CN103616596A - String abnormality detection method and system based on inverter grid connection - Google Patents

Abstract

The embodiment of the invention discloses a string abnormality detection method and system based on inverter grid connection. The string abnormality detection method and system can be applied to string abnormality detection of a whole grid connection system, can accurately position any abnormal string and is high in efficiency. The method includes the steps of obtaining an abnormality judgment coefficient of a detected string according to power symmetric reference coefficients of the detected string in contextual information of the string, judging whether the abnormality judgment coefficient is a preset abnormality judgment value, and determining that the detected string is abnormal if the answer is positive.

Description

A kind of group string method for detecting abnormality and system based on grid-connected inverters

Technical field

The present invention relates to battery Exception Handling Technique field, be specifically related to a kind of group string method for detecting abnormality and system based on grid-connected inverters.

Background technology

Group string (PV String) is in series by photovoltaic cell component (Photo Voltaic Module), and photovoltaic cell component is to be formed by battery cell (cell) tight encapsulation after effective series connection.Group string is used for absorbing solar energy and will becoming electric energy by light energy conversion very much, becomes effective input of inverter.Because group string is installed in outdoor environment for a long time, be subject to the impacts such as high temperature, high humility or low humidity, along with the time increases, its output power is on a declining curve, namely light energy conversion becomes the decrease in efficiency of electric energy, and under this long-term rugged environment or the in the situation that of being subject to extraneous shock, the battery cell in the photovoltaic cell component of group string may occur that delamination causes unexpected power down so, or under shade blocks, cause the whole output power of group string to decline for a long time, belong to extremely aging.When abnormal aging appearance, need timely prompt alarm so that technician investigates solution.

At present, one of method of abnormality detection is by setting up specially one towards the database of group string in the grid-connected inverters electricity generation system at group string.In grid-connected inverters operation of electric power system process, continue for some time the service data of collection group string.After operational data collection is complete, utilize intelligent algorithm (for example ant group algorithm), calculate the characteristic parameter of each group string, in the operation phase in later stage, be referred to this characteristic parameter, group string power stage is carried out to abnormality detection.Although the method application surface is wider, can carry out abnormality detection to all groups of strings simultaneously, due to the input of group string as inverter, inverter local computing unit is relatively simple, cannot carry the application of intelligent algorithm.

The other method of abnormality detection is the altitude temperature difference effect that is blocked by shade or produce during short circuit for photovoltaic cell component part, a certain road in group string, adopt infrared thermometer to measure the surface temperature of photovoltaic cell component, then infrared image analysis is obtained extremely, locating abnormal photovoltaic cell component.In the method, infrared thermometer can not detect all photovoltaic cell components simultaneously, is of limited application, cannot complete detection abnormal, and infrared technique cost is higher.

Summary of the invention

For above-mentioned defect, the embodiment of the present invention provides a kind of group string method for detecting abnormality and system based on grid-connected inverters, can accurately navigate to abnormal group string way, applied range occur.

First aspect present invention provides a kind of group string method for detecting abnormality based on grid-connected inverters, can comprise:

According to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string;

Judge whether described abnormality juding coefficient meets default abnormal judgment value, if so, determine that described detected group of string occurs abnormal.

In conjunction with first aspect, in the possible implementation of the first, described abnormality juding coefficient is the power deviation coefficient of detected group string; And then described according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string, comprising: obtain the current operate power of detected group string and the current operate power of reference group string; According to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation; According to the power symmetric reference coefficient of detected group string described in described power symmetry coefficient and group string contextual information, obtain the power deviation coefficient of described detected group of string.

In conjunction with first aspect, in the possible implementation of the second, described abnormality juding coefficient is generated energy absolute value deviation and the generated energy Z-factor of detected group string; And then described according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string, comprising: obtain the generated energy of detected group string and the generated energy of reference group string; According to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

In conjunction with the possible implementation of the second of first aspect, in the third possible implementation, described according to the generated energy of the generated energy of described detected group of string and reference group string, and the power symmetric reference coefficient of detected group string described in group string contextual information, the generated energy absolute value deviation that obtains described detected group of string, comprising: calculate the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information; The generated energy that calculates described product and described detected group of string obtains the generated energy absolute value deviation of described detected group of string.

The third possible implementation in conjunction with first aspect, in the 4th kind of possible implementation, described according to the generated energy of the generated energy of described detected group of string and reference group string, and the power symmetric reference coefficient of detected group string described in group string contextual information, the generated energy Z-factor that obtains described detected group of string, comprising: the ratio that calculates the generated energy of described detected group of string and the generated energy of described reference group string obtains the generated energy symmetry coefficient of described detected group of string; Calculate after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, or the ratio of absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

In conjunction with first aspect, in the 5th kind of possible implementation, also comprise: determine reference group string; According to reference group string, the power symmetric reference coefficient of detected group string in study group string contextual information.

In conjunction with the 5th kind of possible implementation of first aspect, in the 6th kind of possible implementation, described definite reference group string comprises: from the group string of normal operation, select one group of group string as going here and there with reference to group.

The 5th kind of possible implementation or the 6th kind of possible implementation in conjunction with first aspect, in the 7th kind of possible implementation, the described power symmetric reference coefficient according to detected group string in reference group string study group string contextual information comprises: collect respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and the individual described reference group string of n the average power content at described Preset Time; Calculate the first power symmetric reference coefficient that the average power content of described detected group of string and the average power content of described reference group string obtain n described detected group of string; The mean value that calculates n described the first power symmetric reference coefficient obtains the power symmetric reference coefficient of described detected group of string.

It is a kind of based on grid-connected inverters group string abnormality detection system that second aspect present invention provides, and can comprise:

Acquiring unit, for according to the power symmetric reference coefficient of the detected group string of group string contextual information, obtains the abnormality juding coefficient of described detected group of string;

Judging unit, for judging whether described abnormality juding coefficient meets default abnormal judgment value, if so, determines that described detected group of string occurs abnormal.

In conjunction with second aspect, in the possible implementation of the first, described acquiring unit comprises the symmetrical detecting unit of power; Wherein, the symmetrical detection module of described power comprises: power acquiring unit, for obtaining the current operate power of detected group string and the current operate power of reference group string; Power symmetry coefficient computing unit, for according to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation; Power deviation computing unit, for obtaining the power deviation coefficient of described detected group of string according to the power symmetric reference coefficient of detected group string described in described power symmetry coefficient and group string contextual information.

In conjunction with second aspect, in the possible implementation of the second, described acquiring unit comprises regularly detecting unit; Wherein, described timing detecting unit comprises: generated energy acquiring unit, obtains the generated energy of detected group string and the generated energy of reference group string; Generated energy deviation computing unit, be used for according to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

In conjunction with the possible implementation of the second of second aspect, in the third possible implementation, described generated energy deviation computing unit comprises: product computing unit, for calculating the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information; Absolute value calculation unit, obtains the generated energy absolute value deviation of described detected group of string for calculating the generated energy of described product and described detected group of string.

The third possible implementation in conjunction with second aspect, in the 4th kind of possible implementation, described generated energy deviation computing unit comprises: generated energy symmetry coefficient computing unit, obtains the generated energy symmetry coefficient of described detected group of string for calculating the ratio of the generated energy of described detected group of string and the generated energy of described reference group string; Generated energy Z-factor computing unit, for calculating after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, the ratio of described absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

In conjunction with second aspect, in the 5th kind of possible implementation, also comprise: reference group string determining unit, for determining reference group string; Power symmetric reference coefficient unit, for the power symmetric reference coefficient of going here and there according to the detected group of reference group string study group string contextual information.

In conjunction with the 5th kind of possible implementation of second aspect, in the 6th kind of possible implementation, described reference group string determining unit is specifically for selecting one group of group string as going here and there with reference to group the group string from normal operation.

The 5th kind of possible implementation or the 6th kind of possible implementation in conjunction with second aspect, in the 7th kind of possible implementation, described power symmetric reference coefficient unit comprises: the first performance number acquiring unit, for collecting respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and the individual described reference group string of n the average power content at described Preset Time; The first average calculation unit, obtains the first power symmetric reference coefficient of n described detected group of string for calculating the average power content of described detected group of string and the average power content of described reference group string; The second average calculation unit, obtains the power symmetric reference coefficient of described detected group of string for calculating the mean value of n described the first power symmetric reference coefficient.

As can be seen from the above technical solutions, the embodiment of the present invention has the following advantages:

In the embodiment of the present invention, by according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of detected group string, by abnormality juding coefficient and the detected group string of abnormal judgment value judgement, whether occur abnormal.Compared with prior art, the embodiment of the present invention is by the detection that group string power is changed, test set string abnormal conditions effectively, and can accurately navigate to abnormal group string way, applied range occur.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, to the accompanying drawing of required use in the embodiment of the present invention be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 for one embodiment of the invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 2 for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 3 for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 4-a for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 4-b for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 5-a for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 5-b for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

Fig. 5-c for another embodiment of the present invention provide based on grid-connected inverters group string method for detecting abnormality schematic flow sheet;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 6 provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 7-a provides for another one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 7-b provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 8-a provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 8-b provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 9-a provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detection system that Fig. 9-b provides for one embodiment of the invention;

The basic structure schematic diagram based on grid-connected inverters group string abnormality detecting apparatus that Figure 10 provides for one embodiment of the invention.

Embodiment

Below in conjunction with the accompanying drawing of the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.

The embodiment of the present invention provides a kind of group string method for detecting abnormality and system based on grid-connected inverters, and that for detection of group in inverter, goes here and there is abnormal, and can accurately navigate to the way of abnormal group of string, applied range, and efficiency is high.

As shown in Figure 1, a kind of group string method for detecting abnormality based on grid-connected inverters, can comprise:

Step S110, according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string, whether described abnormality juding coefficient is used to indicate described detected group of string and occurs extremely;

Be understandable that, abnormality juding coefficient can be the power deviation coefficient of detected group string, or generated energy absolute value deviation and the generated energy Z-factor of detected group string.

Wherein, under the normal operation of group string, group crosstalk stream is symmetrical operation, and then the fluctuation range of group string output power is determined; When the misoperation of group string, group crosstalk stream is asymmetric operation, and then power variation range is also uncertain, especially when the abnormal disconnection of group string, therefore group string output power can be undergone mutation, and causes power likely lower than 50W,, the embodiment of the present invention can judge by the power swing situation of test set string when organizing string operation whether group string occurs extremely, and it is abnormal that the power deviation coefficient being produced by power swing judges whether group string occurs.

In addition, if group string is abnormal aging or be subject to for a long time pollutant and block, after its long-time running, the generated energy of group string also will be subject to obvious impact, and therefore, it is abnormal that the embodiment of the present invention can also judge whether group string occurs by generated energy fluctuation situation.

Step S120, judge that whether described abnormality juding coefficient meets default abnormal judgment value, if so, turns to step S130;

Be understandable that, by the study of group string and group string output power and generated energy situation are under normal circumstances preset to reasonably abnormal judgment value, by obtain abnormality juding coefficient in when operation group string, compare with this abnormal judgment value of presetting, when abnormality juding coefficient meets default abnormal judgment value, determine that detected group string occurs abnormal.

Step S130, to determine that described detected group of string occurs abnormal.

In the embodiment of the present invention, by according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormal judgement factor of this detected group string, and abnormality juding coefficient is used to indicate detected group string and whether occurs abnormal; By judge that whether abnormality juding coefficient meets default abnormal judgment value, if met, determine that detected group string is for abnormal group string again, can be towards the group string in grid-connected inverters, direct precision navigates to the way of abnormal group of string, and efficiency is high.

Be understandable that, abnormal judgment value is can be used for normally judging whether group string abnormal numerical value occurs, and preferably, when abnormality juding coefficient is power deviation coefficient, is directed to power deviation coefficient and default abnormal judgment value is greater than 0.3; When abnormality juding coefficient is generated energy absolute value deviation and generated energy Z-factor, be directed to generated energy absolute value deviation and default abnormal judgment value is greater than 7kWh, be directed to generated energy Z-factor and default abnormal judgment value is greater than 0.05.Certainly.It will be understood by those skilled in the art that the variation according to actual conditions, above-mentioned provided numerical range is provided the abnormal judgment value that the embodiment of the present invention provides, and other numerical value that can realize beneficial effect of the present invention is all within protection domain of the present invention.

To introduce in further detail technical solution of the present invention below:

In grid-connected inverters system, be deployed with group string abnormality detection system, can gather the related data that in grid-connected inverters system, group is gone here and there while moving, and according to gathered related data, group string is carried out to anomaly analysis, wherein, related data can be to organize the output power of string, generated energy etc.

Each inverter at least disposes 3 tunnel group strings, and all groups of string arrangement modes (comprising group string deflection, pitch angle) are consistent as far as possible, so that all groups of strings can both normally move.While starting grid-connected inverters system, enter the initialization of group string, in initialization, read group string contextual information in inverter, if the also not study of the detailed content of group string contextual information, the access detection-phase or the power symmetric reference coefficient learning phase that enter afterwards group string are perfect.

Preferably, group string contextual information can comprise group string ID, group string state (reference group string or detected group string), alarm status (alarm clearance, group string are lost, group string is asymmetric, group string aging), generated energy, power symmetric reference coefficient, alarm time, refresh time.

For instance, inverter disposes 6 tunnel group strings, is respectively PV1, PV2, PV3, PV4, PV5 and PV6, and group string contextual information can be expressed as follows form so:

After initial phase reads in group string contextual information, mainly by entering access detection-phase test set string contextual information and definite reference group string of group string, the access of group string detects idiographic flow as shown in Figure 2, a kind ofly based on grid-connected inverters group string method for detecting abnormality, comprises step:

The performance number of group string in step S210, collection Preset Time section, and calculate the average power content of described group of string in described Preset Time section;

Be understandable that, if when initialization first, the content in group string contextual information is not learnt completely, so for each the group string in inverter, the performance number of collection group string; During if not initialization first, the existing content of being learnt in group string contextual information, has particularly learnt reference group string, so now for collecting the performance number of detected group string and reference group string.

Particularly, in order to make result more accurate, the performance number of collection group string in Preset Time section, the average power content of then calculating group string in this Preset Time section, comes to compare with default power average value by average power content.In order not cause excessive computation burden to system, Preset Time section can be advisable with 50 seconds.

Step S220, judge whether described average power content is less than default power average value, if so, turn to step S230; If not, turn to step S290;

Wherein, when grid-connected inverters moves, if abnormal disconnection (group string is lost) occurs a certain road group string, the power input of this road group string is likely undergone mutation so, and lower than 50W, default power average value herein can be set to 50W.When group string average power content is less than 50W, explanation group string may disconnect extremely, and therefore, the access detection-phase of going here and there in group also can be directly by judging that the average power content of group string judges whether group string disconnects extremely.

Step S230, judge that whether described group of string be effective group string, if so, turns to step S240; If not, turn to step S210;

Wherein, from the group string state of above-mentioned table 1, can find out, group string state can be divided into reference group string, detected group string, invalid group of string and unrecognized group of string.Wherein, invalid group of string is to disconnect suddenly the group string that causes being lost, and unrecognized group of string newly accesses inverter and be not also initialised.If be defined as invalid group of string, illustrate that this group string is lost.

Step S240, generation group string are lost alarm, turn to step S250;

Wherein, after determining that by above-mentioned steps S220 group string is lost, for this group string output group string, lose alarm, realize the abnormality alarming of a certain road group string, to repair in time fault.

Whether the group string number that step S250, judgement access detect is less than 3, if so, turns to step S260; If not, turn to step S210;

Be understandable that, inverter at least accesses 3 tunnel group strings, to guarantee normally to move and realize the abnormality detection that the embodiment of the present invention is provided.

Step S260, judge that whether the reference group string in group string contextual information is effective, if so, turn to step S270; If not, turn to step S280;

Be understandable that, reference group string is from all groups of strings of normal operation, selects at random a road group string as going here and there with reference to group.Before study, if the reference group string in group string contextual information is empty, also do not learn reference group string; If but in group string contextual information, learnt reference group string, in operational process, selected reference group string also may occur extremely, and then causes it can not be re-used as the use of reference group string, thereby need to reselect reference group string.Therefore, also do not having study to occur when abnormal, all will relearn definite reference group string to reference group string or original reference group string.

Step S270, judge that whether this group string contextual information is effective, the symmetry that if so, enters group string detects; If not, enter the study of group string power symmetric reference coefficient;

Be understandable that, after determining that reference group string effectively, do not disconnect suddenly phenomenon, further whether the group string contextual information of confirmation group string is effective.

Step S280, select a road group string as with reference to group string, enter the study of group string power symmetric reference coefficient;

Be understandable that, when reference group string is invalid, from other normal operation group string, selects a road as going here and there with reference to group, and need to relearn power symmetry coefficient.

Step S290, determine in group string contextual information, whether this group string has group string to lose alarm record, if so, the alarm status that in group string contextual information, this group is gone here and there is updated to removing; If not, enter symmetrical detection of group string power.

In the embodiment of the present invention, after initialization, by group, be connected in series detection and carry out the content in test set string contextual information, when the content in contextual information is not learnt or has partial content invalid, again from the group string of normal operation, select a road group string as going here and there with reference to group, relearn again the content in group string contextual information, especially by the power symmetric reference coefficient of study group string contextual information, utilize power symmetric reference coefficient as with reference to value, judge whether group string occurs extremely.

From above-described embodiment, group string context also will not relearn group string contextual information after study or gravity treatment reference group string, determines the power symmetric reference coefficient in group string contextual information, and as shown in Figure 3, power symmetric reference coefficient learning process comprises:

Step S310, collect n detected group string and reference group string in the performance number of Preset Time respectively, and calculate the detected group string of n at the average power content of described Preset Time and n reference group string the average power content at described Preset Time, described n is more than or equal to 50 positive integer;

Wherein, to the detected group string in each road, collect the performance number of Preset Time section, then calculate detected group string at the average power content of Preset Time, and so repeat to obtain n time, finally obtain n mean value of detected group string; Reference group string is carried out to same operation, obtain the average power content of n reference group string.

Step S320, judge that whether described average power content is effective, if so, turn to step S330; If not, turn to step S310;

Group string is at normal operating condition, and power can fluctuate within the specific limits, in the study of power symmetric reference coefficient, guarantees that especially the power gathering is effective, and preferably, the effective value in step S320 can be for being greater than 50W and being less than the numerical value of 20KW.

The ratio of the average power content of step S330, the detected group string of calculating and the average power content of reference group string obtains the first power symmetric reference coefficient;

Be understandable that, reference group string has n average power content Pn _major, having equally the average power content of n detected group string is Pn _slave, i the first power symmetric reference coefficient is StringSymmetryCoef(i so), StringSymmetryCoef(i so) computing formula as follows:

StringSymmetryCoef(i)=Pn _slave(i)/Pn _major(i)

Wherein, Pn _slave(i) be the average power content of i detected group string, Pn _major(i) be the average power content of i reference group string.

The mean value of step S340, n described the first power symmetric reference coefficient of calculating obtains the power symmetric reference coefficient of described detected group of string;

Wherein, by getting n group string symmetry coefficient, get its mean value as last power symmetric reference coefficient, can improve the degree of accuracy of power symmetric reference coefficient.

Suppose power symmetric reference coefficients R eferSymmetryCoef, computing formula is as follows so:

$\mathrm{ReferSymmetryCoef}={\mathrm{\Σ}}_{i=1}^n\mathrm{StringSymmetryCoef}\left(i\right)/n$

Wherein, n represents the number of the symmetrical symmetric reference coefficient of the first power, is StringSymmetryCoef(i) the above-mentioned i calculating a first power symmetric reference coefficient.To the cumulative summation of n the first power reference coefficient, then average and obtain the power symmetric reference coefficient of detected group string.

Step S350, judge that whether described power symmetric reference coefficient is effective, if so, ingoing power is symmetrical detects; If not, turn to step S310.

The power symmetric reference coefficient of the embodiment of the present invention by putting into practice acquisition group string is normally in certain limit, preferably, in the embodiment of the present invention, the effective range of power symmetric reference coefficient is 0.2～5, therefore judge that power symmetric reference coefficient is whether effectively time, can be by judging that power symmetric reference coefficient is whether in 0.2～5.

Main by the study to power symmetric reference coefficient in the embodiment of the present invention, in the follow-up abnormality detection stage, according to power symmetric reference coefficient, judge whether group string occurs abnormal.

Group string contextual information has been arrived in study in the above-described embodiments, when the operation of group string, group string is carried out to abnormality detection afterwards, wherein, abnormality juding coefficient can be power deviation coefficient, below the situation that to coefficient of determination is power deviation coefficient is elaborated, as shown in Fig. 4-a, a kind of group string method for detecting abnormality based on grid-connected inverters, can comprise:

Step S4101, the current operate power of obtaining detected group string and the current operate power of reference group string;

When group string moves in inverter, obtain the current operate power of detected group string, and the current operate power of reference group string, to judge extremely by detection power fluctuation situation.

Wherein, the current operate power of detected group string is Pm _slave, the current operate power of reference group string is Pm _major.

Step S4102, according to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation;

Power symmetry coefficient while obtaining detected group string operation by the current operate power of detected group string and the current operate power of reference group string, wherein, power symmetry coefficient is RunSymmetryCoef.

Step S4103, calculate the absolute value of the difference of described power symmetry coefficient and default power symmetric reference coefficient, ratio rear and described power symmetric reference coefficient obtains the power deviation coefficient of described detected group of string;

Wherein, the power symmetric reference coefficient of described detected group of string can obtain in group string contextual information, power symmetry coefficient while obtaining detected group string operation from above-mentioned steps S4102, suppose that power deviation coefficient is InSymmetryCoef, the computing formula of this InSymmetryCoef is so:

$\mathrm{InSymmetryCoef}=\frac{\mathrm{abs}(\mathrm{RunSymmetryCoef}-\mathrm{ReferSymmetryCoef})}{\mathrm{ReferSymmetryCoef}}$

Wherein, ReferSymmetryCoef is the power symmetric reference coefficient of detected group string in group string contextual information.

Step S4104, according to described power deviation coefficient, judge whether described detected group of string occurs extremely, if so, to turn to step S4105;

Step S4105, export the abnormality alarming of described detected group of string.

Wherein, the embodiment of the present invention is by obtaining the current operate power of detected group string and the current operate power of reference group string, the current operate power of being gone here and there by detected group and the current operate power of reference group string, power symmetry coefficient while obtaining detected group string operation, the power symmetric reference coefficient of detected group of string in the power symmetry coefficient during again by operation and the group string contextual information of learning before obtains power deviation coefficient, by judging that power deviation coefficient determines group string and whether occurs extremely, can accurately navigate to group string way afterwards.

Particularly, will further to above-described embodiment, be introduced below, as shown in Fig. 4-b, a kind of group string method for detecting abnormality based on grid-connected inverters, can comprise:

Step S4201, obtain the current operate power of detected group string and the current operate power of reference group string m time respectively, described m is more than or equal to 10 positive integer;

Wherein, when group string moves in inverter, obtain the current operate power of detected group string, and the current operate power of reference group string, to judge extremely by detection power fluctuation situation.

Particularly, can obtain the current operate power of a plurality of detected group of strings and the current operate power of a plurality of reference group strings, be selected and obtain m time in embodiments of the present invention, m is one and is more than or equal to 10 positive integer, and then obtains the current operate power of m detected group string and the current operate power of m corresponding reference group string.

Step S4202, judge that whether the current operate power of described detected group of string and reference group string is effective, if so, turn to step S4203; If not, turn to step S4201;

Preferably, in step S4202, between the effective value span of current operate power Wei – 200W～20KW, therefore, can, by between the current operate power Shi Fou – 200W～20KW of judgement, judge that whether current operate power is effective.

Step S4203, judge that whether the current operate power of described detected group of string and/or reference group string meets default firm power scope, if so, turns to step S4204; If not, entering group is connected in series into detection;

Be understandable that, can be simply by current operate power, detected group string and/or reference group string being made to preliminary abnormality detection judges, wherein, power bracket when normal according to group string, a default firm power scope, in embodiments of the present invention, can this default firm power scope be set to 500W.If the current operate power of detected group string and/or reference group string is less than 500W, likely occurred extremely, to enter group and be connected in series into detection, again detect and study group string contextual information; If the current operate power of detected group string and/or reference group string is greater than 500W, will enter step S4204 so, further detect the abnormal conditions of detected group string.

The first power symmetry coefficient when step S4204, the ratio that calculates the current operate power of described detected group of string and the current operate power of described reference group string obtain described detected group of string operation;

Wherein, first by the current operate power of detected group string and the current operate power of reference group string, obtain the first power symmetry coefficient RunStringSymmetryCoef of detected group string.

The current operate power of supposing detected group string is Pm _slave, the current operate power of reference group string is Pm _magor, and the power symmetry coefficient that detected group is gone here and there while moving is Pm _slavewith Pm _magorratio, therefore, RunStringSymmetryCoef computing formula is:

StringSymmetryCoef=Pm _slave/Pm _major

Step S4205, calculate the mean value of described the first power symmetry coefficient, obtain the power symmetry coefficient of described detected group of string;

Be understandable that, obtain the current operate power of m detected group string and the current operate power of corresponding reference group string, thereby obtain corresponding m the first power symmetry coefficient, in order to make result of calculation more accurate, the value of m in the embodiment of the present invention is to be more than or equal to 10 positive integer, thereby power symmetry coefficient RunSymmetryCoef during detected group string operation is:

$\mathrm{RunSymmetrycoef}={\mathrm{\Σ}}_{j=1}^m\left(\mathrm{StringSymmetryCoef}\right(j)/m$

Wherein, m is for being detected the number of the first power symmetry coefficient of group string, and StringSymmetryCoef (j) represents that m the j in the first power symmetry coefficient is individual.

Step S4206, judge that whether described power symmetry coefficient is effective, if so, turn to step S4207; If not, turn to step S4201;

Similarly, the effective range of the power symmetry coefficient obtaining in S4205 is identical with the effective range of power reference symmetry coefficient, and preferably effectively value range is 0.2～5, therefore, can judge that power symmetry coefficient is whether between effective range value 0.2～5.

Step S4207, calculate the absolute value of the difference of described power symmetry coefficient and initialized power symmetric reference coefficient, ratio rear and described power symmetric reference coefficient obtains the power deviation coefficient of described detected group of string;

Power deviation coefficient is InSymmetryCoef, and RunSymmetryCoef calculates in above-mentioned formula, and power deviation coefficient is so:

$\mathrm{InSymmetryCoef}=\frac{\mathrm{abs}(\mathrm{RunSymmetryCoef}-\mathrm{ReferSymmetryCoef})}{\mathrm{ReferSymmetryCoef}}$

Step S4208, judge that whether described power deviation coefficient meets default abnormal judgment value, if so, turns to step S4209; If not, turn to step S4210;

Preferably, be directed to power deviation coefficient, default abnormal judgment value is greater than 0.3, therefore, by above-mentioned formula, calculates power deviation coefficient, if power deviation coefficient is greater than 0.3, explanation group string occurs abnormal.

Step S4209, judge whether the alarm status in group string contextual information is removing state, if so, turns to step 4211;

Step S4210, judge whether the alarm status in group string contextual information is asymmetrical state, if so, turns to step S4212;

Step S4211, the asymmetric alarm of generation group string;

Asymmetric alarm in step S4212, removing group string context.

The embodiment of the present invention is by under detected group string and reference group string running status, obtain respectively the current operate power of detected group string and reference group string, then by the detected ratio of organizing the current operate power of the current operate power of string and reference group string, obtain the first power symmetry coefficient, repeat above-mentioned steps and obtain m the first power symmetry coefficient, then ask the mean value of m the first power symmetry coefficient to obtain the power deviation coefficient that detected group is gone here and there while moving, the absolute value of the difference of the power symmetric reference coefficient of the detected group string of rated output Z-factor and this in group string contextual information again, if described difference and power symmetric reference coefficient ratio are greater than 0.3, the detected group string of explanation occurs abnormal, if the alarm status of this detected group string is for removing state in group string contextual information, so by the asymmetric alarm of generation group string, the embodiment of the present invention can detection and localization to any one group string in grid-connected system, utilization scope is wide.

By introducing abnormality juding coefficient for the generated energy absolute value deviation of detected group string and the situation of generated energy Z-factor, as shown in Fig. 5-a, a kind of based on grid-connected inverters group string method for detecting abnormality below, comprising:

Step S510, the generated energy that obtains detected group string and the generated energy of reference group string;

Arrange and regularly obtain the generated energy of a certain detected group of string and the generated energy of reference group string, the generated energy of detected group string is △ SlaveStringYield, the generated energy △ MajorStringYield of reference group string.

Wherein, if the generated energy numerical value of detected group of string while measuring during last time is LastStringYield, and the generated energy numerical value of detected group of string when pre-test is CurrentStringYield, the generated energy △ SlaveStringYield=CurrentStringYield-LastStringYield of so detected group string, the generated energy △ MajorStringYield that in like manner obtains reference group string, does not repeat them here.

Step S520, according to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

Wherein, by generated energy △ SlaveStringYield, the generated energy △ MajorStringYield of reference group string of detected group string and generated energy absolute value deviation and the generated energy Z-factor of organizing the detected group string of power symmetric reference coefficient acquisition of this detected group string in string contextual information, whether normal by generated energy absolute value deviation and the detected group string of generated energy Z-factor judgement generated energy within a certain period of time, thus whether the detected group string of judgement occurs abnormal.

Below the group string method for detecting abnormality based on grid-connected inverters of further Fig. 5-a being introduced is described, as shown in Fig. 5-b, a kind of group string method for detecting abnormality based on grid-connected inverters, specifically comprises:

Step S5101, the generated energy that obtains detected group string and the generated energy of reference group string;

Arrange and regularly obtain the generated energy of a certain detected group of string and the generated energy of reference group string, the generated energy of detected group string is △ SlaveStringYield, the generated energy △ MajorStringYield of reference group string.

Wherein, if the generated energy numerical value of detected group of string while measuring during last time is LastStringYield, and the generated energy numerical value of detected group of string when pre-test is CurrentStringYield, the generated energy △ SlaveStringYield=CurrentStringYield-LastStringYield of so detected group string, the generated energy △ MajorStringYield that in like manner obtains reference group string, does not repeat them here.

Step S5102, the generated energy and the product of power symmetric reference coefficient at detected group string described in group string contextual information that calculate described reference group string obtain the prediction generated energy of detected group string;

If the prediction generated energy of reference group string is PredictStringYield, the computing formula of this PredictStringYield is as follows so:

PredictStringYield=ReferSymmetryCoef*△MajorStringYield

Step S5103, the difference of calculating the generated energy of described prediction generated energy and described detected group of string obtain the generated energy absolute value deviation of described detected group of string;

Suppose that described generated energy absolute value deviation is StringYieldDeviation, the computing formula of so described StringYieldDeviation is as follows:

StringYieldDeviation=△PredictStringYield-△SlaveStringYield

Step S5104, the ratio that calculates the generated energy of described detected group of string and the generated energy of described reference group string obtain the generated energy symmetry coefficient of described detected group of string;

Wherein, suppose that generated energy symmetry coefficient is SlaveYieldChangeCoef, the computing formula of this SlaveYieldChangeCoef is as follows so:

$\mathrm{SlaveYieldChangeCoef}=\frac{\mathrm{\ΔSlaveStringYield}}{\mathrm{\ΔMajorStringYield}}$

Step S5105, calculate after the absolute value of difference of described generated energy symmetry coefficient and described power symmetric reference coefficient, the ratio of described absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string;

Wherein, first calculate the difference of generated energy symmetry coefficient and power symmetric reference coefficient, then get the absolute value of difference, the ratio that calculates again absolute value and power symmetric reference coefficient obtains generated energy Z-factor, and whether the detected group string of this generated energy Z-factor explanation fluctuates within the specific limits on generated energy.

Suppose that generated energy Z-factor is SlaveYieldSymmetryCoef, the computing formula of this SlaveYieldSymmetryCoef is as follows so:

$\mathrm{SlaveYieldSymmetryCoef}=\frac{\mathrm{abs}(\mathrm{SlaveYieldChangeCoef}-\mathrm{ReferSymmetryCoef})}{\mathrm{ReferSymmetryCoef}}$

Step S5106, judge that whether described generated energy absolute value deviation and described generated energy Z-factor meet default judgment value, if so, turn to step S5107;

Preferably, be directed to generated energy absolute value deviation, default abnormal judgment value, for being greater than 7kWh, is directed to generated energy Z-factor, and default abnormal judgment value is greater than 0.05.

Step S5107, generation group string abnormality alarming.

The power symmetric reference coefficient of going here and there in contextual information according to group in the embodiment of the present invention, and then calculate generated energy absolute value deviation and generated energy Z-factor, judge whether generated energy absolute value deviation and generated energy Z-factor meet default abnormal judgment value and judge whether detected group string occurs abnormal.

Preferably, if StringYieldDeviation>7kWh, and during SlaveYieldSymmetryCoef>0.05, determining this detected group, to go here and there within a certain period of time generated energy fluctuation excessive, to be that detected group string occurs abnormal for excessive reason to cause generated energy to fluctuate, thereby detect extremely from the generated energy fluctuation situation of detected group string.

Wherein, can first perform step S5102 and S5103, rear execution step S5104 and S5105, also can first interlock execution step S5102 and S5104, rear staggered execution step S5105, in this no limit.

Further, as shown in Fig. 5-c, a kind of group string method for detecting abnormality based on grid-connected inverters, can comprise:

Step S5201, read the refresh time of detected group string in group string contextual information;

Wherein, refresh time represents the time that the group string contextual information of detected group string is updated for the last time.

Step S5202, according to described refresh time, judge that whether the time of renewal group string contextual information surpass the default time limit, turn to step S5204; If not, turn to step S5203;

Step S5203, judge that whether alarm time surpasses Preset Time, the abnormality alarming in if so, removing group string contextual information;

Step S5204, the generated energy that obtains detected group string and the generated energy of reference group string;

Arrange and regularly obtain the generated energy of a certain detected group of string and the generated energy of reference group string, the generated energy of detected group string is △ SlaveStringYield, the generated energy △ MajorStringYield of reference group string.

Wherein, if the generated energy numerical value of detected group of string while measuring during last time is LastStringYield, and the generated energy numerical value of detected group of string when pre-test is CurrentStringYield, the generated energy △ SlaveStringYield=CurrentStringYield-LastStringYield of so detected group string, the generated energy △ MajorStringYield that in like manner obtains reference group string, does not repeat them here.

Step S5205, the generated energy and the product of power symmetric reference coefficient at detected group string described in group string contextual information that calculate described reference group string obtain the prediction generated energy of detected group string;

If the prediction generated energy of reference group string is PredictStringYield, the computing formula of this PredictStringYield is as follows so:

PredictStringYield=ReferSymmetryCoef*△MajorStringYield

Step S5206, the difference of calculating the generated energy of described prediction generated energy and described detected group of string obtain the generated energy absolute value deviation of described detected group of string;

Suppose that described generated energy absolute value deviation is StringYieldDeviation, the computing formula of so described StringYieldDeviation is as follows:

StringYieldDeviation=△PredictStringYield-△SlaveStringYield

Step S5207, the ratio that calculates the generated energy of described detected group of string and the generated energy of described reference group string obtain the generated energy symmetry coefficient of described detected group of string;

Wherein, suppose that generated energy symmetry coefficient is SlaveYieldChangeCoef, the computing formula of this SlaveYieldChangeCoef is as follows so:

$\mathrm{SlaveYieldChangeCoef}=\frac{\mathrm{\ΔSlaveStringYield}}{\mathrm{\ΔMajorStringYield}}$

Step S5208, calculate the absolute value of the difference of described generated energy symmetry coefficient and described power symmetric reference coefficient, ratio rear and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string;

Wherein, first calculate the difference of generated energy symmetry coefficient and power symmetric reference coefficient, then get the absolute value of difference, the ratio that calculates again absolute value and power symmetric reference coefficient obtains generated energy Z-factor, and whether the detected group string of this generated energy Z-factor explanation fluctuates within the specific limits on generated energy.

Suppose that generated energy Z-factor is SlaveYieldSymmetryCoef, the computing formula of this SlaveYieldSymmetryCoef is as follows so:

$\mathrm{SlaveYieldSymmetryCoef}=\frac{\mathrm{abs}(\mathrm{SlaveYieldChsngeCoef}-\mathrm{ReferSymmetryCoef})}{\mathrm{ReferSymmetryCoef}}$

Step S5209, judge that whether described generated energy absolute value deviation and generated energy Z-factor meet default abnormal judgment value, if so, turn to step S5210;

Preferably, be directed to generated energy absolute value deviation, default abnormal judgment value, for being greater than 7kWh, is directed to generated energy Z-factor, and default abnormal judgment value is greater than 0.05.

Step S5210, generation group string abnormality alarming.

The power symmetric reference coefficient of going here and there in contextual information according to group in the embodiment of the present invention, and then calculate generated energy absolute value deviation and generated energy Z-factor, by generated energy absolute value deviation and generated energy Z-factor, combine the detected group string of judgement and whether occur abnormal.

Preferably, if StringYieldDeviation>7kWh, and during SlaveYieldSymmetryCoef>0.05, determining this detected group, to go here and there within a certain period of time generated energy fluctuation excessive, to be that detected group string occurs abnormal for excessive reason to cause generated energy to fluctuate, thereby detect extremely from the generated energy fluctuation situation of detected group string.

Wherein, can first perform step S5202 and S5203, rear execution step S5204 and S5205, also can first interlock execution step S5202 and S5204, rear staggered execution step S5205, in this no limit.

As shown in Figure 6, it is a kind of based on grid-connected inverters group string abnormality detection system that the embodiment of the present invention also provides, and can comprise:

Acquiring unit 610, for according to the power symmetric reference coefficient of the detected group string of group string contextual information, obtains the abnormality juding coefficient of described detected group of string;

Judging unit 620, for judging whether described abnormality juding coefficient meets default abnormal judgment value, if so, determines that described detected group of string occurs abnormal.

Be understandable that, abnormality juding coefficient can be the power deviation coefficient of detected group string, or generated energy absolute value deviation and the generated energy Z-factor of detected group string.

Be understandable that, abnormal judgment value is can be used for normally judging whether group string abnormal numerical value occurs, and preferably, when abnormality juding coefficient is power deviation coefficient, is directed to power deviation coefficient and default abnormal judgment value is greater than 0.3; When abnormality juding coefficient is generated energy absolute value deviation and generated energy Z-factor, be directed to generated energy absolute value deviation and default abnormal judgment value is greater than 7kWh, be directed to generated energy Z-factor and default abnormal judgment value is greater than 0.05.Certainly.It will be understood by those skilled in the art that the variation according to actual conditions, above-mentioned provided numerical range is provided the abnormal judgment value that the embodiment of the present invention provides, and other numerical value that can realize beneficial effect of the present invention is all within protection domain of the present invention.

In the embodiment of the present invention, by acquiring unit 610, according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormal judgement factor of detected group string, and abnormality juding coefficient is used to indicate detected group string and whether occurs abnormal; By judging unit 620, pass through to judge whether abnormality juding coefficient meets default abnormal judgment value, if met, determine that detected group string is for abnormal group string, can be towards the group string in grid-connected inverters, directly precision navigates to the way of abnormal group of string, applied range.

As a preferred embodiment, as shown in Fig. 7-a, above-mentioned acquiring unit 610 can comprise the symmetrical detecting unit 7110 of power:

Wherein, the symmetrical detecting unit 7110 of described power comprises:

Power acquiring unit 7111, for obtaining the current operate power of detected group string and the current operate power of reference group string;

Power symmetry coefficient computing unit 7112, for according to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation;

Power deviation computing unit 7113, for obtaining the power deviation coefficient of described detected group of string according to the power symmetric reference coefficient of detected group string described in described power symmetry coefficient and group string contextual information.

Wherein, if power symmetry coefficient is RunSymmetryCoef, power deviation coefficient is InSymmetryCoef, and the computing formula of this InSymmetryCoef is so:

$\mathrm{InSymmetryCoef}=\frac{\mathrm{abs}(\mathrm{RunSymmetryCoef}-\mathrm{ReferSymmetryCoef})}{\mathrm{ReferSymmetryCoef}}$

Wherein, ReferSymmetryCoef is the power symmetric reference coefficient of detected group string in group string contextual information.

As a preferred embodiment, as shown in Fig. 7-b, above-mentioned acquiring unit 610 can comprise regularly detecting unit 7210;

Wherein, described timing detecting unit 7210 comprises:

Generated energy acquiring unit 7211, for obtaining the generated energy of detected group string and the generated energy of reference group string;

Generated energy deviation computing unit 7212, be used for according to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

As a preferred embodiment, as shown in Fig. 8-a, above-mentioned generated energy deviation computing unit 7212 comprises:

Product computing unit 810, for calculating the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information;

Absolute value calculation unit 820, obtains the generated energy absolute value deviation of described detected group of string for calculating the generated energy of described product and described detected group of string.

As a preferred embodiment, as shown in Fig. 8-b, above-mentioned generated energy deviation computing unit 7212 comprises:

Generated energy symmetry coefficient computing unit 830, obtains the generated energy symmetry coefficient of described detected group of string for calculating the ratio of the generated energy of described detected group of string and the generated energy of described reference group string;

Generated energy Z-factor computing unit 840, for calculating after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, the ratio of described absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

Wherein, if the generated energy numerical value of detected group of string while measuring during last time is LastStringYield, and the generated energy numerical value of detected group of string when pre-test is CurrentStringYield, the generated energy △ SlaveStringYield=CurrentStringYield-LastStringYield of so detected group string, the generated energy △ MajorStringYield that in like manner obtains reference group string, does not repeat them here.

If the prediction generated energy of reference group string is PredictStringYield, the computing formula of this PredictStringYield is as follows so:

PredictStringYield=ReferSymmetryCoef*△MajorStringYield

Suppose that described generated energy absolute value deviation is StringYieldDeviation, the computing formula of so described StringYieldDeviation is as follows:

StringYieldDeviation=△PredictStringYield-△SlaveStringYield

Wherein, suppose that generated energy symmetry coefficient is SlaveYieldChangeCoef, the computing formula of this SlaveYieldChangeCoef is as follows so:

$\mathrm{SlaveYieldChangeCoef}=\frac{\mathrm{\ΔSlaveStringYield}}{\mathrm{\ΔMajorStringYield}}$ As a preferred embodiment, as shown in Fig. 9-a, should can also comprise based on grid-connected inverters group string abnormality detection system:

Reference group string determining unit 910, for determining reference group string;

Power symmetric reference coefficient unit 920, for the power symmetric reference coefficient of going here and there according to the detected group of reference group string study group string contextual information.

Wherein, above-mentioned reference group string determining unit 910 is specifically for selecting one group of group string as going here and there with reference to group the group string from normal operation.

As a preferred embodiment, as shown in Fig. 9-b, above-mentioned power symmetric reference coefficient unit 920 comprises:

The first performance number acquiring unit 9210, for collecting respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and the individual described reference group string of n the average power content at described Preset Time;

The first average calculation unit 9220, obtains the first power symmetric reference coefficient of n described detected group of string for calculating the average power content of described detected group of string and the average power content of described reference group string;

The second average calculation unit 9230, obtains the power symmetric reference coefficient of described detected group of string for calculating the mean value of n described the first power symmetric reference coefficient.

Wherein, reference group string has n average power content Pn _major, having equally the average power content of n detected group string is Pn _slave, the symmetrical symmetric reference coefficient of i the first power is StringSymmetryCoef(i so), StringSymmetryCoef(i so) computing formula as follows:

StringSymmetryCoef(i)=Pn _slave(i)/Pn _major(i)

Wherein, Pn _slave(i) be the average power content of i detected group string, Pn _major(i) be the average power content of i reference group string.

Suppose power symmetric reference coefficients R eferSymmetryCoef, computing formula is as follows so:

$\mathrm{ReferSymmetryCoef}={\mathrm{\Σ}}_{i=1}^n\mathrm{StringSymmetryCoef}\left(i\right)/n$

Wherein, n represents the number of the symmetrical symmetric reference coefficient of the first power, is StringSymmetryCoef(i) the above-mentioned i calculating a first power symmetric reference coefficient.To the cumulative summation of n the first power reference coefficient, then average and obtain the power symmetric reference coefficient of detected group string.

As described in Figure 10, it is a kind of based on grid-connected inverters group string abnormality detecting apparatus that the embodiment of the present invention also provides, and can comprise: the processor of take in storer 1010 and at least one processor 1020(Figure 10 is example).In some embodiment of the embodiment of the present invention, storer 1010 can be connected by bus or alternate manner with processor 1020, and wherein, Figure 10 is to be connected to example by bus.

Wherein, processor 1020 can be carried out following steps: according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string; Judge whether described abnormality juding coefficient meets default abnormal judgment value, if so, determine that described detected group of string occurs abnormal.

In some embodiments of the invention, processor 1020 can also be carried out following steps: obtain the current operate power of detected group string and the current operate power of reference group string; According to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation; Calculate described power symmetry coefficient and organize after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in string contextual information, the ratio of described absolute value and described power symmetric reference coefficient obtains the power deviation coefficient of described detected group of string.

In some embodiments of the invention, processor 1020 can also be carried out following steps: obtain the generated energy of detected group string and the generated energy of reference group string; According to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

In some embodiments of the invention, processor 1020 can also be carried out following steps: calculate the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information; The generated energy that calculates described product and described detected group of string obtains the generated energy absolute value deviation of described detected group of string.

In some embodiments of the invention, processor 1020 can also be carried out following steps: the ratio that calculates the generated energy of described detected group of string and the generated energy of described reference group string obtains the generated energy symmetry coefficient of described detected group of string; The absolute value that calculates the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, ratio rear and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

In some embodiments of the invention, processor 1020 can also be carried out following steps: determine reference group string; According to reference group string, the power symmetric reference coefficient of detected group string in study group string contextual information.

In some embodiments of the invention, processor 1020 can also be carried out following steps: collect respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and n described reference group string the average power content at described Preset Time; Calculate the first power symmetric reference coefficient that the average power content of described detected group of string and the average power content of described reference group string obtain n described detected group of string; The mean value that calculates n described the first power symmetric reference coefficient obtains the power symmetric reference coefficient of described detected group of string.

In some embodiments of the invention, processor 1020 can also be carried out following steps: from the group string of normal operation, select one group of group string as going here and there with reference to group.

In some embodiments of the invention, storer 1010 can be used for storage sets string contextual information, abnormality juding coefficient, default abnormal judgment value.

In some embodiments of the invention, storer 1010 can be used for storage power Z-factor.

In some embodiments of the invention, storer 1010 can be used for storing generated energy absolute value deviation and generated energy Z-factor.

One of ordinary skill in the art will appreciate that all or part of step realizing in above-described embodiment method is to come the hardware that instruction is relevant to complete by program, described program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium of mentioning can be ROM (read-only memory), disk or CD etc.

Above a kind of group string method for detecting abnormality and system based on grid-connected inverters provided by the present invention is described in detail, for one of ordinary skill in the art, thought according to the embodiment of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (16)

1. the group string method for detecting abnormality based on grid-connected inverters, is characterized in that, comprising:

According to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string;

Judge whether described abnormality juding coefficient meets default abnormal judgment value, if so, determine that described detected group of string occurs abnormal.

2. method according to claim 1, is characterized in that, described abnormality juding coefficient is the power deviation coefficient of detected group string;

And then described according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string, comprising:

Obtain the current operate power of detected group string and the current operate power of reference group string;

According to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation;

According to the power symmetric reference coefficient of detected group string described in described power symmetry coefficient and group string contextual information, obtain the power deviation coefficient of described detected group of string.

3. method according to claim 1, is characterized in that, described abnormality juding coefficient is generated energy absolute value deviation and the generated energy Z-factor of detected group string;

And then described according to the power symmetric reference coefficient of detected group string in group string contextual information, obtain the abnormality juding coefficient of described detected group of string, comprising:

Obtain the generated energy of detected group string and the generated energy of reference group string;

According to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

4. method according to claim 3, it is characterized in that, described according to the generated energy of the generated energy of described detected group of string and reference group string, and the power symmetric reference coefficient of detected group string described in group string contextual information, the generated energy absolute value deviation that obtains described detected group of string, comprising:

Calculate the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information;

The generated energy that calculates described product and described detected group of string obtains the generated energy absolute value deviation of described detected group of string.

5. method according to claim 4, it is characterized in that, described according to the generated energy of the generated energy of described detected group of string and reference group string, and the power symmetric reference coefficient of detected group string described in group string contextual information, the generated energy Z-factor that obtains described detected group of string, comprising:

The ratio that calculates the generated energy of described detected group of string and the generated energy of described reference group string obtains the generated energy symmetry coefficient of described detected group of string;

Calculate after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, the ratio of described absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

6. method according to claim 1, is characterized in that, also comprises:

Determine reference group string;

According to reference group string, the power symmetric reference coefficient of detected group string in study group string contextual information.

7. according to the method described in 6 described in claim, it is characterized in that, described definite reference group string comprises:

From the group string of normal operation, select one group of group string as going here and there with reference to group.

8. according to the method described in claim 6 or 7, it is characterized in that, the described power symmetric reference coefficient according to detected group string in reference group string study group string contextual information comprises:

Collect respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and n described reference group string the average power content at described Preset Time;

Calculate the first power symmetric reference coefficient that the average power content of described detected group of string and the average power content of described reference group string obtain n described detected group of string;

The mean value that calculates n described the first power symmetric reference coefficient obtains the power symmetric reference coefficient of described detected group of string.

9. based on a grid-connected inverters group string abnormality detection system, it is characterized in that, comprising:

Acquiring unit, for according to the power symmetric reference coefficient of the detected group string of group string contextual information, obtains the abnormality juding coefficient of described detected group of string;

Judging unit, for judging whether described abnormality juding coefficient meets default abnormal judgment value, if so, determines that described detected group of string occurs abnormal.

10. system according to claim 9, is characterized in that, described acquiring unit comprises the symmetrical detecting unit of power;

Wherein, the symmetrical detecting unit of described power comprises:

Power acquiring unit, for obtaining the current operate power of detected group string and the current operate power of reference group string;

Power symmetry coefficient computing unit, for according to the current operate power of the current operate power of described detected group of string and described reference group string, the power symmetry coefficient while obtaining described detected group of string operation;

Power deviation computing unit, for obtaining the power deviation coefficient of described detected group of string according to the power symmetric reference coefficient of detected group string described in described power symmetry coefficient and group string contextual information.

11. systems according to claim 9, is characterized in that, described acquiring unit comprises regularly detecting unit;

Wherein, described timing detecting unit comprises:

Generated energy acquiring unit, for obtaining the generated energy of detected group string and the generated energy of reference group string;

Generated energy deviation computing unit, be used for according to the generated energy of the generated energy of described detected group of string and reference group string, and be detected the power symmetric reference coefficient that group is gone here and there described in group string contextual information, obtain respectively generated energy absolute value deviation and the generated energy Z-factor of described detected group of string.

12. systems according to claim 11, is characterized in that, described generated energy deviation computing unit comprises:

Product computing unit, for calculating the generated energy of described reference group string and the product of the power symmetric reference coefficient of detected group string described in group string contextual information;

Absolute value calculation unit, obtains the generated energy absolute value deviation of described detected group of string for calculating the generated energy of described product and described detected group of string.

13. systems according to claim 12, is characterized in that, described generated energy deviation computing unit comprises:

Generated energy symmetry coefficient computing unit, obtains the generated energy symmetry coefficient of described detected group of string for calculating the ratio of the generated energy of described detected group of string and the generated energy of described reference group string;

Generated energy Z-factor computing unit, for calculating after the absolute value of the difference of the power symmetric reference coefficient of detected group string described in described generated energy symmetry coefficient and group string contextual information, the ratio of described absolute value and described power symmetric reference coefficient obtains the generated energy Z-factor of described detected group of string.

14. systems according to claim 9, is characterized in that, also comprise:

Reference group string determining unit, for determining reference group string;

Power symmetric reference coefficient unit, for the power symmetric reference coefficient of going here and there according to the detected group of reference group string study group string contextual information.

15. systems according to claim 14, is characterized in that, described reference group string determining unit is specifically for selecting one group of group string as going here and there with reference to group the group string from normal operation.

16. according to the system described in claims 14 or 15, it is characterized in that, described power symmetric reference coefficient unit comprises:

The first performance number acquiring unit, for collecting respectively the performance number of detected group of string and the reference group string of n Preset Time, and calculate n described detected group of string at the average power content of described Preset Time and the individual described reference group string of n the average power content at described Preset Time;

The first average calculation unit, obtains the first power symmetric reference coefficient of n described detected group of string for calculating the average power content of described detected group of string and the average power content of described reference group string;

The second average calculation unit, obtains the power symmetric reference coefficient of described detected group of string for calculating the mean value of n described the first power symmetric reference coefficient.

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