CN107681688B - Grid-connected converter with VSG (voltage source generator) characteristics and island judgment method and device thereof - Google Patents
Grid-connected converter with VSG (voltage source generator) characteristics and island judgment method and device thereof Download PDFInfo
- Publication number
- CN107681688B CN107681688B CN201710855172.0A CN201710855172A CN107681688B CN 107681688 B CN107681688 B CN 107681688B CN 201710855172 A CN201710855172 A CN 201710855172A CN 107681688 B CN107681688 B CN 107681688B
- Authority
- CN
- China
- Prior art keywords
- voltage
- grid
- disturbance
- vsg
- positive
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 30
- 230000005284 excitation Effects 0.000 claims description 3
- 238000004422 calculation algorithm Methods 0.000 description 10
- 238000005516 engineering process Methods 0.000 description 7
- 238000001514 detection method Methods 0.000 description 4
- 230000001360 synchronised effect Effects 0.000 description 4
- 238000013016 damping Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011217 control strategy Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000012850 discrimination method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Images
Classifications
-
- 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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention relates to a grid-connected converter with VSG characteristics and an island distinguishing method and device thereof. The invention can quickly identify the islanding phenomenon, and the voltage for disturbance each time is very small, thereby not influencing the stability and reliability of the power grid system.
Description
Technical Field
The invention belongs to the technical field of intelligent power grids, and particularly relates to a grid-connected converter with VSG characteristics and an island judgment method and device thereof.
Background
With the continuous increase of the permeability of the distributed power supply, the rotating reserve capacity and the rotational inertia in the power system are relatively reduced, which brings a serious challenge to the safe and stable operation of the power grid. In recent years, Virtual Synchronous Generator (VSG) technology has become a research hotspot for scholars at home and abroad. The VSG technology essentially implants the droop characteristic, the inertia characteristic and the damping characteristic of the traditional synchronous generator into the control strategy of the grid-connected converter, so that the VSG technology can participate in voltage regulation and frequency modulation of a power grid, avoids rapid change of voltage and frequency and system oscillation under the disturbance condition, and has the power grid friendly characteristic and the networking characteristic of the converter.
In the prior art, a conventional grid-connected converter generally adopts power control or direct current control, the active island judgment of the conventional grid-connected converter basically adopts methods of frequency shift, power disturbance or harmonic injection and the like for the output of a grid-connected inverter, and such detection methods are all directed at a current control type grid-connected converter.
After the grid-connected converter based on the VSG technology is disconnected from the power grid, the characteristic of the voltage source is still kept, the voltage and the frequency are kept stable, and the island judgment is invalid due to the fact that the existing detection method for introducing disturbance such as frequency shift or power cannot break the balance of the voltage or the frequency in the power grid, so that an active island judgment method is needed for island detection of the converter with the VSG characteristics.
Disclosure of Invention
The invention aims to provide a grid-connected converter with VSG characteristics and an island distinguishing method and device thereof, which are used for solving the problem that the existing active island detection technology cannot detect that the grid-connected converter with VSG characteristics has an island.
In order to solve the technical problem, the invention provides a grid-connected converter island judgment method with VSG characteristics, which comprises the following steps:
after the grid-connected converter with the VSG characteristic is connected to the grid, continuous positive or negative voltage disturbance is carried out on the voltage of the power grid side, the voltage value of the power grid side after each positive or negative voltage disturbance is used as a given reference value of the output voltage of the grid-connected converter, the voltage condition of the power grid side after each positive or negative voltage disturbance is detected, and when the voltage of the power grid side after the continuous positive voltage disturbance is larger than a set first voltage threshold value or when the voltage of the power grid side after the continuous negative voltage disturbance is smaller than a set second voltage threshold value, islanding is judged.
Further, when the voltage of the power grid side after the continuous disturbance of the positive voltage or the negative voltage is recovered to the voltage in the normal operation state, it is determined that the island does not occur.
Further, before grid connection, the grid-connected converter with the VSG characteristic also comprises a step of pre-synchronizing grid connection adjustment of the amplitude difference and the phase difference between the output side voltage of the grid-connected converter and the grid side voltage.
In order to solve the above technical problem, the present invention further provides a grid-connected converter island determination device with VSG characteristics, including the following units:
a disturbance unit: after the grid-connected converter with the VSG characteristic is connected to the grid, continuous positive or negative voltage disturbance is carried out on the voltage of the power grid side, and the voltage value of the power grid side after each positive or negative voltage disturbance is used as a given reference value of the output voltage of the grid-connected converter;
a comparison unit: the voltage comparison module is used for comparing the collected power grid side voltage after each positive voltage disturbance with a set first voltage threshold value, or comparing the collected power grid side voltage after each negative voltage disturbance with a set second voltage threshold value;
a judging unit: and when the grid-side voltage after the continuous disturbance of the positive voltage is greater than a first voltage threshold value or when the grid-side voltage after the continuous disturbance of the negative voltage is less than a second voltage threshold value, judging that the islanding occurs.
Further, the device further comprises a unit for judging that the islanding does not occur when the grid side voltage after the continuous disturbance of the positive voltage or the negative voltage is recovered to the voltage in the normal operation state.
The device further comprises a unit for performing pre-synchronization grid connection adjustment on the amplitude difference and the phase difference between the output side voltage of the grid-connected converter and the grid side voltage.
In order to solve the above technical problem, the present invention further provides a grid-connected converter with VSG characteristics, including a converter main circuit and a control system, wherein the control system includes an excitation controller and an island determination module, and the island determination module includes the following units:
a disturbance unit: after the grid-connected converter with the VSG characteristic is connected to the grid, continuous positive or negative voltage disturbance is carried out on the voltage of the power grid side, and the voltage value of the power grid side after each positive or negative voltage disturbance is used as a given reference value of the output voltage of the grid-connected converter;
a comparison unit: the voltage comparison module is used for comparing the collected power grid side voltage after each positive voltage disturbance with a set first voltage threshold value, or comparing the collected power grid side voltage after each negative voltage disturbance with a set second voltage threshold value;
a judging unit: and when the grid-side voltage after the continuous disturbance of the positive voltage is greater than a first voltage threshold value or when the grid-side voltage after the continuous disturbance of the negative voltage is less than a second voltage threshold value, judging that the islanding occurs.
Further, the island determination module further comprises a unit for determining that an island does not occur when the grid-side voltage after the continuous disturbance of the positive or negative voltage is restored to the voltage in the normal operation state.
Further, the island judgment module further comprises a unit for performing pre-synchronization grid connection adjustment on the amplitude difference and the phase difference between the output side voltage of the grid-connected converter and the grid side voltage before the grid-connected converter with the VSG characteristics is connected to the grid.
The invention has the beneficial effects that: the invention aims at a grid-connected converter with a VSG technology, adopts a voltage disturbance method at the grid side to carry out small-amplitude positive voltage disturbance or negative voltage disturbance on the voltage of a power grid, uses the disturbed voltage as a given reference value of the output voltage of the grid-connected converter, and judges that an island is generated when the voltage at the grid side after the voltage continuous disturbance is greater than a first voltage threshold value or less than a second voltage threshold value. The invention can quickly identify the islanding phenomenon, and the voltage for disturbance each time is very small, thereby not influencing the stability and reliability of the power grid system.
Drawings
FIG. 1 is a general architecture diagram of a grid-connected converter with VSG characteristics connected to a power grid;
FIG. 2 is a block diagram of a control algorithm implemented by the present invention;
FIG. 3 is a flow chart of an implementation of the active island determination method of the present invention;
fig. 4 is a simulation diagram of the island determination method of the present invention.
Detailed Description
The following further describes embodiments of the present invention with reference to the drawings.
As shown in fig. 1, the VSG mainly includes a converter main circuit and a control system. The main circuit of the converter is a conventional grid-connected inverter topology and comprises a direct-current side voltage source (generally, light storage, wind storage and the like which can be regarded as a prime mover), a DC/AC converter and the like (corresponding to the electric energy conversion process of a synchronous generator), wherein the DC/AC converter comprises a current conversion link and a filtering link of the converter; the control system is the core for realizing the VSG and mainly comprises a control algorithm, a pre-synchronization algorithm and an active island discrimination algorithm.
Control Algorithm As shown in FIG. 2, virtual excitationThe magnetic controller, the virtual speed regulator and the inertial damping link belong to a VSG control algorithm, and respectively output a voltage amplitude reference value E*And phase theta0The phase difference and the amplitude difference between the voltage at the output side of the converter and the voltage at the power grid side are adjusted to be within a small range through an amplitude and phase adjusting unit, then switching-on and grid-connection are carried out, after grid-connection is carried out, the voltage at the power grid side and the voltage at the output side of the converter are sent to an active island judging module, and after the island judging module carries out island judgment through the island judging method, the active island judging module is finally sent to a voltage and current double closed loop to carry out PWM control.
The flow of the grid-connected converter island distinguishing method (i.e. the control algorithm) with the VSG characteristics of the invention is shown in FIG. 3, and comprises the following steps:
step one, initializing relevant parameters: including the nominal frequency f involved in the VSG control algorithmNRated voltage E0Initial active power P0Reactive power QNInertia J and damping parameters D, and phase difference threshold ξ related to presynchronization and island discrimination methodθVoltage difference threshold ξuPhase adjustment step size stepPHeta, voltage adjustment step size stepU, actual phase difference adjustment quantity d theta, actual amplitude difference adjustment quantity dU and voltage minimum threshold value UminAnd disturbance step size and the like.
Step two, the grid-connected converter with VSG characteristics needs to be pre-synchronized before grid connection, and the amplitude difference and the phase difference between the output side voltage of the grid-connected converter and the grid side voltage are adjusted, specifically as follows:
as shown in figure 1, a switch K2 is closed, K1 and K3 are opened, the grid-connected converter runs in an idle mode, and three-phase voltage U on the side of a power grid is collectedgabcThree-phase voltage U at the output side of the converterabcObtaining the given voltage amplitude E and the given voltage phase theta of the output side of the converter after the VSG control algorithm0Reading the amplitude U obtained after the voltage at the power grid side passes through the phase-locked loopdgAnd phase thetagDefining the amplitude difference and the phase difference between the output side voltage of the converter and the side voltage of the power grid, wherein the calculation formula is as follows:
in the formula of UrefoutIn order to carry out output voltage peak value of VSG under disturbance on a power grid, delta U is the amplitude difference between the output side voltage of the converter and the side voltage of the power grid, delta theta is the phase difference between the output side voltage of the converter and the side voltage of the power grid, dU is an adjustable amplitude difference variable, d theta is an adjustable phase difference variable, wherein the initial values of d theta and dU are set to be 0, and theta is the phase of the output side voltage of the converter.
The presynchronization algorithm, shown in FIG. 3, compares whether the absolute value of Δ θ is less than or equal to a set phase difference threshold ξθWhether the absolute value of Δ U is less than or equal to the set voltage difference threshold ξuAnd correcting the actual amplitude difference regulating variable dU and the actual phase difference regulating variable d theta:
in the formula, stepTHeta is phase adjustment step length, stepU is voltage adjustment step length, sign1 and sign2 are correction coefficients, the values are respectively 1, -1 or 0, and when delta theta is more than ξθWhen sign1 is 1, when delta theta is less than- ξθWhen sign1 is-1, and | Δ θ | ≦ ξθWhen the sign1 is 0, when the delta U is more than ξuWhen sign2 is 1, when Δ U < ξuWhen sign2 is-1, and | Δ U ≦ ξuWhen sign2 is 0.
After the amplitude difference adjustment variable dU and the phase adjustment difference variable d theta are continuously corrected, when the absolute value of delta theta is less than or equal to the set phase difference threshold ξθThe absolute value of Δ U is less than or equal to the set voltage difference threshold ξuWhen the pre-synchronization is finished, the closing grid-connected condition is met, the grid-connected switch K1 can be closed at any time, the non-impact grid connection can be realized after the K1 is closed, and then the load switch K3 is closed to operate with load.
Step three, the island judgment process after the converter is connected to the grid is as follows: the voltage amplitude U of the power grid sidedgThe step size is reduced, i.e. a negative perturbation is performed (in fact a positive perturbation may be performed, here described as a negative perturbation), wherein the step is set to a very small value(e.g., set to 0.02V or other small value), the disturbed value is used as a given reference value of the converter output side voltage, and the calculation formula is:
Urefout＝Udg-step
in the formula, the grid voltage is reduced by step, namely, one-time negative disturbance is carried out, the disturbed value is used as the voltage reference amplitude value of the output side of the converter, the disturbance is continuously and circularly carried out, and then the program continuously reads the grid voltage U during the next disturbancedgIf the power grid is normally connected, UdgRemain unchanged (even if there is a fluctuation in the grid voltage, then UdgWill also be within the normal range); if the power grid is disconnected, the three-phase voltage at the power grid side is the three-phase voltage at the output side of the converter due to the loss of the power grid support, and the voltage amplitude value U of the three-phase voltage isdg＝UrefoutTo U, to UdgWill cause U to be generatedrefoutIs always reduced when U isrefoutLess than the voltage minimum threshold UminIn time, the islanding phenomenon can be distinguished.
The invention belongs to a new active island distinguishing method, which aims at a grid-connected converter with VSG technology, the active island distinguishing method is that the grid voltage is subjected to self-disturbance, and the disturbance mode can be the continuous disturbance of the negative voltage or the continuous disturbance of the positive voltage, which is provided by the embodiment, and the difference is that: when the power grid is in an isolated island, a negative voltage disturbance mode is applied to enable the voltage value of the power grid side to be continuously reduced, and when the voltage value is reduced to the lowest voltage threshold value UminWhen the voltage value of the power grid side is increased to a set voltage threshold value, the island is judged to be generated; when the power grid is not in an island state, no matter the voltage on the power grid side is subjected to negative voltage disturbance or positive voltage disturbance continuously, the voltage on the power grid side is recovered to the normal operation voltage. The invention gives the given value of the output voltage of the converter to the voltage value after disturbance on the power grid side, the disturbance value is very small, the stability of the system is basically not influenced, and the method has obvious effect and can quickly identify the islanding phenomenon.
The invention also provides a grid-connected converter island judgment device with the VSG characteristic and a grid-connected converter with the VSG characteristic. The grid-connected converter island distinguishing device with the VSG characteristic comprises the following three units:
a disturbance unit: after the grid-connected converter with the VSG characteristic is connected to the grid, continuously carrying out positive or negative voltage disturbance on the voltage of the power grid side, and taking the voltage value of the power grid side after each positive or negative voltage disturbance as a given reference value of the output voltage of the grid-connected converter;
a comparison unit: the voltage comparison module is used for comparing the collected power grid side voltage after each positive voltage disturbance with a set first voltage threshold value, or comparing the collected power grid side voltage after each negative voltage disturbance with a set second voltage threshold value;
a judging unit: and when the grid-side voltage after the continuous disturbance of the positive voltage is greater than a first voltage threshold value or when the grid-side voltage after the continuous disturbance of the negative voltage is less than a second voltage threshold value, judging that the islanding occurs.
The grid-connected converter with the VSG feature is a DC/AC converter in the VSG shown in fig. 1, a hardware structure of the grid-connected converter is the prior art, a control system of the grid-connected converter with the VSG feature includes an excitation controller, a voltage-current double closed loop and an island determination module, and three units included in the island determination module are the same as three units included in a grid-connected converter island determination device with the VSG feature.
The grid-connected converter island distinguishing device with the VSG characteristics is a computer solution based on the method flow, namely a software framework, and can be applied to a VSG control system, and the device is a processing process corresponding to the method flow. Similarly, the island judgment module in the grid-connected converter with the VSG characteristics is also a processing process corresponding to the method flow. The method is described clearly and completely, and the grid-connected converter island distinguishing device and the grid-connected converter island distinguishing module are actually a software framework, so that the detailed description is omitted.
Claims (9)
1. A grid-connected converter island distinguishing method with VSG characteristics is characterized by comprising the following steps:
after the grid-connected converter with the VSG characteristic is connected to the grid, continuously carrying out positive or negative voltage disturbance on the voltage of a power grid side, taking the voltage value of the power grid side after each positive or negative voltage disturbance as a given reference value of the output voltage of the grid-connected converter, detecting the voltage condition of the power grid side after each positive or negative voltage disturbance, and judging that an island occurs when the voltage of the power grid side after the continuous disturbance of the positive voltage is greater than a set first voltage threshold value or when the voltage of the power grid side after the continuous disturbance of the negative voltage is less than a set second voltage threshold value;
and the positive or negative voltage disturbance is to increase or decrease the voltage amplitude of the power grid side by step, wherein the step is a set value.
2. The grid-connected converter island judgment method with the VSG characteristic as claimed in claim 1, wherein when the grid-side voltage after the continuous disturbance of the positive or negative voltage is recovered to the voltage in the normal operation state, it is judged that an island is not generated.
3. The method for judging the island of the grid-connected converter with the VSG characteristics according to claim 1, wherein before grid connection of the grid-connected converter with the VSG characteristics, the method further comprises a step of performing pre-synchronization grid connection adjustment on the amplitude difference and the phase difference between the output side voltage of the grid-connected converter and the grid side voltage.
4. The utility model provides a grid-connected converter island discriminating gear who possesses VSG characteristic which characterized in that includes the following unit:
a disturbance unit: after the grid-connected converter with the VSG characteristic is connected to the grid, continuous positive or negative voltage disturbance is carried out on the voltage of the power grid side, and the voltage value of the power grid side after each positive or negative voltage disturbance is used as a given reference value of the output voltage of the grid-connected converter;
a comparison unit: the voltage comparison module is used for comparing the collected power grid side voltage after each positive voltage disturbance with a set first voltage threshold value, or comparing the collected power grid side voltage after each negative voltage disturbance with a set second voltage threshold value;
a judging unit: the island judgment method comprises the steps that when the grid side voltage after the continuous disturbance of the positive voltage is larger than a first voltage threshold value or when the grid side voltage after the continuous disturbance of the negative voltage is smaller than a second voltage threshold value, the island is judged to occur;
and the positive or negative voltage disturbance is to increase or decrease the voltage amplitude of the power grid side by step, wherein the step is a set value.
5. The device for judging the islanding of the grid-connected converter with the VSG characteristics as claimed in claim 4, further comprising a unit for judging that no islanding occurs when the grid-side voltage is restored to the voltage in the normal operation state after the continuous disturbance of the positive or negative voltage.
6. The grid-connected converter island determination device with the VSG characteristic as claimed in claim 4, further comprising a unit for performing pre-synchronization grid-connection adjustment on the amplitude difference and the phase difference between the output-side voltage and the grid-side voltage of the grid-connected converter.
7. The utility model provides a grid-connected converter that possesses VSG characteristic, includes converter main circuit and control system, and wherein, control system includes excitation controller, its characterized in that, control system still includes island judgement module, island judgement module includes following unit:
a disturbance unit: after the grid-connected converter with the VSG characteristic is connected to the grid, continuous positive or negative voltage disturbance is carried out on the voltage of the power grid side, and the voltage value of the power grid side after each positive or negative voltage disturbance is used as a given reference value of the output voltage of the grid-connected converter;
a comparison unit: the voltage comparison module is used for comparing the collected power grid side voltage after each positive voltage disturbance with a set first voltage threshold value, or comparing the collected power grid side voltage after each negative voltage disturbance with a set second voltage threshold value;
a judging unit: the island judgment method comprises the steps that when the grid side voltage after the continuous disturbance of the positive voltage is larger than a first voltage threshold value or when the grid side voltage after the continuous disturbance of the negative voltage is smaller than a second voltage threshold value, the island is judged to occur;
and the positive or negative voltage disturbance is to increase or decrease the voltage amplitude of the power grid side by step, wherein the step is a set value.
8. The grid-connected converter with VSG characteristics of claim 7, wherein the islanding determination module further comprises a unit for determining that islanding is not occurring when the grid-side voltage is restored to a voltage in a normal operation state after the continuous disturbance of the positive or negative voltage.
9. The grid-connected converter with the VSG characteristic of claim 7, wherein the island determination module further comprises a unit for performing pre-synchronization grid-connection adjustment on an amplitude difference and a phase difference between an output-side voltage and a grid-side voltage of the grid-connected converter before the grid-connected converter with the VSG characteristic is connected to the grid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2017103588305 | 2017-05-19 | ||
| CN201710358830 | 2017-05-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107681688A CN107681688A (en) | 2018-02-09 |
| CN107681688B true CN107681688B (en) | 2020-08-11 |
Family
ID=61136003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710855172.0A Active CN107681688B (en) | 2017-05-19 | 2017-09-20 | Grid-connected converter with VSG (voltage source generator) characteristics and island judgment method and device thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107681688B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108242815B (en) * | 2018-03-30 | 2024-03-08 | 华北电力科学研究院有限责任公司 | Fan energy storage coordination frequency modulation system and method for fan power drop complement |
| CN109672207B (en) * | 2018-12-04 | 2022-06-14 | 国网江苏省电力有限公司电力科学研究院 | Back-to-back system control method and system based on virtual synchronous machine |
| CN113765137A (en) | 2020-06-03 | 2021-12-07 | 台达电子企业管理（上海）有限公司 | Control method and device of three-phase alternating current system |
| CN113759184B (en) | 2020-06-03 | 2024-09-24 | 台达电子企业管理（上海）有限公司 | Island detection method and device for inverter |
| CN117805541B (en) * | 2024-02-29 | 2024-05-03 | 西安千帆翼数字能源技术有限公司 | Island detection method, protection method and related device of energy storage converter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104767219A (en) * | 2015-03-27 | 2015-07-08 | 国家电网公司 | Household grid-connected inverter control strategy based on virtual synchronous generator |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102420435A (en) * | 2010-09-26 | 2012-04-18 | 武汉理工大学 | Adaptive island detection method for grid-connected photovoltaic power generation system |
| CN102412592A (en) * | 2011-10-09 | 2012-04-11 | 山亿新能源股份有限公司 | Island detection method and system for photovoltaic grid-connected power generation system |
| JP5957094B2 (en) * | 2012-12-27 | 2016-07-27 | 川崎重工業株式会社 | Combined power generation system with power conversion device |
| CN105606921A (en) * | 2015-11-26 | 2016-05-25 | 国家电网公司 | Negative sequence voltage positive feedback-based islanding detection system and method |
-
2017
- 2017-09-20 CN CN201710855172.0A patent/CN107681688B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104767219A (en) * | 2015-03-27 | 2015-07-08 | 国家电网公司 | Household grid-connected inverter control strategy based on virtual synchronous generator |
Non-Patent Citations (2)
| Title |
|---|
| 光伏微网主动式孤岛检测方法综述;余运俊 等;《电测与仪表》;20140110;第51卷(第1期);第22-29页 * |
| 基于自适应负序电压正反馈的孤岛检测方法;王雪 等;《电力自动化设备》;20161231;第36卷(第12期);第26-42页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107681688A (en) | 2018-02-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107681688B (en) | Grid-connected converter with VSG (voltage source generator) characteristics and island judgment method and device thereof | |
| CN110970933B (en) | Active support control-based virtual inertia compensation method for light-storage combined power generation system | |
| CN110212513B (en) | Flexible virtual capacitor control method for stabilizing voltage fluctuation of direct-current micro-grid bus | |
| Lin et al. | Overview of frequency-control technologies for a VSC-HVDC-integrated wind farm | |
| CN113193598B (en) | New energy grid-connected inverter transient stability margin evaluation method | |
| CN104935006A (en) | High voltage ride through control method | |
| Khan et al. | Analytical review on common and state-of-the-art FR strategies for VSC-MTDC integrated offshore wind power plants | |
| CN109842150A (en) | Control method based on virtual synchronous machine low voltage crossing | |
| CN109873458A (en) | A kind of method of adjustment and device of reactive current reference value and watt current reference value | |
| CN113824146A (en) | Wind turbine transient characteristic improving method based on wind storage integration | |
| CN113517715B (en) | Wind power generation grid-connected system transient stability control method based on automatic current adjustment | |
| CN115051404A (en) | Alternating voltage control method of high-voltage network-building type current converter | |
| CN111525605B (en) | Photovoltaic system low voltage ride through method and system based on variable power output control | |
| CN107046296B (en) | MPPT-based adaptive island detection algorithm | |
| CN102064559A (en) | Wind driven generator converter featuring high voltage redundency | |
| CN112421651A (en) | System power balancing method and device in low-voltage ride through process of photovoltaic inverter | |
| CN104218605A (en) | Non-impact-current grid connection method for three-phase voltage source grid-connected inverters | |
| Meng et al. | A two-stage frequency response method for DFIGs under variable wind speeds | |
| CN117856324A (en) | Micro-grid black start control method of voltage-supported optical storage station | |
| CN113852099A (en) | Quick frequency response control system and method for direct-drive wind turbine generator | |
| Alosaimi et al. | Pv system control as statcom with svm-based islanding detection | |
| Xu et al. | A New Adaptive Frequency Control Strategy for VSG Based on Grid Forming Converter of Renewable Energy | |
| CN105375490A (en) | Energy-saving power transmission voltage compensation method | |
| CN111193274A (en) | Inertia response control method and device for high-voltage direct-current power transmission system | |
| CN117578536B (en) | Network-structured energy storage control method and system for weak alternating current system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |