A method for automatically analyzing test results of high voltage ride-through of a photovoltaic inverter

Abstract

The application relates to the field of power system automation technology and discloses a photovoltaic inverter high-voltage ride-through test result automatic analysis method, which reads high-voltage ride-through test data of a photovoltaic inverter, first judges single and continuous high-voltage ride-through faults, classifies single high-voltage ride-through faults into three-phase faults and two-phase faults, further calculates no-load test data, and if the no-load test data is qualified, further calculates voltage drop depth, drop duration, reactive current response time, reactive current duration, reactive current exit time and active power fluctuation of load data; the no-load test data of continuous high-voltage ride-through is calculated, and if the no-load test data is qualified, whether the load test data is off-grid is further judged; if not, unqualified is output. The photovoltaic inverter high-voltage ride-through test result automatic analysis is accurately realized, and the test waveform and the calculation result are automatically stored in a word.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system automation, and in particular to a photovoltaic inverter high-voltage ride-through test result automatic analysis method. BACKGROUND

[0002] With the construction of new power systems, the installed capacity of new energy is becoming higher and higher, and the voltage stability requirement of the power grid is becoming higher and higher. In addition, the national standards and industry standards such as GB / T 19964-2024 "Technical Regulation for Access of Photovoltaic Power Station to Power System", GB / T 40594-2021 "Technical Guide for Power System Source Coordination", GB / T 37408-2019 "Technical Requirements for Photovoltaic Power Generation Grid-connected Inverter", and NB / T10324-2019 "Photovoltaic Power Station High Voltage Ride-through Detection Technical Specification" require that photovoltaic inverters must carry out single and continuous high-voltage ride-through tests, and the test point voltage is required to be 115%, 120%, 125%, and 130% Un. In addition, the no-load and load high-voltage ride-through tests under three-phase and two-phase faults need to be carried out, and the load test is divided into high-power and low-power working conditions. At least two continuous tests need to be carried out under each voltage drop point in each working condition.

[0003] The standard requires that the high-voltage ride-through test results need to be analyzed, but at present, only manual calculation of test data is relied on. After the on-site test is completed, the test results need to be analyzed in time to facilitate the next step of work. The on-site test has many working conditions, and it takes 4 days for a person to complete the high-voltage ride-through test data analysis of a photovoltaic inverter. Therefore, after the on-site data collection is completed, at least 4 days are needed to wait for the next step of work, which seriously affects the next step of work. The irradiance of photovoltaic power stations in some areas of China is unstable, the output fluctuation is large, the test window period is short, and the long test result analysis time exacerbates the test cycle. SUMMARY

[0004] The purpose of the present application is to solve the problems of the prior art and provide a photovoltaic inverter high-voltage ride-through test result automatic analysis method to automatically and quickly carry out photovoltaic inverter high-voltage ride-through result analysis.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A photovoltaic inverter high-voltage ride-through test result automatic analysis method includes the following steps:

[0007] Step 1, read the high-voltage ride-through test results of the photovoltaic inverter based on on-site test, hardware-in-the-loop electromagnetic transient simulation, or non-real-time electromagnetic transient simulation. The test results include the voltage and current instantaneous values of the high-voltage side or low-voltage side of the photovoltaic inverter step-up transformer;

[0008] Step 2, calculate the effective value of photovoltaic inverter high voltage ride through test results;

[0009] Step 3, distinguish single and continuous high voltage ride through test results based on the line voltage of fundamental positive sequence component;

[0010] Step 4, classify single high voltage ride through test data into three-phase fault and two-phase fault; three-phase fault and two-phase fault ride through test data are based on active power P 前1 , P 前2 before voltage rise. 前1 , P 前2 greater than 0.05 times rated active power is load test data, and active power P 前1 , P 前2 less than or equal to 0.05 times rated active power is no-load test data.

[0011] Step 5, calculate voltage rise value and duration for three-phase fault no-load test data, if voltage rise value and duration meet standard requirements, output no-load test data qualified, otherwise output unqualified; for three-phase fault load test data, judge whether it is off-grid, if off-grid, judge as unqualified, otherwise further calculate voltage rise value U swell1 , duration t swell1 based on fundamental positive sequence line voltage, calculate reactive current response time t res1 , reactive current duration t last1 , reactive current exit time t ree1 , calculate active drop depth P dip1 ; if t res1 is greater than 30ms, or t ree1 is greater than 30ms, output unqualified, otherwise judge whether P dip1 is greater than 0.9P 前1 , P dip1 ≥ 0.9P 前1 , store test waveform and calculation results in word document automatically; P dip1 < 0.9P 前1 , calculate active recovery time t re1 , if t re1 ≤ 40ms, store test waveform and calculation results in word document automatically, otherwise output unqualified.

[0012] Step 6, calculate voltage rise value and duration for two-phase fault no-load test data, if voltage rise value and duration meet standard requirements, output no-load test data qualified, otherwise output unqualified; for two-phase fault load test data, judge whether it is off-grid, if off-grid, judge as unqualified, otherwise further calculate voltage rise value Uswell2 duration t swell2 , calculate the reactive current response time t res2 , reactive current duration t last2 , reactive current exit time t ree2 , calculate the active drop depth P dip2 ; determine P dip2 is greater than 0.9 times P 前2 , P dip2 ≥ 0.9P 前2 , the test waveform and the calculation results are automatically stored in the word document; P dip2 < 0.9P 前2 , calculate the active recovery time t re2 , if t re2 ≤ 40ms, the test waveform and the calculation results are automatically stored in the word document, otherwise output unqualified;

[0013] Step 7, based on the active power P 前3 before the voltage rise, the continuous high voltage ride through test data is divided into no-load test data and load test data, the active power P 前3 greater than 0.05 times the rated active power is load test data, and the active power P 前3 less than or equal to 0.05 times the rated active power is no-load test data; Step 8, for the continuous high voltage ride through no-load test data, the voltage rise value and the duration are calculated, and the voltage rise value and the duration meet the standard requirements, then output the no-load test data qualified, otherwise output unqualified; for the continuous high voltage ride through load test data, determine whether it is off-grid, if off-grid, it is judged as unqualified, otherwise the test waveform and the calculation results are automatically stored in the word document.

[0014] Preferably, in step 2, the fundamental phase voltage, line voltage and fundamental positive sequence component of line voltage, active power, active current, reactive power and reactive current effective value are calculated by full-wave FFT.

[0015] Preferably, in step 3, the high voltage ride through data includes single high voltage ride through and continuous high voltage ride through test data, and the single high voltage ride through test working condition includes 115%~130%Un, and the continuous high voltage ride through test working condition includes low-high voltage ride through test: 0%Un-130%Un, or continuous two or more high-high voltage ride through test 130%Un-~130%Un test.

[0016] Preferably, the single high voltage ride through and continuous high-high voltage ride through no-load test data are judged according to GB / T19964 standard, the voltage deviation is ±3%, and the duration deviation is ±20ms, specifically:

[0017] Voltage rise per unit value U swell :1.15±0.03,duration t swell :10000±20ms;

[0018] Voltage rise per unit value U swell :1.2±0.03,duration t swell :10000±20ms;

[0019] Voltage rise per unit value U swell :1.25±0.03,duration t swell :1000±20ms;

[0020] Voltage rise per unit value U swell :1.3±0.03,duration t swell :500±20ms;

[0021] The continuous low-high voltage ride-through no-load test data is judged according to GB / T 19964 standard. The voltage drop deviation is ±5%, the voltage rise deviation is ±3%, and the duration deviation is ±20ms. Specifically:

[0022] Voltage drop amplitude U dip :0.0+0.05,duration t dip :150±20;

[0023] Voltage increase amplitude U swell :1.30±0.03,duration t swell :500±20.

[0024] Preferably, in step 4, the fault classification method is specifically:

[0025] Calculate the average fundamental phase voltage U of phases A, B, and C before the voltage drops avg ; Calculate the fundamental phase voltage average value U of phases A, B, and C respectively Aavg 、U Bavg 、U Cavg ; Set the judgment threshold △U to 0.4;

[0026] The judgment method is:

[0027] If U Aavg -U avg >△U and U Bavg -U avg >△U and U Cavg -U avg >△U, it is an ABC phase fault;

[0028] If U Aavg -U avg >△U and UBavg -U avg >△U and U Cavg -U avg <△U, it is an AB phase fault;

[0029] If U Aavg -U avg >△U and U Bavg -U avg <△U and U Cavg -U avg >△U, it is an AC phase fault;

[0030] If U Aavg -U avg <△U and U Bavg -U avg >△U and U Cavg -U avg >△U, it is a BC phase fault;

[0031] The ABC phase fault is a three-phase fault, and the AB phase fault, the AC phase fault and the BC phase fault are two-phase faults.

[0032] Preferably, in steps 5 and 6, the test result calculation process is as follows:

[0033] S1, the voltage rise value U swell1 , U swell2 is the per-unit value after the voltage is stable after the voltage rise;

[0034] S2, the voltage rise duration t swell1 , t swell2 is t Uend -t Ustart ;

[0035] Wherein, t Ustart is the voltage rise completion time, and t Uend is the voltage recovery start time; the standard deviation of the per-unit value of the fundamental positive sequence line voltage or the fundamental phase voltage is calculated respectively, and the time point at which the standard deviation is less than 0.003 during the period from when the voltage rises to 1.1Un to when the voltage drops to 1.1Un is the voltage rise completion time; the first time point at which the standard deviation is greater than 0.003 during the period from the voltage rise completion time t Ustart to when the voltage drops to 1.1Un is the voltage recovery start time;

[0036] S3, the reactive current response time t res1 , t res2 is t Iqstart -t 1.1start ;

[0037] Wherein, t Iqstartrepresents the starting time point when the reactive current absorbed by the photovoltaic inverter is greater than 90% of the reactive current injection reference value; 1.1start represents the time point when the voltage rises to 1.1Un;

[0038] The reactive current injection reference value is: 1.5*(U swell -1.1)*I n , wherein I n is the rated current of the photovoltaic inverter, and the maximum reactive current does not exceed 1.05I n ;

[0039] S4, the reactive current duration t last1 , t last2 is: t Iqend -t Iqstart ;

[0040] , wherein t Iqend represents the ending time point when the reactive current absorbed by the photovoltaic inverter is greater than 90% of the reactive current injection reference value;

[0041] S5, the reactive current exit time t ree1 , t ree2 is: t Iqtuichu -t Iqend ;

[0042] , wherein t Iqtuichu represents the reactive current increment exit, that is, the time point when the standard deviation of the reactive current is less than 0.003 after the time point t Iqend ;

[0043] S6, the active power recovery time t re1 , t re2 is: t Pend -t Uend ;

[0044] , wherein t Pend represents the time point when the active power recovers to the value under the current illumination, and t Uend represents the time point when the standard deviation of the active power is less than 0.003 after the time point when the voltage starts to recover, which is the time point when the active power recovers to the value under the current illumination.

[0045] Preferably, in the step (1), the voltage and current instantaneous values of the high-voltage side or the low-voltage side of the voltage boost transformer of the photovoltaic inverter are read based on the high-voltage ride-through test results of the photovoltaic inverter, including field test, hardware-in-the-loop electromagnetic transient simulation or non-real-time electromagnetic transient simulation.

[0046] The present application discloses a photovoltaic inverter high-voltage ride-through test result automatic analysis method, which has the following beneficial effects.

[0047] The application realizes efficient automatic analysis, does not need manual calculation, can batch process high voltage ride through test results of photovoltaic inverters, shortens analysis time from 4 days to 1 hour, automatically generates and stores detailed results including fundamental line voltage, active and reactive power and the like. The phase voltage average value comparison method is adopted to judge fault types, and the no-load and load test data analysis results are analyzed respectively for three-phase faults and two-phase faults. Meanwhile, the standard deviation method is adopted to identify the key time points of active power recovery and reactive current exit, and the analysis accuracy is improved. The method is suitable for various high voltage ride through tests, and the results are not affected by voltage changes and power size, and has the advantages of high efficiency and high accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is a flow chart of the photovoltaic inverter high voltage ride through test result automatic analysis method of the application;

[0049] Figure 2 is a test result calculation and determination schematic diagram of the application;

[0050] Figure 3 is a photovoltaic inverter 130%Un three-phase no-load high voltage ride through test result waveform diagram of application example 1 of the application;

[0051] Figure 4 is a photovoltaic inverter 130%Un three-phase load high voltage ride through test result waveform diagram of application example 1 of the application;

[0052] Figure 5 is a photovoltaic inverter 125%Un two-phase no-load high voltage ride through test result summary diagram of application example 2 of the application;

[0053] Figure 6 is a photovoltaic inverter 125%Un two-phase load high voltage ride through test result summary diagram of application example 2 of the application;

[0054] Figure 7 is a photovoltaic inverter continuous no-load high voltage ride through test result summary diagram of application example 3 of the application;

[0055] Figure 8 is a photovoltaic inverter continuous load high voltage ride through test result summary diagram of application example 3 of the application; DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all embodiments of the application.

[0057] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0058] The high voltage ride through test result of the photovoltaic inverter is mainly calculated manually, and the embodiment of the present application provides a photovoltaic inverter high voltage ride through test result automatic analysis method, which can automatically, batch, efficiently complete the high voltage ride through test result of the photovoltaic inverter, and automatically store the test waveform and calculation result in word without manual calculation.

[0059] As shown in Figure 1 and Figure 2 A photovoltaic inverter high voltage ride through test result automatic analysis method, comprising the following steps:

[0060] Step 1, read the high voltage ride through test result of the photovoltaic inverter based on field test, hardware-in-the-loop electromagnetic transient simulation or non-real-time electromagnetic transient simulation; as preferred, the high voltage ride through test result of the photovoltaic inverter based on field test, hardware-in-the-loop electromagnetic transient simulation or non-real-time electromagnetic transient simulation read in step (1) includes the voltage and current instantaneous value of the high voltage side or low voltage side of the photovoltaic inverter step-up transformer.

[0061] Step 2, calculate the effective value of the high voltage ride through test result of the photovoltaic inverter;

[0062] As preferred, in step 2, the effective value of the fundamental phase voltage, line voltage, fundamental positive sequence component line voltage, active power, active current, reactive power and reactive current is calculated by full-wave FFT.

[0063] Step 3, distinguish single and continuous high voltage ride through test results based on the line voltage of the fundamental positive sequence component;

[0064] As preferred, in step 3, the high voltage ride through data includes single high voltage ride through and continuous high voltage ride through test data, and the single high voltage ride through test working condition includes 115%~130%Un, and the continuous high voltage ride through test working condition includes low-high voltage ride through test: 0%Un-130%Un, or continuous twice and more high-high voltage ride through test 130%Un-~130%Un test.

[0065] Step 4, fault classification is made on single high voltage ride through test data, into three-phase fault, two-phase fault; three-phase fault, two-phase fault ride through test data is based on active power P 前1 , P 前2 before voltage rise 前1 , P 前2 greater than 0.05 times rated active power is load test data, active power P 前1 , P 前2 less than or equal to 0.05 times rated active power is no-load test data avg ;

[0066] As preferred, in step 4, the fault classification method is specifically:

[0067] The average value of the fundamental phase voltage U Aavg , U Bavg , U Cavg of A, B, C three-phase before voltage drop is calculated

[0068] The judgment method is:

[0069] If U Aavg -U avg >△U and U Bavg -U avg >△U and U Cavg -U avg >△U, then it is ABC phase fault

[0070] If U Aavg -U avg >△U and U Bavg -U avg >△U and U Cavg -U avg <△U, then it is AB phase fault

[0071] If U Aavg -U avg >△U and U Bavg -U avg <△U and U Cavg -U avg >△U, then it is AC phase fault

[0072] If U Aavg -U avg <△U and U Bavg -U avg >△U and U Cavg -U avg >△U, then it is BC phase fault

[0073] ABC phase fault is three-phase fault, AB phase fault, AC phase fault and BC phase fault are two-phase faults.

[0074] Step 5, for three-phase fault no-load test data, calculate voltage rise value and duration, if the voltage rise value and duration meet the standard requirements, output no-load test data qualified, otherwise output unqualified; for three-phase fault load test data, judge whether to off-grid, if off-grid, judge as unqualified, otherwise further calculate voltage rise value Uswell1 and duration tswell1 based on fundamental positive sequence line voltage, calculate reactive current response time tres1, reactive current duration tlast1, reactive current exit time tree1, calculate active power dip depth Pdip1; if tres1 is greater than 30ms or tree1 is greater than 30ms, output unqualified, otherwise judge whether Pdip1 is greater than 0.9 times Pfront1, if Pdip1≥0.9Pfront1, automatically store test waveform and calculation results in word document; if Pdip1<0.9Pfront1, calculate active power recovery time tre1, if tre1≤40ms, automatically store test waveform and calculation results in word document, otherwise output unqualified;

[0075] Step 6, for two-phase fault no-load test data, calculate voltage rise value and duration, if the voltage rise value and duration meet the standard requirements, output no-load test data qualified, otherwise output unqualified; for two-phase fault load test data, judge whether to off-grid, if off-grid, judge as unqualified, otherwise further calculate voltage rise value Uswell2 and duration tswell2 based on fundamental line voltage, calculate reactive current response time tres2, reactive current duration tlast2, reactive current exit time tree2, calculate active power dip depth Pdip2; judge whether Pdip2 is greater than 0.9 times Pfront2, if Pdip2≥0.9Pfront2, automatically store test waveform and calculation results in word document; if Pdip2<0.9Pfront2, calculate active power recovery time tre2, if tre2≤40ms, automatically store test waveform and calculation results in word document, otherwise output unqualified; Step 7, for continuous high voltage ride through test data, calculate voltage rise value U 前 The judgment is divided into no-load test data and load test data, active power P 前3 greater than 0.05 times rated active power is load test data, active power P 前3 less than or equal to 0.05 times rated active power is no-load test data;

[0076] As preferred, in steps 5 and 6, the test result calculation process is as follows:

[0077] S1, voltage rise value U swell1 , Uswell2 is the standard value of the voltage after the voltage is stable after the voltage is raised;

[0078] S2, the voltage rise duration t swell1 , t swell2 is the voltage rise duration t Uend ; Ustart ;

[0079] Wherein, t Ustart is the voltage rise completion time, t Uend is the voltage recovery start time; the standard deviation of the standard value of the fundamental positive sequence line voltage or the fundamental phase voltage is calculated respectively, and the time point when the standard deviation is less than 0.003 during the period from when the voltage is raised to 1.1Un to when the voltage is lowered to 1.1Un is the voltage rise completion time; the first time point when the standard deviation is greater than 0.003 during the period from the voltage rise completion time t Ustart to when the voltage is lowered to 1.1Un is the voltage recovery start time;

[0080] S3, the reactive current response time t res1 , t res2 is the reactive current response time t Iqstart ; 1.1start ;

[0081] Wherein, t Iqstart represents the start time when the reactive current absorbed by the photovoltaic inverter is greater than 90% of the reactive current injection reference value; t 1.1start represents the time when the voltage is raised to 1.1Un;

[0082] The reactive current injection reference value is: 1.5*(U swell -1.1)*I n , wherein I n is the rated current of the photovoltaic inverter, and the maximum reactive current is not more than 1.05I n ;

[0083] S4, the reactive current duration t last1 , t last2 is the reactive current duration t Iqend ; Iqstart ;

[0084] Wherein, t Iqend represents the end time when the reactive current absorbed by the photovoltaic inverter is greater than 90% of the reactive current injection reference value;

[0085] S5, the reactive current exit time t ree1 , t ree2 is the reactive current exit time t Iqtuichu ; Iqend ;

[0086] Wherein, tIqtuichu represents the reactive current increment exit, i.e. t Iqend After the time point, the time point at which the standard deviation of the reactive current is less than 0.003 is the time point at which the reactive current increment exits;

[0087] S6, active power recovery time t re1 , t re2 is: t Pend -t Uend ;

[0088] Wherein, t Pend represents the time point at which the active power recovers to the value under the current illumination, t Uend represents the time point at which the standard deviation of the active power is less than 0.003 after the time point at which the voltage starts to recover.

[0089] Step 8, calculate the voltage rise value and duration for continuous high voltage ride through no-load test data, if the voltage rise value and duration meet the standard requirements, output the no-load test data qualified, otherwise output unqualified; judge whether the continuous high voltage ride through load test data is off-grid, if off-grid, judge as unqualified, otherwise automatically store the test waveform and calculation results in a word document.

[0090] As preferred, the single high voltage ride through and continuous high-high voltage ride through no-load test data are judged according to GB / T19964 standard, the voltage deviation is ±3%, the duration deviation is ±20ms, specifically:

[0091] The voltage rise standard value U swell : 1.15±0.03, the duration t swell : 10000±20ms;

[0092] The voltage rise standard value U swell : 1.2±0.03, the duration t swell : 10000±20ms;

[0093] The voltage rise standard value U swell : 1.25±0.03, the duration t swell : 1000±20ms;

[0094] The voltage rise standard value U swell : 1.3±0.03, the duration t swell : 500±20ms;

[0095] The continuous low-high voltage ride through no-load test data is judged according to GB / T 19963 standard, the voltage drop deviation is ±5%, the voltage rise deviation is ±3%, the duration deviation is ±20ms, specifically:

[0096] Voltage dip amplitude U dip : 0.0+0.05, duration t dip : 150±20;

[0097] Voltage rise amplitude U swell : 1.30±0.03, duration t swell : 500±20.

[0098] Application Example 1

[0099] The 130%Un high voltage ride through test result of a photovoltaic inverter with rated active power of 3.15 MW and rated voltage of 35 kV is automatically analyzed, the effective values of fundamental phase voltage, line voltage and line voltage of fundamental positive sequence component, active power, active current, reactive power and reactive current are calculated by full-wave FFT; based on the line voltage of fundamental positive sequence component, it is screened as single high voltage ride through test; then according to the fundamental phase voltage, it is screened as three-phase fault, and according to the active power before voltage rise, it is divided into no-load test data and load test data; wherein, the waveform of 130%Un three-phase no-load high voltage ride through test result of the photovoltaic inverter is as shown in Figure 3 , the voltage rise value U swell1 is 130.76%Un, the duration t swell1 is 510.78 ms, which meets the requirements; the waveform of 130%Un three-phase load high voltage ride through test result of the photovoltaic inverter is as shown in Figure 4 , the photovoltaic inverter does not off-grid during high voltage ride through, the voltage rise value U swell1 is calculated as 124.83%Un, the duration t swell1 is 526.56 ms, the reactive current response time t res1 is 15.31 ms, the duration t last1 is 533.59 ms, the exit time t ree1 is 5.63 ms; the reactive current response time t res1 is less than 30 ms, the exit time t ree1 is less than 30 ms, the active power during fault is 99% of that before fault, the result meets the requirements, and the waveforms of fundamental line voltage and line voltage of fundamental positive sequence component, active power, reactive power, active current and reactive current and the output values of calculation results are output in word document.

[0100] The test results of all working conditions of 130%Un high voltage ride through of the photovoltaic inverter are shown in Table 1:

[0101] Table 1 Summary table of 130%Un high voltage ride through test results of photovoltaic inverter

[0102]

[0103]

[0104] Application Example 2

[0105] The 125%Un high voltage ride through test result of a photovoltaic inverter with rated active power of 3.15 MW and rated voltage of 35 kV is automatically analyzed, the effective values of fundamental phase voltage, line voltage and fundamental positive sequence component line voltage, active power, active current, reactive power and reactive current are calculated by full-wave FFT; based on the line voltage of the fundamental positive sequence component, it is screened as a single high voltage ride through test; then according to the fundamental phase voltage, it is screened as two-phase fault, and according to the active power before voltage rise, it is divided into no-load test data and load test data; wherein, the waveform of the 125%Un two-phase no-load high voltage ride through test result of the photovoltaic inverter is as shown in Figure 5 , the voltage rise value U swell1 is 124.64%Un, the duration t swell1 is 1015 ms, which meets the requirements; the waveform of the 125%Un two-phase load high voltage ride through test result of the photovoltaic inverter is as shown in Figure 6 , the photovoltaic inverter does not disconnect from the grid during high voltage ride through, the voltage rise value U swell1 is 123.17%Un, the duration t swell1 is 1014 ms, the standard does not require asymmetric fault to provide reactive current support voltage recovery, and the reactive current does not reach the calculated reference value, so the reactive current response calculation is not carried out; the active power during the fault is 99% of that before the fault, the result meets the requirements, and the fundamental line voltage and the fundamental positive sequence component line voltage, active power, reactive power, active current and reactive current waveform and the calculation result output value word document.

[0106] The test results of all working conditions of the 125%Un high voltage ride through of the photovoltaic inverter are shown in Table 2:

[0107] Table 2 Summary of photovoltaic inverter 125%Un high voltage ride through test results

[0108]

[0109]

[0110] Application Example 3

[0111] The high voltage ride through test results of a photovoltaic inverter with rated active power of 3.15 MW and rated voltage of 35 kV are automatically analyzed, the full-wave FFT is used to calculate the effective values of fundamental phase voltage, line voltage, fundamental positive sequence component line voltage, active power, active current, reactive power and reactive current; based on the fundamental positive sequence component line voltage, the continuous high voltage ride through test is selected; according to the active power before voltage rise, the load test data and the no-load test data are divided; wherein, the waveform of the continuous no-load high voltage ride through test results of the photovoltaic inverter is as shown in Figure 7 , the voltage drop depth U dip1 is 0.005%Un, the duration t dip1 is 164 ms, the voltage rise value U swell1 is 128.27%Un, the duration t swell1 is 517 ms, which meets the requirements; the waveform of the continuous load high voltage ride through test results of the photovoltaic inverter is as shown in Figure 8 , the photovoltaic inverter is not off-grid during the continuous high voltage ride through, the voltage drop depth U dip1 is 0.12%Un, the duration t dip1 is 157 ms, the voltage rise value U swell1 is 127.39%Un, the duration t swell1 is 507 ms, the results meet the requirements, and the fundamental line voltage and the fundamental positive sequence component line voltage, active power, reactive power, active current and reactive current waveforms and the calculation results are output in the word document.

[0112] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. The substitution can be the substitution of part of the structure, device, method step, or the complete technical solution. According to the technical solution and the inventive concept of the present application, equivalent substitution or change should be covered in the protection scope of the present application.

Claims

1. A photovoltaic inverter high voltage ride through test result automatic analysis method, characterized in that, The method comprises the following steps: Step 1, reading the high voltage ride through test result of the photovoltaic inverter based on field test, hardware-in-loop electromagnetic transient simulation or non-real-time electromagnetic transient simulation, the test result including voltage and current instantaneous value of the high voltage side or low voltage side of the step-up transformer of the photovoltaic inverter; Step 2, calculating the effective value of the high voltage ride through test result of the photovoltaic inverter; Step 3, distinguishing the single high voltage ride through test result and the continuous high voltage ride through test result based on the line voltage of the fundamental positive sequence component; Step 4, fault classification is made on single high voltage ride through test data, which is divided into three-phase fault and two-phase fault; three-phase fault and two-phase fault ride through test data is based on active power P 前1 , P 前2 before voltage rise 前1 , P 前2 is greater than 0.05 times rated active power for load test data 前1 , P 前2 is less than or equal to 0.05 times rated active power for no-load test data; Step 5, for three-phase fault no-load test data, calculate the voltage rise value, duration, voltage rise value, duration meet the standard requirements, then output no-load test data qualified, otherwise output unqualified; for three-phase fault load test data, judge whether off-grid, if off-grid, then judge unqualified, otherwise further based on the fundamental positive sequence line voltage to calculate the voltage rise value U swell1 , duration t swell1 , calculate the reactive current response time t res1 , reactive current duration t last1 , reactive current exit time t ree1 , calculate the active drop depth P dip1 ; if t res1 greater than 30ms, or t ree1 greater than 30ms, then output unqualified, otherwise judge P dip1 whether greater than 0.9 times P 前1 , P dip1 ≥0.9P 前1 , then the test waveform and the calculation results are automatically stored in the word document; P dip1 <0.9P 前1 , calculate the active recovery time t re1 , if t re1 ≤40ms, then the test waveform and the calculation results are automatically stored in the word document, otherwise output unqualified; Step 6, for two-phase fault no-load test data, calculate the voltage rise value, duration, voltage rise value, duration meet the standard requirements, then output no-load test data qualified, otherwise output unqualified; for two-phase fault load test data, judge whether off-grid, if off-grid, then judge unqualified, otherwise further based on the fundamental line voltage calculation voltage rise value U swell2 , duration t swell2 , calculate the reactive current response time t res2 , reactive current duration t last2 , reactive current exit time t ree2 , calculate the active drop depth P dip2 ; judge P dip2 whether greater than 0.9 times P 前2 , P dip2 ≥0.9P 前2 , the test waveform and the calculation results are automatically stored in the word document; P dip2 <0.9P 前2 , calculate the active recovery time t re2 , if t re2 ≤40ms, then the test waveform and the calculation results are automatically stored in the word document, otherwise output unqualified; Step 7, classify the continuous high voltage ride through test data based on the active power P before voltage rise 前3 The classification is divided into no-load test data and load test data, active power P 前3 Greater than 0.05 times the rated active power is load test data, active power P 前3 Less than or equal to 0.05 times the rated active power is no-load test data; Step 8, calculating the voltage rise value and the duration of the continuous high voltage ride through no-load test data, if the voltage rise value and the duration meet the standard requirement, outputting that the no-load test data is qualified, otherwise outputting that the no-load test data is unqualified; judging whether the continuous high voltage ride through load test data is off-grid, if off-grid, judging that the load test data is unqualified, otherwise automatically storing the test waveform and the calculation result in a word document.

2. The photovoltaic inverter high voltage ride through test result automatic analysis method of claim 1, wherein, In the step 2, the full-wave FFT is used to calculate the effective value of the fundamental phase voltage, the line voltage, the line voltage of the fundamental positive sequence component, the active power, the active current, the reactive power and the reactive current.

3. The photovoltaic inverter high voltage ride through test result automatic analysis method of claim 1, wherein, In the step 3, the high voltage ride through data includes the single high voltage ride through test data and the continuous high voltage ride through test data, the single high voltage ride through test condition includes 115% to 130% Un, the continuous high voltage ride through test condition includes the low-high voltage ride through test: 0% Un to 130% Un, or the continuous high-high voltage ride through test: 130% Un to 130% Un.

4. The photovoltaic inverter high voltage ride through test result automatic analysis method of claim 3, wherein, The single high voltage ride through and the continuous high-high voltage ride through no-load test data are judged according to the GB / T 19964 standard, the voltage deviation is ±3%, the duration deviation is ±20ms, and specifically: The continuous low-high voltage ride through no-load test data is judged according to the GB / T 19964 standard, the voltage drop deviation is ±5%, the voltage rise deviation is ±3%, the duration deviation is ±20ms, and specifically: Voltage rise reference value U swell : 1.15 ± 0.03, duration t swell : 10000 ± 20 ms; Voltage rise reference value U swell : 1.2 ± 0.03, duration t swell : 10000 ± 20 ms; Voltage rise in volts U swell : 1.25 ± 0.03, duration t swell : 1000 ± 20 ms; Voltage rise in volts U swell : 1.3 ± 0.03, duration t swell : 500 ± 20 ms; In the step 4, the fault classification method is specifically: voltage dip amplitude U dip : 0.0+0.05, duration t dip : 150+20; voltage rise amplitude U swell : 1.30 ± 0.03, duration t swell : 500 ± 20.

5. The photovoltaic inverter high voltage ride through test result automatic analysis method of claim 1, wherein, The judgment threshold value ΔU is set to 0.4; Calculate the average value of the fundamental phase voltage U of A, B, C three phases before voltage drop avg ; Calculate the average value of the fundamental phase voltage U of A, B, C three phases respectively Aavg , Bavg , Cavg ; The judgment method is: The ABC phase fault is a three-phase fault, the AB phase fault, the AC phase fault and the BC phase fault are two-phase faults. If U Aavg -U avg >△U and U Bavg -U avg >△U and U Cavg -U avg >△U, it is an ABC phase fault; If U Aavg - U avg >△U and U Bavg - U avg >△U and U Cavg - U avg <△U, it is AB phase fault; If U Aavg - U avg >△U and U Bavg - U avg <△U and U Cavg - U avg >△U, it is an AC phase fault; If U Aavg - U avg <△U and U Bavg - U avg >△U and U Cavg - U avg >△U, it is a BC fault; In the steps 5 and 6, the test result calculation process is as follows:

6. The photovoltaic inverter high voltage ride through test result automatic analysis method of claim 1, wherein, ​ S1, voltage rise value U swell1 , U swell2 : unit value after voltage rise and voltage stabilization S2, voltage rise duration t swell1 , t swell2 t Uend -t Ustart ; Wherein, t Ustart is the voltage rising process completion time, t Uend is the voltage recovery start time; the standard deviation of the line voltage or phase voltage of the fundamental positive sequence is calculated respectively, and the time point when the standard deviation is less than 0.003 during the period after the voltage rises to 1.1Un and before the voltage drops to 1.1Un is the voltage rising process completion time; the first time point when the standard deviation is greater than 0.003 during the period after the voltage rising process completion time t Ustart and before the voltage drops to 1.1Un is the voltage recovery start time; S3, the response time t of the reactive current res1 res2 Iqstart 1.1start ;​​​ wherein t Iqstart represents the instant at which the reactive current absorbed by the photovoltaic inverter is greater than 90% of the reference value of the reactive current injected for more than 5 seconds; t 1.1start represents the instant at which the voltage rises to 1.1 Un; The reactive current injection reference value is: 1.5*(U swell -1.1)*I n , wherein I n is the rated current of the photovoltaic inverter, and the maximum reactive current is not more than 1.05I n ; S4, reactive current duration t last1 , t last2 is: t Iqend -t Iqstart ; where t Iqend represents the end time of the reactive current absorbed by the photovoltaic inverter for more than 90% of the reactive current injection reference value; S5, reactive current exit time t ree1 , t ree2 is: t Iqtuichu -t Iqend ; Wherein, t Iqtuichu represents the reactive current increment exit, that is, t Iqend The time point when the standard deviation of the reactive current is less than 0.003 after the time point t is the reactive current increment exit time point. S6, active power recovery time t re1 , t re2 is: t Pend -t Uend ; wherein t Pend represents the point in time at which the active power is restored to the value under the current illumination, t Uend represents the point in time at which the standard deviation of the active power is less than 0.003 after the point in time at which the voltage starts to be restored as the point in time at which the active power is restored to the value under the current illumination.

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