CN203352170U - A microgrid countercurrent-preventing protection system - Google Patents
A microgrid countercurrent-preventing protection system Download PDFInfo
- Publication number
- CN203352170U CN203352170U CN 201320361591 CN201320361591U CN203352170U CN 203352170 U CN203352170 U CN 203352170U CN 201320361591 CN201320361591 CN 201320361591 CN 201320361591 U CN201320361591 U CN 201320361591U CN 203352170 U CN203352170 U CN 203352170U
- Authority
- CN
- China
- Prior art keywords
- micro
- electrical network
- protection system
- microgrid
- bus
- 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.)
- Expired - Fee Related
Links
- 238000010248 power generation Methods 0.000 claims abstract description 10
- 238000004146 energy storage Methods 0.000 claims description 13
- 239000002028 Biomass Substances 0.000 claims description 4
- 230000005611 electricity Effects 0.000 abstract description 6
- 238000005516 engineering process Methods 0.000 description 4
- 230000002265 prevention Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000001172 regenerating effect Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The utility model relates to a microgrid countercurrent-preventing protection system and belongs to the field of distributed power generation. The microgrid countercurrent-preventing protection system comprises a microgrid. The micogrid comprises a distributed power supply, an energy-saving system, and user loads. The distributed power supply and the energy-saving system are joined to an AC bus through a respective energy converting device. The user loads are joined to the AC bus in a grouping manner. The AC bus is joined to a public grid through a common connection point. A countercurrent-preventing system is disposed in the microgrid. The microgrid countercurrent-preventing protection system is characterized in that the microgrid countercurrent-preventing protection system also comprises an extra load which is connected with the AC bus through a controllable switch and is connected with the public grid. On the premise of not powering off the distributed power supply, the microgrid countercurrent-preventing protection system achieves countercurrent-preventing control of the microgrid system by reasonably managing the energy of the microgrid so as to prevent influences on the public grid and to generate electricity with renewable energy to the utmost extent.
Description
Technical field
The utility model relates to a kind of counterflow-preventing protection system of micro-electrical network, belongs to the distributed power generation field.
Background technology
Current, energy-saving and emission-reduction and green energy resource become the focus that the whole world is paid close attention to, and are also one of construction objects of China's intelligent grid simultaneously.As intelligent grid, require its access that can adapt to large power supply, also to support regenerative resource with the friendly access of the mode of distributed power generation, meet the requirement of electric power and natural environment, social economy's harmonious development.
But, the characteristics such as photovoltaic distributed power supply has intermittence, randomness, response speed is slow, inertia is little, grid-connected rear easily cause voltage fluctuation and flickering, especially when the large-capacity distributing power supply is incorporated to low and medium voltage distribution network, realize the power-balance of power distribution network, and guarantee comparatively difficulty of power supply reliability and the quality of power supply.In order to reduce impact and the negative effect of large-scale distributed power grid to outside public electric wire net, carry out the integrating distributed generation system by micro-electric power network technique, can solve well the technical barrier of the grid-connected existence of current distributed power generation.
Micro-electrical network according to and site power delivery direction be divided into " grid-connected do not surf the Net " and " grid-connected and surf the Net " two kinds of modes.Under " grid-connected do not surf the Net " mode, micro-electrical network site power can only be carried to micro-electrical network user load by public electric wire net; Under " grid-connected and online " mode, and site power can two-way flow, and the rich power of micro-electrical network can flow to public electric wire net.Yet, for adopting " grid-connected and online " micro-electrical network that mode is moved, its power supply characteristic shown with respect to outside public electric wire net still can cause certain influence to the stable operation of electrical network, specifically mainly contains three aspects:
The first, the harmonic wave that in micro-electrical network, a large amount of power electronic equipments produces impacts the quality of power supply of public electric wire net.
The second, when public electric wire net breaks down, the inverse probability that micro-electrical network produces can cause damage to machinery equipment, the personal safety that even jeopardizes the maintainer when serious.
The 3rd, due to the power supply characteristic of micro-electrical network, changed the characteristics of public electric wire net single supply, radial pattern, unidirectional trend, thereby made the existing current protection measure no longer applicable.
Micro-electrical network that " grid-connected do not surf the Net " mode is moved for adopting; the Chinese patent that application number is 201210173096.2 discloses a kind of grid-connected micro-grid system and control method thereof of not surfing the Net; preventing by micro-electrical network central controller and the reverse power protection device that is arranged on the points of common connection place that inverse probability is counter send; guarantee that whole micro-grid system is not only to the public electric wire net power taking and to the public electric wire net power transmission, thereby avoided micro-electrical network to impact public electric wire net.But this technology is mainly to export the means of even excising distributed power source by the restriction distributed power source to eliminate inverse probability, this had not both met the policy of the remaining electricity online of national requirements, also be unfavorable for the normal operation of distributed power source, do not take full advantage of new forms of energy yet, caused the waste of regenerative resource simultaneously.
For above policy and the state of the art; be necessary to propose a kind of counterflow-preventing protection system of micro-electrical network; under the prerequisite of not excising distributed power source; by reasonably microgrid energy being managed; realize the counterflow-preventing control of micro-grid system; thereby avoid public electric wire net is impacted, simultaneously the maximum using renewable energy power generation.
The utility model content
Technical problem to be solved in the utility model is to overcome deficiency of the prior art and counterflow-preventing protection system that a kind of micro-electrical network reasonable in design is provided; under the prerequisite of not excising distributed power source; by reasonably microgrid energy being managed; realize the counterflow-preventing control of micro-grid system; thereby avoid public electric wire net is impacted, simultaneously the maximum using renewable energy power generation.
The technical scheme in the invention for solving the above technical problem is: a kind of counterflow-preventing protection system of micro-electrical network, comprise micro-electrical network, and described micro-electrical network comprises distributed power source, energy-storage system, user load; Described distributed power source and energy-storage system are by energy converter incoming transport bus separately; User load is with the mode incoming transport bus of grouping; Ac bus accesses public electric wire net by points of common connection; It is characterized in that: described micro-electrical network also disposes extra load, and described extra load is connected with ac bus by gate-controlled switch, and extra load also is connected with public electric wire net.
The power of extra load described in the utility model is greater than the rich power of micro-electrical network.
Be provided with the inverse probability checkout gear on the circuit that extra load described in the utility model is connected with public electric wire net.
Also be provided with the unidirectional electric energy metering device on the circuit that extra load described in the utility model is connected with ac bus.The effect of unidirectional electric energy metering device is for measuring the remaining electric electricity volume of micro-electrical network, thereby the policy that can formulate according to country and standard provide electricity charge subsidy for micro-electrical network user.
Extra load described in the utility model comprises electric automobile charging station or public place lighting apparatus.While planning micro-electrical network, can select the extra load of the so round-the-clock load of electric automobile charging station, public place lighting apparatus as micro-electrical network, so that can be at any time and the rich power of micro-electrical network of all dissolving.
Distributed power source described in the utility model comprises wind generator system, photovoltaic generating system, biomass power generation system.
The utility model compared with prior art, has following advantage and effect:
(1) for the grid-connected problem of micro-electrical network, by micro-electrical network being carried out to the counterflow-preventing protection, control, eliminate the power supply characteristic of micro-electrical network, thereby made micro-electrical network greatly reduce the impact of the public electric wire net quality of power supply, relaying protection, electricity consumption reliability, fail safe.
(2) for the policy requirements of electricity online more than the national requirements distributed generation system, existing counterflow-preventing control technology is made to improvement, by to micro-electrical network configuration extra load, making the rich electric weight of micro-electrical network to be sold to electrical network under the prerequisite that power distribution network is not produced to adverse current, do not need to excise distributed power source, further improved the renewable energy utilization rate.
(3) the utility model has adopted two judgment thresholds on control logic: countercurrent prevention system starts threshold value and countercurrent prevention system is closed threshold value, it is 5 percent of current micro-electrical network user load capacity that two threshold values can be set, thereby under the prerequisite that guarantees micro-electrical network load normal operation, avoided micro-electrical network grid-connecting apparatus in critical point frequent movement and energy-storage system repeated charge, extended the micro-grid system life-span.
The accompanying drawing explanation
The structural representation that Fig. 1 is the utility model embodiment.
Embodiment
Below in conjunction with accompanying drawing and by embodiment, the utility model is described in further detail.
Referring to Fig. 1, micro-electrical network of the utility model embodiment comprises distributed power source, energy-storage system BAT, user load LOAD1～LOADn.Distributed power source comprises wind generator system PW, photovoltaic generating system PV, biomass power generation system PB etc.Energy-storage system BAT comprises lead accumulator, lithium battery, super capacitor etc.
Distributed power source and energy-storage system BAT access the ac bus of 400V by energy converter separately.User load LOAD1～LOADn accesses the ac bus of 400V in the mode of grouping.Ac bus is by points of common connection PCC access public electric wire net.
Extra load LOAD is connected with ac bus by gate-controlled switch K, closed gate-controlled switch K, and extra load LOAD and ac bus are connected, and disconnect gate-controlled switch K, and extra load LOAD and ac bus disconnect.Be provided with unidirectional electric energy metering device W on the circuit that extra load LOAD is connected with ac bus.
Extra load LOAD also is connected with public electric wire net, is provided with inverse probability checkout gear N on the circuit be connected with public electric wire net at extra load LOAD.By micro-electrical network and public electric wire net, jointly extra load LOAD is powered.
The power of extra load LOAD is greater than the rich power of micro-electrical network, and the rich power that sends of micro-electrical network of dissolving at any time.
The points of common connection PCC place of micro-electrical network and public electric wire net is provided with static switch, and the Main Function of static switch is when micro-electrical network produces inverse probability and inverse probability disappearance, and the operational mode (grid-connected/isolated island) of micro-electrical network is switched.In addition, when outside public electric wire net breaks down, can make micro-electrical network exit rapidly public electric wire net, enter the island mode operation.
While planning micro-electrical network, can select the extra load LOAD of the round-the-clock loads such as electric automobile charging station, public place lighting apparatus as micro-electrical network, so that can be at any time and the rich power of micro-electrical network of all dissolving.
It is Ps that the distributed power source generate output is set, and micro-electrical network user load capacity is Pl, and it is Pa that countercurrent prevention system starts threshold value, and it is Pb that countercurrent prevention system is closed threshold value; Ps is the total power generating capacity of the power supplys such as wind generator system PW, photovoltaic generating system PV, the biomass power generation system PB of access; Pl is the total capacity of the user load LOAD1～LOADn of access.Pa and Pb, for to adopt on control logic, arrange Pa=Pb=0.05 * Pl.
This counterflow-preventing protection control method of the utility model is further comprising the steps of:
(1) detect after system initialization, when Ps-Pl>Pa, go to step (2);
When Pl-Ps>Pb, go to step (3);
When-Pb≤Ps-Pl≤Pa, micro-electrical network keeps standing state constant, repeats to start step (1);
(2) detect the current capacity of energy-storage system BAT;
The current capacity of energy-storage system BAT does not reach its upper energy limit, goes to step (4);
The current capacity of energy-storage system BAT has reached its upper energy limit, goes to step (5);
(3) micro-electrical network switches to grid-connected pattern, by public electric wire net and energy-storage system BAT, supplements micro-network load breach, and micro-electrical network keeps existing grid-connected mode state constant, repeats to start step (1);
(4) micro-electrical network switches to island mode, and energy-storage system BAT charging absorbs unnecessary distributed power source generate output, and micro-electrical network keeps existing island mode state constant, repeats to start step (1);
(5) micro-electrical network switches to island mode, the gate-controlled switch K on the circuit that closed extra load LOAD is connected with ac bus, and extra load LOAD and ac bus are connected, by the extra load LOAD rich power that micro-electrical network sends of dissolving; Now, when inverse probability checkout gear N detects inverse probability at this connection line place, be that public electric wire net is while breaking down, gate-controlled switch K on the circuit that disconnection extra load LOAD is connected with ac bus, extra load LOAD and ac bus disconnect, and micro-electrical network is switched to island mode, micro-electrical network keeps existing island mode state constant, repeats to start step (1); When inverse probability checkout gear N does not detect inverse probability at this connection line place, when public electric wire net does not break down, repeat to start step (1).
Although the utility model with embodiment openly as above; but it is not in order to limit protection range of the present utility model; any technical staff who is familiar with this technology, the change of doing within not breaking away from design of the present utility model and scope and retouching, all should belong to protection range of the present utility model.
Claims (6)
1. the counterflow-preventing protection system of a micro-electrical network, comprise micro-electrical network, and described micro-electrical network comprises distributed power source, energy-storage system, user load; Described distributed power source and energy-storage system are by energy converter incoming transport bus separately; User load is with the mode incoming transport bus of grouping; Ac bus accesses public electric wire net by points of common connection; It is characterized in that: described micro-electrical network also disposes extra load, and described extra load is connected with ac bus by gate-controlled switch, and extra load also is connected with public electric wire net.
2. the counterflow-preventing protection system of micro-electrical network according to claim 1, it is characterized in that: the power of described extra load is greater than the rich power of micro-electrical network.
3. the counterflow-preventing protection system of micro-electrical network according to claim 1, is characterized in that: be provided with the inverse probability checkout gear on the circuit that described extra load is connected with public electric wire net.
4. the counterflow-preventing protection system of micro-electrical network according to claim 1, is characterized in that: also be provided with the unidirectional electric energy metering device on the circuit that described extra load is connected with ac bus.
5. the counterflow-preventing protection system of micro-electrical network according to claim 1, it is characterized in that: described extra load comprises electric automobile charging station or public place lighting apparatus.
6. the counterflow-preventing protection system of micro-electrical network according to claim 1, it is characterized in that: described distributed power source comprises wind generator system, photovoltaic generating system, biomass power generation system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320361591 CN203352170U (en) | 2013-06-24 | 2013-06-24 | A microgrid countercurrent-preventing protection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320361591 CN203352170U (en) | 2013-06-24 | 2013-06-24 | A microgrid countercurrent-preventing protection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203352170U true CN203352170U (en) | 2013-12-18 |
Family
ID=49752021
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320361591 Expired - Fee Related CN203352170U (en) | 2013-06-24 | 2013-06-24 | A microgrid countercurrent-preventing protection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203352170U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109768525A (en) * | 2019-02-12 | 2019-05-17 | 南京师范大学 | Integral relay protection method and device for electric vehicle photovoltaic charging station |
| CN112838587A (en) * | 2021-03-16 | 2021-05-25 | 阳光新能源开发有限公司 | A new energy grid-connected hydrogen production system and its anti-countercurrent control method |
-
2013
- 2013-06-24 CN CN 201320361591 patent/CN203352170U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109768525A (en) * | 2019-02-12 | 2019-05-17 | 南京师范大学 | Integral relay protection method and device for electric vehicle photovoltaic charging station |
| CN112838587A (en) * | 2021-03-16 | 2021-05-25 | 阳光新能源开发有限公司 | A new energy grid-connected hydrogen production system and its anti-countercurrent control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102931653B (en) | Comprehensive coordination control method of wind-solar direct current micro-grid | |
| CN102916486B (en) | Intelligent micro-grid diesel-storage coordination control method | |
| CN103199564A (en) | Intelligent power grid distributed self-supporting photovoltaic power supply system | |
| CN104281977A (en) | Hybrid microgrid application platform and control method theref | |
| CN205092592U (en) | Distributing type photovoltaic power generation and control system | |
| CN204179989U (en) | Based on the scene oil complementary power generation system of DC bus | |
| CN202712876U (en) | Solar photovoltaic microgrid grid-connected power generation system | |
| CN105428735A (en) | Storage-control-integrated solar energy lithium battery module | |
| CN203951202U (en) | Micro-mains supply system for a kind of wind light mutual complementing family | |
| CN203747661U (en) | Pre-charge device of wind power current transformer and wind power current transformer | |
| CN103326400B (en) | Countercurrent-preventing protection and control method for microgrid | |
| CN203026959U (en) | Multifunctional energy storage inversion system | |
| CN204205617U (en) | A kind of power conversion is generated electricity by way of merging two or more grid systems electric power system | |
| CN103812140A (en) | Wind energy, solar energy and commercial power complementary electric vehicle charging system | |
| CN203352170U (en) | A microgrid countercurrent-preventing protection system | |
| CN204190669U (en) | A kind of wind and solar hybrid generating system | |
| CN201038817Y (en) | Super capacitor controller for wind power generation | |
| CN207926199U (en) | A kind of family's energy-storage system | |
| CN102355002A (en) | An isolated grid-connected power generation island effect protection device and system | |
| CN202978320U (en) | Wind energy, solar energy and commercial power complementary electric vehicle charging station | |
| CN202121367U (en) | Lithium battery pack charger of wind-power pitch control system | |
| CN206517073U (en) | A kind of new friendly intelligent micro-grid | |
| CN104348244A (en) | Intelligent photovoltaic distribution type generating system | |
| CN104009496B (en) | A kind of dual threshold for micro-capacitance sensor anti-backflow device judges switching circuit | |
| CN202737479U (en) | Distributed power generating apparatus based on renewable energy source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131218 Termination date: 20150624 |
|
| EXPY | Termination of patent right or utility model |