CN105529737B - Grid disconnection device and method - Google Patents
Grid disconnection device and method Download PDFInfo
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- CN105529737B CN105529737B CN201511004942.8A CN201511004942A CN105529737B CN 105529737 B CN105529737 B CN 105529737B CN 201511004942 A CN201511004942 A CN 201511004942A CN 105529737 B CN105529737 B CN 105529737B
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- threshold value
- frequency
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- voltage
- grid
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Classifications
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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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
Abstract
The present invention provides a kind of grid disconnection device, for being electrically connected to power grid and power generation end, including electrical network parameter detecting unit and controller.The electrical network parameter detecting unit is used to detect the voltage parameter and frequency parameter of the power grid；The controller is used for the voltage parameter that detects according to the electrical network parameter detecting unit and frequency parameter to judge whether isolated network occurs, and by the power generation end and the grid disconnection after isolated network generation.The present invention also provides a kind of grid disconnection methods.Above-mentioned grid disconnection device and method, can be when there is unfavorable condition in power grid by the voltage and frequency of detecting power grid, quick off-the-line power generation terminal group.
Description
Technical field
The present invention relates to technical field of power generation more particularly to a kind of grid disconnection device and methods.
Background technique
In the power system, a large amount of medium and small-scale water and electricity factories pass through 10kV route access power grid, are herein collectively referred to as small power supply.
Small power supply is since installed capacity is small, and device configuration is mostly relatively simple, and 10kV only has disconnecting link to connect with system in side, no configuration open circuit
Device, relay protection scheme aspect only has overvoltage protection, after line tripping of surfing the Internet, if occurring higher fortune in isolated power grid
Row voltage then disconnects the side generator 380V switch, and the off-the-line as unit is protected.In the area that small power supply is concentrated, power station is most
The access way in 10kV route is all connect using T, it is conllinear with power load.When power station generates electricity, it need to be lifted voltage, Cai Nengbao step by step
Card electric energy is sent outside, especially long transmission line, and the voltage of line end is higher, when night, power load was lighter, user's voltage mistake
High phenomenon becomes apparent.Based on the above reasons, the protection circuit being mounted in power station be easy to cause malfunction, and generator is sent
Electric switch disconnects, and affects normal power generation, it is all that protection circuit is out of service to lead to most of power station, or protected definite value
It is set as very high voltage value.It is therefore desirable to propose a kind of follow-on IGBT protection circuit to overcome drawbacks described above.
Summary of the invention
The object of the present invention is to provide a kind of grid disconnection device, off-the-line unit reliability is high, movement is quick,
System normal operating voltage will not malfunction when higher.
Another object of the present invention is to provide a kind of grid disconnection method, off-the-line unit reliability is high, movement is fast
Speed will not be malfunctioned when system normal operating voltage is higher.
To achieve the goals above, the present invention provides a kind of grid disconnection device, for being electrically connected to power grid and power generation end,
Including electrical network parameter detecting unit and controller.The electrical network parameter detecting unit be used for detect the power grid voltage parameter and
Frequency parameter；The controller is used for the voltage parameter that detects according to the electrical network parameter detecting unit and frequency parameter to sentence
Whether disconnected isolated network occurs, and by the power generation end and the grid disconnection after isolated network generation.
Preferably, the controller is provided with first voltage threshold value and first frequency threshold value, and the controller is used in institute
Voltage parameter is stated greater than the first voltage threshold value and when the frequency parameter is greater than the first frequency threshold value, by the power generation
End and the grid disconnection.
Preferably, the controller is additionally provided with second voltage threshold value and second frequency threshold value, and the controller is used for
The voltage parameter is greater than the second voltage threshold value and when the frequency parameter is greater than the second frequency threshold value, by the hair
Electric end and the grid disconnection；Wherein, the first voltage threshold value is greater than the second voltage threshold value, the first frequency threshold value
Less than the second frequency threshold value.
Preferably, the controller is additionally provided with tertiary voltage threshold value, and the controller is used for big in the voltage parameter
When the tertiary voltage threshold value, by the power generation end and the grid disconnection；Wherein, the tertiary voltage threshold value is greater than described
First voltage threshold value.
Preferably, the controller is additionally provided with third frequency threshold, and the controller is used for big in the frequency parameter
When the third frequency threshold, by the power generation end and the grid disconnection；Wherein, the third frequency threshold is greater than described
Second frequency threshold value.
To achieve the goals above, the present invention also provides a kind of grid disconnection methods, are used in electric power networks, the electric power
Network includes power grid and power generation end.The grid disconnection method is the following steps are included: detect the voltage parameter and frequency of the power grid
Rate parameter；Judge whether isolated network occurs according to the voltage parameter detected and frequency parameter, and will after isolated network generation
The power generation end and the grid disconnection.
Preferably, the voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and
Include: with the step of grid disconnection by the power generation end after isolated network generation
Whether the voltage parameter detected described in judgement is greater than first voltage threshold value and the frequency parameter detected is
It is no to be greater than first frequency threshold value, and be greater than the first voltage threshold value in the voltage parameter detected and described detect
When frequency parameter is greater than the first frequency threshold value, by the power generation end and the grid disconnection.
Preferably, the voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and
The step of after isolated network generation by the power generation end and the grid disconnection further include:
Whether the voltage parameter detected described in judgement is greater than second voltage threshold value and the frequency parameter detected is
It is no to be greater than second frequency threshold value, and be greater than the second voltage threshold value in the voltage parameter detected and described detect
When frequency parameter is greater than the second frequency threshold value, by the power generation end and the grid disconnection；Wherein, the first voltage threshold
Value is greater than the second voltage threshold value, and the first frequency threshold value is less than the second frequency threshold value.
Preferably, the voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and
The step of after isolated network generation by the power generation end and the grid disconnection further include:
Whether the voltage parameter detected described in judgement is greater than tertiary voltage threshold value, and in the voltage parameter detected
When greater than the tertiary voltage threshold value, by the power generation end and the grid disconnection；Wherein, the tertiary voltage threshold value is greater than institute
State first voltage threshold value.
Preferably, the voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and
The step of after isolated network generation by the power generation end and the grid disconnection further include:
Whether the frequency parameter detected described in judgement is greater than third frequency threshold, and in the frequency parameter detected
When greater than the third frequency threshold, by the power generation end and the grid disconnection；Wherein, the third frequency threshold is greater than institute
State second frequency threshold value.
Beneficial effects of the present invention: the present invention provides a kind of grid disconnection device and method, be configured with overfrequency overvoltage protection,
Overvoltage protection, overfrequency protection, has combined reliability, rapidity, sensitivity, a variety of bad feelings can occurs in power grid
When condition, quick off-the-line power generation terminal group, while can be to avoid off-the-line protection misoperation.
For further understanding of the features and technical contents of the present invention, it please refers to below in connection with of the invention detailed
Illustrate and attached drawing, however, the drawings only provide reference and explanation, is not intended to limit the present invention.
Detailed description of the invention
Fig. 1 is the module map of grid disconnection device in an embodiment of the present invention；
Fig. 2 is the module map of grid disconnection device in another embodiment of the present invention
The flow chart of grid disconnection method in Fig. 3 an embodiment of the present invention.
Specific embodiment
Further to illustrate technological means and its effect adopted by the present invention, below in conjunction with preferred implementation of the invention
Example and its attached drawing are described in detail.
Fig. 1 is the module map of grid disconnection device 100 in an embodiment of the present invention.Grid disconnection device 100 can make
With in electric power networks, electric power networks include power grid 200 and power generation end 300, and power generation end 300 can be medium and small-scale water and electricity factory, fire
Power grid 200, if 10kV line tripping, grid disconnection device at this time are generally accessed by 10kV route in power plant etc., power generation end 300
100 can be used as the off-the-line protection at power generation end 300.In the present embodiment, grid disconnection device 100 is electrically connected to power grid
200 include electrical network parameter detecting unit 10 and controller 20 with power generation end 300, grid disconnection device 100.Electrical network parameter detecting is single
Member 10 is for detecting the voltage parameter and frequency parameter of power grid 200；Controller 20 according to electrical network parameter detecting unit 10 for detecing
The voltage parameter and frequency parameter that measure judges whether isolated network occurs, and by power generation end 300 and power grid 200 after isolated network generation
Off-the-line.In the present embodiment, isolated network phenomenon refers to jumps when breaking when the power supply of power grid 200 because of failure accident or power failure maintenance due to, hair
Electric end 300 fails to detect isolated network state in time, and then fails to cut off power grid 200 in time, is formed and is born by power generation end 300 and surrounding
The isolated network of a self-energizing of composition is carried, isolated network will damage the personal safety of power equipment or operations staff, and
Influence power supply quality.Electric power networks to work as by internal grid disconnection device 100 detects that the failure jump of power grid 200 is disconnected
When, in time by power generation end 300 and 200 off-the-line of power grid, so that the personal safety to power equipment or operations staff be avoided to cause to hurt
Evil.
In an embodiment of the present invention, controller 20 is provided with first voltage threshold value and first frequency threshold value, controller
20 voltage parameter for detecting in electrical network parameter detecting unit 10 is greater than first voltage threshold value and frequency parameter is greater than first
When frequency threshold, by power generation end 300 and 200 off-the-line of power grid.When electric power networks operate normally, even if overtension, due to power grid
200 frequency maintains power frequency 50Hz, and grid disconnection device 100 will not malfunction.When the tripping of power grid 200 forms isolated network, electricity
Pressure is raised simultaneously with frequency, and grid disconnection device 100 just acts, by this kind of voltage and frequency simultaneously compared with setting, raising
The reliability of off-the-line protection.
As a further refinement of the present invention, controller 20 is additionally provided with second voltage threshold value and second frequency threshold value.
The voltage parameter that controller 20 is also used to detect in electrical network parameter detecting unit 10 is greater than second voltage threshold value and frequency parameter
When greater than second frequency threshold value, by power generation end 300 and 200 off-the-line of power grid.Wherein, first voltage threshold value is greater than second voltage threshold
Value, first frequency threshold value are less than second frequency threshold value.Electric power networks pass through setting two-part overfrequency overvoltage protection, one of mistake
Its voltage threshold of frequency overvoltage protection is higher, frequency threshold is lower, focuses on off-the-line rapidity, its voltage of another overfrequency overvoltage protection
Threshold value is lower, frequency threshold is higher, focuses on off-the-line sensitivity.
As a further refinement of the present invention, controller 20 is additionally provided with tertiary voltage threshold value, controller 20 is also used to
When the voltage parameter that electrical network parameter detecting unit 10 detects is greater than tertiary voltage threshold value, power generation end 300 is solved with power grid 200
Column.Wherein, tertiary voltage threshold value is greater than first voltage threshold value, and tertiary voltage threshold value is also greater than first voltage threshold value.For example,
Since the variation of frequency depends on the revolving speed of power generation 300 hydraulic turbine of end, when the tripping of power grid 200 forms isolated power grid, voltage wink
Between rise, but frequency cannot be mutated, and rising for frequency need to pass through certain delay, therefore depend merely on overfrequency overvoltage protection, controller
20 can not quickly disconnect power generation end 300 switch after the tripping of power grid 200 inhibits overvoltage, therefore the serious overvoltage the case where
Under, the electrical equipment of user terminal is also possible that damage.Controller 20 is by setting one than first voltage threshold value and the second electricity
The tertiary voltage threshold value for pressing threshold value high, so that ustomer premises access equipment, which can escape electric power networks, operates normally the excessively high height electricity occurred
Pressure, when serious overvoltage occurs in isolated network, although frequency parameter is not above preset threshold at this time, grid disconnection device 100 is same
It can be quickly by power generation end 300 and 200 off-the-line of power grid.
As a further refinement of the present invention, controller 20 is additionally provided with third frequency threshold, controller 20 is also used to
When the frequency parameter that electrical network parameter detecting unit 10 detects is greater than third frequency threshold, power generation end 300 is solved with power grid 200
Column.Wherein, third frequency threshold is greater than second frequency threshold value, and third frequency threshold is also greater than first frequency threshold value.For example,
When the tripping of power grid 200 forms isolated power grid, under conditions of water power power output is balanced with power load, overvoltage will not be generated,
Although will not directly contribute the damage of user terminal electrical equipment at this time, voltage, frequency are constantly fluctuated during isolated power grid, power supply
Quality is lower, while also will affect the movement of route checkout voltage reclosing, and controller 20 passes through one ratio first of setting at this time
Frequency threshold and the high third frequency threshold of second frequency threshold value, grid disconnection device 100 equally can be quickly by the end that generates electricity
300 with 200 off-the-line of power grid, create conditions for reclosing checkout voltage, shorten the time that electric power networks restore electricity.
Please refer to Fig. 2, as a further refinement of the present invention, grid disconnection device 100 further includes man-machine interface
30, the parameter information and control command that can be used to set required for inputting.In the other embodiments of invention, man-machine interface
30 can also be used to the operating status of real-time display electric power networks.
Further, in order to meet the convenience that grid disconnection device 100 is installed, hardware design of the invention can be direct
In the generator control cabinet at power generation end 300, specification is consistent with the measurement meter of cabinet internal standard of existing generator, designs ruler
It is very little to may is that length × wide × depth=116mm × 120mm × 88mm；Mounting means is installation by adhering, and mounting opening size can be with
Be: length × wide=110mm*110mm, aperture are preferably square hole.
Fig. 3 is the flow chart of grid disconnection method in an embodiment of the present invention.The grid disconnection method can be used in
In grid disconnection device 100.In the present embodiment, grid disconnection method is the following steps are included: S100, detects the voltage of power grid
Parameter and frequency parameter；S102, judges whether isolated network occurs according to the voltage parameter and frequency parameter that detect, and in isolated network
By power generation end and grid disconnection after generation.Specifically, the voltage ginseng of power grid can be detected by electrical network parameter detecting unit 10
Several and frequency parameter, while can judge that isolated network is according to the voltage parameter and frequency parameter that detect by controller 20
No generation, and by power generation end and grid disconnection after isolated network generation.
As the further improvement to step S102, controller 20 judges whether the voltage parameter detected is greater than the first electricity
Whether pressure threshold value and the frequency parameter detected are greater than first frequency threshold value, and are greater than first voltage in the voltage parameter detected
When threshold value and the frequency parameter detected are greater than first frequency threshold value, by power generation end and grid disconnection.
As the further improvement to step S102, controller 20 judges whether the voltage parameter detected is greater than the second electricity
Whether pressure threshold value and the frequency parameter detected are greater than second frequency threshold value, and are greater than second voltage in the voltage parameter detected
When threshold value and the frequency parameter detected are greater than second frequency threshold value, by power generation end and grid disconnection.Wherein, first voltage threshold value
Greater than second voltage threshold value, first frequency threshold value is less than second frequency threshold value.
As the further improvement to step S102, controller 20 judges whether the voltage parameter detected is greater than third electricity
Threshold value is pressed, and when the voltage parameter arrived is greater than tertiary voltage threshold value, by power generation end and grid disconnection.Wherein, third electricity
It presses threshold value to be greater than first voltage threshold value and is greater than second voltage threshold value.
As the further improvement to step S102, controller 20 judges whether the frequency parameter detected is greater than third frequency
Rate threshold value, and when the frequency parameter detected is greater than third frequency threshold, by power generation end and grid disconnection.Wherein, third frequency
Rate threshold value is greater than first frequency threshold value and is greater than second frequency threshold value.
In conclusion grid disconnection device and method provided by the invention, is configured with overfrequency overvoltage protection, overvoltage is protected
Shield, overfrequency protection, has combined reliability, rapidity, sensitivity, can be when a variety of unfavorable conditions occurs in power grid, fastly
Fast off-the-line power generation terminal group, while can be to avoid off-the-line protection misoperation.
The above for those of ordinary skill in the art can according to the technique and scheme of the present invention and technology
Other various corresponding changes and modifications are made in design, and all these change and modification all should belong to the claims in the present invention
Protection scope.
Claims (2)
1. a kind of grid disconnection device, for being electrically connected to power grid and power generation end characterized by comprising electrical network parameter detecting
Unit, for detecting the voltage parameter and frequency parameter of the power grid；Controller, for according to the electrical network parameter detecting unit
The voltage parameter and frequency parameter detected judges whether isolated network occurs, and after isolated network generation by the power generation end with it is described
Grid disconnection；The controller is provided with first voltage threshold value and first frequency threshold value, and the controller is used in the voltage
Parameter is greater than the first voltage threshold value and when the frequency parameter is greater than the first frequency threshold value, by the power generation end and institute
State grid disconnection；The controller is additionally provided with second voltage threshold value and second frequency threshold value, and the controller is used for described
Voltage parameter is greater than the second voltage threshold value and when the frequency parameter is greater than the second frequency threshold value, by the power generation end
With the grid disconnection；Wherein, the first voltage threshold value is greater than the second voltage threshold value, and the first frequency threshold value is less than
The second frequency threshold value；The controller is additionally provided with tertiary voltage threshold value, and the controller is used in the voltage parameter
When greater than the tertiary voltage threshold value, by the power generation end and the grid disconnection；Wherein, the tertiary voltage threshold value is greater than institute
State first voltage threshold value；The controller is additionally provided with third frequency threshold, and the controller is used for big in the frequency parameter
When the third frequency threshold, by the power generation end and the grid disconnection；Wherein, the third frequency threshold is greater than described
Second frequency threshold value.
2. a kind of grid disconnection method is used in electric power networks, the electric power networks include power grid and power generation end, and feature exists
In the grid disconnection method is the following steps are included: detect the voltage parameter and frequency parameter of the power grid；According to the detecting
To voltage parameter and frequency parameter judge whether isolated network occurs, and by the power generation end and the power grid after isolated network generation
Off-the-line；Judge whether isolated network occurs according to the voltage parameter detected and frequency parameter, and by institute after isolated network generation
The step of stating power generation end and the grid disconnection includes: whether the voltage parameter detected described in judgement is greater than first voltage threshold value
And whether the frequency parameter detected is greater than first frequency threshold value, and is greater than described the in the voltage parameter detected
When one voltage threshold and the frequency parameter detected are greater than the first frequency threshold value, by the power generation end and the power grid
Off-the-line；The voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and after the isolated network generation
The step of by the power generation end and the grid disconnection further include: whether the voltage parameter detected described in judgement is greater than the second electricity
It presses threshold value and whether the frequency parameter detected is greater than second frequency threshold value, and be greater than in the voltage parameter detected
When the second voltage threshold value and the frequency parameter detected are greater than the second frequency threshold value, by the power generation end and institute
State grid disconnection；Wherein, the first voltage threshold value is greater than the second voltage threshold value, and the first frequency threshold value is less than described
Second frequency threshold value；The voltage parameter detected according to and frequency parameter judge whether isolated network occurs, and in orphan
The step of after net generation by the power generation end and the grid disconnection further include: whether the voltage parameter detected described in judgement is big
In tertiary voltage threshold value, and when the voltage parameter detected is greater than the tertiary voltage threshold value, by the power generation end and
The grid disconnection；Wherein, the tertiary voltage threshold value is greater than the first voltage threshold value；The electricity detected according to
Parameter and frequency parameter is pressed to judge whether isolated network occurs, and by the power generation end and the grid disconnection after isolated network generation
Step further include: whether the frequency parameter detected described in judgement is greater than third frequency threshold, and in the frequency detected
When parameter is greater than the third frequency threshold, by the power generation end and the grid disconnection；Wherein, the third frequency threshold is big
In the second frequency threshold value.
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| CN106410796A (en) * | 2016-11-22 | 2017-02-15 | 新奥泛能网络科技股份有限公司 | Method for separating generator set from grid and measuring and controlling device |
| CN108631319A (en) * | 2018-05-29 | 2018-10-09 | 广东电网有限责任公司 | Off-the-line method, apparatus and equipment |
| CN110429608A (en) * | 2019-08-19 | 2019-11-08 | 广东电网有限责任公司 | A kind of network system and its disconnection device and Splitting Control |
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| CN103956766A (en) * | 2013-12-27 | 2014-07-30 | 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 | Distributed-power-supply connection measurement and control and protection all-in-one machine and method |
| CN104467024A (en) * | 2014-12-31 | 2015-03-25 | 国家电网公司 | Islanding detection system and method for inverter power source |
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| CN102183733B (en) * | 2011-03-07 | 2013-06-05 | 河海大学 | Photovoltaic grid connected inverter island detection method for improving quality of electric energy |
| CN102324741B (en) * | 2011-08-17 | 2013-10-16 | 国家电网公司 | Micro-power grid off-grid energy balance and control device and method |
| CN102355002A (en) * | 2011-08-28 | 2012-02-15 | 大连中隆新能源科技有限公司 | Device and system for protecting islanding effect in isolated-type grid-connected power generation |
| CN104716651B (en) * | 2013-12-12 | 2017-02-01 | 国家电网公司 | Low-frequency reactive power disturbance island detection method for photovoltaic grid-connected inverter |
| CN104218618B (en) * | 2014-10-09 | 2016-04-13 | 南京磐能电力科技股份有限公司 | A kind of adjustment control method of micro-capacitance sensor stable operation of master-slave control mode |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103956766A (en) * | 2013-12-27 | 2014-07-30 | 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 | Distributed-power-supply connection measurement and control and protection all-in-one machine and method |
| CN104467024A (en) * | 2014-12-31 | 2015-03-25 | 国家电网公司 | Islanding detection system and method for inverter power source |
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