CN103364723B - Based on the running status of wind generator analytical approach of electric current and voltage balance - Google Patents

Abstract

The present invention relates to a kind of running state analysis method of aerogenerator, particularly relate to a kind of running status of wind generator analytical approach based on three-phase voltage current balance.(1) history three-phase voltage and current data read; (2) three-phase voltage and the uneven drift correction of current system; (the calculating of 3 tri-phase unbalance factor limit values; (4) three-phase voltage and current data collection in real time; (5) tri-phase unbalance factor calculates in real time; (6) running status of wind generator analysis.The present invention can realize more effectively and running status of wind generator monitoring and prediction accurately, is also aerogenerator maintenance and repair and provides more effective and decision support accurately.

Description

Based on the running status of wind generator analytical approach of electric current and voltage balance

Technical field

The present invention relates to a kind of aerogenerator, particularly relate to a kind of running status of wind generator analytical approach based on electric current and voltage balance.

Background technology

Along with country is to the input energetically of wind-powered electricity generation energy industry, the scale of wind energy turbine set expands rapidly, causes the operation management of wind-powered electricity generation enterprise to be faced with huge pressure, especially in aerogenerator management and maintenance.Meanwhile, aerogenerator disorderly closedown happens occasionally, and the generation of burst accident is worried by wind-powered electricity generation enterprise.At present, the aerogenerator operation maintenance maintenance means of employing have certain hysteresis quality, and on-the-spot aerogenerator maintenance and repair Personnel Skill Levels is general lower, is difficult to carry out maintenance and repair to aerogenerator timely and effectively.

Constantly build up due to wind energy turbine set and put into effect, aerogenerator quantity increases rapidly, and carrying out operation maintenance maintenance to aerogenerator is timely and effectively a problem demanding prompt solution.Due to the limited amount of aerogenerator operation maintenance maintenance personal, the contradictions such as running status of wind generator monitoring technology means are single highlight, owing to cannot carry out the risk increase of the aerogenerator fault that maintenance and repair causes in time to aerogenerator.Usually, the warning system that wind energy turbine set can be installed based on data acquisition and supervisor control is monitored running status of wind generator, but because it is fault post-event alarm, maintenance personal can only keep in repair aerogenerator after fault occurs, and cannot provide running status of wind generator information for maintenance and repair personnel.For most wind energy turbine set, it adopts the mode of regular visit and fault correction maintenance to carry out maintenance to aerogenerator more than the maintenance and repair of aerogenerator.Because aerogenerator Maintenance Resource is in short supply and technical conditions are limited; be difficult to reach on-call maintenance to the maintenance and repair of aerogenerator; cause patrolling and examining in interval and cannot carry out maintenance and repair timely to aerogenerator; just can be keeped in repair after aerogenerator breaks down patrolling and examining in interval to only have; not only can cause maintenance shutdown loss, too increase aerogenerator maintenance cost.

Wind-power electricity generation has very large different from conventional Power Generation Modes such as thermal power generation, and wind-power electricity generation has intermittence and randomness.The generating set running state analysis method adopted in the conventional Power Generation Modes such as thermal power generation is difficult to be applied in wind power plant running state analysis.For the problems referred to above, the invention provides a kind of running status of wind generator analytical approach based on electric current and voltage balance, real-time analysis can be carried out to running status of wind generator.The running status of wind generator information that imply in the three-phase voltage exported by utilizing aerogenerator and three-phase current data, realizes analyzing running status of wind generator.

Summary of the invention

The invention provides a kind of running status of wind generator analytical approach based on electric current and voltage balance to solve the problems of the technologies described above, object analyzes running status of wind generator.

For reaching above-mentioned purpose, the present invention is based on the running status of wind generator analytical approach of electric current and voltage balance, comprise the steps: that (1) history three-phase voltage and current data read: from wind farm data collection and supervisor control database, read effective history three-phase voltage and current data; (2) three-phase voltage and the uneven drift correction of current system: the phase voltage in the history three-phase voltage data that employing is read is as benchmark, the uneven drift correction of system is carried out to other two phase voltages, with one for benchmark, least square method is adopted to carry out linear fit to other two-phase respectively, after linear matching, obtain other two phase voltage value revised; A phase current in the history three-phase current data that employing is read is as benchmark, the uneven drift correction of system is carried out to other biphase current, with a phase current for benchmark, least square method is adopted to carry out linear fit to other biphase current respectively, after linear matching, obtain other biphase current value revised; (3) calculating of tri-phase unbalance factor limit value: the every phase degree of unbalancedness first calculating history three-phase voltage data respectively; Secondly, non-equilibrium among three phase voltages △ V=max{ △ V is calculated _a, △ V _b, △ V _c, the standard deviation of the non-equilibrium among three phase voltages △ V of last statistical history three-phase voltage data, and it can be used as non-equilibrium among three phase voltages limit value; Calculate history three-phase current unbalance degree limit value: first, calculate every phase degree of unbalancedness of history three-phase current data respectively; Secondly, three-phase current unbalance degree △ I=max{ △ I is calculated _a, △ I _b, △ I _c, the standard deviation of the three-phase current unbalance degree △ I of last statistical history three-phase current data, and it can be used as three-phase current unbalance degree limit value; (4) three-phase voltage and current data collection in real time: read three-phase voltage and current data in real time from wind farm data collection and supervisor control; (5) tri-phase unbalance factor calculates in real time: first, to the three-phase voltage of Real-time Collection and current data three-phase voltage and the uneven drift correction of current system, then, three-phase voltage and the non-equilibrium among three phase voltages corresponding to electric current and three-phase current unbalance degree is calculated; (6) running status of wind generator analysis: tri-phase unbalance factor is contrasted with tri-phase unbalance factor limit value, judge running status of wind generator, after completing running status of wind generator judgement, be back to (4) step and repeat.

The history three-phase voltage of described reading and current data time span are at least 15 days, and the acquisition time of data is spaced apart 1 minute, carry out pre-service to the historical data read, and remove the invalid data read in data.

The data that described invalid data gathers when being and shutting down, the data gathered during fault, the data gathered under extreme weather conditions, the data gathered during network failure, the data gathered when the data gathered during sensor fault and aerogenerator debugging; Wherein, extreme weather conditions refers to thunderbolt, hail, hurricane, earthquake, tsunami, flood, volcanic eruption.

The uneven drift correction of described three-phase voltage system is with A phase voltage V _aas benchmark, to B phase voltage V _bwith C phase voltage V _ccarry out the uneven drift correction of system, revised B phase voltage value V _b'=k ₁v _b+ t ₁with C phase voltage value V _c'=k ₂v _c+ t ₂, wherein k ₁, k ₂, t ₁, t ₂for fitting parameter, k ₁and k ₂span be [0,1], t ₁and t ₂span be [0,480]; The uneven drift correction of three-phase current system is with A phase current I _aas benchmark, to B phase current I _bwith C phase current I _ccarry out the uneven drift correction of system, revised B phase current values I' _b=k ₃i _b+ t ₃with C phase current values I' _c=k ₄i _c+ t ₄, wherein k ₃, k ₄, t ₃, t ₄for fitting parameter, k ₃and k ₄span be [0,1], t ₃and t ₄span be [0,480].

Every phase computing formula in the calculating of described non-equilibrium among three phase voltages is: ${\mathrm{\ΔV}}_A=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_A},{\mathrm{\ΔV}}_B=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_B}$ With ${\mathrm{\ΔV}}_C=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_C};$ Every phase computing formula in the calculating of described three-phase current unbalance degree is: ${\mathrm{\ΔI}}_A=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_A},{\mathrm{\ΔI}}_B=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_B}$ With

${\mathrm{\ΔI}}_C=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_C}.$

The time interval of the data acquisition in described real-time three-phase voltage and current data collection is 1 minute.

Described tri-phase unbalance factor contrasts with tri-phase unbalance factor limit value, when the three-phase voltage of Real-time Collection or the tri-phase unbalance factor of electric current are in non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value, judge that aerogenerator is as normal operating condition; When the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current are in the non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value interval of 1 times and 3 times, judge that aerogenerator is as abnormal operational conditions; 3., when non-equilibrium among three phase voltages limit value more than 3 times of the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current or three-phase current unbalance degree limit value, judge that aerogenerator is as malfunction.

Advantageous effect of the present invention: the present invention can contrast with tri-phase unbalance factor limit value according to the real-time tri-phase unbalance factor of aerogenerator, judge running status of wind generator, effectively can analyze the running status of aerogenerator, maintenance and repair can be carried out to aerogenerator in advance.

Accompanying drawing explanation

The following drawings is only intended to schematically illustrate the present invention and explain, not delimit the scope of the invention.Wherein,

Fig. 1 is process flow diagram of the present invention.

Embodiment

In order to there be understanding clearly to technical characteristic of the present invention, object and effect, now contrast accompanying drawing and the specific embodiment of the present invention is described.

Embodiment

The present invention implements under wind energy turbine set is provided with data acquisition and supervisor control (SCADA), and SCADA system has following functions.

(1) can gather and store aerogenerator sensing data, especially, the three-phase voltage data that SCADA system can gather and store and three-phase current data, and the fetch interface of the database storing three-phase voltage data and three-phase current data is provided.

(2) be not less than 15 days the working time of SCADA system, especially, must store in its database and be not less than the three-phase voltage of 15 days and the historical data of three-phase current, and data collection interval be not more than 1 minute.When data collection interval is less than 1 minute, collection need be subtracted to data, to meet the present invention to be spaced apart 1 minute requirement to acquisition time.

(3) SCADA system also needs the fetch interface providing real-time data collection.

Except above-mentioned points, enforcement of the present invention also needs wind energy turbine set to provide following record, and the time of record is not less than the working time of SCADA system, and synchronous for working time with SCADA system during record:

(1) aerogenerator outage record, comprises shutdown initial time.

(2) aerogenerator failure logging, comprises fault generation or discovery time and fault and removes the time.

(3) extreme weather record, comprises extreme weather phenomenon and initial times thereof such as referring to thunderbolt, hail, hurricane, earthquake, tsunami, flood, volcanic eruption.

(4) network failure record, comprises network and occurs or discovery time and failure recovery time.

(5) sensor fault record, comprises sensing and to shout or discovery time and fault remove the time.

(6) aerogenerator debugging recording, comprises aerogenerator debugging initial time.

The present invention is based on the running status of wind generator analytical approach of electric current and voltage balance, comprise the steps; (1) history three-phase voltage and current data read: from SCADA system database, read effective history three-phase voltage and current data; It is 30 days that history three-phase voltage and current data read time span; the sampling time interval of data is 1 minute; pre-service is carried out to the historical data read; pre-service is remove the invalid data read in data; the data that invalid data gathers when comprising shutdown, the data gathered during fault, the data gathered under extreme weather conditions; the data gathered during network failure, the data gathered when the data gathered during sensor fault and aerogenerator debugging.

(2) three-phase voltage and the uneven drift correction of current system: the phase voltage in the history three-phase voltage data that employing is read is as benchmark, to other two phase voltage with carry out the uneven drift correction of system, with one for benchmark, least square method is adopted to carry out linear fit to other two-phase respectively, after linear matching, obtain other two phase voltage value revised, the uneven drift correction of three-phase voltage system is with A phase voltage V _aas benchmark, to B phase voltage V _bwith C phase voltage V _ccarry out the uneven drift correction of system, revised B phase voltage value V _b'=k ₁v _b+ t ₁with C phase voltage value V _c'=k ₂v _c+ t ₂, wherein k ₁, k ₂, t ₁, t ₂for fitting parameter, k ₁and k ₂span be [0,1], t ₁and t ₂span be [0,480]; A phase current in the history three-phase current data that employing is read is as benchmark, the uneven drift correction of system is carried out to other biphase current, with a phase current for benchmark, least square method is adopted to carry out linear fit to other biphase current respectively, after linear matching, obtain other biphase current value revised, the uneven drift correction of three-phase current system is with A phase current I _aas benchmark, to B phase current I _bwith C phase current I _ccarry out the uneven drift correction of system, revised B phase current values I' _b=k ₃i _b+ t ₃with C phase current values I' _c=k ₄i _c+ t ₄, wherein k ₃, k ₄, t ₃, t ₄for fitting parameter, k ₃and k ₄span be [0,1], t ₃and t ₄span be [0,480].

(3) calculating of tri-phase unbalance factor limit value: the every phase degree of unbalancedness first calculating history three-phase voltage data respectively; Secondly, non-equilibrium among three phase voltages △ V=max{ △ V is calculated _a, △ V _b, △ V _c, the standard deviation of the non-equilibrium among three phase voltages △ V of last statistical history three-phase voltage data, and it can be used as non-equilibrium among three phase voltages limit value; Calculate history three-phase current unbalance degree limit value: first, calculate every phase degree of unbalancedness of history three-phase current data respectively; Secondly, three-phase current unbalance degree △ I=max{ △ I is calculated _a, △ I _b, △ I _c, the standard deviation of the three-phase current unbalance degree △ I of last statistical history three-phase current data, and it can be used as three-phase current unbalance degree limit value; Every phase computing formula in the calculating of non-equilibrium among three phase voltages limit value is: ${\mathrm{\ΔV}}_A=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_A},{\mathrm{\ΔV}}_B=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_B}$ With ${\mathrm{\ΔV}}_C=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_C};$ Every phase computing formula in the calculating of described three-phase current unbalance degree limit value is: ${\mathrm{\ΔI}}_A=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_A},$ ${\mathrm{\ΔI}}_B=\frac{\max \{I_A-I_B^{\′}|,|I_B^{\′}-I_C^{\′}|,|I_C^{\′}-I_A|\}}{I_B}$ With ${\mathrm{\ΔI}}_C=\frac{\max \left\{\right|I_A-I_B^{\′}|,|I_B^{\′}-I_C^{\′}|,|I_C^{\′}-I_A\left|\right\}}{I_C},$ Ask for the maximal value in braces in sequence of values, it is to technology as well known to those skilled in the art;

(4) three-phase voltage and current data collection in real time: read three-phase voltage and current data in real time from SCADA system; The time interval of the data sampling in real-time three-phase voltage and current data collection is 1 minute;

(5) in real time tri-phase unbalance factor calculates: first to the three-phase voltage of Real-time Collection and current data three-phase voltage and the uneven drift correction of current system, then, three-phase voltage and the non-equilibrium among three phase voltages corresponding to electric current and three-phase current unbalance degree is calculated in real time;

(6) running status of wind generator analysis: real-time tri-phase unbalance factor is contrasted with tri-phase unbalance factor limit value, judge running status of wind generator, when tri-phase unbalance factor contrasts with tri-phase unbalance factor limit value, when the three-phase voltage of Real-time Collection or the tri-phase unbalance factor of electric current are in non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value, judge that aerogenerator is as normal operating condition; When the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current are in the non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value interval of 1 times and 3 times, judge that aerogenerator is as abnormal operational conditions; When non-equilibrium among three phase voltages limit value more than 3 times of the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current or three-phase current unbalance degree limit value, judge that aerogenerator is as malfunction.After completing running status of wind generator judgement, be back to (4) step and repeat.

Based on analyzing the aerogenerator three kinds of running statuses drawn above, maintenance personal can realize:

(1) adjust according to the patrol time interval of running status of wind generator to aerogenerator.Usually the patrol time interval being in the aerogenerator of normal operating condition can proper extension 20%;

According to running status of wind generator to aerogenerator in time or safeguard when selecting, and suitably shorten monitoring time interval (2).As aerogenerator belongs to abnormal operational conditions, then when needing immediately or select, aerogenerator is safeguarded, and suitably shorten monitoring time interval, usually can shorten 50%;

(3) according to running status of wind generator to aerogenerator on-call maintenance, as aerogenerator belong to malfunction run, then need to keep in repair aerogenerator immediately.

Three-phase voltage of the present invention and three-phase electricity flow valuve are the three-phase alternating voltage of aerogenerator output and the effective value of three-phase alternating current.Fan operation state normally refers to that in the two weeks after gathering the date corresponding to the historical data read, aerogenerator non-fault occurs.

The present invention, suppose that the probability distribution that it exports three-phase voltage or current unbalance factor when aerogenerator normally runs meets Gaussian distribution, the standard deviation of the non-equilibrium among three phase voltages of 1 times or three-phase current unbalance degree Gaussian distribution corresponding to three-phase voltage or current unbalance factor.The validity of Gaussian distribution hypothesis is professional and technical personnel in the field's common practise.

The standard variance of the present invention to non-equilibrium among three phase voltages and three-phase current unbalance degree is added up, and its statistical method is professional and technical personnel in the field's common practise.

The present invention also can with B phase voltage V _bas benchmark, to A phase voltage V _awith C phase voltage V _ccarry out the uneven drift correction of system.

The foregoing is only the schematic embodiment of the present invention, and be not used to limit scope of the present invention.Any those skilled in the art, the equivalent variations done under the prerequisite not departing from design of the present invention and principle and amendment, all should belong to the scope of protection of the invention.

Claims (7)

1., based on the running status of wind generator analytical approach of electric current and voltage balance, it is characterized in that comprising the steps: that history three-phase voltage and current data read: from wind farm data collection and supervisor control database, read effective history three-phase voltage and current data;

Three-phase voltage and the uneven drift correction of current system: the phase voltage in the history three-phase voltage data that employing is read is as benchmark, the uneven drift correction of system is carried out to other two phase voltages, with one for benchmark, least square method is adopted to carry out linear fit to other two-phase respectively, after linear matching, obtain other two phase voltage value revised; A phase current in the history three-phase voltage data that employing is read is as benchmark, the uneven drift correction of system is carried out to other biphase current, with a phase current for benchmark, least square method is adopted to carry out linear fit to other biphase current respectively, after linear matching, obtain other biphase current value revised;

The calculating of tri-phase unbalance factor limit value: the every phase degree of unbalancedness first calculating history three-phase voltage data respectively; Secondly, non-equilibrium among three phase voltages △ V=max{ △ V is calculated _a, △ V _b, △ V _c, the standard deviation of the non-equilibrium among three phase voltages △ V of last statistical history three-phase voltage data, and it can be used as non-equilibrium among three phase voltages limit value; Calculate history three-phase current unbalance degree limit value: first, calculate every phase degree of unbalancedness of history three-phase current data respectively; Secondly, three-phase current unbalance degree △ I=max{ △ I is calculated _a, △ I _b, △ I _c, the standard deviation of the three-phase current unbalance degree △ I of last statistical history three-phase current data, and it can be used as three-phase current unbalance degree limit value;

Real-time three-phase voltage and current data collection: read three-phase voltage and current data in real time from wind farm data collection and supervisor control;

Real-time tri-phase unbalance factor calculates: first, to the three-phase voltage of Real-time Collection and current data three-phase voltage and the uneven drift correction of current system, then, three-phase voltage and the non-equilibrium among three phase voltages corresponding to electric current and three-phase current unbalance degree is calculated in real time;

Running status of wind generator is analyzed: contrasted with tri-phase unbalance factor limit value by tri-phase unbalance factor, judges running status of wind generator.

2. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 1, it is characterized in that described history three-phase voltage and current data read time span is at least 15 days, the acquisition time of data is spaced apart 1 minute, carry out pre-service to the historical data read, pre-service is remove the invalid data read in data.

3. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 2; it is characterized in that the data that described invalid data gathers when comprising shutdown; the data gathered during fault; the data gathered under extreme weather conditions; the data gathered during network failure, the data gathered when the data gathered during sensor fault and aerogenerator debugging.

4. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 1, is characterized in that the uneven drift correction of described three-phase voltage system is with A phase voltage V _aas benchmark, to B phase voltage V _bwith C phase voltage V _ccarry out the uneven drift correction of system, revised B phase voltage value V ' _b=k ₁v _b+ t ₁with C phase voltage value V ' _c=k ₂v _c+ t ₂, wherein k ₁, k ₂, t ₁, t ₂for fitting parameter, k ₁and k ₂span be [0,1], t ₁and t ₂span be [0,480]; The uneven drift correction of three-phase current system is with A phase current I _aas benchmark, to B phase current I _bwith C phase current I _ccarry out the uneven drift correction of system, revised B phase current values I' _b=k ₃i _b+ t ₃with C phase current values I' _c=k ₄i _c+ t ₄, wherein k ₃, k ₄, t ₃, t ₄for fitting parameter, k ₃and k ₄span be [0,1], t ₃and t ₄span be [0,480].

5. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 1, is characterized in that the every phase computing formula in the calculating of described non-equilibrium among three phase voltages is: ${\mathrm{\ΔV}}_A=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_A},{\mathrm{\ΔV}}_B=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_B}$ With ${\mathrm{\ΔV}}_C=\frac{\max \left\{\left|V_A-V_B^{\′}\right|,\left|V_B^{\′}-V_C^{\′}\right|,\left|V_C^{\′}-V_A\right|\right\}}{V_C};$

Every phase computing formula in the calculating of described three-phase current unbalance degree is: ${\mathrm{\ΔI}}_A=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_A},{\mathrm{\ΔI}}_B=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_B}$ With ${\mathrm{\ΔI}}_C=\frac{\max \left\{\left|I_A-I_B^{\′}\right|,\left|I_B^{\′}-I_C^{\′}\right|,\left|I_C^{\′}-I_A\right|\right\}}{I_C}.$

6. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 1, is characterized in that the time interval of the data acquisition in described real-time three-phase voltage and current data collection is 1 minute.

7. the running status of wind generator analytical approach based on electric current and voltage balance according to claim 1, it is characterized in that described tri-phase unbalance factor contrasts with tri-phase unbalance factor limit value, when the three-phase voltage of Real-time Collection or the tri-phase unbalance factor of electric current are in non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value, judge that aerogenerator is as normal operating condition; When the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current are in the non-equilibrium among three phase voltages limit value or three-phase current unbalance degree limit value interval of 1 times and 3 times, judge that aerogenerator is as abnormal operational conditions; When non-equilibrium among three phase voltages limit value more than 3 times of the three-phase voltage of Real-time Collection and the tri-phase unbalance factor of electric current or three-phase current unbalance degree limit value, judge that aerogenerator is as malfunction.