value; the current sensor of the bidirectional DC/AC inversion is marked as CT3 and is used for detecting a value with the grid-connected voltage, controlling grid-connected current and calculating a power factor; the battery current sensor is marked as CT4 and is used for detecting a value with the battery voltage, calculating the battery power and controlling the current of charging and discharging of the battery; the MPPT controller current sensor is marked as CT5 and is used for calculating solar power with a solar voltage detection value to realize maximum power point tracking control.
The bidirectional DC/DC module can control current to flow from the high-voltage direct current bus to the energy storage battery, and can also control current to flow from the energy storage current to the high-voltage direct current bus.
The power of each end is calculated by adopting any method capable of calculating the power, wherein each end comprises a solar end, a battery end, a grid-connected end, a load end and a power grid end.
The control module controls the states of the first switch circuit and the second switch circuit and the working modes of the bidirectional DC/DC module and the bidirectional DC/AC module according to the power of each end.
After the energy conversion circuit of the energy storage inverter is started, the first switch circuit and the second switch circuit are controlled to be closed, and the power grid supplies power to the load; and then the solar energy end generates power to the power grid and supplies power to the load through the MPPT controller and the bidirectional DC/AC module, the bidirectional DC/AC module inverter circuit is in a current type grid-connected power generation working mode and supplies energy to the load, under the current type mode, the current direction of each end represents the current magnitude of each end, if the current of the grid-connected end is larger than the current of the power grid end, the current flows from the grid-connected end to the load end and the power grid end, and at the moment, the power grid end detects that the current flows, if the current of the grid-connected end is smaller than the current of the power grid end, the current flows from the power grid end and flows into the load end together with the current of the grid-connected end.
The solar end stores energy by adopting a photovoltaic cell. The battery end adopts an energy storage battery to store energy.
When the power grid is combined, the energy storage conversion circuit works in a current type grid-connected power generation mode, detects the current and the flow direction of the power grid end, judges whether the energy of the solar end and the energy of the battery end meet the energy requirement of the load end, and controls the work of each end according to the judging result so as to meet the load requirement.
And detecting the current flow direction of the power grid end, and judging whether the power grid provides energy for a load or whether the grid-connected end provides energy for the power grid.
When the power P1 of the solar energy end is larger than the power P2 of the load end, the energy of the solar energy end flows into the grid-connected end through the bidirectional DC/AC module and flows into the grid end and the load end at the same time, the current of the grid end flows from the grid-connected end to the grid end at the moment, the fact that the power grid does not provide energy for the load is explained, the solar energy end not only provides energy for the load, but also provides residual energy, the MPPT module and the bidirectional DC/DC module are started to charge the battery end, the battery power SOC is detected, when the battery power is smaller than a first power set value, the solar energy end supplies power to the load in a maximum power point tracking mode and charges the battery, when the battery power is larger than or equal to the first power set value, the battery is charged in a constant-voltage charging mode, and the residual energy of the solar energy end is transmitted to the power grid and the load.
At this time, the solar energy end is sufficient in energy, and simultaneously provides energy for the load end, the battery end and the power grid end.
When the solar end power P1 is equal to the load end power P2, the solar end energy just meets the load energy requirement, the solar end supplies energy to the load, the battery end and the power grid end do not supply energy, and no current flows in the power grid end.
When the solar end power P1 is smaller than the load end power P2, the solar end energy is smaller than the load end energy, the solar end energy is insufficient, the current of the power grid end flows to the load end from the power grid end, the power grid is stated to provide energy for the load, the bidirectional DC/DC module is started to discharge the energy storage battery, and the battery end and the solar end provide energy for the load.
After the battery discharges, the current flow direction of the power grid end is continuously detected, if the current flow of the power grid end continuously flows from the power grid end to the load end, the fact that the sum of the energy of the solar end and the energy of the battery end cannot meet the load energy requirement is indicated, and the solar end, the battery end and the power grid end are required to jointly provide energy for the load.
When the power grid is in an off-grid state, i.e. the power grid is not incorporated into the energy storage inverter energy conversion circuit, the energy storage inverter energy conversion circuit is in a voltage type power generation mode, and the following working modes are adopted according to the power of a solar end, a battery end and a load end:
after the power-on, the second switch circuit is disconnected, the load is disconnected, the MPPT controller at the solar end works, the bidirectional DC/DC module is started to work, the battery end and the solar end provide high-voltage direct-current bus voltage, the high-voltage direct-current bus voltage is detected, after the high-voltage direct-current bus voltage reaches a set value, the bidirectional DC/AC module is started, and at the moment, the DC/AC module inverter is in a voltage type inversion working mode.
After the bidirectional DC/AC module is stable in an empty state, the second switch circuit is closed, the load is connected, and the power of the solar end is compared with the power of the load.
And detecting load end current, solar end current and high-voltage direct current bus voltage, calculating load end power and solar end power, and judging whether solar energy side energy is larger than load side energy or not.
When the power of the solar energy end is larger than that of the load end, the high-voltage direct-current bus voltage is larger than a first voltage set value, the solar energy end supplies energy to the load, and the redundant energy charges the battery through the bidirectional DC/DC module. And detecting the electric quantity of the energy storage battery, when the electric quantity of the energy storage battery is smaller than a first electric quantity set value, providing energy for a load by the solar end in a maximum power point tracking mode, charging the battery end, and when the electric quantity of the battery is larger than the first electric quantity set value, adjusting the charging current of the battery or changing the charging current into a constant voltage charging mode, wherein the solar end exits from the maximum power point tracking mode.
If the voltage of the high-voltage direct-current bus is detected to be lower than the first voltage set value, the solar energy is insufficient, the control module controls the bidirectional DC/DC module to work in a boosting mode, the battery end and the solar end supply power to the high-voltage direct-current bus at the same time, and the MPPT module supplies energy to a load together in a maximum power point tracking mode and the battery.
As shown in fig. 2, the control method of the control module includes the following steps:
s1, starting up;
s2, detecting whether a power grid exists, if so, entering the next step, and if not, turning to S12;
s3, closing a first switch circuit, closing a second switch circuit, and switching to a grid-connected mode;
s4, the running state of the bidirectional DC/AC module is a current type power generation mode;
s5, judging whether the power of the solar end is larger than the load power, if so, entering the next step, and if not, turning to S9;
s6, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is smaller than or equal to a first electric quantity set value, if so, entering the next step, and if not, turning to S8;
s7, the bidirectional DC/DC module works, the solar end provides energy for the load, and meanwhile the energy storage battery is charged, and S2 is switched;
s8, the solar energy end provides energy for the load, meanwhile, the energy storage battery is charged in a constant voltage mode, and redundant energy is sent to the power grid end and is converted into S2;
s9, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is larger than a second electric quantity set value, if so, entering the next step, and if not, turning to S11;
s10, the solar end and the energy storage battery end jointly provide energy for a load, and S2 is switched;
s11, the solar end and the power grid end jointly provide energy for a load, and meanwhile, the energy storage battery is charged, and S2 is switched;
s12, the first switch circuit is disconnected, the second switch circuit is disconnected, and the off-grid mode is switched;
s13, the running state of the bidirectional DC/AC module is a voltage type power generation mode;
s14, judging whether the power of the solar end is larger than that of the load end, if so, entering the next step, and if not, turning to S16;
s15, the solar end provides energy for the load, and simultaneously charges the energy storage battery, and S2 is switched;
s16, the solar end and the energy storage battery end simultaneously provide energy for the load, and S2 is achieved.
In the energy conversion circuit of the energy storage inverter, the load has little influence on the voltage, and the comparison result of the power is consistent with the comparison result of the current, so the current is adopted for comparison.
Detecting whether the voltage exists at the power grid end, judging that the power grid is off-grid when the voltage exists, and judging that the power grid is connected when the voltage exists.
The first electric quantity set value is larger than 80%, and the second electric quantity set value is smaller than 30%.
The alternating current power of each end is calculated, and the active power value of each alternating current end is calculated.
According to the control method, under the condition that the energy of the solar energy end is sufficient, the energy of the solar energy end is firstly considered to provide energy for a load, then considered to provide energy for a power grid, and secondly, the battery is charged according to the electric quantity of the energy storage battery; under the condition of insufficient energy of the solar energy end, firstly, the solar energy end and the power grid end are considered to provide energy for the load, secondly, the solar energy end, the power grid end and the energy storage battery end are considered to jointly provide energy for the load, repeated charge and discharge of the energy storage battery are avoided, and the service life of the battery is prolonged.
An embodiment of the present invention provides an energy conversion terminal device of an energy storage inverter, where the terminal device of the embodiment includes: a processor, a memory, and a computer program, such as a power calculation program, stored in the memory and executable on the processor, which when executed implements the methods described herein.
Alternatively, the processor may implement the functions of the modules/units in the above-described device embodiments when executing the computer program, for example: and a power calculation module.
The computer program may be divided into one or more modules/units, which are stored in the memory and executed by the processor to accomplish the present invention, for example. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions for describing the execution of the computer program in the energy storage inverter energy conversion terminal device.
The energy-storage inverter energy conversion terminal equipment can be computing equipment such as a desktop computer, a notebook computer, a palm computer and a cloud server. The energy storage inverter energy conversion terminal device may include, but is not limited to, a processor, a memory. It will be appreciated by those skilled in the art that the above examples are merely examples of the energy storage inverter energy conversion terminal device and are not limiting of the energy storage inverter energy conversion terminal device, and may include more or less components than illustrated, or may combine certain components, or different components, e.g., the energy storage inverter energy conversion terminal device may also include input and output devices, network access devices, buses, etc.
The processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, data signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. The general purpose processor may be a microprocessor or the processor may be any conventional processor or the like, which is a control center of the energy storage inverter energy conversion terminal device, and connects various parts of the entire energy storage inverter energy conversion terminal device using various interfaces and lines.
The memory may be used to store the computer program and/or the module, and the processor may implement various functions of the energy storage inverter energy conversion terminal device by running or executing the computer program and/or the module stored in the memory and invoking data stored in the memory. The memory may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program (such as a sound playing function, an image playing function, etc.) required for at least one function, and the like; the storage data area may store data (such as audio data, phonebook, etc.) created according to the use of the handset, etc. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, memory, plug-in hard disk, smart Media Card (SMC), secure digital (SecureDigital, SD) Card, flash Card (Flash Card), at least one disk storage device, flash memory device, or other volatile solid state memory device.
The integrated module/unit of the energy storage inverter energy conversion terminal device may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a stand alone product. Based on such understanding, the present invention may implement all or part of the flow of the method of the above embodiment, or may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of each of the method embodiments described above. Wherein the computer program comprises computer program code which may be in source code form, object code form, executable file or some intermediate form etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer memory, a Read-only memory (ROM), a random access memory (RAM, random Access Memory), an electrical carrier signal, a telecommunications signal, a software distribution medium, and so forth.
The above embodiments are not intended to limit the scope of the present invention, so: all equivalent changes in structure, shape and principle of the invention should be covered in the scope of protection of the invention.
Claims (10)
1. An energy storage inverter energy conversion circuit is characterized in that: the control module is respectively connected with the MPPT module, the detection module, the switching circuit, the bidirectional DC/DC module and the bidirectional DC/AC module, the high-voltage direct current bus end is simultaneously connected to the MPPT module, the bidirectional DC/DC module and the bidirectional DC/AC module, the other end of the MPPT module is connected to the solar end, the other end of the bidirectional DC/DC module is connected to the energy storage battery end, the other end of the bidirectional DC/AC module is connected to the power grid end and the load end through the switching circuit, the detection module is used for detecting electric parameters of the solar end, the battery end, the power grid end, the high-voltage direct current bus end and the load end, the control module calculates and compares the power of each end according to the detection result of the detection module, and the working mode of the energy storage inverter is determined according to the comparison result.
2. The energy storage inverter energy conversion circuit of claim 1, wherein: the control module comprises a power calculation module and a comparison module, wherein the power calculation module comprises a battery end power calculation module, a solar end power calculation module, a grid-connected end power calculation module, a load end power calculation module and a power grid end power calculation module, which are respectively used for calculating the power of each end, and the comparison module is used for comparing the power of each end.
3. The energy storage inverter energy conversion circuit of claim 1, wherein: the device also comprises an isolation driver, one end of the isolation driver is connected with the bidirectional DC/AC module and the bidirectional DC/DC module, and the other end of the isolation driver is connected with the controller and is used for isolating the controller power supply from the bidirectional DC/AC module power supply and the controller power supply from the bidirectional DC/DC module power supply.
4. The energy storage inverter energy conversion circuit of claim 1, wherein: the switching circuit comprises a first switching circuit and a second switching circuit, wherein the first switching circuit is arranged between the grid end and is used for controlling the connection or disconnection of the grid end and the load end; the second switching circuit is arranged between the load end and the grid-connected end and used for controlling the connection or disconnection of the grid-connected end and the load end.
5. A control method of an energy conversion circuit of an energy storage inverter is characterized by comprising the following steps of: detecting the voltage of a power grid terminal, judging whether the power grid is connected or not, and determining the working states of a solar terminal and a battery terminal in each power generation mode according to the power of each terminal; and in the grid-connected mode, controlling the energy storage inverter to work in a current type power generation mode, and in the off-grid mode, controlling the energy storage inverter to work in a voltage type power generation mode.
6. The method for controlling an energy conversion circuit of an energy storage inverter according to claim 5, wherein: comparing the power of the solar end with the load power in a grid-connected mode, and determining the charging mode of the solar end to the energy storage battery according to the electric quantity of the battery when the power of the solar end is larger than the load power; when the power of the solar energy end is smaller than or equal to the load power, determining whether the energy storage battery end is charged or discharged according to the electric quantity of the battery; and in the off-grid mode, comparing the power of the solar end with the power of the load, when the power of the solar end is larger than the power of the load, supplying power to the load end by the solar end and charging the energy storage battery, and when the power of the solar end is smaller than or equal to the power of the load, supplying power to the load by the solar end and the energy storage battery end together.
7. The method for controlling an energy conversion circuit of an energy storage inverter of claim 6, wherein: and in the grid-connected mode, judging the power of the solar end and the power of the load end according to the current direction of the grid end, judging that the power of the solar end is smaller than or equal to the power of the load end when the current of the grid end flows to the load end, and judging that the power of the solar end is larger than the power of the load end when the current of the grid end flows to the grid end from the grid end.
8. The method for controlling an energy conversion circuit of an energy storage inverter of claim 6, wherein: when the power of the solar energy end is larger than the load power, if the electric quantity of the battery is smaller than or equal to a first electric quantity set value, the solar energy end supplies power to the load end and charges the energy storage battery; if the electric quantity of the battery is larger than the first electric quantity set value, the solar end supplies power to the load end, charges the energy storage battery in a constant voltage mode and generates power to the power grid; when the power of the solar end is smaller than or equal to the load power, if the electric quantity of the battery is larger than a second electric quantity set value, the solar energy and the energy storage battery supply power to the load together; if the electric quantity of the battery is smaller than or equal to the second electric quantity set value, the solar end and the power grid end supply power to the load at the same time, and the energy storage battery is charged.
9. The method of controlling an energy conversion circuit of an energy storage inverter of claim 5, comprising the steps of:
s1, starting up;
s2, detecting whether a power grid exists, if so, entering the next step, and if not, turning to S12;
s3, closing a first switch circuit, closing a second switch circuit, and switching to a grid-connected mode;
s4, the running state of the bidirectional DC/AC module is a current type power generation mode;
s5, judging whether the power of the solar end is larger than the load power, if so, entering the next step, and if not, turning to S9;
s6, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is smaller than or equal to a first electric quantity set value, if so, entering the next step, and if not, turning to S8;
s7, the bidirectional DC/DC module works, the solar end provides energy for the load, and meanwhile the energy storage battery is charged, and S2 is switched;
s8, the solar energy end provides energy for the load, meanwhile, the energy storage battery is charged in a constant voltage mode, and redundant energy is sent to the power grid end and is converted into S2;
s9, detecting the electric quantity of the energy storage battery, judging whether the electric quantity of the energy storage battery is larger than a second electric quantity set value, if so, entering the next step, and if not, turning to S11;
s10, the solar end and the energy storage battery end jointly provide energy for a load, and S2 is switched;
s11, the solar end and the power grid end jointly provide energy for a load, and meanwhile, the energy storage battery is charged, and S2 is switched;
s12, the first switch circuit is disconnected, the second switch circuit is disconnected, and the off-grid mode is switched;
s13, the running state of the bidirectional DC/AC module is a voltage type power generation mode;
s14, judging whether the power of the solar end is larger than that of the load end, if so, entering the next step, and if not, turning to S16;
s15, the solar end provides energy for the load, and simultaneously charges the energy storage battery, and S2 is switched;
s16, the solar end and the energy storage battery end simultaneously provide energy for the load, and S2 is achieved.
10. An energy storage inverter energy conversion terminal comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, characterized by: the processor, when executing the computer program, implements the method according to any of claims 5-9.
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