CN111064178B - Autonomous floating micro-grid system and control method thereof - Google Patents
Autonomous floating micro-grid system and control method thereof Download PDFInfo
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- CN111064178B CN111064178B CN201811203152.6A CN201811203152A CN111064178B CN 111064178 B CN111064178 B CN 111064178B CN 201811203152 A CN201811203152 A CN 201811203152A CN 111064178 B CN111064178 B CN 111064178B
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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
- H02J1/12—Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
Abstract
The invention relates to an autonomous floating micro-grid system and a control method thereof, wherein the system comprises: a bus bar; a main bus; an alternating current bus; a power generation device connected to the bus bar; the energy storage device is connected with the main bus; a first control unit that connects the bus bar and the main bus bar; a second control unit that connects the bus bar and the ac bus bar; the current transformation device is connected with the alternating current bus and the main bus; a load connected to the main bus; and the connecting device is used for connecting the alternating current bus into an external alternating current power grid. Compared with the prior art, the invention does not need a micro-grid centralized control system, reduces control objects and complexity to the greatest extent, utilizes the natural rectification outlet of the external alternating current power grid as a micro-grid voltage support base, and reduces systematic risks while reducing the investment of interface power electronic equipment.
Description
Technical Field
The invention relates to the technical field of direct-current micro-grids, in particular to an autonomous floating micro-grid system and a control method thereof.
Background
With the growing maturity and wide application of distributed energy technology, new energy-based micro-grid technology application is also rapidly developed, wherein a direct-current micro-grid becomes a hot spot for research and application due to the natural advantages of the direct-current micro-grid. In the direct-current micro-grid, a direct-current power supply is used as a power supply mode of a main network, and a large number of distributed direct-current power supplies and energy storage systems directly supply power for direct-current loads through the direct-current main grid.
In a direct current micro-grid, bus voltage is the only index for measuring power balance. The voltage stabilization in the network depends on the power balance of the power supply side and the load side, and comprises steady-state stability and dynamic stability, wherein the steady-state stability refers to the realization of the power balance of the power supply and the load under the steady-state condition of the system, so that the voltage of the direct current bus is kept to float within an acceptable range; dynamic stability refers to the dynamic stability of the system when power generation or load is suddenly changed, and the result of expansibility is not caused.
At present, control strategies of the direct current micro-grid are divided into a master-slave control mode and a peer-to-peer control mode. The master-slave mode control structure is complex, a central controller is required to be configured, and the investment cost is high; and peer-to-peer control is easy to generate errors, and the configuration of control parameters is complex.
Whatever the control strategy, the stability of the bus voltage is the control objective. Because of the large number of distributed power sources in the direct current micro-grid, the number of control objects determines the complexity of control strategy design and implementation. The core of the current mainstream control algorithm is a voltage-power droop control method. The configuration of control parameters is complex, controllable power conversion devices with the same quantity as the distributed power sources are needed, and the investment cost is high.
With the development of power electronics technology and energy storage technology, the voltage static stability floating margin of the direct current micro-grid is gradually enlarged, and the dynamic stability is effectively improved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide an autonomous floating micro grid system and a control method thereof.
The aim of the invention can be achieved by the following technical scheme:
an autonomous floating microgrid system comprising:
a bus bar;
a main bus;
an alternating current bus;
a power generation device connected to the bus bar;
the energy storage device is connected with the main bus;
a first control unit that connects the bus bar and the main bus bar;
a second control unit that connects the bus bar and the ac bus bar;
the current transformation device is connected with the alternating current bus and the main bus;
a load connected to the main bus;
and the connecting device is used for connecting the alternating current bus into an external alternating current power grid.
Preferably, the control unit includes:
the detection module is used for detecting bus voltages of the bus and the main bus;
and the execution module is used for executing on-off and current transformation.
Preferably, the power generation device is a distributed energy source, and specifically includes:
the photovoltaic power generation device is connected to the bus bar through the DC/DC converter, and/or the wind power generation device is connected to the bus bar through the AC/DC converter, and/or the fuel cell stack is connected to the bus bar through the DC/DC converter.
The control method of the autonomous floating micro grid system comprises the following steps:
when the bus voltage of the bus is higher than the bus voltage of the main bus and lower than the upper limit voltage Umax of the main bus, the bus is integrated into the main bus to supply power to the load or the energy storage device, and when the bus voltage of the bus is lower than the main bus voltage or higher than the upper limit voltage Umax of the main bus, the bus is integrated into the alternating current bus, and power inversion enters the alternating current bus.
Preferably, the control unit is used for controlling on-off and current transformation of the bus bar, the main bus bar and the alternating current bus bar.
Preferably, the detection module detects a bus voltage difference between the bus and the main bus; the execution module executes on-off or inversion operation according to the voltage difference between the bus bar and the main bus bar detected by the detection module.
Preferably, the upper limit voltage Umax of the main bus is X% of the full charge voltage of the stored energy, and the lower limit voltage of the main bus is the rectified outlet voltage value of the converter device.
Preferably, the X% is a percentage of the energy storage device from constant-current charging to constant-voltage charging or any other method that is beneficial to improving the use efficiency and reliability of energy storage.
Preferably, said energy storage means is connected to said main bus by DC/DC means.
Preferably, the load is a direct current load and an alternating current load of each voltage class, and the access mode is direct connection or connection through a DC/DC or DC/AC device.
Compared with the prior art, the direct current micro-grid system coordination control method provided by the invention has the advantages that the voltage difference between the direct current bus and the main bus is detected in real time through the detection module, and the execution module controls the energy flow between the bus and the direct current bus or the alternating current bus in real time according to the detection result of the detection module.
Compared with the current mainstream micro-grid control technology, the micro-grid centralized control system is not needed, the control objects and complexity are reduced to the greatest extent, the natural rectification outlet of the external alternating-current power grid is used as a micro-grid voltage support base, and the systematic risk is reduced while the investment of interface power electronic equipment is reduced.
Drawings
Fig. 1 is a schematic structural diagram of an autonomous floating dc micro grid system of the present invention;
fig. 2 is a flow chart of the control method of the autonomous floating type direct current micro grid system of the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic diagram of an autonomous floating dc micro grid according to an embodiment of the present invention.
The direct current micro grid includes:
the detection module 100: the bus voltage is used for detecting the bus voltage of the bus and the bus voltage of the main bus;
a direct current main Bus (DC Bus 1) 301; a direct current Bus (DC Bus 2) 302;
a first execution module (Breaker 1) 201 connecting the dc main bus 301 and the dc bus 302;
an energy storage device (ESS) 304 connected to the DC main bus 301 via a DC/DC converter 303;
a Load (Load) 306 of the direct current main bus 301 is connected through a DC/DC converter or DC/AC converter 305;
the power generation device coupled to the dc bus 302 may be a distributed energy source, and may specifically include, but is not limited to: a photovoltaic power generation device (PV) 308 connected to the DC bus 302 via a DC/DC converter 307, a Wind power generation device (wing) 310 connected to the DC bus 302 via an AC/DC converter 309, and/or a distributed energy source such as a fuel cell stack (FC) 312 connected to the DC bus via a DC/DC converter 311;
an alternating current grid-connected device (PCC) 403 connected to the direct current main bus 301 through an AC/DC converter 401;
meanwhile, the PCC is connected to the direct current bus 302 through the DC/AC converter 402 and the second execution module (Breaker 2) 202.
The embodiment of the invention also provides a control method of the autonomous voltage floating micro-grid, which is shown in fig. 2. The direct-current micro-grid comprises a direct-current bus bar, a direct-current main bus bar, an alternating-current bus bar, a power generation device connected with the bus bar, energy storage connected with the main bus bar, a first control unit connected between the bus bar and the main bus bar, a second control unit connected between the bus bar and the alternating-current bus bar, a converter connected between the alternating-current bus bar and the main bus bar, a load connected with the main bus bar, and a connecting device connected with an external alternating-current power grid through the alternating-current bus bar. The control unit is used for controlling the on-off of the bus bar, the main bus bar and the alternating current bus bar, when the bus voltage of the bus bar is higher than the bus voltage of the main bus bar and lower than the main bus bar upper limit voltage Umax, the bus bar is integrated into the main bus bar to supply power to the load or the energy storage, and when the bus voltage of the bus bar is lower than the main bus bar voltage or higher than the main bus bar upper limit voltage Umax, the bus bar is integrated into the alternating current bus bar, and the power is inverted into the alternating current bus bar, the method comprises the following steps:
s1, a detection module detects a bus voltage difference between the bus and a main bus;
s2, an execution module executes on-off or inversion operation according to the voltage difference between the bus bar and the main bus bar detected by the detection module;
the upper limit voltage Umax of the main bus is X% of the full charge voltage of the stored energy, and the lower limit of the main bus is the rectified outlet voltage value of the converter.
The X% is the percentage of the energy storage constant-current charging to constant-voltage charging point or any other point which is favorable for improving the use efficiency and reliability of energy storage.
The stored energy is connected to the main bus by a DC/DC device.
The power generation device includes, but is not limited to: photovoltaic power generation devices, wind power generation devices, fuel cells, and the like.
The load is a direct current load and an alternating current load of each voltage class, and the access modes are direct connection, connection through DC/DC, DC/AC devices and the like.
While the invention has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.
Claims (8)
1. A control method employing an autonomous floating microgrid system, the system comprising:
a bus bar;
a main bus;
an alternating current bus;
a power generation device connected to the bus bar;
the energy storage device is connected with the main bus;
a first control unit that connects the bus bar and the main bus bar;
a second control unit that connects the bus bar and the ac bus bar;
the current transformation device is connected with the alternating current bus and the main bus; a load connected to the main bus;
the connecting device is used for connecting an alternating current bus into an external alternating current power grid;
the control unit includes:
the detection module is used for detecting bus voltages of the bus and the main bus;
the execution module is used for executing on-off and current transformation;
the control method comprises the following steps:
when the bus voltage of the bus is higher than the bus voltage of the main bus and lower than the upper limit voltage Umax of the main bus, the bus is integrated into the main bus to supply power to the load or the energy storage device, and when the bus voltage of the bus is lower than the main bus voltage or higher than the upper limit voltage Umax of the main bus, the bus is integrated into the alternating current bus, and power inversion enters the alternating current bus.
2. The control method according to claim 1, wherein the power generation device is a distributed energy source, and specifically comprises:
the photovoltaic power generation device is connected to the bus bar through the DC/DC converter, and/or the wind power generation device is connected to the bus bar through the AC/DC converter, and/or the fuel cell stack is connected to the bus bar through the DC/DC converter.
3. The method of claim 1, wherein the control unit is configured to control on-off and current conversion of the bus bar to the main bus bar and to the ac bus bar.
4. The method of claim 3, wherein the detection module detects a bus voltage difference between the bus and the main bus; the execution module executes on-off or inversion operation according to the voltage difference between the bus bar and the main bus bar detected by the detection module.
5. The method according to claim 1, wherein the upper limit voltage Umax of the main bus is X% of the full charge voltage of the stored energy, and the lower limit voltage of the main bus is the rectified outlet voltage value of the converter device.
6. The method of claim 5, wherein X% is a percentage of the energy storage device from a constant current charging to a constant voltage charging point or any other method that is beneficial to improving the efficiency and reliability of the energy storage.
7. The method of claim 1, wherein the energy storage device is connected to the main bus by a DC/DC device.
8. The method of claim 1, wherein the load is a DC load and an AC load of each voltage class, and the access is direct connection or is connected by a DC/DC or DC/AC device.
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| CN111064178B true CN111064178B (en) | 2023-10-17 |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205429765U (en) * | 2016-03-15 | 2016-08-03 | 华北电力大学（保定） | Little grid system of hybrid AC/DC based on distributing type bus structure |
| CN106385044A (en) * | 2016-09-30 | 2017-02-08 | 安徽工程大学 | Composite energy storage control system used for wind power plant power generation plan tracking and control method thereof |
| CN107104433A (en) * | 2017-05-15 | 2017-08-29 | 国网江苏省电力公司电力科学研究院 | A kind of light-preserved system participates in the acquisition methods of power distribution network Optimal Operation Strategies |
| CN107394831A (en) * | 2017-08-29 | 2017-11-24 | 国家电网公司 | A kind of harbour alternating current-direct current series-parallel connection power distribution network and its integrated dispatch management-control method |
| CN107516906A (en) * | 2017-08-31 | 2017-12-26 | 青岛特来电新能源有限公司 | A kind of micro-grid system and micro-capacitance sensor method of supplying power to |
| CN207283164U (en) * | 2017-09-30 | 2018-04-27 | 三峡大学 | A kind of high reliability DC distribution net system containing more busbares |
| CN108155638A (en) * | 2016-12-05 | 2018-06-12 | 珠海格力电器股份有限公司 | Control device and control method, the DC micro power grid system of direct-current grid |
| CN108347063A (en) * | 2018-01-17 | 2018-07-31 | 武汉理工大学 | A kind of ship grid-connected photovoltaic system based on super capacitor energy-storage |
-
2018
- 2018-10-16 CN CN201811203152.6A patent/CN111064178B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205429765U (en) * | 2016-03-15 | 2016-08-03 | 华北电力大学（保定） | Little grid system of hybrid AC/DC based on distributing type bus structure |
| CN106385044A (en) * | 2016-09-30 | 2017-02-08 | 安徽工程大学 | Composite energy storage control system used for wind power plant power generation plan tracking and control method thereof |
| CN108155638A (en) * | 2016-12-05 | 2018-06-12 | 珠海格力电器股份有限公司 | Control device and control method, the DC micro power grid system of direct-current grid |
| CN107104433A (en) * | 2017-05-15 | 2017-08-29 | 国网江苏省电力公司电力科学研究院 | A kind of light-preserved system participates in the acquisition methods of power distribution network Optimal Operation Strategies |
| CN107394831A (en) * | 2017-08-29 | 2017-11-24 | 国家电网公司 | A kind of harbour alternating current-direct current series-parallel connection power distribution network and its integrated dispatch management-control method |
| CN107516906A (en) * | 2017-08-31 | 2017-12-26 | 青岛特来电新能源有限公司 | A kind of micro-grid system and micro-capacitance sensor method of supplying power to |
| CN207283164U (en) * | 2017-09-30 | 2018-04-27 | 三峡大学 | A kind of high reliability DC distribution net system containing more busbares |
| CN108347063A (en) * | 2018-01-17 | 2018-07-31 | 武汉理工大学 | A kind of ship grid-connected photovoltaic system based on super capacitor energy-storage |
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