WO2021098595A1 - 孤岛扰动方法、系统及终端设备 - Google Patents

孤岛扰动方法、系统及终端设备 Download PDF

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Publication number
WO2021098595A1
WO2021098595A1 PCT/CN2020/128585 CN2020128585W WO2021098595A1 WO 2021098595 A1 WO2021098595 A1 WO 2021098595A1 CN 2020128585 W CN2020128585 W CN 2020128585W WO 2021098595 A1 WO2021098595 A1 WO 2021098595A1
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Prior art keywords
value
disturbance
difference
islanding
preset
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PCT/CN2020/128585
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English (en)
French (fr)
Inventor
刘富广
张惠珍
许林毅
谢程洲
曾立钊
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科华恒盛股份有限公司
漳州科华技术有限责任公司
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Publication of WO2021098595A1 publication Critical patent/WO2021098595A1/zh

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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

Definitions

  • This application relates to the technical field of power grid protection, in particular to an island disturbance method, system and terminal equipment.
  • the islanding effect refers to an effect in which the grid-connected photovoltaic power generation system still maintains the power supply status of adjacent parts of the power grid when the grid suddenly loses voltage.
  • the island will damage the safety of the public and the maintenance personnel of the power company and the quality of power supply.
  • the power supply switch is automatically or manually reclosed to re-power the island grid, it may damage the equipment. Therefore, island protection is very necessary.
  • islanding disturbance protection is generally performed by over-frequency protection or under-frequency protection of the grid frequency for islanding protection, but different national standards require different time for over-frequency or under-frequency protection.
  • national standards and En50438 standards require islanding.
  • the protection time is 2 seconds.
  • the British G83/G99 standard requires the islanding protection time to be 0.5 seconds. This method of islanding disturbance only by frequency cannot meet the requirements of islanding protection time in different countries.
  • the embodiments of the present application provide an islanding disturbance method, system, and terminal equipment to solve the problem that in the prior art, the method of islanding disturbance that only relies on frequency cannot meet the requirements of islanding protection time in different countries.
  • the first aspect of the embodiments of the present application provides an islanding disturbance method, including:
  • the initial phase disturbance is determined according to the current acquisition period value and the last acquisition period value, and the final phase is determined according to the initial phase disturbance and the increase in the initial phase disturbance.
  • the amount of disturbance is the amount of disturbance.
  • determining the direction of islanding disturbance and the amount of initial phase disturbance according to the current grid frequency and the grid rated frequency includes:
  • the initial phase disturbance is determined to be the negative value of the preset initial disturbance.
  • the islanding disturbance method further includes:
  • the islanding disturbance direction is determined to be non-directional, and the initial phase disturbance value is determined to be the preset initial disturbance value The negative value of.
  • the increase in the initial phase disturbance amount is determined according to the current capture period value and the last capture period value, including:
  • the third difference is greater than the preset period threshold, it is determined that the increase in the initial phase disturbance amount is a negative value of the preset increase, and the current capture period value is used as the new last capture period value.
  • the islanding disturbance method further includes:
  • the second difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency;
  • the islanding disturbance method After calculating the difference value obtained by subtracting the previous capture period value from the current capture period value, and recording the difference value as the third difference value, the islanding disturbance method also includes:
  • the third difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency.
  • the islanding disturbance method further includes:
  • the increase in the initial phase disturbance is determined to be the preset increase, and the current capture period value is used as the new last capture period value, including:
  • the filtered second difference is greater than the preset period threshold, determining the increase in the initial phase disturbance amount as the preset increase, and taking the current capture period value as the new last capture period value;
  • the islanding disturbance method After calculating the difference value obtained by subtracting the previous capture period value from the current capture period value, and recording the difference value as the third difference value, the islanding disturbance method also includes:
  • the third difference is greater than the preset period threshold, it is determined that the increase in the initial phase disturbance amount is the negative value of the preset increase, and the current capture period value is used as the new last capture period value, including:
  • the filtered third difference is greater than the preset period threshold, it is determined that the increase in the initial phase perturbation amount is a negative value of the preset increase, and the current capture period value is used as the new last capture period value.
  • the preset period threshold C is:
  • ⁇ 0 is the initial phase disturbance
  • f c is the CPU frequency of the DSP of the inverter
  • f 0 is the rated frequency of the grid.
  • an island disturbance system including:
  • the islanding disturbance direction determination module is used to obtain the current grid frequency, and determine the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency;
  • the period value acquisition module is used to obtain the current capture period value and the last capture period value
  • the phase disturbance amount determination module is configured to determine the increase amount of the initial phase disturbance amount according to the current capture period value and the last capture period value if the islanding disturbance direction is a positive direction or a negative direction, and The final phase disturbance amount is determined according to the initial phase disturbance amount and the increase amount of the initial phase disturbance amount.
  • the third aspect of the embodiments of the present application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and running on the processor.
  • the processor executes the computer program as follows The steps of the islanding disturbance method described in the first aspect.
  • the fourth aspect of the embodiments of the present application provides a computer-readable storage medium.
  • the computer-readable storage medium stores a computer program.
  • the implementation is as in the first aspect The steps of the islanding disturbance method.
  • This application provides an islanding disturbance method, system and terminal equipment. Firstly, the current grid frequency is obtained, and the direction of islanding disturbance and the initial phase disturbance are determined according to the current grid frequency and the rated frequency of the grid, and then the current capture period value and the previous value are obtained. Capture period value. If the islanding disturbance direction is positive or negative, determine the increase of the initial phase disturbance according to the current capture cycle value and the last capture cycle value, and according to the initial phase disturbance and the increase of the initial phase disturbance The final phase disturbance is determined by the amount of phase disturbance.
  • the embodiment of the present application adds the acquisition period value protection on the basis of the phase positive feedback islanding disturbance, and no longer depends on frequency for protection, which can meet the requirements of islanding protection time in different countries.
  • FIG. 1 is a schematic diagram of an implementation process of an islanding disturbance method provided by an embodiment of the present application
  • FIG. 2 is a schematic diagram of an implementation process of an islanding disturbance method provided by another embodiment of the present application.
  • FIG. 3 is a schematic diagram of the difference between the current capture period value and the last period capture value provided by an embodiment of the present application;
  • FIG. 4 is a schematic diagram of island protection time provided by an embodiment of the present application.
  • FIG. 5 is a schematic diagram of island protection time provided by another embodiment of the present application.
  • Fig. 6 is a schematic block diagram of an island disturbance system provided by an embodiment of the present application.
  • FIG. 7 is a schematic block diagram of a terminal device provided by an embodiment of the present application.
  • FIG. 1 is a schematic diagram of the implementation process of the islanding disturbance method provided by an embodiment of the present application. For ease of description, only the parts related to the embodiment of the present application are shown.
  • the execution subject of the embodiment of the present application may be a terminal device. As shown in Figure 1, the method may include the following steps:
  • S101 Obtain the current grid frequency, and determine the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency.
  • the current grid frequency is the current grid frequency; if the current grid is in an abnormal state, that is, an islanding effect occurs, the current grid frequency is the current inverse Change the output frequency.
  • the current grid frequency is obtained without disturbance, and the islanding disturbance direction and the initial phase disturbance amount are determined according to the current grid frequency and the grid rated frequency.
  • the rated frequency of the power grid is 50Hz; the direction of island disturbance can include positive direction, negative direction and no direction.
  • step S101 may include the following steps:
  • the initial phase disturbance is determined to be the negative value of the preset initial disturbance.
  • the difference obtained by subtracting the rated frequency of the grid from the current grid frequency is recorded as the first difference.
  • the preset frequency value may be 0.02 Hz, and correspondingly, the negative value of the preset frequency value is -0.02 Hz.
  • the preset initial disturbance amount may be 0.002 ⁇ , and correspondingly, the negative value of the preset initial disturbance amount is -0.002 ⁇ .
  • the value of the preset initial disturbance amount is determined through experimental tests.
  • the islanding disturbance method may further include:
  • the islanding disturbance method may further include:
  • the islanding disturbance method may further include the following steps:
  • the islanding disturbance direction is determined to be non-directional, and the initial phase disturbance value is determined to be the preset initial disturbance value The negative value of.
  • the capture period value is a CAP (capture) capture period value, which can be obtained according to the CAP phase lock.
  • the current capture period value is the value of the current capture period; the last capture period value is the value of the previous capture period adjacent to the current capture period.
  • S103 If the islanding disturbance direction is positive or negative, determine the increase in the initial phase disturbance according to the current capture period value and the last capture period value, and determine the increase in the initial phase disturbance and the initial phase disturbance The final amount of phase disturbance.
  • the increase in the initial phase disturbance can be determined according to the current capture period value and the last capture period value, and the initial phase disturbance is added to the initial phase disturbance increase to get The final amount of phase disturbance.
  • step S103 "if the islanding disturbance direction is positive or negative, the initial phase disturbance is determined according to the current capture period value and the previous capture period value)
  • the increase in "" can include the following steps:
  • the islanding disturbance direction is the positive direction
  • the difference obtained by subtracting the current capture period value from the last capture period value is calculated, and the difference value is recorded as the second difference value, and the step is continued. S202.
  • S202 If the second difference value is greater than the preset period threshold value, determine the increase amount of the initial phase disturbance amount as the preset increase amount, and use the current capture period value as the new last capture period value.
  • the second difference is compared with the preset period threshold; if the second difference is greater than the preset period threshold, positive feedback is entered, and it can be determined that the increase in the initial phase disturbance is the preset increase. At this time, the current capture period value is taken as the new last capture period value.
  • the increase of the initial phase perturbation amount is the increased amount of phase perturbation on the basis of the initial phase perturbation amount.
  • the preset period threshold may be 400, and the preset period threshold is obtained through experimental data.
  • the preset increase amount can be 0.005 ⁇ , and this value can be determined through experimental tests.
  • the foregoing islanding disturbance method may further include:
  • the second difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency.
  • the magnitude of the second difference value and the preset period threshold value is compared; if the second difference value is less than or equal to the preset period threshold value, return to step S101 to continue execution, that is, re-determine the islanding disturbance direction.
  • the foregoing islanding disturbance method may further include:
  • step S202 may include:
  • the increase in the initial phase disturbance is determined to be the preset increase, and the current capture period value is used as the new last capture period value.
  • the preset time can be set according to actual needs, for example, it can be set to 10 power frequency cycles.
  • step S204 is continued.
  • the third difference is compared with the preset period threshold; if the third difference is greater than the preset period threshold, negative feedback is entered, and it can be determined that the increase in the initial phase disturbance is a negative value of the preset increase. At this time, the current capture period value is taken as the new last capture period value.
  • the preset increase amount may be 0.005 ⁇ , and correspondingly, the negative value of the preset increase amount may be -0.005 ⁇ .
  • the foregoing islanding disturbance method may further include:
  • the third difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency.
  • the third difference value is compared with the preset period threshold value; if the third difference value is less than or equal to the preset period threshold value, return to step S101 to continue execution, that is, re-determine the islanding disturbance direction.
  • the foregoing islanding disturbance method may further include:
  • step S204 may include:
  • the filtered third difference is greater than the preset period threshold, it is determined that the increase in the initial phase perturbation amount is a negative value of the preset increase, and the current capture period value is used as the new last capture period value.
  • the aforementioned islanding disturbance method further includes: superimposing the final phase disturbance amount on the reference angle obtained by phase locking.
  • the final phase disturbance amount ⁇ island is superimposed on the phase-locked reference angle ⁇ , that is, sin ( ⁇ + ⁇ island ).
  • the preset period threshold C is:
  • ⁇ 0 is the initial phase disturbance
  • f c is the frequency of the CPU (central processing unit, central processing unit) of the DSP (Digital Signal Processor) of the inverter
  • the inverter in the embodiment of the application may be a single-phase energy storage inverter
  • the DSP model of the single-phase energy storage inverter may be TMS320F28069
  • the embodiment of the present application adopts a comprehensive method of phase positive feedback islanding disturbance plus frequency period value protection for islanding protection.
  • the frequency exceeds a certain range, the phase disturbance is increased for positive feedback, which effectively breaks the frequency of the inverter output, thereby detecting the islanding state; and when the voltage amplitude and frequency change range are less than a certain value, the phase or frequency deviation
  • the frequency period value protection method can be used to successfully avoid the detection blind zone, quickly detect the islanding effect and protect it within the specified time.
  • the islanding disturbance method provided by the embodiments of the application is suitable for single-phase islanding disturbance.
  • the frequency is changed by changing the phase.
  • the phase change is affected by the phase-locked control loop, active power control, and reactive power control, resulting in
  • the logic of re-judging the direction of the islanding disturbance is entered; if the negative feedback is entered, the conditions of the negative feedback will also not be met, and the direction of re-judge the islanding disturbance
  • the logic is repeated in this way, as shown in Figure 3, resulting in an extended island protection time, as shown in Figure 4.
  • the reason why the positive feedback or negative feedback cannot be entered is that the initial phase disturbance is relatively small. If the initial phase disturbance is increased, the stability of the system will be affected.
  • a new type of islanding disturbance protection is proposed on the basis of phase positive feedback islanding disturbance, that is, the capture period value protection.
  • the protection is performed by judging the difference between the current capture period value and the last capture period value when the island is disturbed, instead of relying on frequency for protection. If the grid is normal at this time, the difference between the two is relatively small, and the angle of islanding disturbance will not affect the frequency of the grid. If it is in an islanding state at this time, due to the existence of initial disturbance, even if it does not enter positive feedback, the current capture period value The difference between the value of the previous capture period will also be relatively large. Therefore, a sliding filter of 10 power frequency cycles is performed on the difference between the two. After judging that the difference after filtering is greater than a certain fixed value C , the islanding protection achieves the standard requirement of islanding protection time within 0.5s.
  • Fig. 6 is a schematic block diagram of an island disturbance system provided by an embodiment of the present application. For ease of description, only parts related to the embodiment of the present application are shown.
  • the island disturbance system 60 may include an island disturbance direction determination module 601, a period value acquisition module 602, and a phase disturbance amount determination module 603.
  • the islanding disturbance direction determination module 601 is configured to obtain the current grid frequency, and determine the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency;
  • the period value obtaining module 602 is used to obtain the current capture period value and the last capture period value
  • the phase disturbance amount determining module 603 is configured to determine the increase amount of the initial phase disturbance amount according to the current capture period value and the last capture period value if the islanding disturbance direction is a positive direction or a negative direction, And the final phase disturbance amount is determined according to the initial phase disturbance amount and the increase amount of the initial phase disturbance amount.
  • the island disturbance direction determination module 601 may include a first difference calculation unit, a first island disturbance direction determination unit, and a second island disturbance direction determination unit;
  • the first difference calculation unit is used to calculate the difference obtained by subtracting the current grid frequency from the grid rated frequency, and record the difference as the first difference;
  • the first islanding disturbance direction determination unit is configured to determine that the islanding disturbance direction is a positive direction if the first difference is greater than the preset frequency value, and determine the initial phase disturbance amount as the preset initial disturbance amount;
  • the second islanding disturbance direction determination unit is configured to determine that the islanding disturbance direction is a negative direction if the first difference is less than the negative value of the preset frequency value, and determine that the initial phase disturbance is the negative value of the preset initial disturbance.
  • the island disturbance direction determination module 601 may further include a third island disturbance direction determination unit.
  • the third islanding disturbance direction determining unit is configured to determine that the islanding disturbance direction is non-directional if the first difference value is less than or equal to the preset frequency value, and the first difference value is greater than or equal to the negative value of the preset frequency value, and determining The initial phase disturbance is the negative value of the preset initial disturbance.
  • the phase disturbance amount determination module 603 may include a second difference value calculation unit, a first increase amount determination unit, a third difference value calculation unit, and a second increase amount determination unit.
  • the second difference calculation unit is configured to calculate the difference obtained by subtracting the current capture period value from the previous capture period value if the island disturbance direction is a positive direction, and record the difference as the second difference value;
  • the first increase determination unit is configured to determine the increase of the initial phase disturbance amount as the preset increase if the second difference is greater than the preset period threshold, and use the current capture period value as the new last capture period value ;
  • the third difference calculation unit is configured to calculate the difference obtained by subtracting the previous capture period value from the current capture period value if the island disturbance direction is a negative direction, and record the difference as the third difference value;
  • the second increase determination unit is configured to determine that the increase of the initial phase disturbance is the negative value of the preset increase if the third difference is greater than the preset period threshold, and use the current capture period value as the new last time Capture period value.
  • the phase disturbance amount determining module 603 may further include a first circulation unit and a second circulation unit.
  • the first circulation unit is used for if the second difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency ;
  • the second circulation unit is used for if the third difference is less than or equal to the preset period threshold, continue to perform the steps of obtaining the current grid frequency, and determining the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency.
  • the phase disturbance amount determining module 603 may further include a first filtering unit and a second filtering unit.
  • the first filtering unit is configured to perform sliding filtering on the second difference value for a preset time to obtain the filtered second difference value
  • the first increase determination unit is configured to determine the increase of the initial phase disturbance amount as the preset increase if the filtered second difference is greater than the preset period threshold, and use the current capture period value as the new The last capture period value;
  • the second filtering unit is configured to perform sliding filtering on the third difference for a preset time to obtain the filtered third difference
  • the second increase determination unit is configured to determine the increase of the initial phase disturbance amount as the preset increase if the filtered third difference is greater than the preset period threshold, and use the current capture period value as the new The value of the last capture period.
  • the foregoing preset period threshold C is:
  • ⁇ 0 is the initial phase disturbance
  • f c is the CPU frequency of the DSP of the inverter
  • f 0 is the rated frequency of the power grid.
  • FIG. 7 is a schematic block diagram of a terminal device provided by an embodiment of the present application.
  • the terminal device 70 of this embodiment includes: one or more processors 701, a memory 702, and a computer program 703 that is stored in the memory 702 and can run on the processor 701.
  • the steps in the above-mentioned island disturbance method embodiments are implemented, for example, steps S101 to S103 shown in FIG. 1.
  • the processor 701 executes the computer program 703 the functions of the modules/units in the embodiment of the island disturbance system are realized, for example, the functions of the modules 601 to 603 shown in FIG. 6.
  • the computer program 703 may be divided into one or more modules/units, and the one or more modules/units are stored in the memory 702 and executed by the processor 701 to complete This application.
  • the one or more modules/units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 703 in the terminal device 70.
  • the computer program 703 can be divided into an island disturbance direction determination module, a period value acquisition module, and a phase disturbance amount determination module.
  • the specific functions of each module are as follows:
  • the islanding disturbance direction determination module is used to obtain the current grid frequency, and determine the islanding disturbance direction and the initial phase disturbance amount according to the current grid frequency and the grid rated frequency;
  • the period value acquisition module is used to obtain the current capture period value and the last capture period value
  • the phase disturbance quantity determination module is used to determine the increase of the initial phase disturbance quantity according to the current capture period value and the last capture period value if the island disturbance direction is positive or negative direction, and according to the initial phase disturbance quantity and the initial phase The increase in the amount of disturbance determines the final amount of phase disturbance.
  • the terminal device 70 may be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server.
  • the terminal device 70 includes but is not limited to a processor 701 and a memory 702.
  • FIG. 7 is only an example of the terminal device 70, and does not constitute a limitation on the terminal device 70. It may include more or less components than those shown in the figure, or a combination of certain components, or different components. Components, for example, the terminal device 70 may also include an input device, an output device, a network access device, a bus, and so on.
  • the processor 701 may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), and application specific integrated circuits (Application Specific Integrated Circuits). Integrated Circuit, ASIC), Field Programmable Gate Array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.
  • the general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.
  • the memory 702 may be an internal storage unit of the terminal device 70, such as a hard disk or a memory of the terminal device 70.
  • the memory 702 may also be an external storage device of the terminal device 70, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), and a secure digital (Secure Digital, SD) equipped on the terminal device 70. Card, Flash Card, etc.
  • the memory 702 may also include both an internal storage unit of the terminal device 70 and an external storage device.
  • the memory 702 is used to store the computer program 703 and other programs and data required by the terminal device 70.
  • the memory 702 can also be used to temporarily store data that has been output or will be output.
  • the disclosed island disturbance system and method can be implemented in other ways.
  • the island disturbance system embodiment described above is only illustrative.
  • the division of the modules or units is only a logical function division.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.
  • the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • the above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.
  • the integrated module/unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium.
  • the present application implements all or part of the processes in the above-mentioned embodiments and methods, and can also be completed by instructing relevant hardware through a computer program.
  • the computer program can be stored in a computer-readable storage medium. When the program is executed by the processor, it can implement the steps of the foregoing method embodiments.
  • the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate forms.
  • the computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory) , Random Access Memory (RAM, Random Access Memory), electrical carrier signal, telecommunications signal, and software distribution media, etc.
  • ROM Read-Only Memory
  • RAM Random Access Memory
  • electrical carrier signal telecommunications signal
  • software distribution media etc.
  • the content contained in the computer-readable medium can be appropriately added or deleted according to the requirements of the legislation and patent practice in the jurisdiction.
  • the computer-readable medium Does not include electrical carrier signals and telecommunication signals.

Abstract

一种孤岛扰动方法、系统及终端设备，适用于电网保护技术领域，包括：获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量（S101）；获取当前捕获周期值和上一次的捕获周期值（S102）；若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并根据初始相位扰动量和初始相位扰动量的增加量确定最终相位扰动量（S103）。在相位正反馈式孤岛扰动的基础上增加了捕获周期值保护，不再依赖频率进行保护，能够满足不同国家的孤岛保护时间的要求。

Description

孤岛扰动方法、系统及终端设备
本申请要求于2019年11月22日提交中国专利局、申请号为2019111547700、发明名称为“孤岛扰动方法、系统及终端设备”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电网保护技术领域，特别是涉及一种孤岛扰动方法、系统及终端设备。
 背景技术
孤岛效应是指电网突然失压时，并网光伏发电系统仍保持对电网中的邻近部分线路供电状态的一种效应。孤岛会损害公众和电力公司维修人员的安全和供电的质量，在自动或手动重新闭合供电开关向孤岛电网重新供电时，有可能损坏设备。因此，孤岛保护是很有必要的。
目前，孤岛扰动的保护一般是通过电网频率的过频保护或者欠频保护来进行孤岛保护，但是不同的国家标准要求的过频或者欠频保护的时间不同，比如，国标和En50438等标准要求孤岛保护时间为2秒，英国G83/G99标准中要求孤岛保护时间为0.5秒，这种仅依靠频率进行孤岛扰动的方法无法满足不同国家的孤岛保护时间的要求。
 技术问题
本申请实施例提供了一种孤岛扰动方法、系统及终端设备，以解决现有技术中，仅依靠频率进行孤岛扰动的方法无法满足不同国家的孤岛保护时间的要求的问题。
 技术解决方案
为解决上述技术问题，本申请实施例的第一方面提供了一种孤岛扰动方法，包括：
获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
获取当前捕获周期值和上一次的捕获周期值；
若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并根据初始相位扰动量和初始相位扰动量的增加量确定最终相位扰动量。
优选地，根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量，包括：
计算当前电网频率减去电网额定频率得到的差值，并将该差值记为第一差值；
若第一差值大于预设频率值，则确定孤岛扰动方向为正方向，并确定初始相位扰动量为预设初始扰动量；
若第一差值小于预设频率值的负值，则确定孤岛扰动方向为负方向，并确定初始相位扰动量为预设初始扰动量的负值。
优选地，在计算当前电网频率减去电网额定频率得到的差值，并将该差值记为第一差值之后，孤岛扰动方法还包括：
若第一差值小于或等于预设频率值，且第一差值大于或等于预设频率值的负值，则确定孤岛扰动方向为无方向，并确定初始相位扰动量为预设初始扰动量的负值。
优选地，若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，包括：
若孤岛扰动方向为正方向，则计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值；
若第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值；
若孤岛扰动方向为负方向，则计算当前捕获周期值减去上一次的捕获周期值得到的差值，并将该差值记为第三差值；
若第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值。
优选地，在计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值之后，孤岛扰动方法还包括：
若第二差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤；
在计算当前捕获周期值减去上一次的捕获周期值得到的差值，并将该差值记为第三差值之后，孤岛扰动方法还包括：
若第三差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤。
优选地，在计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值之后，孤岛扰动方法还包括：
对第二差值进行预设时间的滑动滤波，得到滤波后的第二差值；
相应的，若第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值，包括：
若滤波后的第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值；
在计算当前捕获周期值减去上一次的捕获周期值得到的差值，并将该差值记为第三差值之后，孤岛扰动方法还包括：
对第三差值进行预设时间的滑动滤波，得到滤波后的第三差值；
相应的，若第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值，包括：
若滤波后的第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值。
优选地，预设周期阈值 C为：
Figure dest_path_image001
其中，θ 0为初始相位扰动量， f c 为逆变器的DSP的CPU频率， f 0为电网额定频率。
为解决上述技术问题，本申请实施例的第二方面提供了一种孤岛扰动系统，包括：
孤岛扰动方向确定模块，用于获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
周期值获取模块，用于获取当前捕获周期值和上一次的捕获周期值；
相位扰动量确定模块，用于若所述孤岛扰动方向为正方向或负方向，则根据所述当前捕获周期值和所述上一次的捕获周期值确定所述初始相位扰动量的增加量，并根据所述初始相位扰动量和所述初始相位扰动量的增加量确定最终相位扰动量。
为解决上述技术问题，本申请实施例的第三方面提供了一种终端设备，包括存储器、处理器以及存储在存储器中并可在处理器上运行的计算机程序，处理器执行计算机程序时实现如第一方面所述孤岛扰动方法的步骤。
为解决上述技术问题，本申请实施例的第四方面提供了一种计算机可读存储介质，计算机可读存储介质存储有计算机程序，计算机程序被一个或多个处理器执行时实现如第一方面所述孤岛扰动方法的步骤。
 有益效果
本申请提供了一种孤岛扰动方法、系统及终端设备，首先获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量，然后获取当前捕获周期值和上一次的捕获周期值，若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并根据初始相位扰动量和初始相位扰动量的增加量确定最终相位扰动量，本申请实施例在相位正反馈式孤岛扰动的基础上增加了捕获周期值保护，不再依赖频率进行保护，能够满足不同国家的孤岛保护时间的要求。
 附图说明
为了更清楚地说明本申请实施例中的技术方案，下面将对现有技术和实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本申请一实施例提供的孤岛扰动方法的实现流程示意图；
图2是本申请另一实施例提供的孤岛扰动方法的实现流程示意图；
图3是本申请一实施例提供的当前捕获周期值与上一次的周期捕获值的差值的示意图；
图4是本申请一实施例提供的孤岛保护时间的示意图；
图5是本申请又一实施例提供的孤岛保护时间的示意图；
图6是本申请一实施例提供的孤岛扰动系统的示意框图；
图7是本申请一实施例提供的终端设备的示意框图。
 本发明的实施方式
以下描述中，为了说明而不是为了限定，提出了诸如特定系统结构、技术之类的具体细节，以便透彻理解本申请实施例。然而，本领域的技术人员应当清楚，在没有这些具体细节的其它实施例中也可以实现本申请。在其它情况中，省略对众所周知的系统、装置、电路以及方法的详细说明，以免不必要的细节妨碍本申请的描述。
为了说明本申请所述的技术方案，下面通过具体实施例来进行说明。
图1是本申请一实施例提供的孤岛扰动方法的实现流程示意图，为了便于说明，仅示出了与本申请实施例相关的部分。本申请实施例的执行主体可以是终端设备。如图1所示，该方法可以包括以下步骤：
S101：获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量。
在本申请实施例中，若当前电网处于正常状态，即未出现孤岛效应，则当前电网频率为当前的电网频率；若当前电网处于异常状态，即出现孤岛效应，则当前电网频率为当前的逆变输出的频率。
本申请实施例在没有进行扰动的情况下，获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量。其中，电网额定频率为50Hz；孤岛扰动方向可以包括正方向、负方向和无方向。
在本申请的一个实施例中，上述步骤S101中的“根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量”，可以包括以下步骤：
计算当前电网频率减去电网额定频率得到的差值，并将该差值记为第一差值；
若第一差值大于预设频率值，则确定孤岛扰动方向为正方向，并确定初始相位扰动量为预设初始扰动量；
若第一差值小于预设频率值的负值，则确定孤岛扰动方向为负方向，并确定初始相位扰动量为预设初始扰动量的负值。
在本申请实施例中，将当前电网频率减去电网额定频率得到的差值，记为第一差值。比较第一差值与预设频率值的大小；若第一差值大于预设频率值，则确定孤岛扰动方向为正方向，并确定初始相位扰动量为预设初始扰动量；若第一差值小于预设频率值，则比较第一差值与预设频率值的负值的大小；若第一差值小于预设频率值的负值，则确定孤岛扰动方向为负方向，并确定初始相位扰动量为预设初始扰动量的负值。
其中，预设频率值可以为0.02Hz，对应的，预设频率值的负值为-0.02Hz。预设初始扰动量可以为0.002π，对应的，预设初始扰动量的负值为-0.002π。预设初始扰动量的值是通过实验测试确定的。
可选地，在确定初始相位扰动量为预设初始扰动量之后，孤岛扰动方法还可以包括：
实时获取当前电网频率，若当前电网频率继续增大，则将初始相位扰动量按照预设增加量不断叠加。
在确定初始相位扰动量为预设初始扰动量的负值之后，孤岛扰动方法还可以包括：
实时获取当前电网频率，若当前电网频率继续减小，则将初始相位扰动量按照预设增加量的负值不断叠加。
在本申请的一个实施例中，在上述计算当前电网频率减去电网额定频率得到的差值，并将该差值记为第一差值之后，孤岛扰动方法还可以包括以下步骤：
若第一差值小于或等于预设频率值，且第一差值大于或等于预设频率值的负值，则确定孤岛扰动方向为无方向，并确定初始相位扰动量为预设初始扰动量的负值。
比较第一差值和预设频率值与预设频率值的负值的大小；若第一差值小于或等于预设频率值，且第一差值大于或等于预设频率值的复制，则确定孤岛扰动方向为无方向，并确定初始相位扰动量为预设初始扰动量的负值。
由上述描述可知，当孤岛扰动方向既不是正方向，也不是负方向时，按照负方向扰动的初始相位扰动量进行扰动，避免逆变器频率一直处于无方向扰动对应的频率范围内，而无法进行孤岛保护。
S102：获取当前捕获周期值和上一次的捕获周期值。
在本申请实施例中，捕获周期值为CAP（capture）捕获周期值，可以根据CAP锁相得到。当前捕获周期值为当前所处的捕获周期的值；上一次的捕获周期值为与当前所处的捕获周期相邻的上一次的捕获周期的值。
S103：若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并根据初始相位扰动量和初始相位扰动量的增加量确定最终相位扰动量。
当孤岛扰动方向为正方向或者负方向时，可以根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并将初始相位扰动量加上初始相位扰动量的增加量得到最终相位扰动量。
在本申请的一个实施例中，如图2所示，上述步骤S103中的“若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量”可以包括以下步骤：
S201：若孤岛扰动方向为正方向，则计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值。
在本申请实施例中，若孤岛扰动方向为正方向，则计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值，并继续执行步骤S202。
S202：若第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值。
比较第二差值与预设周期阈值的大小；若第二差值大于预设周期阈值，则进入正反馈，可以确定初始相位扰动量的增加量为预设增加量。此时，将当前捕获周期值作为新的上一次的捕获周期值。
其中，初始相位扰动量的增加量为在初始相位扰动量的基础上，增加的相位扰动量。预设周期阈值可以为400，该预设周期阈值是通过实验数据得到的。预设增加量可以为0.005π，该值可以通过实验测试确定。
在本申请的一个实施例中，在上述步骤S201之后，上述孤岛扰动方法还可以包括：
若第二差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤。
在本申请实施例中，比较第二差值与预设周期阈值的大小；若第二差值小于或等于预设周期阈值，则返回步骤S101继续执行，即重新判断孤岛扰动方向。
在本申请的一个实施例中，在上述步骤S201之后，上述孤岛扰动方法还可以包括：
对第二差值进行预设时间的滑动滤波，得到滤波后的第二差值；
相应的，上述步骤S202可以包括：
若滤波后的第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值。
其中，预设时间可以根据实际需求进行设置，例如，可以设置为10个工频周期。
S203：若孤岛扰动方向为负方向，则计算当前捕获周期值减去上一次的捕获周期值得到的差值，并将该差值记为第三差值。
若孤岛扰动方向是负方向，则用当前捕获周期值减去上一次的捕获周期值得到第三差值，并继续执行步骤S204。
S204：若第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值。
比较第三差值与预设周期阈值的大小；若第三差值大于预设周期阈值，则进入负反馈，可以确定初始相位扰动量的增加量为预设增加量的负值。此时，将当前捕获周期值作为新的上一次的捕获周期值。其中，预设增加量可以为0.005π，对应的，预设增加量的负值可以为-0.005π。
在本申请的一个实施例中，在上述步骤S203之后，上述孤岛扰动方法还可以包括：
若第三差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤。
在本申请实施例中，比较第三差值与预设周期阈值的大小；若第三差值小于或等于预设周期阈值，则返回步骤S101继续执行，即重新判断孤岛扰动方向。
在本申请的一个实施例中，在上述步骤S203之后，上述孤岛扰动方法还可以包括：
对第三差值进行预设时间的滑动滤波，得到滤波后的第三差值；
相应的，上述步骤S204可以包括：
若滤波后的第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值。
可选地，在步骤S103之后，上述孤岛扰动方法还包括：将最终相位扰动量叠加到锁相得到的基准角度上。
具体地，将最终相位扰动量 θ island 叠加到锁相出来的基准角度 θ上，即sin( θ+ θ island )。
在本申请的一个实施例中，所述预设周期阈值 C为：
Figure dest_path_image002
其中，θ 0为所述初始相位扰动量， f c 为逆变器的DSP（Digital Signal Processor，数字信号处理器）的CPU（central processing unit，中央处理器）频率， f 0为所述电网额定频率， f 0=50Hz。
本申请实施例中的中的逆变器可以为单相储能逆变器，该单相储能逆变器的DSP的型号可以为TMS320F28069，该DSP的CPU频率为90MHz，即 f c =90MHz。
由上述描述可知，本申请实施例采用相位正反馈式孤岛扰动加上频率周期值保护的综合方法进行孤岛保护。当频率超出一定范围时，增加相位扰动量进行正反馈，有效地打破逆变器输出的频率，从而检测到孤岛状态；而当电压幅值和频率变化范围小于某一值时，相位或频率偏移法无法检测到孤岛效应时，采用频率周期值保护方法，可以成功避免检测盲区，快速检测出孤岛效应并且在规定时间内进行保护。
本申请实施例提供的孤岛扰动方法适用于单相孤岛扰动，通过改变相位的方法来使频率发生改变，相位的改变受到锁相控制环路、有功功率控制和无功功率控制的影响，导致在进行孤岛时，在进入正方向时不满足进入正反馈的条件，进入重新判断孤岛扰动方向的逻辑；如果进入负反馈，同样也会出现不满足负反馈的条件，而进入重新判断孤岛扰动方向的逻辑，以此反复，如图3所示，从而导致孤岛保护时间延长，如图4所示。无法进入正反馈或者负反馈的原因为初始相位扰动量比较小，如果加大初始相位扰动量，会影响系统的稳定性。
基于以上因素，在相位正反馈式孤岛扰动的基础上提出一种新的孤岛扰动保护即捕获周期值保护。通过判断孤岛扰动时，当前捕获周期值和上一次的捕获周期值的差值的大小来进行保护，不再依赖频率进行保护。如果此时电网正常，两者的差值比较小，孤岛扰动的角度不会影响电网的频率，如果此时处于孤岛状态，由于有初始扰动量的存在，即使没有进入正反馈，当前捕获周期值和上一次的捕获周期值的差值也会比较大。因此对两者的差值进行10个工频周期的滑动滤波。判断该滤波后的差值大于某一固定值 C后，即孤岛保护实现0.5s内的孤岛保护时间的标准要求。
通过上述孤岛扰动方法再次进行实验，即使出现如图3所示的孤岛扰动量的检测盲区，也可以根据本申请实施例提供的孤岛扰动方法快速的进行保护，测试结果如图5所示。
应理解，上述实施例中各步骤的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
图6是本申请一实施例提供的孤岛扰动系统的示意框图，为了便于说明，仅示出与本申请实施例相关的部分。
在本申请实施例中，孤岛扰动系统60可以包括孤岛扰动方向确定模块601、周期值获取模块602和相位扰动量确定模块603。
其中，孤岛扰动方向确定模块601，用于获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
周期值获取模块602，用于获取当前捕获周期值和上一次的捕获周期值；
相位扰动量确定模块603，用于若所述孤岛扰动方向为正方向或负方向，则根据所述当前捕获周期值和所述上一次的捕获周期值确定所述初始相位扰动量的增加量，并根据所述初始相位扰动量和所述初始相位扰动量的增加量确定最终相位扰动量。
可选地，孤岛扰动方向确定模块601可以包括第一差值计算单元、第一孤岛扰动方向确定单元和第二孤岛扰动方向确定单元；
其中，第一差值计算单元，用于计算当前电网频率减去电网额定频率得到的差值，并将该差值记为第一差值；
第一孤岛扰动方向确定单元，用于若第一差值大于预设频率值，则确定孤岛扰动方向为正方向，并确定初始相位扰动量为预设初始扰动量；
第二孤岛扰动方向确定单元，用于若第一差值小于预设频率值的负值，则确定孤岛扰动方向为负方向，并确定初始相位扰动量为预设初始扰动量的负值。
可选地，孤岛扰动方向确定模块601还可以包括第三孤岛扰动方向确定单元。
第三孤岛扰动方向确定单元，用于若第一差值小于或等于预设频率值，且第一差值大于或等于预设频率值的负值，则确定孤岛扰动方向为无方向，并确定初始相位扰动量为预设初始扰动量的负值。
可选地，相位扰动量确定模块603可以包括第二差值计算单元、第一增加量确定单元、第三差值计算单元和第二增加量确定单元。
其中，第二差值计算单元，用于若孤岛扰动方向为正方向，则计算上一次的捕获周期值减去当前捕获周期值得到的差值，并将该差值记为第二差值；
第一增加量确定单元，用于若第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值；
第三差值计算单元，用于若孤岛扰动方向为负方向，则计算当前捕获周期值减去上一次的捕获周期值得到的差值，并将该差值记为第三差值；
第二增加量确定单元，用于若第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量的负值，并将当前捕获周期值作为新的上一次的捕获周期值。
可选地，相位扰动量确定模块603还可以包括第一循环单元和第二循环单元。
其中，第一循环单元，用于若第二差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤；
第二循环单元，用于若第三差值小于或等于预设周期阈值，则继续执行获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤。
可选地，相位扰动量确定模块603还可以包括第一滤波单元和第二滤波单元。
其中，第一滤波单元，用于对第二差值进行预设时间的滑动滤波，得到滤波后的第二差值；
相应的，第一增加量确定单元，用于若滤波后的第二差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值；
第二滤波单元，用于对第三差值进行预设时间的滑动滤波，得到滤波后的第三差值；
相应的，第二增加量确定单元，用于若滤波后的第三差值大于预设周期阈值，则确定初始相位扰动量的增加量为预设增加量，并将当前捕获周期值作为新的上一次的捕获周期值。
可选地，上述预设周期阈值 C为：
Figure dest_path_image003
其中，θ 0为所述初始相位扰动量， f c 为逆变器的DSP的CPU频率， f 0为所述电网额定频率。
所属领域的技术人员可以清楚地了解到，为了描述的方便和简洁，仅以上述各功能单元、模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能单元、模块完成，即将所述孤岛扰动系统的内部结构划分成不同的功能单元或模块，以完成以上描述的全部或者部分功能。实施例中的各功能单元、模块可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中，上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。另外，各功能单元、模块的具体名称也只是为了便于相互区分，并不用于限制本申请的保护范围。上述装置中单元、模块的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
图7是本申请一实施例提供的终端设备的示意框图。如图7所示，该实施例的终端设备70包括：一个或多个处理器701、存储器702以及存储在所述存储器702中并可在所述处理器701上运行的计算机程序703。所述处理器701执行所述计算机程序703时实现上述各个孤岛扰动方法实施例中的步骤，例如图1所示的步骤S101至S103。或者，所述处理器701执行所述计算机程序703时实现上述孤岛扰动系统实施例中各模块/单元的功能，例如图6所示模块601至603的功能。
示例性地，所述计算机程序703可以被分割成一个或多个模块/单元，所述一个或者多个模块/单元被存储在所述存储器702中，并由所述处理器701执行，以完成本申请。所述一个或多个模块/单元可以是能够完成特定功能的一系列计算机程序指令段，该指令段用于描述所述计算机程序703在所述终端设备70中的执行过程。例如，所述计算机程序703可以被分割成孤岛扰动方向确定模块、周期值获取模块和相位扰动量确定模块，各模块具体功能如下：
孤岛扰动方向确定模块，用于获取当前电网频率，并根据当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
周期值获取模块，用于获取当前捕获周期值和上一次的捕获周期值；
相位扰动量确定模块，用于若孤岛扰动方向为正方向或负方向，则根据当前捕获周期值和上一次的捕获周期值确定初始相位扰动量的增加量，并根据初始相位扰动量和初始相位扰动量的增加量确定最终相位扰动量。
其它模块或者单元可参照图6所示的实施例中的描述，在此不再赘述。
所述终端设备70可以是桌上型计算机、笔记本、掌上电脑及云端服务器等计算设备。所述终端设备70包括但不仅限于处理器701、存储器702。本领域技术人员可以理解，图7仅仅是终端设备70的一个示例，并不构成对终端设备70的限定，可以包括比图示更多或更少的部件，或者组合某些部件，或者不同的部件，例如所述终端设备70还可以包括输入设备、输出设备、网络接入设备、总线等。
所述处理器701可以是中央处理单元(Central Processing Unit，CPU)，还可以是其他通用处理器、数字信号处理器 (Digital Signal Processor，DSP)、专用集成电路 (Application Specific Integrated Circuit，ASIC)、现场可编程门阵列 (Field-Programmable Gate Array，FPGA) 或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
所述存储器702可以是所述终端设备70的内部存储单元，例如终端设备70的硬盘或内存。所述存储器702也可以是所述终端设备70的外部存储设备，例如所述终端设备70上配备的插接式硬盘，智能存储卡（Smart Media Card, SMC），安全数字（Secure Digital, SD）卡，闪存卡（Flash Card）等。进一步地，所述存储器702还可以既包括终端设备70的内部存储单元也包括外部存储设备。所述存储器702用于存储所述计算机程序703以及所述终端设备70所需的其他程序和数据。所述存储器702还可以用于暂时地存储已经输出或者将要输出的数据。
在上述实施例中，对各个实施例的描述都各有侧重，某个实施例中没有详述或记载的部分，可以参见其它实施例的相关描述。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
在本申请所提供的实施例中，应该理解到，所揭露的孤岛扰动系统和方法，可以通过其它的方式实现。例如，以上所描述的孤岛扰动系统实施例仅仅是示意性的，例如，所述模块或单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通讯连接可以是通过一些接口，装置或单元的间接耦合或通讯连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。
所述集成的模块/单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请实现上述实施例方法中的全部或部分流程，也可以通过计算机程序来指令相关的硬件来完成，所述的计算机程序可存储于一计算机可读存储介质中，该计算机程序在被处理器执行时，可实现上述各个方法实施例的步骤。其中，所述计算机程序包括计算机程序代码，所述计算机程序代码可以为源代码形式、对象代码形式、可执行文件或某些中间形式等。所述计算机可读介质可以包括：能够携带所述计算机程序代码的任何实体或装置、记录介质、U盘、移动硬盘、磁碟、光盘、计算机存储器、只读存储器（ROM，Read-Only Memory）、随机存取存储器（RAM，Random Access Memory）、电载波信号、电信信号以及软件分发介质等。需要说明的是，所述计算机可读介质包含的内容可以根据司法管辖区内立法和专利实践的要求进行适当的增减，例如在某些司法管辖区，根据立法和专利实践，计算机可读介质不包括是电载波信号和电信信号。
以上所述实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围，均应包含在本申请的保护范围之内。

Claims (10)

  1. 一种孤岛扰动方法，其特征在于，包括：
    获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
    获取当前捕获周期值和上一次的捕获周期值；
    若所述孤岛扰动方向为正方向或负方向，则根据所述当前捕获周期值和所述上一次的捕获周期值确定所述初始相位扰动量的增加量，并根据所述初始相位扰动量和所述初始相位扰动量的增加量确定最终相位扰动量。
  2. 根据权利要求1所述的孤岛扰动方法，其特征在于，所述根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量，包括：
    计算所述当前电网频率减去所述电网额定频率得到的差值，并将该差值记为第一差值；
    若所述第一差值大于预设频率值，则确定所述孤岛扰动方向为正方向，并确定所述初始相位扰动量为预设初始扰动量；
    若所述第一差值小于所述预设频率值的负值，则确定所述孤岛扰动方向为负方向，并确定所述初始相位扰动量为所述预设初始扰动量的负值。
  3. 根据权利要求2所述的孤岛扰动方法，其特征在于，在所述计算所述当前电网频率减去所述电网额定频率得到的差值，并将该差值记为第一差值之后，所述孤岛扰动方法还包括：
    若所述第一差值小于或等于所述预设频率值，且所述第一差值大于或等于所述预设频率值的负值，则确定所述孤岛扰动方向为无方向，并确定所述初始相位扰动量为所述预设初始扰动量的负值。
  4. 根据权利要求1至3任一项所述的孤岛扰动方法，其特征在于，所述若所述孤岛扰动方向为正方向或负方向，则根据所述当前捕获周期值和所述上一次的捕获周期值确定所述初始相位扰动量的增加量，包括：
    若所述孤岛扰动方向为正方向，则计算所述上一次的捕获周期值减去所述当前捕获周期值得到的差值，并将该差值记为第二差值；
    若所述第二差值大于预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量，并将所述当前捕获周期值作为新的所述上一次的捕获周期值；
    若所述孤岛扰动方向为负方向，则计算所述当前捕获周期值减去所述上一次的捕获周期值得到的差值，并将该差值记为第三差值；
    若所述第三差值大于所述预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量的负值，并将所述当前捕获周期值作为新的所述上一次的捕获周期值。
  5. 根据权利要求4所述的孤岛扰动方法，其特征在于，在所述计算所述上一次的捕获周期值减去所述当前捕获周期值得到的差值，并将该差值记为第二差值之后，所述孤岛扰动方法还包括：
    若所述第二差值小于或等于所述预设周期阈值，则继续执行所述获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤；
    在所述计算所述当前捕获周期值减去所述上一次的捕获周期值得到的差值，并将该差值记为第三差值之后，所述孤岛扰动方法还包括：
    若所述第三差值小于或等于所述预设周期阈值，则继续执行所述获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量的步骤。
  6. 根据权利要求4所述的孤岛扰动方法，其特征在于，在所述计算所述上一次的捕获周期值减去所述当前捕获周期值得到的差值，并将该差值记为第二差值之后，所述孤岛扰动方法还包括：
    对所述第二差值进行预设时间的滑动滤波，得到滤波后的第二差值；
    相应的，所述若所述第二差值大于预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量，并将所述当前捕获周期值作为新的所述上一次的捕获周期值，包括：
    若所述滤波后的第二差值大于预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量，并将所述当前捕获周期值作为新的所述上一次的捕获周期值；
    在所述计算所述当前捕获周期值减去所述上一次的捕获周期值得到的差值，并将该差值记为第三差值之后，所述孤岛扰动方法还包括：
    对所述第三差值进行预设时间的滑动滤波，得到滤波后的第三差值；
    相应的，所述若所述第三差值大于所述预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量的负值，并将所述当前捕获周期值作为新的所述上一次的捕获周期值，包括：
    若所述滤波后的第三差值大于所述预设周期阈值，则确定所述初始相位扰动量的增加量为预设增加量的负值，并将所述当前捕获周期值作为新的所述上一次的捕获周期值。
  7. 根据权利要求4所述的孤岛扰动方法，其特征在于，所述预设周期阈值 C为：
    Figure dest_path_image001
    其中，θ 0为所述初始相位扰动量， f c 为逆变器的DSP的CPU频率， f 0为所述电网额定频率。
  8. 一种孤岛扰动系统，其特征在于，包括：
    孤岛扰动方向确定模块，用于获取当前电网频率，并根据所述当前电网频率和电网额定频率确定孤岛扰动方向和初始相位扰动量；
    周期值获取模块，用于获取当前捕获周期值和上一次的捕获周期值；
    相位扰动量确定模块，用于若所述孤岛扰动方向为正方向或负方向，则根据所述当前捕获周期值和所述上一次的捕获周期值确定所述初始相位扰动量的增加量，并根据所述初始相位扰动量和所述初始相位扰动量的增加量确定最终相位扰动量。
  9. 一种终端设备，包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机程序，其特征在于，所述处理器执行所述计算机程序时实现如权利要求1至7任一项所述孤岛扰动方法的步骤。
  10. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质存储有计算机程序，所述计算机程序被一个或多个处理器执行时实现如权利要求1至7任一项所述孤岛扰动方法的步骤。
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