CN103595052B - Method for stably controlling switchover from micro-grid connection into island state - Google Patents
Method for stably controlling switchover from micro-grid connection into island state Download PDFInfo
- Publication number
- CN103595052B CN103595052B CN201310509652.3A CN201310509652A CN103595052B CN 103595052 B CN103595052 B CN 103595052B CN 201310509652 A CN201310509652 A CN 201310509652A CN 103595052 B CN103595052 B CN 103595052B
- Authority
- CN
- China
- Prior art keywords
- micro
- power
- capacitance sensor
- grid
- grid connection
- 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
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000004146 energy storage Methods 0.000 claims description 27
- 238000005516 engineering process Methods 0.000 claims description 5
- 230000000087 stabilizing effect Effects 0.000 claims description 4
- 238000011156 evaluation Methods 0.000 claims description 3
- 230000009897 systematic effect Effects 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 abstract description 7
- 230000001052 transient effect Effects 0.000 description 4
- 238000012423 maintenance Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention relates to a method for stably controlling switchover from micro-grid connection into an island state. When switchover is planned, a micro-grid stability control system collects grid connection point power before the micro-grid is sectionalized from an electric system, a power source and a load are configured to be basically balanced, and meanwhile the grid connection point transmission power before sectionalization is sent to an inverter; a grid connection point breaker is stably cut off, the output power of the inverter is maintained as the grid connection point transmission power before the sectionalization, and power can reach the balance immediately after the micro-grid becomes off-grid. When the switchover is not planned, the micro-grid is sectionalized with the electric system suddenly to form an island, the load or the partial power branch circuit is cut within 10ms according to the difference between currents before the sectionalization of a grid connection point and the maximum output power of an energy storing inverter, and the stability of the system switchover moment is ensured; the energy storing inverter with the maximum capacity is immediately transferred into V/F control, and other power sources are set to be P/Q control. According to the method, the micro-grid connection can be smoothly switched over to the island state.
Description
Technical field
The present invention relates to stable control method when a kind of micro-grid connection switches to island state, belong to technical field of electric power system control.
Background technology
Micro-capacitance sensor has two kinds of operational modes, and under normal circumstances, micro-capacitance sensor to be connected with power distribution network by PCC point and to be incorporated into the power networks, and carries out Power Exchange with power distribution network; When detecting that Voltage Drop, fault or interruption maintenance appear in power distribution network, micro-capacitance sensor initiatively disconnects with power distribution network and enters islet operation pattern, and micro battery is independent powers to the load in micro-capacitance sensor.
Accordingly, micro-capacitance sensor has four kinds of running statuses: two kinds of steady operational status: the state that is incorporated into the power networks and island operation state; Two kinds of transient state running statuses: grid-connected switching transient state and isolated island switch transient state.
The transient characterisitics of micro-capacitance sensor are comparatively complicated, closely related with the distributed power source characteristic of its inside, part throttle characteristics, energy-storage system characteristic.Such as, the natural energy resources non-scheduling of photovoltaic, this class of wind power generation, and this kind of generating is different from conventional electric generators, its output is this class power electronic equipment of inverter, this just determines wind, light generating micro-grid system lacks inertia, is unfavorable for system stable operation.The natural energy resources micro-capacitance sensor of independent operating can to configure the energy storage of certain capacity.In addition, micro-capacitance sensor, when being incorporated into the power networks with electric power system, also interacting with electric power system, directly affects the stability of micro-capacitance sensor and electric power system.Therefore, the stable operation of micro-capacitance sensor needs perfect stabilizing control system.
Micro-capacitance sensor is stable main in the past regulates (calling in the following text from master control) by inverter itself, and inverter, by acquisition system electric parameters, finds electric parameters change, judges that micro-grid load fluctuation or unexpected and electric power system disconnect.Micro-grid load fluctuation or suddenly and electric power system disconnect, namely there is unplanned isolated island, in order to maintain micro-capacitance sensor voltage, frequency, need an energy storage inverter to make an immediate response the change of micro-capacitance sensor operational mode, for micro-grid system provides the reference value of voltage and frequency, and balance the meritorious and idle supply and demand in micro-capacitance sensor inside simultaneously.
From the shortcoming of master control be:
1, control hysteresis.Inverter is by acquisition system electric parameters, and when judging that micro-capacitance sensor electric parameters changes, micro-capacitance sensor runs under unbalanced power state, and has presented the parameters such as P, V, Q, f to unstable future development, and this control is delayed.
2, response speed cannot ensure micro-grid system stability.Determine response from measurement, the time that inverter realizes exporting adjustment is approximately 100ms.When also site Power Exchange is larger, micro-capacitance sensor and electric power system disconnect suddenly, and the imbalance of its power can cause within a few tens of milliseconds, and micro-capacitance sensor just loses stable.
Therefore, the regulation and control maintenance micro-capacitance sensor only by inverter is stablized, and is not perfect solution.
Summary of the invention
The technical problem that the present invention solves is: propose a kind of micro-capacitance sensor stable control method, can control in real time, realize grid-connected taking over seamlessly to island state to micro-capacitance sensor state variation.
In order to solve the grid-connected technical problem switched to plan island state, one of technical scheme that the present invention proposes is that stable control method when a kind of micro-grid connection switches to island state plan, comprises the following steps:
A) when micro-capacitance sensor is in and is incorporated into the power networks state, by the load fluctuation of electric power system tracking balance, the preferential use micro-capacitance sensor energy;
B) micro-capacitance sensor receives grid-connected after isolated island switching command, before micro-capacitance sensor and electric power system off-the-line, the collection of micro-capacitance sensor stabilizing control system site power, configuration generators and loads makes it in a basic balance, before sending off-the-line to energy storage inverter and the transmission power of site simultaneously;
C) steadily grid-connected point breaker is cut off, the power output of described energy storage inverter is made to remain the front also site transmission power of described off-the-line, micro-capacitance sensor reaches balance immediately from the rear power of net, realize micro-capacitance sensor and the steady off-the-line of electric power system, thus complete micro-capacitance sensor and switch from the state of being incorporated into the power networks to the plan of island operation state.
The further improvement of one of technique scheme is: configuring the method that generators and loads makes it in a basic balance in step b) is: before piconet controller sends off-the-line to energy storage inverter and the power of site, it is before described off-the-line and site power that order energy storage inverter increases power, configuration generators and loads, makes both balances; If energy storage inverter has reached maximum power and can not meet that to increase power be before described off-the-line and site power, then cut-out load, by reducing load power, power supply and load balancing are made.
In order to solve the technical problem that unplanned island state switches, two of the technical scheme that the present invention proposes is: a kind of micro-capacitance sensor, is comprised the following steps to stable control method during unplanned isolated island switching by grid-connected:
1) when micro-capacitance sensor is in and is incorporated into the power networks state, by the load fluctuation of electric power system tracking balance, the preferential use micro-capacitance sensor energy;
2) micro-capacitance sensor suddenly with electric power system off-the-line and form isolated island, according to and the difference of trend before the off-the-line of site and energy storage inverter Maximum Power Output, at the inline cutting load of 10ms or cut away independent power source branch road, guarantee systematic evaluation stability instantaneously;
3) energy storage inverter arranging heap(ed) capacity transfers V/F immediately to and controls, and sets up voltage and the frequency of micro-capacitance sensor;
4) arranging other power supplys is that P/Q controls, and namely completes the unplanned switching of micro-grid connection to isolated island.
The further improvement of technique scheme two is: step 4) complete after, by regulate energy storage inverter and load power balance, corrective system enters lonely net steady operation.
Improving further again of technique scheme two is: adopt the unplanned isolated island of islanding detect, judgment technology active detecting to occur.
The beneficial effect that the present invention brings is: the present invention by micro-capacitance sensor and and the data acquisition and processing (DAP) of site electric parameters, can the state variation of anticipation micro-capacitance sensor, realize the real-time control to micro-capacitance sensor state variation, thus realize micro-grid connection taking over seamlessly to isolated island.Compared with prior art, fast response time of the present invention, can realize real-time power output balance when plan switches; Adopt the unplanned isolated island of islanding detect, judgment technology active detecting to occur during unplanned switching, power output balance can be realized in 10ms.
Embodiment
Embodiment one
The present embodiment is the stable control method of micro-grid connection when switching to island state plan, and if the through-put power of site is Pc, energy storage inverter power output is Ppcs, comprises the following steps:
A) when micro-capacitance sensor is in and is incorporated into the power networks state, by the load fluctuation of electric power system tracking balance, the preferential use micro-capacitance sensor energy;
B) micro-capacitance sensor receives grid-connected after isolated island switching command, before micro-capacitance sensor and electric power system off-the-line, the collection of micro-capacitance sensor stabilizing control system site power, configuration generators and loads makes it in a basic balance, before sending off-the-line to energy storage inverter and the transmission power of site simultaneously;
Configuring the method that generators and loads makes it in a basic balance in the present embodiment is: gather and site power P c(set flow out microgrid as on the occasion of, during inflow microgrid, power is negative value), piconet controller to send before off-the-line and site transmission power Pc to energy storage inverter, order energy storage inverter increases Gong and Shuais ⊿ Ppcs=Pc, configuration generators and loads, makes both balances; If energy storage inverter has reached maximum power and can not meet and increase Gong and Shuai ⊿ Ppcs=Pc, then cut-out load, by reducing load power, power supply and load balancing are made;
C) steadily grid-connected point breaker is cut off, the power output of described inverter is made to remain the front also site transmission power of described off-the-line, micro-capacitance sensor reaches balance immediately from power after net, realizes micro-capacitance sensor and the steady off-the-line of electric power system, thus completes micro-grid connection and switch to the plan of isolated island.
Embodiment two
The present embodiment be micro-capacitance sensor by grid-connected switch to unplanned isolated island time stable control method, comprise the following steps:
1) when micro-capacitance sensor is in and is incorporated into the power networks state, by the load fluctuation of electric power system tracking balance, the preferential use micro-capacitance sensor energy.
2) micro-capacitance sensor suddenly with electric power system off-the-line and form isolated island, according to and the difference of trend before the off-the-line of site and energy storage inverter Maximum Power Output, at the inline cutting load of 10ms or cut away independent power source branch road, guarantee systematic evaluation stability instantaneously.
The present embodiment adopts the unplanned isolated island of islanding detect, judgment technology active detecting to occur.
3) energy storage inverter arranging heap(ed) capacity transfers V/F immediately to and controls, and sets up voltage and the frequency of micro-capacitance sensor.
4) arranging other power supplys is that P/Q controls, and namely completes the unplanned switching of micro-grid connection to isolated island.
The present embodiment is in step 4) complete after, by regulate energy storage inverter and load power balance, in 10ms, corrective system enters isolated island steady operation.
Micro-capacitance sensor stable control method of the present invention is not limited to the concrete technical scheme described in above-described embodiment, and all employings are equal to replaces the protection range that the technical scheme formed is application claims.
Claims (5)
1. stable control method when micro-grid connection switches to island state plan, comprises the following steps:
A), when micro-capacitance sensor is in and is incorporated into the power networks state, fluctuated by electric power system tracking, balanced load, the preferential use micro-capacitance sensor energy;
B) micro-capacitance sensor receives grid-connected after isolated island switching command, before micro-capacitance sensor and electric power system off-the-line, and the collection of micro-capacitance sensor stabilizing control system site power, configuration generators and loads makes it in a basic balance, before sending off-the-line to energy storage inverter and the power of site simultaneously;
C) steadily grid-connected point breaker is cut off, the power output of described energy storage inverter is made to remain the front also site power of described off-the-line, micro-capacitance sensor reaches balance immediately from power after net, realizes micro-capacitance sensor and the steady off-the-line of electric power system, thus completes micro-grid connection and switch to the plan of isolated island.
2. stable control method when micro-grid connection according to claim 1 switches to island state plan, it is characterized in that, configuring the method that generators and loads makes it in a basic balance in step b) is: before piconet controller sends off-the-line to energy storage inverter and the power of site, it is before described off-the-line and site power that order energy storage inverter increases power, configuration generators and loads, makes both balances; If energy storage inverter has reached maximum power and can not meet that to increase power be before described off-the-line and site power, then cut-out load, by reducing load power, power supply and load balancing are made.
3. stable control method when micro-grid connection switches to island state is unplanned, comprises the following steps:
1) when micro-capacitance sensor is in and is incorporated into the power networks state, by the load fluctuation of electric power system tracking balance, the preferential use micro-capacitance sensor energy;
2) micro-capacitance sensor suddenly with electric power system off-the-line and form isolated island, according to and the difference of trend before the off-the-line of site and energy storage inverter Maximum Power Output, at the inline cutting load of 10ms or cut away independent power source branch road, guarantee systematic evaluation stability instantaneously;
3) energy storage inverter arranging heap(ed) capacity transfers V/F immediately to and controls, and sets up voltage and the frequency of micro-capacitance sensor;
4) arranging other power supplys is that P/Q controls, and namely completes the unplanned switching of micro-grid connection to isolated island.
4. micro-grid connection according to claim 3 to island state unplanned switch time stable control method, it is characterized in that: step 4) complete after, by regulate energy storage inverter and load power balance, corrective system enters isolated island steady operation.
5. stable control method when micro-grid connection according to claim 3 switches to island state is unplanned, is characterized in that: adopt the unplanned isolated island of islanding detect, judgment technology active detecting to occur.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310509652.3A CN103595052B (en) | 2013-10-25 | 2013-10-25 | Method for stably controlling switchover from micro-grid connection into island state |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310509652.3A CN103595052B (en) | 2013-10-25 | 2013-10-25 | Method for stably controlling switchover from micro-grid connection into island state |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103595052A CN103595052A (en) | 2014-02-19 |
| CN103595052B true CN103595052B (en) | 2015-07-01 |
Family
ID=50085087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310509652.3A Expired - Fee Related CN103595052B (en) | 2013-10-25 | 2013-10-25 | Method for stably controlling switchover from micro-grid connection into island state |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103595052B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103795084B (en) * | 2014-02-24 | 2015-11-18 | 国电南瑞科技股份有限公司 | The one-touch grid-connected net that leaves of micro-capacitance sensor takes over seamlessly control method |
| CN107112761B (en) | 2014-11-04 | 2019-07-26 | Abb瑞士股份有限公司 | Control method and system for micro-capacitance sensor |
| CN106786592B (en) * | 2017-01-13 | 2023-01-24 | 全球能源互联网研究院有限公司 | Island switching control method and device suitable for flexible direct current transmission system |
| CN109842148A (en) * | 2018-02-01 | 2019-06-04 | 大全集团有限公司 | A kind of micro-grid connection turns the stable control method of isolated operation mode |
| CN110336315B (en) * | 2019-06-04 | 2023-03-03 | 深圳供电局有限公司 | Isolated network operation control system for local power grid of receiving-end city |
| CN111628525B (en) * | 2020-05-29 | 2022-03-08 | 辽宁工业大学 | Switching system-based micro-grid dual-mode stable control method |
| CN112165116B (en) * | 2020-09-18 | 2022-06-28 | 广东电网有限责任公司韶关供电局 | Handling method and device for small hydropower system with unplanned island effect |
| CN114123181A (en) * | 2021-11-24 | 2022-03-01 | 许继集团有限公司 | Mode switching control method and device for power distribution network flexible loop closing device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102496956A (en) * | 2011-11-25 | 2012-06-13 | 北京金风科创风电设备有限公司 | Mode switching method for switching grid-connected mode to island mode of microgrid |
| CN102497010A (en) * | 2011-12-19 | 2012-06-13 | 天津市电力公司 | Method and system for switching microgrid from grid-connected mode to island mode |
| EP2615710A1 (en) * | 2012-01-10 | 2013-07-17 | DG ECOENERGY S.a.s. di Diego Federico Giannuzzi & C. | Circuit and method for accumulating energy produced by renewable sources. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0888978A (en) * | 1994-09-14 | 1996-04-02 | Nissin Electric Co Ltd | Method of detecting single operation of distributed power supply system |
-
2013
- 2013-10-25 CN CN201310509652.3A patent/CN103595052B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102496956A (en) * | 2011-11-25 | 2012-06-13 | 北京金风科创风电设备有限公司 | Mode switching method for switching grid-connected mode to island mode of microgrid |
| CN102497010A (en) * | 2011-12-19 | 2012-06-13 | 天津市电力公司 | Method and system for switching microgrid from grid-connected mode to island mode |
| EP2615710A1 (en) * | 2012-01-10 | 2013-07-17 | DG ECOENERGY S.a.s. di Diego Federico Giannuzzi & C. | Circuit and method for accumulating energy produced by renewable sources. |
Non-Patent Citations (3)
| Title |
|---|
| Operation of a prototype microgrid system based on micro-sources equipped with fast-acting power electronics interfaces;D.Georgakis et al.;《2004 35th Annual IEEE Power Electronics Specialists Conference》;20041231;第2521-2526页 * |
| 基于储能的微网并网和孤岛运行模式平滑切换综合控制策略;赵冬梅等;《电网技术》;20130228;第37卷(第2期);第301-306页 * |
| 基于复合储能的微电网运行模式平滑切换控制;刘志文等;《电网技术》;20130430;第37卷(第4期);第906-913页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103595052A (en) | 2014-02-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103595052B (en) | Method for stably controlling switchover from micro-grid connection into island state | |
| CN105552962B (en) | Micro-grid system and its control method | |
| CN102570489A (en) | Dynamic power coordination control method for battery energy storage system | |
| CN104052078B (en) | Micro-grid connection operational mode switches regulate and control method and the system of islet operation pattern | |
| TWI774142B (en) | Ac load power supply system and method | |
| CN102931662B (en) | Distributive load dynamic regulation-based microgrid monitoring system and control method | |
| CN103560538A (en) | Microgrid protection and switchover integrated control method based on storing energy at PCC | |
| Katiraei et al. | Planned islanding on rural feeders—utility perspective | |
| US20200136540A1 (en) | Method for supplying electric power by means of a converter-controlled generator unit, in particular a wind turbine | |
| CN106842946B (en) | Load emergency adjusting method and device under AGC mode of thermal power generating unit | |
| CN111987723A (en) | Micro-grid operation control method | |
| CN104065104A (en) | Micro grid rapid grid connection method based on three-phase independent regulation | |
| Zhang et al. | Hierarchical coordinated control of DC microgrid with wind turbines | |
| Kumar et al. | A review on microgrids with distributed energy resources | |
| CN104578084A (en) | Dynamic reactive compensating mechanism and AVC (Automatic Voltage Control) combined control system | |
| CN110544938A (en) | Low-voltage microgrid grid-connected and off-grid control method containing battery and super capacitor | |
| CN105244900B (en) | A kind of micro-capacitance sensor off-network energy equilibrium control method based on shift frequency control | |
| JP7311564B2 (en) | Intelligent switch device and power generation system | |
| CN112448418A (en) | Water and electricity microgrid and power adjusting method thereof | |
| CN104078982A (en) | Method for switching from grid-connected operation mode to off-network operation mode of microgrid based on load control | |
| Li et al. | Control and protection system design of zhangbei VSC-HVDC grid | |
| CN111682588A (en) | Microgrid system control method and microgrid system controller | |
| CN115378031A (en) | Low-voltage distributed photovoltaic metering and collecting system and control method | |
| CN109494800B (en) | Control method and system for mutual switching between grid connection and grid disconnection of micro-grid | |
| CN110445158B (en) | Energy storage power station system based on multi-network integration and transient control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| 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: 20150701 Termination date: 20171025 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |