CN108063455B - Off-grid and grid-connected photovoltaic energy storage inverter power control method - Google Patents
Off-grid and grid-connected photovoltaic energy storage inverter power control method Download PDFInfo
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- H02J3/385—
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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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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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
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/48—Controlling the sharing of the in-phase component
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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
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/50—Controlling the sharing of the out-of-phase component
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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
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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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
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- 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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Abstract
The invention discloses a power control method of an off-grid and grid-connected photovoltaic energy storage inverter, which is used for controlling the working mode and the state of a photovoltaic energy storage power generation system, wherein the photovoltaic energy storage power generation system comprises a photovoltaic component, an emergency load, a common load, an energy storage battery and an inverter and is characterized in that the inverter is the off-grid and grid-connected photovoltaic energy storage inverter; and the photovoltaic energy storage power generation system has a grid-connected working mode and an off-grid working mode through the off-grid photovoltaic energy storage inverter. The advantages are that: the maximum utilization of photovoltaic energy is realized, and the defect that the photovoltaic energy is seriously wasted because a common inverter can only output to a power grid or a user load in a one-way mode is overcome. The problem of the grid voltage stability of a photovoltaic system in the peak period of power generation is solved, the peak shifting function of electric energy is achieved, and the photovoltaic energy utilization efficiency is maximized. And meanwhile, the emergency power source EPS function is achieved, and the photovoltaic energy can be still utilized to the maximum under the condition of no power grid.
Description
Technical Field
The invention relates to a power control method for an off-grid and grid-connected photovoltaic energy storage inverter, and belongs to the technical field of photovoltaic energy storage power generation.
Background
With the increasingly prominent problem of environmental pollution, a plurality of policies are put forward in China to encourage the development of clean energy, wherein the most powerful solar energy is used. China is popularizing civil photovoltaic power generation in a large range, and solar power generation is spread throughout our lives in the future. However, the utilization of new energy such as photovoltaic is significantly influenced and limited by natural conditions, including weather, season, time, region, topography, and the like. Mainstream renewable energy sources are not able to stably and continuously provide energy sources compared to conventional fossil fuel energy sources. The actual power grid is not ideal energy with infinite capacity and infinite impedance and a reactive throughput source, the power grades of a large number of medium and small-capacity power supplies are dispersed, the equivalent impedance is large, the output power fluctuates violently, and the stability and the power supply quality of the power grid are influenced.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a power control method of an off-grid and grid-connected photovoltaic energy storage inverter, which is used for carrying out power management on the off-grid and grid-connected photovoltaic energy storage inverter, reducing the active power and reactive power consumption of a user on a system to the greatest extent, reducing the impact on a power grid, outputting the power smoothly and improving the use efficiency of new energy electric energy of the user.
In order to solve the technical problems, the invention provides a power control method of an off-grid photovoltaic energy storage inverter, which is used for controlling the working mode and the state of a photovoltaic energy storage power generation system, wherein the photovoltaic energy storage power generation system comprises a photovoltaic component, an emergency load, a common load, an energy storage battery and an inverter, and is characterized in that the inverter is the off-grid photovoltaic energy storage inverter, the off-grid photovoltaic energy storage inverter comprises a unidirectional DC/DC inverter, a bidirectional DC/AC inverter and a direct current bus capacitor, the photovoltaic component is input into the unidirectional DC/DC inverter, is connected into the direct current bus capacitor through the boosting of the unidirectional DC/DC inverter, converts the energy in the photovoltaic component onto the direct current bus, and the direct current bus capacitor is connected with the bidirectional DC/AC inverter by one way and is finally connected into a power grid, energy can be obtained or deficient from a power grid, the other path of the direct current bus capacitor is connected with the bidirectional DC/DC inverter and is finally connected with the energy storage battery, and the energy of the energy storage battery can be used for supplying power to a load or storing the energy of photovoltaic or the power grid in the energy storage battery;
enabling the photovoltaic energy storage power generation system to have a grid-connected working mode and an off-grid working mode through an off-grid photovoltaic energy storage inverter;
the photovoltaic module input power Ppv is positive, the energy storage battery discharge power Pbat is positive, the charging is negative, the active power Pg and the reactive power Qg on the power grid side flow to the power grid to be positive, and the flow to the load is negative;
under the grid-connected working mode, a power grid is used as a main power supply to supply power, the direct-current bus voltage of a bidirectional DC/AC inverter is stabilized, an energy storage battery and a photovoltaic assembly are used as a standby power supply, the photovoltaic assembly automatically realizes MPPT tracking, outputs maximum photovoltaic power, detects the grid-side active power Pg and reactive power Qg of the photovoltaic energy storage power generation system in real time, and transmits the Pg and Qg to the off-grid-connected photovoltaic energy storage inverter;
when the power Pg of the power grid side is larger than the electricity selling threshold P of the photovoltaic energy storage power generation system0When the off-grid photovoltaic energy storage inverter is used, the energy storage battery is controlled by the off-grid photovoltaic energy storage inverter to reduce the discharge power Pbat, and the battery is switched to a battery charging state after the discharge power Pbat of the battery is reduced to 0 until the maximum charging power-Pbatmax is reached;
when the power Pg of the power grid side is smaller than the electricity purchasing threshold-P of the photovoltaic energy storage power generation system0And then, the off-grid photovoltaic energy storage inverter controls the battery to increase the discharge power Pbat, if the battery is in the charging state originally, the battery charging power Pbat is reduced to 0 and then the battery is switched to the discharging state until the maximum discharge power Pbatmax, and finally the photovoltaic energy storage inverter performs reactive compensation on the power grid to ensure that the reactive power Qg is smaller than the threshold reactive power Q of the photovoltaic energy storage power generation system0；
In the off-grid working mode, the energy storage battery is used as a main power supply to supply power, the direct current bus voltage of the energy storage inverter is stabilized, constant alternating current voltage is output, the photovoltaic module is used as a standby power supply,
when Pbatmax is greater than Pbackup, Pbackup is emergency load power, the energy storage battery discharges to stabilize DC bus voltage, and outputs stable emergency voltage, the photovoltaic module realizes MPPT power tracking, reduces discharge power Pbat, and the battery is switched to a battery charging state after the battery discharge power Pbat is reduced to 0 until the maximum charge power-Pbatmax;
when Pbatmax is less than or equal to Pbackup, Ppvmax + Pbatmax is greater than or equal to Pbackup, the discharge power of the energy storage battery can not stabilize the voltage of the direct current bus, Ppv directly outputs power to stabilize the voltage of the direct current bus, and finally outputs stable emergency alternating current voltage; pbatmax < Pbackup, Ppvmax + Pbatmax < Pbackup, the power of the photovoltaic and battery is not enough to stabilize the DC bus voltage, and the overload stops.
Further, the intelligent electric meter or the CT is connected with a signal line of the off-grid and grid-connected photovoltaic energy storage inverter through parameters of active power and reactive power of a power grid collected by the intelligent electric meter or the CT connected with the power grid, and collected data are transmitted to the off-grid and grid-connected photovoltaic energy storage inverter through an RS485 bus.
Further, in the grid-connected working mode, the detected grid-side output active power Pg is greater than P0, the off-grid photovoltaic energy storage inverter sells electricity to the grid, the off-grid photovoltaic energy storage inverter controls the output power of the energy storage battery to give a target Pbatref = Pbatnow- | P0|/2= Pbatnow-P0/2, and Pbatnow is the current output power of the energy storage battery.
Further, in the grid-connected mode, the detected grid-side output active power Pg < -P0, the off-grid photovoltaic energy storage inverter buys power to the grid, the off-grid photovoltaic energy storage inverter controls the output power of the energy storage battery to give a target Pbatref = Pbatnow + | P0|/2= Pbatnow-P0/2, and Pbatnow is the current output power of the energy storage battery.
Further, in the grid-connected mode, the detected reactive power | Qg & lt & gt output by the power grid side>|Q0An output reactive power given target Qref = Qnow-Q of the off-grid photovoltaic energy storage inverter0And/2, Qnow is the current output reactive power of the off-grid photovoltaic energy storage inverter.
Further, in the off-grid operating mode, the sum of the maximum output power Ppvmax of the photovoltaic module and the maximum output power Pbatmax of the energy storage battery is required to be greater than the emergency load power Pbackup, Ppvmax + Pbatmax > Pbackup, the photovoltaic module automatically carries out MPPT tracking, the battery output power target of the off-grid photovoltaic energy storage inverter is not required to be given, only the direct-current bus voltage target value Udcref is required to be given, and the off-grid photovoltaic energy storage inverter controls the power and outputs the voltage with stable amplitude and frequency; and otherwise, reporting the overload software fault by the off-grid and grid-connected photovoltaic energy storage inverter power control method.
Furthermore, the detection frequency of the active power Pg and the reactive power Qg at the power grid side is kept synchronous with the photovoltaic MPPT tracking frequency of the off-grid photovoltaic energy storage inverter and the output power detection frequency of the energy storage battery.
The invention achieves the following beneficial effects:
the method can overcome the defect that the photovoltaic module is unstable in power generation due to weather change, provide stable pure current with very low harmonic content for the power grid, and improve the quality of the power grid; the electric energy is stored through the wave trough, the electric energy is output through the wave crest, the peak power generation amount of the power grid can be greatly reduced, the capacity of the power grid can also be greatly increased, and the utilization rate of the power grid is improved. Meanwhile, reactive compensation is carried out on the power grid, the power factor of power supply is greatly improved, the power regulation fee is changed from fine to reward, and the power consumption cost is saved.
Drawings
FIG. 1 is a flow chart of a method for controlling power of an off-grid and grid-connected photovoltaic energy storage inverter according to the present invention;
FIG. 2 is a power control flow diagram of the photovoltaic input power and the energy storage battery discharge in the off-grid and grid-connected photovoltaic energy storage inverter grid-connected mode according to the present invention;
FIG. 3 is a power control flow diagram of the photovoltaic input power and the energy storage battery charging in the off-grid and grid-connected photovoltaic energy storage inverter grid-connected mode according to the present invention;
fig. 4 is a power control flow diagram of the photovoltaic input power and the energy storage battery discharging in the off-grid mode of the off-grid and grid-connected photovoltaic energy storage inverter of the invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
The first embodiment is as follows: the photovoltaic energy storage power generation system comprises a photovoltaic module, an emergency load, a common load, an energy storage battery and a photovoltaic energy storage inverter, wherein the photovoltaic energy storage inverter controls charging and discharging of the energy storage battery according to the power flow direction. The off-grid and grid-connected photovoltaic energy storage inverter power control method is realized through the photovoltaic energy storage inverter, so that the photovoltaic energy storage power generation system has a grid-connected working mode and an off-grid working mode.
1. Grid-connected mode of operation
Referring to fig. 1, in a grid-connected mode, the smart meter or the CT is connected to a signal line of the off-grid photovoltaic energy storage inverter through grid active power and reactive power parameters collected by the smart meter or the CT connected to the grid, and transmits active power Pg and reactive power Qg parameters to the photovoltaic energy storage inverter.
When the detected grid-side output active power Pg is greater than P0, the off-grid photovoltaic energy storage inverter sells electricity to the grid, the system is in a light load state, and the photovoltaic energy is abundant, the output power of the energy storage battery of the off-grid photovoltaic energy storage inverter is given a target Pbatref = Pbatnow-P0/2 = Pbatnow-P0/2, and Pbatnow is the current output power of the energy storage battery. The given energy storage battery output power target Pbatref is gradually reduced, the energy storage battery output power is reduced to Pbatref according to the instruction power, and finally the energy storage battery is charged according to the instruction power, wherein the emergency load is an important load in practical application and does not allow the power supply to stop, or irretrievable loss, such as data loss and the like, is caused after the power supply is stopped; the normal load is a general load in practical applications, and allows the power supply to be stopped, or has little influence on users after the power supply is stopped, such as normal lighting, a fan, and the like, as shown in fig. 3.
When the detected grid-side output active power Pg < -P0, the off-grid photovoltaic energy storage inverter buys power to the grid, the system is in a heavy load state, and the photovoltaic energy is insufficient, the battery output power of the off-grid photovoltaic energy storage inverter gives a target Pbatref = Pbatnow + | P0|/2= Pbatnow-P0/2, and Pbatnow is the current output power of the energy storage battery. The given energy storage battery output power target Pbatref is gradually increased, the energy storage battery output power is increased to Pbatref according to the commanded power, and the energy storage battery is increased in discharge power according to the commanded power. As shown in fig. 2.
When the detected active power Pg < | P0| is output by the power grid side, the reactive power Qg is greater than Q0, at the moment, the active power of the system is balanced, the active power of all loads is provided by photovoltaic cells and energy storage batteries, but the reactive power of all loads is still provided by the power grid, the reactive power is overcompensated, the power factor is extremely low, and the power regulation fee penalty is huge. The output reactive power of the off-grid photovoltaic energy storage inverter gives a target Qref = Qnow-Q0/2, and Qnow is the current output reactive power of the off-grid photovoltaic energy storage inverter. And reducing the instruction power to Qref by the output power of the energy storage inverter, and reducing the reactive power output according to the instruction power of the energy storage inverter.
When the detected active power Pg < | P0| and reactive power Qg < -Q0 are output by the power grid side, the active power of the system is balanced, the active power of all loads is provided by photovoltaic cells and energy storage batteries, but the reactive power of all loads is still provided by the power grid, the reactive power is under-compensated, the power factor is extremely low, and the power regulation fee penalty is huge. The output reactive power of the off-grid photovoltaic energy storage inverter gives a target Qref = Qnow-Q0/2, and Qnow is the current output reactive power of the off-grid photovoltaic energy storage inverter. The energy storage inverter output power increases the commanded power down to Qref, which increases the reactive power output based on the commanded power.
When the detected active power Pg < | P0| and reactive power Qg < | Q0| output by the power grid side are in a power balance state from the grid-connected photovoltaic energy storage system, the charging and discharging power of the battery and the power output by the inverter keep the current state unchanged.
2. Off-grid operating mode
When the mains supply is interrupted, the voltage of a stable direct current bus of the grid-connected photovoltaic energy storage inverter is required to be higher than the emergency load power Pbackup, the sum of the maximum output power Ppvmax of the photovoltaic assembly and the maximum output power Pbatmax of the energy storage battery is required to be larger than the emergency load power Pbackup, Ppvmax + Pbatmax > Pbackup, and the photovoltaic assembly is automatically subjected to MPPT tracking. The battery output power target of the off-grid and grid-connected photovoltaic energy storage inverter is not required to be given, and only the direct-current bus voltage target value Udcref is required to be given, and the off-grid and grid-connected photovoltaic energy storage inverter outputs voltage with stable amplitude and frequency under power control. Otherwise, the off-grid and grid-connected photovoltaic energy storage inverter power control method reports the overload fault. As shown in fig. 4.
The off-grid and grid-connected photovoltaic energy storage inverter is controlled by the control method, and the function of maximum utilization of photovoltaic energy is realized in a grid-connected mode and an off-grid mode. In a grid-connected operation mode, a power grid is used as a main power supply to stabilize the voltage of a direct current capacitor of the off-grid photovoltaic energy storage inverter, and a photovoltaic cell panel and an energy storage battery are used as standby power supplies. And detecting active power and reactive power at the power metering position of the total entrance of the power grid in real time, and transmitting power data to a control module of the off-grid photovoltaic energy storage inverter in real time. And the off-grid photovoltaic energy storage inverter determines the active power output size and direction of the battery and the reactive power output size and direction of the inverter according to the power direction and size of the power grid. Under the off-grid operation mode, the energy storage battery is used as a main power supply to stabilize the voltage of a direct current capacitor of the off-grid photovoltaic energy storage inverter, and the photovoltaic cell panel is used as a standby power supply. And analyzing the power input by the photovoltaic cell panel and the power of the energy storage battery in real time, realizing MPPT tracking of the photovoltaic cell panel and optimizing the working state of the energy storage battery. The photovoltaic energy utilization method and the inverter realize the maximum utilization of photovoltaic energy, and avoid the defect that the common inverter can only output the photovoltaic energy to a power grid or a user load in a one-way manner, so that the photovoltaic energy is seriously wasted. The problem of the grid voltage stability of a photovoltaic system in the peak period of power generation is solved, the peak shifting function of electric energy is achieved, and the photovoltaic energy utilization efficiency is maximized. And meanwhile, the emergency power source EPS function is achieved, and the photovoltaic energy can be still utilized to the maximum under the condition of no power grid.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (3)
1. A power control method of an off-grid and grid-connected photovoltaic energy storage inverter is used for controlling the working mode and the state of a photovoltaic energy storage power generation system, the photovoltaic energy storage power generation system comprises a photovoltaic component, an emergency load, a common load, an energy storage battery and an inverter, and is characterized in that the inverter is the off-grid and grid-connected photovoltaic energy storage inverter, the off-grid and grid-connected photovoltaic energy storage inverter comprises a unidirectional DC/DC inverter, a bidirectional DC/AC inverter and a direct current bus capacitor, the photovoltaic component is input to the unidirectional DC/DC inverter and is connected to the direct current bus capacitor through the boosting of the unidirectional DC/DC to convert the energy in the photovoltaic component to the direct current bus, one path of the direct current bus capacitor is connected with the bidirectional DC/AC inverter and is finally connected to a power grid to obtain or lack the energy from the power grid, the other path of the direct current, finally, the energy storage battery is connected, so that the energy of the energy storage battery can be supplied to a load, or the energy of a photovoltaic or power grid is stored in the energy storage battery;
enabling the photovoltaic energy storage power generation system to have a grid-connected working mode and an off-grid working mode through an off-grid photovoltaic energy storage inverter;
the photovoltaic module input power Ppv is positive, the energy storage battery discharge power Pbat is positive, the charging is negative, the active power Pg and the reactive power Qg on the power grid side flow to the power grid to be positive, and the flow to the load is negative;
under the grid-connected working mode, a power grid is used as a main power supply to supply power, the direct-current bus voltage of a bidirectional DC/AC inverter is stabilized, an energy storage battery and a photovoltaic assembly are used as a standby power supply, the photovoltaic assembly automatically realizes MPPT tracking, outputs maximum photovoltaic power, detects the grid-side active power Pg and reactive power Qg of the photovoltaic energy storage power generation system in real time, and transmits the Pg and Qg to the off-grid-connected photovoltaic energy storage inverter;
when the power Pg of the power grid side is larger than the electricity selling threshold P of the photovoltaic energy storage power generation system0When the off-grid photovoltaic energy storage inverter is used, the energy storage battery is controlled by the off-grid photovoltaic energy storage inverter to reduce the discharge power Pbat, and the battery is switched to a battery charging state after the discharge power Pbat of the battery is reduced to 0 until the maximum charging power-Pbatmax is reached;
when the power Pg of the power grid side is smaller than the electricity purchasing threshold-P of the photovoltaic energy storage power generation system0When the grid-off-grid photovoltaic energy storage inverter controls the battery to increase the discharge power Pbat, if the battery is in the charging state originally, the battery charging power Pbat is reduced to 0, and then the battery is turned toEntering a discharging state until the maximum discharging power Pbatmax, and finally performing reactive compensation on the power grid by the photovoltaic energy storage inverter to ensure that the reactive power Qg is less than the threshold reactive power Q of the photovoltaic energy storage power generation system0；
In the off-grid working mode, the energy storage battery is used as a main power supply to supply power, the direct current bus voltage of the energy storage inverter is stabilized, constant alternating current voltage is output, the photovoltaic module is used as a standby power supply,
when Pbatmax is greater than Pbackup, Pbackup is emergency load power, the energy storage battery discharges to stabilize DC bus voltage, and outputs stable emergency voltage, the photovoltaic module realizes MPPT power tracking, reduces discharge power Pbat, and the battery is switched to a battery charging state after the battery discharge power Pbat is reduced to 0 until the maximum charge power-Pbatmax;
when Pbatmax is less than or equal to Pbackup, Ppvmax + Pbatmax is greater than or equal to Pbackup, the discharge power of the energy storage battery can not stabilize the voltage of the direct current bus, Ppv directly outputs power to stabilize the voltage of the direct current bus, and finally outputs stable emergency alternating current voltage; pbatmax < Pbackup, Ppvmax + Pbatmax < Pbackup, the power of the photovoltaic and the battery is not enough to stabilize the direct current bus voltage, and the overload is stopped;
in the grid-connected working mode, the detected grid-side output active power Pg is greater than P0, the off-grid photovoltaic energy storage inverter sells electricity to the grid, the off-grid photovoltaic energy storage inverter controls the output power of the energy storage battery to give a target Pbatref = Pbatnow- | P0|/2= Pbatnow-P0/2, and Pbatnow is the current output power of the energy storage battery;
in the grid-connected mode, the detected grid-side output active power Pg < -P0, the off-grid photovoltaic energy storage inverter buys electricity to the grid, and the off-grid photovoltaic energy storage inverter controls the output power of the energy storage battery to give a target Pbatref = Pbatnow + | P0|/2= Pbatnow-P0/2;
in the grid-connected mode, detected reactive power | Qg & lt & gt output by the power grid side>|Q0An output reactive power given target Qref = Qnow-Q of the off-grid photovoltaic energy storage inverter0(vii)/2, Qnow is the current output reactive power of the off-grid photovoltaic energy storage inverter;
in the off-grid working mode, the sum of the maximum output power Ppvmax of the photovoltaic assembly and the maximum output power Pbatmax of the energy storage battery is required to be larger than the emergency load power Pbackup, Ppvmax + Pbatmax > Pbackup, the photovoltaic assembly automatically carries out MPPT tracking, the battery output power target of the off-grid photovoltaic energy storage inverter is not required to be given, only the direct-current bus voltage target value Udcref is required to be given, and the off-grid photovoltaic energy storage inverter controls the power and outputs the voltage with stable amplitude and frequency; and otherwise, reporting the overload software fault by the off-grid and grid-connected photovoltaic energy storage inverter power control method.
2. The method as claimed in claim 1, wherein the grid active power and reactive power parameters are collected by a smart meter or a CT connected to the grid, the smart meter or the CT is connected to a signal line of the off-grid and grid-connected photovoltaic energy storage inverter, and the collected data is transmitted to the off-grid and grid-connected photovoltaic energy storage inverter through an RS485 bus.
3. The method for controlling the power of the off-grid and grid-connected photovoltaic energy storage inverter as claimed in claim 1, wherein the detection frequency of the grid-side active power Pg and the reactive power Qg is kept synchronous with the photovoltaic MPPT tracking frequency of the off-grid and grid-connected photovoltaic energy storage inverter and the detection frequency of the output power of the energy storage battery.
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| CN117650634B (en) * | 2024-01-30 | 2024-05-07 | 国网山东省电力公司青州市供电公司 | Intelligent management and control device, system and management and control method for power grid energy storage equipment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI384720B (en) * | 2008-07-17 | 2013-02-01 | Atomic Energy Council | Dc power system for household appliances |
| CN104810858A (en) * | 2015-05-27 | 2015-07-29 | 广西大学 | Control method for grid-connected power generation system of optical storage microgrid |
| CN104868840A (en) * | 2015-05-12 | 2015-08-26 | 江苏固德威电源科技有限公司 | Photovoltaic energy storage inverter off-grid MPPT perturbation method |
| CN104868534A (en) * | 2015-05-12 | 2015-08-26 | 江苏固德威电源科技有限公司 | Photovoltaic energy storage inverter energy management method |
| CN106712090A (en) * | 2017-01-20 | 2017-05-24 | 合肥聚能新能源科技有限公司 | Modular photovoltaic energy-storage inverter |
-
2017
- 2017-12-11 CN CN201711307812.0A patent/CN108063455B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI384720B (en) * | 2008-07-17 | 2013-02-01 | Atomic Energy Council | Dc power system for household appliances |
| CN104868840A (en) * | 2015-05-12 | 2015-08-26 | 江苏固德威电源科技有限公司 | Photovoltaic energy storage inverter off-grid MPPT perturbation method |
| CN104868534A (en) * | 2015-05-12 | 2015-08-26 | 江苏固德威电源科技有限公司 | Photovoltaic energy storage inverter energy management method |
| CN104810858A (en) * | 2015-05-27 | 2015-07-29 | 广西大学 | Control method for grid-connected power generation system of optical storage microgrid |
| CN106712090A (en) * | 2017-01-20 | 2017-05-24 | 合肥聚能新能源科技有限公司 | Modular photovoltaic energy-storage inverter |
Non-Patent Citations (2)
| Title |
|---|
| A grid connected PV micro-inverter with optimized battery storage utilization;Vikram Roy Chowdhury et al.;《2015 IEEE Energy Conversion Congress and Exposition (ECCE)》;20151029;第3455-3461页 * |
| 一种新型光伏储能逆变器系统;张彦虎等;《电器与能效管理技术》;20140531(第9期);第45-48页 * |
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