CN100588070C - System for controlling and managing micro power network - Google Patents
System for controlling and managing micro power network Download PDFInfo
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- CN100588070C CN100588070C CN200610114703A CN200610114703A CN100588070C CN 100588070 C CN100588070 C CN 100588070C CN 200610114703 A CN200610114703 A CN 200610114703A CN 200610114703 A CN200610114703 A CN 200610114703A CN 100588070 C CN100588070 C CN 100588070C
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Abstract
The related control and management system for mini power network comprises: the top organization layer to start system and send connection command to next layer for channel building, the middle coordinate layer as connected loop structure to receive command from last layer and start to build communication channel, and the bottom execution layer to control distributed energy combination when the middle layer decides the energy fit to be combined. Wherein, from top to bottom, the control precision increases successively, while the AI level decreases successively.
Description
Technical field
The present invention relates to distributed energy and electric power networks supervisory control system, particularly micro power network control and management system.
Background technology
Present electric power networks especially distribution system automation management is made up of electrical power distribution automatization system main website (being Surveillance center), power distribution automation substation, monitoring system of electric substation, synthesis monitoring instrument, meter-copy collector and distribution control unit etc. on theoretical structure.The power distribution automation main website is responsible for the supervision and the control of whole distract power distribution network, finishes in the whole city each transformer station and all open and close collection, the arrangement of feeder line data in one's power, and is uploaded to man-machine work station, is finished the supervision and the control task of system by the operations staff.Failure diagnosis, Fault Isolation and the service restoration of main website appointed area finished in the power distribution automation substation.Distribution terminal equipment and kilowatt meter reading-out system are finished each switch, switching station, user's information gathering and processing capacity.Automated system overall structure below the substation is loose, and the operation of whole system and control and management all need to be with the people to feed back execution, promptly need the operations staff to monitor running status, the Control Network operation.
Micro power network makes distribution net work structure that basic variation take place as the novel organizational form of distributed energy resource system, becomes active, a structure flexible net by original passive radial network.And distributed energy may have variform and multiple service conditions, the micro power network geographic range is little, need to realize autonomous operation, unattended, to this, the loose couplings structure of traditional distribution automation system bottom and limited functional structure can't adapt to complexity like this and active network management role flexibly.
Summary of the invention
The objective of the invention is to overcome the birth defect that existing distribution automation system can't the managing distributed energy, for the monitoring management of micro power network provide a cover perfect, reliably, the control management system of standard.
The present invention adopts a kind of layering to pass the control and management structure on rank, is divided into three layers, comprises highest organized layer, middle cooperation layer and rudimentary execution level.Structure is tree structure from top to bottom, and middle cooperation layer is inner for being communicated with circulus.Each layer control precision from top to bottom passed on the rank and risen, and artificial intelligence is passed rank and descended.
1, highest organized layer is made up of micro power network administrative center, as system-wide top, can learn and produce decision-making, differentiates the micro power network running status, forms corresponding task.Major function is divided into data acquisition process, online in real time control, senior autonomous management and man-machine auxiliary management four major parts.Wherein:
(1) data acquisition process is mainly finished collection, the processing of each cell data and is explained, stores and show, and these real time information are passed to other application module.Flow chart of data processing is for can be divided into following steps: preposition acceptance, deal with data, deposit real-time data base in, be transmitted to the online in real time control system, deposit historical data base in, be transmitted to senior autonomous management system and show handle.Above flow process order is successively carried out.
(2) online in real time control is to come little real-time power network control according to measurement data and simple reaction formula rule, and its reaction equation control law is on-the-fly modified by senior autonomous management.And whether it instructing and should being transmitted to the backstage by the time profile data, is correctly proofreaied and correct instruction by senior autonomous management after the instruction of sending to middle cooperation layer simultaneously.
(3) senior autonomous management, it obtains up-to-date data section, starts to analyze to be used for assessing present, following state of little electrical network, sends corresponding control law; Regularly obtain historical data, formulate generation schedule, assess contingent fault, formulate safety and trouble shooting or the like response rule, be handed down to online in real time control;
(4) man-machine auxiliary management provides the interface that the operations staff gets involved the micro power network management.In case man-machine management is activated, senior autonomous management will no longer be responsible for keeping the micro power network operation, and its analysis result only provides reference to operations staff's instruction.
2, middle cooperation layer: comprise distributed energy and network interface and protection switch control device.Major function is for consulting and coordinate the control action of each controller mutually, finishes the task that top micro power network administrative center assigns jointly.When collapse or other accidents took place in micro power network administrative center, each unit of middle cooperation layer can be consulted mutually and coordinate, and keeps micro power network jointly and normally moves.Wherein:
(1) distributed energy and network interface, under micro power network administrative center normal operating condition, it accepts the distributed energy related data that the distributed energy controller is uploaded, and gather distributed energy be incorporated into the power networks three-phase voltage, electric current and the frequency of node, and calculate active power, reactive power, harmonic wave, power factor, active electrical degree, idle electric degree, corresponding data is sent to micro power network administrative center.It accepts the instruction of micro power network administrative center simultaneously, according to the ruuning situation interpretative order of distributed energy, obtains concrete quantification instruction, is issued to the distributed energy controller of rudimentary execution level.When the collapse of micro power network administrative center or breaking down, it will intercourse data with each unit that is in middle cooperation layer together, judge present residing environment with this, make the control corresponding decision-making.
(2) protection switch control device, protection switch control device can be when accident oneself judge deciliter, and can communicate by letter with each distributed energy and network interface and micro power network administrative center, accepts and carry out the instruction of micro power network administrative center.Under micro power network administrative center normal operating condition, it gathers the on off state and the interface data that is incorporated into the power networks, and corresponding data is sent to micro power network administrative center.Accept micro power network administrative center and instruct separating brake or combined floodgate.When the collapse of micro power network administrative center or breaking down, it will intercourse data with each unit that is in middle cooperation layer together, judge present residing environment with this, make control corresponding.
3, rudimentary execution level: comprise each distributed energy controller and protection switch.Major function is cooperation layer instruction in the middle of high accuracy is carried out.Under micro power network and net state, each distributed energy controller can make its stable operation by controlling its pairing distributed energy active power of output and reactive power.Under micro power network independent operating state, each distributed energy controller can make its stable operation by controlling its pairing distributed energy output voltage and frequency.While distributed energy controller self can be measured and control data is uploaded to the interface platform that is incorporated into the power networks, and can accept and carry out the control and management order of the interface platform that is incorporated into the power networks.
The present invention can use multiple communication modes such as Ethernet, GPRS, power line carrier at Wide Area Network, and LAN can be used multiple communication modes such as CAN, HPI, serial ports.
The present invention can structurally manage inner each distributed energy of micro power network and protection switch efficiently, reliably, realizes micro power network unattended, autonomous operation.
Description of drawings
Fig. 1 is micro power network control of the present invention and management system overall construction drawing.
Fig. 2 is a FB(flow block) of the present invention.
Fig. 3 is the distributed energy interface structure figure that is incorporated into the power networks.
Fig. 4 is a micro power network administrative center hardware structure diagram.
Embodiment
The invention will be further described below in conjunction with the drawings and specific embodiments.
Figure 1 shows that micro power network of the present invention control and management system general structure, as shown in Figure 1, structure of the present invention is tree structure from top to bottom, and middle cooperation layer is inner to be the connection circulus.Highest organized layer is made up of micro power network administrative center; Middle cooperation layer is made up of distributed energy and network interface, protection switch control device and existing distribution protection device; Rudimentary execution level comprises each distributed energy controller and protection switch.Each layer control precision from top to bottom passed on the rank and risen, and artificial intelligence is passed rank and descended.
Figure 2 shows that micro power network control of the present invention and management process block diagram.Total system is at first started by highest organized layer administrative center, and sends bind command to each unit of middle cooperation layer, requires to set up communication pipe.After each unit of middle cooperation layer receives the bind command at maximum tissue layer-management center, begin to start, and corresponding bind command and maximum tissue layer are set up communication pipe.After communication pipe is set up successfully, each unit inspection of middle cooperation layer interface and distributed energy state separately, and judge whether distributed energy meets the condition of being incorporated into the power networks.If meet, then be incorporated into the power networks, and beginning communicates by letter with middle cooperation layer by low layer controller control distributed energy, system enters operate as normal.If do not meet, then continue to wait for and regularly start and judge.
Be illustrated in figure 3 as distributed energy and network interface, comprise ancillary equipment such as DSP acquisition processing module, ARM communication module, liquid crystal display and keyboard.The DSP acquisition processing module is responsible for the acquisition interface data, accepts bottom controller and uploads information.And will send the ARM communication module to by LAN after the information processing of distributed energy and interface.Receive simultaneously following the sending instructions of ARM communication module explanation again.Adopt the CAN bus mode among Fig. 3, can select different LAN according to different situations.The ARM communication module is repacked the data of uploading, and sends to administrative center or other distributed energy interfaces by Wide Area Network.The order at receiving management center simultaneously, make a concrete analysis of explain after, time deliver to bottom controller.Ancillary equipment such as keyboard, liquid crystal display connects by ARM communication module interface, is used for the distributed energy interface such as is artificially set at operation.
As shown in Figure 4, micro power network administrative center comprises advance data central server, control and management server and interactive workstation.Whole center can be mixed with unit, two-shipper or two web frame according to system's actual conditions, is two-shipper list web frame among Fig. 4, and one main one can guarantee management reliability fully.The micro power network geographic range is little, relative large-scale EMS of measured equipment, facility and data volume and distribution management system are little a lot, so need not to be provided with specially front end processor,, finish tasks such as stipulations explanation, data processing by data center server double as system front end processor.Data center server is finished tasks such as data base administration, data issue simultaneously.Control and management server main task is accepted the data of data center server, and all data are analyzed, and assesses present, following state of little electrical network, sends corresponding real-time control command and long-term control rule; Formulate generation schedule, assess contingent fault, formulate safety and trouble shooting or the like.Interactive workstation offers the interface that the operations staff gets involved the micro power network management, and relevant assistant service is provided.
Claims (6)
1, a kind of control of micro power network and management system, the tree structure from top to bottom that it is characterized in that serving as reasons control of described micro power network and management system highest organized layer, middle cooperation layer and rudimentary execution level form, middle cooperation layer is inner for being communicated with circulus; Each layer control precision from top to bottom passed on the rank and risen, and artificial intelligence is passed rank and descended; Highest organized layer is made up of micro power network administrative center, and major function is data acquisition process, online in real time control, senior autonomous management and man-machine auxiliary management; Middle cooperation layer is made up of distributed energy and network interface and protection switch control device and existing distribution protection device, its major function is finished the task that highest organized layer micro power network administrative center assigns jointly for consulting and coordinate the control action of each distributed energy controller of rudimentary execution level mutually; When collapse or other accidents took place in micro power network administrative center, the distributed energy of middle cooperation layer and network interface, protection switch control device, distribution protection device can be consulted mutually and coordinate, and keep micro power network jointly and normally move; Rudimentary execution level comprises each distributed energy controller and protection switch; major function is cooperation layer instruction in the middle of carrying out; under micro power network and net state, each distributed energy controller makes micro power network stable operation by controlling its pairing distributed energy active power of output and reactive power.
2, the control of micro power network as claimed in claim 1 and management system is characterized in that the data acquisition process flow process is following steps: preposition acceptance, deal with data, deposit real-time data base in, be transmitted to the online in real time control system, deposit historical data base in, be transmitted to senior autonomous management system and show handle; The online in real time control system is to come micro power network is controlled in real time according to measurement data and simple reaction formula rule, described simple reaction formula rule is revised by the senior autonomous management system dynamics of described micro power network administrative center, and in senior autonomous management system after middle cooperation layer sends instruction, simultaneously instruction and this instruction time corresponding profile data are transmitted to the backstage, whether correctly proofread and correct instructing by senior autonomous management system; Senior autonomous management system obtains up-to-date time profile data, starts to analyze to be used for assessing the present and following state of micro power network, sends corresponding control law; Senior autonomous management system regularly obtains historical data from historical data base, formulate generation schedule, assesses contingent fault, formulates safety and trouble shooting, is handed down to the online in real time control system; Man-machine auxiliary management provides the interface that the operations staff gets involved the micro power network management, in case man-machine auxiliary management is activated, senior autonomous management system will no longer be responsible for keeping the micro power network operation, and the analysis result of senior autonomous management system only provides with reference to operational order for the operations staff.
3, the control of micro power network as claimed in claim 1 and management system, it is characterized in that distributed energy and network interface are under micro power network administrative center normal operating condition, accept the distributed energy related data that the distributed energy controller is uploaded, and gather distributed energy be incorporated into the power networks three-phase voltage, electric current and the frequency of node, and calculate active power, reactive power, harmonic wave, power factor, active electrical degree, idle electric degree, corresponding data is sent to micro power network administrative center; And accept the instruction of micro power network administrative center simultaneously, and according to the ruuning situation interpretative order of distributed energy, obtain concrete quantification instruction, be issued to the distributed energy controller of rudimentary execution level; When the collapse of micro power network administrative center or breaking down, described distributed energy and network interface are intercoursed data with each unit that is in middle cooperation layer together, judge present residing environment with this, make the control corresponding decision-making;
The protection switch control device can be when accident oneself judges deciliter, and can communicate by letter with each distributed energy and network interface and micro power network administrative center, receives and carry out the instruction of micro power network administrative center; Under micro power network administrative center normal operating condition, described protection switch control device is gathered the on off state and the interface data that is incorporated into the power networks, and corresponding data is sent to micro power network administrative center, accepts micro power network administrative center and instructs separating brake or combined floodgate; When the collapse of micro power network administrative center or breaking down, described protection switch control device is intercoursed data with each unit that is in middle cooperation layer together, judges present residing environment with this, makes control corresponding.
4,, it is characterized in that distributed energy and network interface mainly comprise DSP acquisition processing module, ARM communication module as the control and the management system of claim 1 or 3 described micro power networks; The DSP acquisition processing module is responsible for the acquisition interface data, accepts the information that each distributed energy controller in the rudimentary execution level is uploaded, and with distributed energy self and and the information processing of network interface after send the ARM communication module to by LAN; Receive simultaneously following the sending instructions of ARM communication module explanation again; The ARM communication module is repacked the data of uploading, and send to micro power network administrative center or other distributed energies and network interface by Wide Area Network, receive the order of micro power network administrative center simultaneously, after being made a concrete analysis of explanation, deliver to the distributed energy controller in the rudimentary execution level down.
5, the control of micro power network as claimed in claim 1 and management system, it is characterized in that under micro power network and net state, each distributed energy controller of rudimentary execution level makes micro power network stable operation by control its pairing distributed energy active power of output and reactive power; Under micro power network independent operating state, each distributed energy controller makes micro power network stable operation by control its pairing distributed energy output voltage and frequency; Self is measured while distributed energy controller and control data is uploaded to distributed energy and network interface, and receive and carry out the control and management order of distributed energy and network interface.
6, the control of micro power network as claimed in claim 1 and management system, it is characterized in that micro power network control is as follows with management process: highest organized layer micro power network administrative center at first starts total system, and, require to set up communication pipe to each unit transmission bind command of middle cooperation layer; After each unit of middle cooperation layer receives the bind command of highest organized layer micro power network administrative center, begin to start, and the response bind command, communication pipe set up with highest organized layer; After communication pipe is set up successfully, each unit inspection of middle cooperation layer interface and distributed energy state separately, and judge whether distributed energy meets the condition of being incorporated into the power networks; If meet, then be incorporated into the power networks by the distributed energy controller in rudimentary execution level control distributed energy, and beginning communicates by letter with middle cooperation layer, described micro power network control and management system enter operate as normal, if do not meet, then continue to wait for and regularly start and judge.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102710023A (en) * | 2012-06-13 | 2012-10-03 | 中国东方电气集团有限公司 | Monitoring system applicable to different types of wind photovoltaic storage microgrid systems |
| WO2013040837A1 (en) * | 2011-09-25 | 2013-03-28 | 国网电力科学研究院 | Computer monitoring method for microgrid system |
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| CN101510685B (en) * | 2009-03-12 | 2010-12-29 | 上海交通大学 | Distributed intelligent control system based on biology immunity principle |
| US8401709B2 (en) * | 2009-11-03 | 2013-03-19 | Spirae, Inc. | Dynamic distributed power grid control system |
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| CN105634015A (en) * | 2016-03-24 | 2016-06-01 | 国网辽宁省电力有限公司经济技术研究院 | Distributed wind power generation gird-connected interface device |
| CN106487093B (en) * | 2016-10-24 | 2019-07-16 | 国家电网公司 | Towards distribution net side distributed photovoltaic integrated operation control system and control method |
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| CN114239324B (en) * | 2022-02-23 | 2022-07-19 | 南方电网数字电网研究院有限公司 | Micro energy network state transition space modeling method based on hybrid automaton |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1770585A (en) * | 2004-10-25 | 2006-05-10 | 中国科学院电工研究所 | Variable-speed constant-frequency doubly-fed generator system and its parallel network controlling method |
| US20060208574A1 (en) * | 2005-03-18 | 2006-09-21 | Wisconsin Alumni Research Foundation | Control of small distributed energy resources |
-
2006
- 2006-11-22 CN CN200610114703A patent/CN100588070C/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1770585A (en) * | 2004-10-25 | 2006-05-10 | 中国科学院电工研究所 | Variable-speed constant-frequency doubly-fed generator system and its parallel network controlling method |
| US20060208574A1 (en) * | 2005-03-18 | 2006-09-21 | Wisconsin Alumni Research Foundation | Control of small distributed energy resources |
Non-Patent Citations (1)
| Title |
|---|
| 变流技术在分布式发电和微电网上的应用. 彭方正.变流技术与电力牵引，第2期. 2006 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013040837A1 (en) * | 2011-09-25 | 2013-03-28 | 国网电力科学研究院 | Computer monitoring method for microgrid system |
| CN102710023A (en) * | 2012-06-13 | 2012-10-03 | 中国东方电气集团有限公司 | Monitoring system applicable to different types of wind photovoltaic storage microgrid systems |
| CN102710023B (en) * | 2012-06-13 | 2016-01-20 | 东方电气集团国际合作有限公司 | Be applicable to the supervisory control system of dissimilar wind-light storage micro-grid system |
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