CN112310957A - Double-layer bus island micro-grid system - Google Patents
Double-layer bus island micro-grid system Download PDFInfo
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- CN112310957A CN112310957A CN202011158798.4A CN202011158798A CN112310957A CN 112310957 A CN112310957 A CN 112310957A CN 202011158798 A CN202011158798 A CN 202011158798A CN 112310957 A CN112310957 A CN 112310957A
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- direct current
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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
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
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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
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/02—Arrangements for reducing harmonics or ripples
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/345—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering using capacitors as storage or buffering devices
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
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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
- H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J2207/50—Charging of capacitors, supercapacitors, ultra-capacitors or double layer capacitors
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/22—The renewable source being solar energy
- H02J2300/24—The renewable source being solar energy of photovoltaic origin
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a double-layer bus island microgrid system which comprises two microgrid subsystems and a hybrid energy storage system, wherein the two microgrid subsystems and the hybrid energy storage system are connected with a middle bus through a bidirectional DC/DC converter; the microgrid subsystem comprises an independent direct current sub-network bus, and the direct current bus is used for connecting a power supply end and a load; the hybrid energy storage system is formed by connecting a super capacitor and a lead-acid storage battery in parallel. The invention adopts a multi-bus structure, is flexible to control, can not influence other microgrid subsystems even if a certain section of direct current bus fails, and avoids the problem that the whole system is broken down once a single direct current bus structure fails in the prior art, thereby effectively improving the reliability and stability of direct current power supply.
Description
Technical Field
The invention relates to the technical field of direct current micro-grids, in particular to a double-layer bus island micro-grid system.
Background
There are 6500 islands in China, and 433 islands where residents live. Because the isolated islands are far away from the continents, the cost of accessing the mains supply is high, and therefore the isolated islands are not covered by the mains supply. The power supply problem of the island with the residents is very prominent. Fortunately, the periphery of the isolated island is provided with various resources, such as wave energy, solar energy, wind energy and the like, and the power supply problem of the isolated island in China can be completely solved by fully utilizing the resources. This also corresponds to the direction in our country to vigorously develop marine economy.
The ocean land area of China is about 300 ten thousand square kilometers, the sea is moving all the time, and an article indicates that about twenty thousand kilowatts can be generated per second on the sea surface of 1 square kilometer, and the energy of wave energy is still considerable. Wave energy is characterized by small instantaneous energy but good persistence. Since many studies have been made on wave energy power generation, it is of practical significance to effectively use wave energy to supply power to isolated islands.
The traditional island direct current micro-grid mostly uses a single bus or a single bus segmented architecture, and the system power supply reliability is low. Once a failure occurs, the entire system is vulnerable to a crash condition.
Disclosure of Invention
In order to solve the above mentioned shortcomings in the background art, the present invention aims to provide an island microgrid system of double-layer buses for effectively utilizing multiple energy sources, which effectively utilizes multiple energy sources, improves the stability of energy output, increases the power generation capacity, and simultaneously improves the reliability and stability of direct current power supply.
The purpose of the invention can be realized by the following technical scheme:
a double-layer bus island microgrid system comprises two microgrid subsystems and a hybrid energy storage system, wherein the two microgrid subsystems and the hybrid energy storage system are connected with a middle bus through a bidirectional DC/DC converter;
the micro-grid subsystem comprises an independent direct current sub-grid bus, and the direct current bus is used for connecting a power supply end and a load;
the hybrid energy storage system is formed by connecting a super capacitor and a lead-acid storage battery in parallel.
Preferably, the dc sub-network bus is a double-layer bus structure.
Preferably, the power supply end comprises a wave energy power generation unit, a photovoltaic power generation unit and a wind power generation unit.
Preferably, the wind power generation unit comprises a wind turbine, a permanent magnet synchronous generator PMSG and a three-phase controllable rectification circuit which are sequentially connected, and the wind power generation unit is connected to a direct current sub-network bus;
the wind generating set is used for generating alternating current through wind power, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
Preferably, the photovoltaic power generation unit comprises a photovoltaic battery pack and a unidirectional DC/DC device which are sequentially connected, and the photovoltaic power generation unit is connected to the direct current sub-network bus;
the photovoltaic battery pack is used for generating direct current through sunlight, and the unidirectional DC/DC device is used for converting the direct current into direct current with another voltage level which can be connected to a direct current bus.
Preferably, the wave energy power generation unit comprises a wave energy converter WEC, a permanent magnet linear generator PMLG and a three-phase controllable rectifying circuit which are connected in sequence, and the wave energy power generation unit is connected to the direct current sub-network bus;
the wave power generation unit is used for generating alternating current through wave energy, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
Preferably, the load includes a direct current load and an alternating current load.
Preferably, the direct current load is connected to the sub-network bus through a bidirectional DC/DC device, and the alternating current load is connected to the sub-network bus through a three-phase controllable rectifying circuit.
The invention has the beneficial effects that:
1. the invention effectively utilizes various energy sources, improves the output stability of the energy sources and increases the power generation capacity.
2. The invention adopts a double-layer bus structure, consists of two subnets, is flexible to control, and can not influence other microgrid subsystems even if a certain section of direct current bus fails, thereby effectively improving the reliability and stability of direct current power supply.
3. The invention adopts a hybrid energy storage system, reduces voltage fluctuation and current pulsation and improves the stability of the system.
4. The invention adopts the same energy storage device shared by the two sub-networks, saves the cost, improves the utilization rate of the energy storage device, and realizes the exchange of power between the 2 sub-networks and mutual standby.
Drawings
The invention will be further described with reference to the accompanying drawings.
FIG. 1 is an overall block diagram of the architecture of the system of the present invention;
FIG. 2 is a diagram of the DC subnet architecture of the present invention;
FIG. 3 is a block diagram of the hybrid energy storage system of the present invention;
FIG. 4 is a three-phase controllable rectifier circuit diagram of the present invention;
fig. 5 is a photovoltaic DC/DC circuit diagram of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be understood that the terms "opening," "upper," "lower," "thickness," "top," "middle," "length," "inner," "peripheral," and the like are used in an orientation or positional relationship that is merely for convenience in describing and simplifying the description, and do not indicate or imply that the referenced component or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present invention.
As shown in fig. 1, the double-layer bus island microgrid system comprises two microgrid subsystems (a direct-current subnetwork 1 and a direct-current subnetwork 2) and a hybrid energy storage system, wherein each microgrid subsystem comprises an independent direct-current bus, and the direct-current buses are used for connecting a power supply end and a load.
The invention adopts a double-layer bus structure, consists of two subnets, is flexible to control, and can not influence other microgrid subsystems even if a certain section of direct current bus fails, thereby effectively improving the reliability and stability of direct current power supply.
The hybrid energy storage system comprises hybrid energy storage elements, the hybrid energy storage elements are connected with the lead-acid storage battery in parallel through a super capacitor, the hybrid energy storage system is connected to the middle bus through a bidirectional DC/DC device, and then the hybrid energy storage system is connected with the two subnetworks through the bidirectional DC/DC device.
Fig. 2 is a schematic structural diagram of the dc subnetwork 1 according to the embodiment of the present invention. The sub-network system comprises a wind power generation unit, a photovoltaic power generation unit and a wave power generation unit, and the structure of the direct current sub-network 2 is the same as that of the direct current sub-network 1.
The wind power generation unit comprises a wind turbine, a permanent magnet synchronous generator PMSG, a three-phase controllable rectifying circuit and a large capacitor C1 which are sequentially connected, and is connected to a direct current sub-network bus. The wind generating set is used for generating alternating current through wind power, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
The photovoltaic power generation unit comprises a photovoltaic battery, a unidirectional DC/DC device and a large capacitor C2 which are sequentially connected, and the photovoltaic power generation unit is connected to the direct current sub-network bus. The photovoltaic cell is used for generating direct current through sunlight, and the unidirectional DC/DC device is used for converting the direct current into direct current of another voltage level which can be connected to a direct current bus.
The wave power generation unit comprises a wave power converter WEC, a permanent magnet linear generator PMLG, a three-phase controllable rectifying circuit and a large capacitor C3 which are sequentially connected, and is connected to a direct current sub-network bus. The wave power generation unit is used for generating alternating current through wave energy, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
The DC load is connected to the sub-network bus via a bi-directional DC/DC device and a large capacitor C4.
The AC load is connected to the sub-network bus via the filter capacitor and the three-phase controllable rectifying circuit.
Fig. 3 is a circuit diagram of a hybrid energy storage system according to an embodiment of the present invention, which is composed of a super capacitor, an acid storage battery pack, a filter inductor L1, IGBT modules Sa1-Sa2 of antiparallel diodes, and a large capacitor C5, and a connection manner of cascade connection of the super capacitor and the lead-acid storage battery pack is adopted, so that reasonable distribution of high-frequency and low-frequency fluctuation power of a micro-grid between the super capacitor 301 and the lead-acid storage battery pack is realized, and thus, not only is the working condition of the lead-acid battery optimized, but also the energy storage capacity and cost are.
When the internal power of the direct current sub-network 1 and the internal power of the direct current sub-network 2 are respectively kept balanced, the bus voltage is stabilized at a rated value, power exchange is not carried out between the two sub-networks, and the energy storage system does not participate in bus voltage regulation.
When the bus voltage is higher due to surplus power of the direct current sub-network 1 and the bus voltage is lower due to shortage of power of the direct current sub-network 2, the direct current sub-network 1 compensates the power of the direct current sub-network 2, surplus power of the direct current sub-network 1 is transferred to the direct current sub-network 2 through the power pool, and the bus voltages of the direct current sub-network 1 and the direct current sub-network 2 are stable in an allowable fluctuation range
When the power surplus or the power loss of the direct current sub-network 1 (or the direct current sub-network 2) is caused and the voltage of the bus of the 2 direct current sub-networks cannot be maintained to be stable only by the power exchange among the 2 direct current sub-networks, the micro-network power pool maintains the voltage of the bus of the 2 sub-networks within an allowable fluctuation range by compensating the unbalanced power of the sub-networks.
Fig. 4 is a three-phase controllable rectifier circuit diagram, which is composed of I GBT modules Sb 1-Sb 6 with anti-parallel diodes and a large capacitor C.
Fig. 5 is a photovoltaic DC/DC circuit, which is composed of a filter inductor L2, an I GBT module Sc1 with anti-parallel diodes, a diode VD1 and a large capacitor C6.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.
Claims (8)
1. A double-layer bus island microgrid system is characterized by comprising two microgrid subsystems and a hybrid energy storage system, wherein the two microgrid subsystems and the hybrid energy storage system are connected with a middle bus through a bidirectional DC/DC converter;
the micro-grid subsystem comprises an independent direct current sub-grid bus, and the direct current bus is used for connecting a power supply end and a load;
the hybrid energy storage system is formed by connecting a super capacitor and a lead-acid storage battery in parallel.
2. The double-layer bus island microgrid system of claim 1, wherein the direct current sub-network buses are of a double-layer bus structure.
3. The double-layer bus island microgrid system of claim 1, wherein the power supply end comprises wave power generation units, photovoltaic power generation units and wind power generation units.
4. The double-layer bus island microgrid system as claimed in claim 3, wherein the wind power generation unit comprises a wind turbine, a permanent magnet synchronous generator PMSG and a three-phase controllable rectification circuit which are connected in sequence, and the wind power generation unit is connected to a bus of the direct current sub-network;
the wind generating set is used for generating alternating current through wind power, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
5. The double-layer bus island microgrid system as claimed in claim 3, wherein the photovoltaic power generation units comprise photovoltaic battery packs and unidirectional DC/DC devices which are connected in sequence, and the photovoltaic power generation units are connected on the direct current sub-network buses;
the photovoltaic battery pack is used for generating direct current through sunlight, and the unidirectional DC/DC device is used for converting the direct current into direct current with another voltage level which can be connected to a direct current bus.
6. The double-layer bus island microgrid system as claimed in claim 3, wherein the wave energy power generation unit comprises a Wave Energy Converter (WEC), a Permanent Magnet Linear Generator (PMLG) and a three-phase controllable rectification circuit which are connected in sequence, and the wave energy power generation unit is connected to a bus of the direct current sub-network;
the wave power generation unit is used for generating alternating current through wave energy, and the three-phase controllable rectifying circuit is used for converting the alternating current into direct current with fixed voltage.
7. The double-layer bus-bar island microgrid system of claim 1, wherein the loads comprise direct current loads and alternating current loads.
8. The double-layer bus island microgrid system as claimed in claim 7, wherein the direct current loads are connected to the sub-network buses through bidirectional DC/DC devices, and the alternating current loads are connected to the sub-network buses through three-phase controllable rectification circuits.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011158798.4A CN112310957A (en) | 2020-10-26 | 2020-10-26 | Double-layer bus island micro-grid system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011158798.4A CN112310957A (en) | 2020-10-26 | 2020-10-26 | Double-layer bus island micro-grid system |
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| CN112310957A true CN112310957A (en) | 2021-02-02 |
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| CN202011158798.4A Pending CN112310957A (en) | 2020-10-26 | 2020-10-26 | Double-layer bus island micro-grid system |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904696A (en) * | 2014-03-08 | 2014-07-02 | 哈尔滨工程大学 | Capacity allocation optimization method for island/offshore platform independent new energy resource micro-grid |
| CN106505552A (en) * | 2016-11-10 | 2017-03-15 | 太原理工大学 | A kind of double-deck bus direct-current grid and its control method based on power pond |
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2020
- 2020-10-26 CN CN202011158798.4A patent/CN112310957A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103904696A (en) * | 2014-03-08 | 2014-07-02 | 哈尔滨工程大学 | Capacity allocation optimization method for island/offshore platform independent new energy resource micro-grid |
| CN106505552A (en) * | 2016-11-10 | 2017-03-15 | 太原理工大学 | A kind of double-deck bus direct-current grid and its control method based on power pond |
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Application publication date: 20210202 |