CN113241797B - Direct current coupling system and control method thereof - Google Patents
Direct current coupling system and control method thereof Download PDFInfo
- Publication number
- CN113241797B CN113241797B CN202110643769.5A CN202110643769A CN113241797B CN 113241797 B CN113241797 B CN 113241797B CN 202110643769 A CN202110643769 A CN 202110643769A CN 113241797 B CN113241797 B CN 113241797B
- Authority
- CN
- China
- Prior art keywords
- voltage
- power
- battery system
- converter
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 62
- 230000008878 coupling Effects 0.000 title claims abstract description 46
- 238000010168 coupling process Methods 0.000 title claims abstract description 46
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 46
- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 claims abstract description 158
- 238000010248 power generation Methods 0.000 claims description 19
- 230000001105 regulatory effect Effects 0.000 claims description 9
- 238000007599 discharging Methods 0.000 claims description 8
- 230000008859 change Effects 0.000 claims description 7
- 230000001276 controlling effect Effects 0.000 claims description 6
- 230000004044 response Effects 0.000 abstract description 7
- 230000008569 process Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 229920006395 saturated elastomer Polymers 0.000 description 6
- 230000010354 integration Effects 0.000 description 4
- 238000005286 illumination Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 101100119135 Mus musculus Esrrb gene Proteins 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000002222 downregulating effect Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- 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
- H02J3/381—Dispersed generators
-
- 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
-
- 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
-
- 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
-
- 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
- Y02E70/00—Other energy conversion or management systems reducing GHG emissions
- Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Electrical Variables (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention provides a direct current coupling system and a control method thereof.A DCAC converter takes a grid-connected power limit value as an upper limit to control itself to maximize power output; the DCDC converter aims at maximizing output power and controls the DCDC converter to output power; because the two converters are connected with the battery system common direct current bus, the two converters can realize voltage regulation of the battery system through the direct current bus for corresponding voltage control of the two converters, so that the battery system can work according to the voltage and power requirements on the direct current bus; and furthermore, the automatic control on the system operation is realized through the two converters, the EMS or the main control system is not needed to participate in scheduling, the dynamic response speed of the system is improved, and the difficulty of a control algorithm in the EMS or the main control system is reduced.
Description
Technical Field
The invention relates to the technical field of photovoltaic grid-connected control, in particular to a direct current coupling system and a control method thereof.
Background
As shown in fig. 1, a single-system series dc-coupled system generally includes: the photovoltaic power generation branch, the battery branch and the inversion branch are connected through a direct current bus; the series direct current coupling system of the multiple systems is shown in fig. 2, wherein the photovoltaic power generation branches are multiple. Corresponding power converters, such as the DCDC converter and the DCAC converter shown in the figures, are typically provided in each leg of the two systems, respectively, to achieve power regulation for the corresponding leg, respectively.
Currently, the power regulation control of each branch is mainly realized by energy scheduling of an energy management system EMS or a main control system of the system; however, the method is realized through communication scheduling, so that the problems of slow response and the like exist on the dynamic performance, the fault protection of the system is easy to be caused, and meanwhile, the difficulty of a control algorithm in an EMS or a main control system is increased.
Disclosure of Invention
In view of this, the present invention provides a dc coupling system and a control method thereof, so as to improve the dynamic response speed and reduce the difficulty of the control algorithm in the EMS or the master control system.
In order to achieve the above purpose, the present invention provides the following technical solutions:
the invention provides a control method of a direct current coupling system, which comprises a battery system, an inversion branch and at least one photovoltaic power generation branch, wherein the battery system, a DCDC converter arranged in the photovoltaic power generation branch and a DCAC converter arranged in the inversion branch are connected with a common direct current bus; the control method of the direct current coupling system comprises the following steps:
the DCAC converter takes the grid-connected limit power value as an upper limit and controls the DCAC converter to output maximum power;
The DCDC converter aims at maximizing output power and controls the DCDC converter to output power;
the battery system operates according to the voltage and power requirements on the dc bus.
Optionally, the DCAC converter uses the grid-connected power limit value as an upper limit, and controls itself to perform the maximized power output, including:
the DCAC converter takes the lower limit voltage of the battery system as a reference quantity to control the direct current side voltage of the DCAC converter; the method comprises the steps of,
and the DCAC converter takes the grid-connected power limiting value as an upper limit to carry out maximized power output.
Optionally, the DCAC converter uses a lower limit voltage of the battery system as a reference, and controls a direct current side voltage of the DCAC converter, including:
the DCAC converter takes the lower limit voltage as a given value of a self voltage outer ring, takes the voltage of the battery system as a negative feedback value of the self voltage outer ring, and controls the self direct current side voltage.
Optionally, the DCAC converter performs maximum power output with the grid-connected limited power value as an upper limit, and includes:
and the DCAC converter adjusts the current inner loop input quantity limiting value of the DCAC converter according to the grid-connected limiting value and controls the current of the alternating current side of the DCAC converter.
Optionally, the DCDC converter aims at maximizing output power, controls itself to perform power output, and includes:
and the DCDC converter takes the upper limit voltage of the battery system as a reference quantity to control the output voltage of the DCDC converter.
Optionally, the DCDC converter controls its own output voltage with an upper limit voltage of the battery system as a reference, and includes:
the DCDC converter takes the upper limit voltage as a given value of a self voltage outer ring, takes the voltage of the battery system as a negative feedback value of the self voltage outer ring, and controls the self output voltage.
Optionally, the DCDC converter aims at maximizing output power, controls itself to output power, and further includes:
if the input power of the DCDC converter is smaller than the preset power threshold value, the input voltage is ensured to be larger than the starting voltage of the DCDC converter in a mode of reducing the output power of the DCDC converter.
Optionally, in a manner of reducing the output power thereof, to ensure that the input voltage is greater than the start-up voltage thereof, includes:
according to the input voltage of the self-body, the limiting value of the input quantity of the current inner loop of the self-body is regulated so that the input voltage of the self-body is larger than the starting voltage of the self-body.
Optionally, adjusting the limiting value of the input quantity of the current inner loop according to the input voltage of the current inner loop comprises:
if the input voltage of the self-body is between the preset power-reduction starting voltage and the maximum power voltage lower limit, regulating the output current of the self-body to change in the same direction according to the change condition of the input voltage of the self-body by a preset step length; the maximum power voltage lower limit is less than the reduced power starting voltage;
and if the input voltage of the self-body is smaller than the lower limit of the maximum power voltage, regulating the output current of the self-body to be zero.
Optionally, the preset step length has a corresponding relationship with the magnitude of the input voltage change condition.
Optionally, the battery system performs charging and discharging or stops running according to the voltage and power requirements on the dc bus, including:
if the voltage of the battery system is smaller than the lower limit voltage of the battery system, the voltage of the battery system is controlled by the DCAC converter; and when the sum of the output power of all the DCDC converters is larger than the grid-connected limit power value, the battery system is charged; when the sum of the output power of all the DCDC converters is smaller than or equal to the grid-connected limit power value, stopping the operation of the battery system;
If the voltage of the battery system is greater than the upper limit voltage of the battery system, the voltage of the battery system is controlled by the DCDC converter; and when the sum of the output power of all the DCDC converters is greater than or equal to the grid-connected limit power value, stopping the operation of the battery system; discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value;
if the voltage of the battery system is between the lower limit voltage and the upper limit voltage, charging the battery system when the sum of the output powers of all the DCDC converters is greater than the grid-connected limit power value; discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value; and stopping the operation of the battery system when the sum of the output powers of the DCDC converters is equal to the grid-connected limit power value.
A second aspect of the present invention provides a dc coupling system comprising: the system comprises a battery system, an inversion branch and at least one photovoltaic power generation branch; wherein:
the photovoltaic power generation branch circuit comprises: a photovoltaic sub-array and a DCDC converter connected in series;
The inversion branch circuit comprises: a DCAC converter;
the battery system, the DCDC converter and the DCAC converter are connected through a common direct current bus;
the battery system, the DCDC converter and the DCAC converter control their own operations through the respective steps in the control method of the dc coupling system as described in any one of the above paragraphs, respectively.
Based on the control method of the direct current coupling system, the DCAC converter takes the grid-connected limit power value as the upper limit, controls the DCDC converter to output the maximum power, and controls the DCDC converter to output the power with the aim of maximizing the output power; because the two converters are connected with the battery system common direct current bus, the two converters can control the corresponding voltage of the two converters, and the voltage of the battery system can be regulated through the direct current bus, so that the battery system can work according to the voltage and power requirements on the direct current bus. That is, the method realizes the automatic control of the system operation through the two converters, does not need to participate in scheduling by the EMS or the main control system, improves the dynamic response speed of the system, and reduces the difficulty of a control algorithm in the EMS or the main control system.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a single-system series dc coupling system provided in the prior art;
FIG. 2 is a schematic diagram of a serial DC coupling system of multiple systems according to the prior art;
fig. 3a is a schematic structural diagram of a dc coupling system of a single system according to an embodiment of the present invention;
fig. 3b is a schematic structural diagram of a dc coupling system of a multi-system according to an embodiment of the present invention;
fig. 4 is a flowchart of a control method of a dc coupling system according to an embodiment of the present invention;
fig. 5 is a specific flowchart of a control method of a dc coupling system according to an embodiment of the present invention;
FIG. 6a is a partial logic block diagram of a DCAC converter according to an embodiment of the present invention;
FIG. 6b is a partial logic block diagram of a DCDC converter according to an embodiment of the present invention;
Fig. 7 is a schematic diagram of voltage division of a battery system according to an embodiment of the present invention;
FIGS. 8a and 8b are schematic diagrams of two power flows provided by embodiments of the present invention, respectively;
fig. 9 is a schematic diagram of voltage division of a photovoltaic subarray according to an embodiment of the present invention;
fig. 10 is a partial specific flowchart of a control method of a dc coupling system according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The invention provides a control method of a direct current coupling system, which is used for improving the dynamic response speed and reducing the difficulty of a control algorithm in an EMS or a main control system.
Referring to fig. 3a and 3b, the dc coupling system includes: the system comprises a battery system, an inversion branch and at least one photovoltaic power generation branch (one photovoltaic power generation branch is shown as an example in fig. 3a and a plurality of photovoltaic power generation branches are shown in fig. 3 b); the battery system, the DCDC converter arranged in the photovoltaic power generation branch and the DCAC converter arranged in the inversion branch are connected through a common direct current bus; that is, unlike the prior art, the battery system is directly connected to the dc bus, and no corresponding DCDC converter is provided therebetween.
As shown in fig. 4, the control method of the dc coupling system includes:
s101, controlling the DCAC converter to carry out maximized power output by taking the grid-connected power limit value as an upper limit.
In practical application, the direct current coupling system receives the scheduling instruction, and limits the grid-connected power of the direct current coupling system not to exceed a limit value, namely the grid-connected limit power value. If the power which can be received by the DCAC converter, namely the sum of the power of all the DCDC converters and the power which can be achieved by the discharge of the battery system, does not exceed the grid-connected limit power value, the DCAC converter can output the maximum power which can be received by the DCAC converter, namely the DCAC converter enters a full power state; if the receivable power exceeds the grid-connected limit power value, the power output is carried out at the grid-connected limit power value, namely, the power is in a limited power state. That is, the DCAC converter controls itself to maximize power output in a full power state or a limited power state with the grid-connected limited power value as an upper limit.
S102, the DCDC converter aims at maximizing output power and controls the DCDC converter to output power.
The DCDC converter receives the power of the photovoltaic subarrays in the photovoltaic power generation branch, and outputs the power after corresponding conversion.
In practical applications, the DCDC converter aims at maximizing output power, and controls itself to perform power output in a maximum power state or a limited power state. Specific:
if the dc bus allows the DCDC converter to output at its maximum power, for example, if the output power of the DCDC converter is less than the grid-connected limit power value of the DCAC converter, or if the output power of the DCDC converter is not less than the grid-connected limit power value but the battery system is able to receive charging power, the DCDC converter will output power at the maximum power state and operate at the maximum power of the photovoltaic subarrays received by itself.
If the dc bus does not allow the DCDC converter to output at its maximum power, for example, if the output power of the DCDC converter is greater than or equal to the grid-connected limited power value and the battery system is full and unable to receive charging power, the DCDC converter will output power in a limited power state.
It can be obtained that the DCDC converter will operate in the maximum power state in most cases, and will operate in the limited power state only in a few cases where the battery system is full and the light is strong, so that the output power of the DCDC converter is larger than the grid-connected limited power value. Therefore, as long as the output power of the DCAC converter does not exceed the grid-connected limit power value, the DCDC converter is operated in the maximum power state as much as possible, and only a few cases can be operated in the limit power state, that is, the DCDC converter is operated with the aim of maximizing the output power all the time, and the maximum utilization of the power of the photovoltaic subarray at the front stage can be realized.
And S103, the battery system works according to the voltage and power requirements on the direct current bus.
According to the voltage and power requirements on the dc bus, the state of the battery system is specifically the following:
(1) If the input power received by the DCDC converter is larger, the DCAC converter needs limited power and the voltage of the battery system is lower, the voltage on the dc bus needs to be increased, and the grid-connected power demand on the dc bus is not large, but there is a large demand for charging power, the DCDC converter can output power in a maximum power state, and the DCDC converter is used for charging the remaining power of the DCAC converter after limited power grid connection by the battery system.
(2) If the input power received by the DCDC converter is larger, the DCAC converter does not reach the power limiting state and the voltage of the battery system is lower, the voltage on the direct current bus needs to be increased at the moment, but the direct current bus has larger requirements for grid-connected power and charging power, the DCDC converter can output power in the maximum power state, the DCAC converter is used for full-power grid connection, no residual power on the direct current bus can charge the battery system, and the battery system cannot discharge due to lower voltage.
(3) If the input power received by the DCDC converter is larger, the DCAC converter needs limited power and the voltage of the battery system is higher, the voltage on the direct current bus needs to be reduced at the moment, but the requirements on grid-connected power and charging power on the direct current bus are not large, the DCDC converter needs to output power in a power limiting state, the power of the DCAC converter is ensured not to exceed the grid-connected power limiting value, and the battery system is not charged or discharged.
(4) If the input power received by the DCDC converter is larger, the DCAC converter does not reach the power limit state and the voltage of the battery system is higher, the voltage on the direct current bus needs to be reduced at the moment, the charging power demand on the direct current bus is not large, but the grid-connected power is required to be larger, the DCDC converter can output power in the maximum power state, the battery system discharges, and the DCDC converter and the battery system are used for full-power grid connection of the DCAC converter together.
(5) If there is a small input power received by one or more DCDC converters, but the DCAC converter needs limited power and the voltage of the battery system is low, the voltage on the dc bus needs to be raised, and the grid-connected power demand on the dc bus is not large, but there is a large demand for charging power, all DCDC converters can output power in the maximum power state, and the remaining power after the DCAC converter limited power is connected can be charged by the battery system.
(6) If there is a small input power received by one or more DCDC converters, but the DCAC converter does not reach the limited power state and the voltage of the battery system is low, the voltage on the dc bus needs to be increased at this time, and there is a large demand on both grid-connected power and charging power on the dc bus, all DCDC converters need to output power in the maximum power state, which is used for full-power grid connection of the DCAC converter, but no residual power on the dc bus can charge the battery system, and the battery system will not discharge due to the low voltage.
(7) If there are some or some DCDC converters that receive smaller input power, but the DCAC converter needs limited power and the voltage of the battery system is higher, the voltage on the dc bus needs to be reduced at this time, but the requirements on grid-connected power and charging power on the dc bus are not large, the DCDC converters can output power in the maximum power state, and the DCDC converters with other larger input power need to output power in the limited power state, so that the power of the DCAC converter is ensured not to exceed the grid-connected limited power value, and the battery system is not charged or discharged.
(8) If there is one or several DCDC converters receiving smaller input power, but the DCAC converter does not reach the power limit state and the voltage of the battery system is higher, the voltage on the dc bus needs to be reduced, and there is a larger demand for grid-connected power on the dc bus but not a larger demand for charging power, the DCDC converter can output power in the maximum power state, the battery system discharges, and the two are used together for full-power grid connection of the DCAC converter.
As can be seen from the above analysis, in the control method of the dc coupling system provided in this embodiment, since the two converters are connected to the dc bus of the battery system, the two converters control their respective voltages, and can implement voltage regulation on the battery system through the dc bus, so that the battery system can perform charge and discharge or stop operation according to the voltage and power requirements on the dc bus. Namely, the method realizes the automatic control of the system operation through the two converters, realizes the rapid balanced control inside the system, does not need the EMS or the main control system to participate in the scheduling, improves the dynamic response speed of the system, and reduces the development difficulty and cost of the control algorithm in the EMS or the main control system.
In practical applications, the execution sequence of steps S101 and S102 is not limited to that shown in fig. 4, and may be implemented according to the cycle of each control loop, and fig. 4 is only a schematic example.
Based on the above embodiment, the control method of the dc-coupled system according to the present embodiment provides a part of specific execution process, referring to fig. 5, and step S101 includes:
s201, the DCAC converter controls the direct current side voltage by taking the lower limit voltage of the battery system as a reference.
In practical application, an upper limit voltage and a lower limit voltage can be set for the battery system, wherein the upper limit voltage refers to a voltage value corresponding to the battery system when the battery system is fully charged, and the lower limit voltage refers to a voltage value corresponding to the battery system when the battery system is fully discharged; the upper limit voltage is greater than the lower limit voltage.
In practical application, no matter what position the converter is, the converter is provided with a voltage and current control loop of the converter, such as a double closed loop of a voltage outer loop and a current inner loop, and each loop is provided with corresponding setting parameters, acquisition feedback parameters and the like; in this step, the voltage control of the respective side can be achieved by setting the respective reference quantity to the voltage outer ring given value of the corresponding converter.
At this time, the specific procedure of this step S201 may be: the DCAC converter takes the lower limit voltage as the given value of the outer voltage loop of the DCAC converter, and takes the voltage of the battery system as the negative feedback value of the outer voltage loop of the DCAC converter to control the voltage of the DCAC converter.
The voltage outer loop set point vpcs_ref of the DCAC inverter is set to the lower limit voltage vbat_low of the battery system, i.e., vpcs_ref=vbat_low. The voltage Vbat of the battery system is taken as a negative feedback value of a voltage outer loop, as shown in a partial logic block diagram of fig. 6a, and the voltage outer loop set value vpcs_ref is differenced with the negative feedback battery system voltage Vbat to obtain a real-time difference value err2=vpcs_ref-vbat_low >0. From the control theory point of view, an integration link, such as PID adjustment shown in the figure, is arranged subsequently, and if there is a difference between the given value and the negative feedback value, the difference will be accumulated, and a maximum value will be output, and the maximum purpose is that the device operates according to the maximum power without reaching the controlled target maximum voltage.
S202, the DCAC converter takes the grid-connected power limit value as an upper limit to carry out maximum power output. The specific process of this step S202 may be: the DCAC converter adjusts the current inner loop input quantity iref2 limiting value I_limit2 of the DCAC converter according to the grid-connected limiting value, and controls the current of the alternating current side of the DCAC converter; and the output power of the alternating current side of the power supply is not over the grid-connected limit power value under the condition that the voltage of the alternating current side is kept unchanged.
Similarly, referring to fig. 5, step S102 includes:
s301, the DCDC converter controls its own output voltage with the upper limit voltage of the battery system as a reference.
The specific process of the step can be as follows: the DCDC converter takes the upper limit voltage as a given value of a self voltage outer ring, takes the voltage of the battery system as a negative feedback value of the self voltage outer ring, and controls the self output voltage.
The voltage outer loop given value vdc_ref of the DCDC converter is set to the upper limit voltage vbat_high of the battery system, that is, vdc_ref=vbat_high. The voltage Vbat of the battery system is taken as a negative feedback value of a voltage outer loop, as shown in a partial logic block diagram of fig. 6b, and the voltage outer loop given value vdc_ref is differenced from the negative feedback battery system voltage Vbat to obtain a real-time difference value err1=vdc_ref-vbat_high <0. The subsequent link is the same as fig. 6a, and the current inner loop input amount iref1 can be realized through PID adjustment or PI adjustment, and due to the existence of the integration link, when there is a difference between the given value and the negative feedback value, the integration will be accumulated, the integration will be saturated, and the maximum value will be output, so that the current inner loop input amount iref1 operates according to the maximum power.
That is, for both converters, as long as their outer rings are saturated, they will operate at a limited maximum power. The voltage outer ring set value of the DCDC converter is set as the upper limit voltage of the full charge of the battery system, so that the output of the DCDC converter is realized according to the maximum power, and the photovoltaic subarray outputs power through the DCDC converter because the output voltage of the DCDC converter is larger than the voltage of the battery system. The set voltage outer ring set value of the DCAC converter is set as the lower limit voltage of the battery system after discharging, so that the DCAC converter always discharges according to the maximum power when the battery system does not discharge the cut-off voltage, namely, the lower limit voltage is not discharged; until the voltage of the battery system is less than the lower limit voltage, the DCAC stops the down-regulating operation of the DC side voltage, and the battery system is not discharged any more.
Since the battery system is connected in parallel on the dc bus between the DCDC converter and the DCAC converter, the voltages at the common dc coupling point are equal; before executing step S101, the control method defines a lower limit voltage vbat_low and an upper limit voltage vbat_high of a battery system according to a specific application environment thereof, so as to adapt to the corresponding application environment, and values of the lower limit voltage vbat_low and the upper limit voltage vbat_high are not specifically limited, as long as vbat_low < vbat_high is shown in fig. 7. In practical application, the following situations exist:
When the voltage of the battery system is greater than the upper limit voltage, that is, when Vbat > vbat_high corresponding to the corresponding battery high voltage region shown in fig. 7, the voltage outer loop of the DCAC converter is in a saturated state, the voltage outer loop of the DCDC converter is desaturated, and the voltage of the battery system is changed by the output voltage of the DCDC converter; at this time, by limiting the output power of the DCDC converter, it is ensured that the battery system is overcharged.
When the voltage of the battery system is smaller than the lower limit voltage, namely, corresponds to a corresponding battery low-voltage region shown in fig. 7, and when Vbat < vbat_low, the voltage outer ring of the DCDC converter is in a saturated state, the voltage outer ring of the DCAC converter is desaturated, and the voltage of the battery system is changed by the voltage of the direct current side of the DCAC converter; at this time, by limiting the output power of the DCAC converter, it is possible to ensure that the battery system is overdischarged.
When the voltage of the battery system is between the lower limit voltage and the upper limit voltage, that is, when vbat_low_rec < vbat_high_rec in the corresponding double outer ring saturation region shown in fig. 7, the voltage outer rings of the DCDC converter and the DCAC converter are in saturation states, the DCDC converter and the DCAC converter output according to the respective maximum power, if excessive electric energy exists on the direct current bus, the direct current bus is charged and absorbed by the battery system, and if the electric energy is insufficient, the direct current bus is discharged and supplemented by the battery system.
Therefore, the reference amount of the output end voltage of the DCDC converter is set as the upper limit voltage of the battery system, so that the maximum power output can be realized, the voltage of the battery system can not be excessively high, and the battery system can not be overcharged; the reference amount of the DC side voltage of the DCAC converter is set to be the lower limit voltage of the battery system, so that the maximum power output can be realized, the voltage of the battery system can not be too low, and the battery system can not be overdischarged.
The rest of the processes and principles are the same as those of the previous embodiment, and will not be described in detail here.
Based on the above embodiments, the control method of the dc coupling system according to the present embodiment provides a part of specific execution process, where step S103 specifically includes:
(1) If the voltage of the battery system is smaller than the lower limit voltage of the battery system, the voltage of the battery system is controlled by the DCAC converter; when the sum of the output power of all the DCDC converters is larger than the grid-connected limit power value, the battery system is charged; and stopping the operation of the battery system when the sum of the output power of all the DCDC converters is smaller than or equal to the grid-connected limit power value.
(2) If the voltage of the battery system is greater than the upper limit voltage of the battery system, the voltage of the battery system is controlled by the DCDC converter; when the sum of the output power of all the DCDC converters is larger than or equal to the grid-connected limit power value, the battery system stops running; and discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value.
(3) If the voltage of the battery system is between the lower limit voltage and the upper limit voltage, charging the battery system when the sum of the output power of all the DCDC converters is larger than the grid-connected limit power value; discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value; and stopping the operation of the battery system when the sum of the output power of all the DCDC converters is equal to the grid-connected limit power value.
Specifically, the power of the photovoltaic subarray is Ppv, the power of the DCDC converter of the photovoltaic subarray can be ppcd, the grid-connected limit power value of the DCAC converter can be Ppcs, and when the power of the photovoltaic subarray is larger than the power of the DCDC converter, the following situations are specifically presented:
1. when the voltage Vbat of the battery system is in the low-voltage region of the battery, that is, when Vbat < = vbat_low, the voltage of the battery system is controlled by the DCAC converter, at this time, the voltage outer loop of the DCDC converter is in a saturated state, and the maximum current (power) is a current limit value (limit value) of DCDC according to the maximum current (power) output of the DCDC converter.
(1) When Pdcdc > Ppcs, the electric energy of the photovoltaic subarrays is output through the DCDC converter, and the redundant electric energy charges the battery system. The power flow is shown in fig. 8 a.
(2) When Pdcdc < Ppcs, the electric energy of the photovoltaic subarrays is output through the DCDC converter and is output through the DCAC converter, and the battery system is in a constant-voltage state and is not discharged or charged.
2. When the voltage Vbat of the battery system is in the battery high voltage region, that is, vbat > =vbat_high, the voltage of the battery system is controlled by the DCDC converter, and at this time, the voltage outer loop of the DCAC converter is in a saturated state, and the maximum current/power is the current limit value/grid-connected limit power value Ppcs of the DCAC according to the maximum current/power output of the DCAC converter.
(1) When pdcd > Ppcs, the electric energy of the photovoltaic subarrays is output through the DCDC converter according to the limit maximum power (grid-connected limit power value Ppcs) of the DCAC converter, and the redundant electric energy is limited by the DCDC converter.
(2) When Pdcdc < Ppcs, the electric energy of the photovoltaic subarrays is output through the DCDC converter and the DCAC converter, and the insufficient electric energy is discharged and supplemented by the battery system. The power flow is shown in fig. 8 b.
3. The voltage Vbat of the battery system is in the double outer loop saturation region, vbat_low < Vbat < vbat_high, and the voltage outer loops of both the DCDC converter and the DCAC converter are in saturation, i.e. the DCDC converter and the DCAC converter are operated with maximum current limiting power discharge.
(1) When Pdcdc > Ppcs occurs, the excessive electric energy of the DCDC converter is absorbed by charging the battery system, and the power flow chart is shown in fig. 8 a.
(2) When Pdcdc < Ppcs occurs, the insufficient power of the DCDC converter is complemented by the discharge of the battery system, and the power flow chart is shown in fig. 8 b.
Therefore, the whole system realizes automatic control, and external control and scheduling are not needed.
The rest of the processes and principles are the same as those of the previous embodiment, and will not be described in detail here.
It is worth to say that, the actual photovoltaic subarray cannot always be operated in a high-power state due to other reasons such as illumination, and when other power fluctuation caused by cloud shielding and the like occurs, the situation that Ppv < Pdcdc occurs. In order to prevent the DCDC converter from being pulled down by the voltage of the photovoltaic sub-array due to high power output, as shown in fig. 5, the control method of the dc coupling system according to the present embodiment further includes, based on the above embodiment, step S102:
s302, if the input power of the DCDC converter is smaller than the preset power threshold value, the input voltage is ensured to be larger than the starting voltage of the DCDC converter in a mode of reducing the output power of the DCDC converter.
That is, if the DCDC converter is currently in the maximum power state and the input power of the DCDC converter is less than the preset power threshold, the DCDC converter needs to exit the maximum power state and reduce the output power of the DCDC converter, so as to ensure that the input voltage is greater than the starting voltage of the DCDC converter and ensure that the DCDC converter can operate as much as possible.
Specifically, the value i_limi1 of the limiting iref1 of the current inner loop input quantity can be adjusted according to the input voltage of the current inner loop, namely, the limiting of the output current is adjusted so that the input voltage of the current inner loop is larger than the starting voltage of the current inner loop.
The process for adjusting the limiting value of the input quantity of the current inner loop according to the input voltage of the current inner loop specifically comprises the following steps:
(1) If the input voltage of the self-body is between the preset power-reduction starting voltage and the maximum power voltage lower limit, regulating the output current of the self-body to change in the same direction according to the change condition of the input voltage of the self-body by a preset step length; the maximum power voltage lower limit is less than the reduced power initiation voltage.
(2) And if the input voltage of the self-body is smaller than the lower limit of the maximum power voltage, regulating the output current of the self-body to be zero.
In practical application, the maximum power voltage lower limit voltage of the photovoltaic subarray is defined as Vmppt_low in advance, and the power reduction initial voltage is defined as Vmppt_low_1; as shown in fig. 9, vmppt_low < vmppt_low_1.
When the photovoltaic sub-array voltage, i.e. the input voltage of the DCDC converter, is smaller than vmppt_low_1, the power reduction starts.
For a photovoltaic subarray low-voltage area, namely when the voltage of the photovoltaic subarray is smaller than Vmppt_low, the DCDC converter reduces the self power to zero power; for a current (power) disturbance area, namely when the voltage of the photovoltaic subarray is between Vmppt_low and Vmppt_low_1, making a difference according to the current voltage and the voltage of the up-sampling period, if the difference is greater than zero, increasing the output current (power) of the DCDC converter until the maximum value I_limit_max; if the difference is smaller than zero, the output current (power) of the DCDC converter is reduced until a minimum value of 0. The variation of the current (power) is achieved by varying the output of the voltage loop, i.e. varying the clipping value i_limit1 (abbreviated as i_limit in fig. 10) of the clipping element in fig. 6b, for a given clipping of the current loop. If the voltage of the photovoltaic subarray is greater than Vppt_low_1, namely the subarray enters a maximum power voltage area of the photovoltaic subarray, the maximum power state can be restored.
Referring to fig. 10, assuming that the current sampled photovoltaic sub-array voltage is Vpv (k), the photovoltaic sub-array voltage sampled at the last sampling period is Vpv (k-1), where k is an integer, Δvpv (k) =vpv (k) -Vpv (k-1). To smooth the transition, a smoothing point is found quickly, and the magnitude of disturbance quantity Δi can be changed according to the magnitude of Δvpv (k). For example, three shift positions are divided, and when Δvpv (k) is between ±Δv1, the disturbance step is Δi1; when DeltaVpv (k) is between (+ -) -DeltaV 2, the disturbance step is Deltai 2; when Δvpv (k) is between ±Δv3, the disturbance step is Δi3. And Δv1< Δv2< Δv3, Δi1< Δi2< Δi3). That is, when the voltage of the photovoltaic subarray is between vmppt_low and vmppt_low_1, the corresponding relationship between the preset step length for adjusting the photovoltaic subarray and the magnitude of the variation condition of the input voltage can be set, and the photovoltaic subarray is not limited to the three gears, and can be in the protection scope of the application according to the specific application environment in practical application.
According to the control method of the direct current coupling system, when illumination is strong, the DCDC converter can operate according to the maximum power of the direct current coupling system, and when illumination is weak, the DCDC converter operates according to the maximum power, namely operates according to the maximum power of the photovoltaic subarrays on the premise of guaranteeing the voltage lower limit of the photovoltaic subarrays.
The rest of the processes and principles are the same as those of the above embodiments, and will not be described in detail here.
Another embodiment of the present invention further provides a dc coupling system, as shown in fig. 3a and 3b, including: the system comprises a battery system, an inversion branch and at least one photovoltaic power generation branch; FIG. 3a shows a single system DC coupling system, with only one photovoltaic power generation branch; fig. 3b shows a dc coupling system with multiple systems, and the number of photovoltaic power generation branches is multiple. Wherein:
the photovoltaic power generation branch circuit comprises: photovoltaic subarrays and DCDC converters connected in series. The inversion branch circuit comprises: the ac side of the DCAC converter is used for connecting to the power grid. The battery system, the output end of the DCDC converter and the DC side of the DCAC converter are connected through a common DC bus. That is, the battery system is directly connected to the direct current bus, and the charge and discharge control of the battery can be realized only through the energy relation between the DCDC converter and the DCAC converter without any power converter.
The battery system, the DCDC converter and the DCAC converter control their own operations through the respective steps in the control method of the dc-coupled system as described in any of the above embodiments, respectively. When the output power of the DCDC converter is larger, if the battery system is chargeable, the DCDC converter can charge the battery system while grid connection is performed through the DCAC converter; if the battery system cannot be charged, the DCDC converter can only be connected in grid through the DCAC converter. However, when the DCDC converter output power is small, it is desirable that the DCDC converter can operate at its maximum power point, regardless of the operation of the battery system. For the DCAC converter, if the limited power instruction is given, the grid-connected limited power value is not exceeded for limited power operation; if there is an infinite power command, power output is performed at the maximum value that it can output. The battery system performs charge and discharge or stops running according to the situation on the direct current bus. The whole direct current coupling system is automatically operated.
The direct current coupling system solves the problem of energy rapid control and scheduling of the series direct current coupling system through the control method, the power of the photovoltaic subarrays is utilized to the greatest extent in real time, and meanwhile, the alternating current side can operate in a grid-connected mode according to the scheduled maximum power. In addition, the dynamic response problem in the running process of the system is solved, the quick balanced control is realized in the system, and the development difficulty and cost of the EMS or the system main control are reduced. The method is suitable for single-system topology and topology of parallel connection and sharing of one set of battery system for the system.
In addition, the direct current coupling system enables the voltage instruction of the voltage ring of the DCDC converter to be the upper limit voltage according to the upper limit voltage and the lower limit voltage value of the battery system through the control method, and when the battery system is full, the direct current coupling system actively limits current; moreover, the voltage command of the voltage ring of the DCAC converter is the lower limit voltage, and when the battery system is empty, the over-discharge of the battery can be actively limited; the battery system is ensured not to have the problem of overcharge and overdischarge.
It is worth to say that the control method is actually another implementation mode of the MPPT, the MPPT of the photovoltaic subarrays is indirectly realized by controlling the power of the public direct current bus side of the DCDC converter, when the power of the photovoltaic subarrays is larger than that of the DCDC converter, the photovoltaic subarrays can operate according to the maximum power of the DCDC converter, and when the power of the photovoltaic subarrays is insufficient, the voltage of the photovoltaic subarrays is ensured to be larger than the minimum voltage of the DCDC converter by limiting the output power of the DCDC converter.
The other principles are the same as those of the above embodiments, and will not be described in detail here.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a system or system embodiment, since it is substantially similar to a method embodiment, the description is relatively simple, with reference to the description of the method embodiment being made in part. The systems and system embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The features described in the various embodiments of the present disclosure may be interchanged or combined with one another in the description of the disclosed embodiments to enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (12)
1. The control method of the direct current coupling system is characterized in that the direct current coupling system comprises a battery system, an inversion branch and at least one photovoltaic power generation branch, wherein the battery system, a DCDC converter arranged in the photovoltaic power generation branch and a DCAC converter arranged in the inversion branch are connected through a common direct current bus, and the battery system is directly connected with the direct current bus; the control method of the direct current coupling system comprises the following steps:
the DCAC converter takes the grid-connected limit power value as an upper limit and controls the DCAC converter to output maximum power;
The DCDC converter aims at maximizing output power and controls the DCDC converter to output power;
the battery system operates according to the voltage and power requirements on the dc bus.
2. The method for controlling a dc coupling system according to claim 1, wherein the DCAC converter controls itself to maximize power output with a grid-connected power limit value as an upper limit, comprising:
the DCAC converter takes the lower limit voltage of the battery system as a reference quantity to control the direct current side voltage of the DCAC converter; the method comprises the steps of,
and the DCAC converter takes the grid-connected power limiting value as an upper limit to carry out maximized power output.
3. The method according to claim 2, wherein the DCAC converter controls the dc side voltage of the dc converter by using the lower limit voltage of the battery system as a reference, and the method comprises:
the DCAC converter takes the lower limit voltage as a given value of a self voltage outer ring, takes the voltage of the battery system as a negative feedback value of the self voltage outer ring, and controls the self direct current side voltage.
4. The method of controlling a dc coupling system according to claim 2, wherein the DCAC converter performs the maximized power output with the grid-connected power limit value as an upper limit, comprising:
And the DCAC converter adjusts the current inner loop input quantity limiting value of the DCAC converter according to the grid-connected limiting value and controls the current of the alternating current side of the DCAC converter.
5. The method according to claim 1, wherein the DCDC converter controls itself to output power with the aim of maximizing output power, comprising:
and the DCDC converter takes the upper limit voltage of the battery system as a reference quantity to control the output voltage of the DCDC converter.
6. The method according to claim 5, wherein the DCDC converter controls its own output voltage with reference to an upper limit voltage of the battery system, comprising:
the DCDC converter takes the upper limit voltage as a given value of a self voltage outer ring, takes the voltage of the battery system as a negative feedback value of the self voltage outer ring, and controls the self output voltage.
7. The method according to claim 5, wherein the DCDC converter controls itself to output power with the aim of maximizing output power, further comprising:
if the input power of the DCDC converter is smaller than the preset power threshold value, the input voltage is ensured to be larger than the starting voltage of the DCDC converter in a mode of reducing the output power of the DCDC converter.
8. The control method of a dc-coupled system according to claim 7, wherein ensuring that the input voltage is greater than the start-up voltage thereof in a manner that reduces the output power thereof, comprises:
according to the input voltage of the self-body, the limiting value of the input quantity of the current inner loop of the self-body is regulated so that the input voltage of the self-body is larger than the starting voltage of the self-body.
9. The control method of the direct current coupling system according to claim 8, wherein adjusting the limiting value of the current inner loop input amount according to the input voltage thereof comprises:
if the input voltage of the self-body is between the preset power-reduction starting voltage and the maximum power voltage lower limit, regulating the output current of the self-body to change in the same direction according to the change condition of the input voltage of the self-body by a preset step length; the maximum power voltage lower limit is less than the reduced power starting voltage;
and if the input voltage of the self-body is smaller than the lower limit of the maximum power voltage, regulating the output current of the self-body to be zero.
10. The method for controlling a dc-coupled system according to claim 9, wherein the preset step size has a correspondence with the magnitude of the input voltage variation.
11. The method of controlling a dc coupling system according to any one of claims 1 to 10, wherein the battery system operates according to the voltage and power requirements on the dc bus, comprising:
if the voltage of the battery system is smaller than the lower limit voltage of the battery system, the voltage of the battery system is controlled by the DCAC converter; and when the sum of the output power of all the DCDC converters is larger than the grid-connected limit power value, the battery system is charged; when the sum of the output power of all the DCDC converters is smaller than or equal to the grid-connected limit power value, stopping the operation of the battery system;
if the voltage of the battery system is greater than the upper limit voltage of the battery system, the voltage of the battery system is controlled by the DCDC converter; and when the sum of the output power of all the DCDC converters is greater than or equal to the grid-connected limit power value, stopping the operation of the battery system; discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value;
if the voltage of the battery system is between the lower limit voltage and the upper limit voltage, charging the battery system when the sum of the output powers of all the DCDC converters is greater than the grid-connected limit power value; discharging the battery system when the sum of the output power of all the DCDC converters is smaller than the grid-connected limit power value; and stopping the operation of the battery system when the sum of the output powers of the DCDC converters is equal to the grid-connected limit power value.
12. A dc coupling system, comprising: the system comprises a battery system, an inversion branch and at least one photovoltaic power generation branch; wherein:
the photovoltaic power generation branch circuit comprises: a photovoltaic sub-array and a DCDC converter connected in series;
the inversion branch circuit comprises: a DCAC converter;
the battery system, the DCDC converter and the DCAC converter are connected through a common direct current bus;
the battery system, the DCDC converter and the DCAC converter control their own operations by respective steps in the control method of a dc coupling system as claimed in any one of claims 1 to 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110643769.5A CN113241797B (en) | 2021-06-09 | 2021-06-09 | Direct current coupling system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110643769.5A CN113241797B (en) | 2021-06-09 | 2021-06-09 | Direct current coupling system and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113241797A CN113241797A (en) | 2021-08-10 |
| CN113241797B true CN113241797B (en) | 2024-04-12 |
Family
ID=77139390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110643769.5A Active CN113241797B (en) | 2021-06-09 | 2021-06-09 | Direct current coupling system and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113241797B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113922329B (en) * | 2021-08-31 | 2024-03-15 | 科华数据股份有限公司 | Power supply circuit adjusting method and device and power supply system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009137969A1 (en) * | 2008-05-15 | 2009-11-19 | Xuan Kun | A photovoltaic grid-connected inverter device without a transformer and its control method |
| CN106374517A (en) * | 2016-11-15 | 2017-02-01 | 湖南省德沃普储能有限公司 | Battery energy storage system for alleviating problem of photovoltaic power generation abandoning and limiting and control method therefor |
| CN106849172A (en) * | 2017-03-22 | 2017-06-13 | 东南大学 | In light storage alternating current-direct current microgrid and off-network seamless switching strategy |
| CN108777494A (en) * | 2018-08-10 | 2018-11-09 | 国网冀北综合能源服务有限公司 | Collecting and distributing type light stores up charging system and its control method |
| CN208955673U (en) * | 2018-09-26 | 2019-06-07 | 深圳古瑞瓦特新能源股份有限公司 | Light stores up all-in-one machine |
-
2021
- 2021-06-09 CN CN202110643769.5A patent/CN113241797B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009137969A1 (en) * | 2008-05-15 | 2009-11-19 | Xuan Kun | A photovoltaic grid-connected inverter device without a transformer and its control method |
| CN106374517A (en) * | 2016-11-15 | 2017-02-01 | 湖南省德沃普储能有限公司 | Battery energy storage system for alleviating problem of photovoltaic power generation abandoning and limiting and control method therefor |
| CN106849172A (en) * | 2017-03-22 | 2017-06-13 | 东南大学 | In light storage alternating current-direct current microgrid and off-network seamless switching strategy |
| CN108777494A (en) * | 2018-08-10 | 2018-11-09 | 国网冀北综合能源服务有限公司 | Collecting and distributing type light stores up charging system and its control method |
| CN208955673U (en) * | 2018-09-26 | 2019-06-07 | 深圳古瑞瓦特新能源股份有限公司 | Light stores up all-in-one machine |
Non-Patent Citations (3)
| Title |
|---|
| Modeling and experimental validation of a DSP controlled photovoltaic power system with battery energy storage;P.I. Muoka et al.;《2013 IEEE Power & Energy Society General Meeting》;第1-5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》(第9期);第45-48页 * |
| 孤岛模式下光储交流微电网能量管理协调控制策略;温素芳等;《可再生能源》;第36卷(第6期);第862-868页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113241797A (en) | 2021-08-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10081259B2 (en) | Charging facility and energy management method for charging facility | |
| CA2841052C (en) | Method and apparatus for controlling a hybrid power system | |
| JP5786330B2 (en) | Discharge control device and discharge control method | |
| CN116349106A (en) | Energy storage system, control method of energy storage system and photovoltaic power generation system | |
| JP2013138530A (en) | Solar cell power generation system | |
| EP4340171A1 (en) | Optical storage control module, optical storage control method and optical storage system | |
| CN102687033A (en) | Method for controlling secondary battery and power storage device | |
| JP2015195674A (en) | Power storage battery assembly control system | |
| CN110323785B (en) | Multi-voltage-level direct-current power distribution network optimization scheduling method for source network load storage interaction | |
| Mangu et al. | Multi-input transformer coupled DC-DC converter for PV-wind based stand-alone single-phase power generating system | |
| US9502903B2 (en) | Energy management systems and methods | |
| Bhattacharyya et al. | DC link voltage control based power management scheme for standalone PV systems | |
| CN113241797B (en) | Direct current coupling system and control method thereof | |
| WO2024061221A1 (en) | Combined-energy power supply circuit applied to aerostat, and power supply control method | |
| Schwertner et al. | Supervisory control for stand-alone photovoltaic systems | |
| CN110994695A (en) | Intraday optimal scheduling method and system for power distribution network | |
| CN116031920A (en) | Hierarchical energy coordination control strategy for multiport power electronic equipment | |
| Zubieta | Power management of a DC bus regulated by multiple energy storage resources | |
| AU2010358881B2 (en) | Management system for variable-resource energy generation systems | |
| CN113422378A (en) | Comprehensive energy system of energy hub | |
| CN114402525A (en) | Photovoltaic optimizer power system supplying power from photovoltaic devices | |
| CN114447993B (en) | Power control method, device, controller and optical storage system | |
| Qian et al. | An integrated four-port converter for compact and efficient hybrid power systems | |
| Anand et al. | Power management control for solar photovoltaic based DC system | |
| Sahoo et al. | Design of controllers for energy management system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |