The first natural environment icing test station in China, jointly built by Chongqing University and Huaihua Electric Power Bureau, has settled in Xuefeng Mountain!
On January 16th, the "Xuefengshan Natural Ice Cover Test Station" Insulator Ice Cover Test Technology Exchange Seminar, jointly organized by Chongqing University and Hunan Huaihua Electric Power Design Institute, was held in Huaihua. Experts in transmission and distribution lines and insulation technology from well-known universities across the country, as well as electrical experts from Japan's NGK company, gathered together to celebrate the official completion of the world's only and China's first natural ice cover test station in Huaihua, Hunan, and to discuss follow-up research matters.
At the meeting, Professor Jiang Xingliang, doctoral supervisor of Chongqing University, first expressed gratitude to Huaihua Electric Power Bureau and various units of the power system for their strong support and assistance in the basic design and construction of the experimental base. The attending experts listened to Associate Professor Zhang Zhijin's report on the construction of the Xuefengshan Natural Ice Cover Test Station and the 2009 Ice Cover Test, shared the ice observation and research results at the test base throughout 2009, and conducted in-depth discussions and research on the existing problems. After the meeting, experts also went to the "Xuefengshan Natural Ice Cover Test Station" for on-site investigation, and representatives expressed their affirmation of the site selection and the construction of the test station.
Professor Jiang Xingliang introduced that since the 2008 ice disaster, in order to prevent a large number of line disconnections, tower collapses, and ice flash accidents caused by severe icing, and to maintain the safe and stable operation of the power grid, the Ministry of Science and Technology of China has listed grid icing and protection technology as one of the important research topics of the National Key Basic Research and Development Plan (973 Plan). With the support of projects such as "Ice Cover, De icing, and Melting Mechanisms of Transmission Lines" by State Grid Corporation of China, Professor Jiang Xingliang's research team conducted a comprehensive investigation of typical ice cover conditions in China, analyzed and compared ice cover phenomena and micro meteorology in Liupanshui, Guizhou, Qinling Mountains, Shaanxi, Jingmen, Sichuan, and Lushan, Jiangxi. Based on the representativeness, duration, and transportation conditions of ice cover, it was determined to establish a "natural ice cover test base" in Xuefengshan, Hunan. It was believed that the natural conditions of Pingshantang in Xuefengshan and the technical strength of Huaihua Design Institute met the requirements for the construction of natural ice cover test bases. Finally, the site selection and cooperation partner were determined.
In 2009, Professor Jiang Xingliang, Associate Professor Zhang Zhijin, and Dr. Hu Jianlin, among other key members of the research group, led more than ten graduate students from the Department of High Voltage and Insulation Technology at Chongqing University to overcome various difficulties in work and life under harsh natural conditions. They worked together with the Huaihua Bureau Design Institute to build a natural experimental base while conducting experimental research. In the first year of the experiment, the icing, thawing, and de icing processes of six typical specifications of conductors commonly used in high voltage, ultra-high voltage, and ultra-high voltage transmission lines were studied. The icing processes of various types of insulators were observed and compared. Multiple technical measures to prevent conductor icing, such as mechanical and hydrophobic coatings, as well as coatings to prevent insulator icing and differences in insulator icing arrangements, were experimentally investigated. The twisting process and mechanism of conductor icing were analyzed, and the tension changes and ice wind load changes after conductor icing were analyzed. In addition, AC and DC icing tests were conducted in natural environments. A large amount of key experimental data was accumulated to overcome the world-class problem of power grid icing, and many effective studies and explorations were made.
Toshiyuki Nakajima, Chief Engineer of the Electric Power Division of NGK Corporation in Japan, stated in an interview with reporters during his inspection of the Xuefengshan Natural Ice Cover Test Station that he has been engaged in research on power grid ice cover in the United States for 10 years. Although international experts have conducted long-term research on power grid ice cover under laboratory artificial simulation conditions, they unanimously believe that there is a significant error between the ice cover form in the artificial simulation environment and the actual situation in the natural environment. The first natural ice cover test station built in Xuefengshan will undoubtedly greatly promote the research process of ice cover and melting mechanisms of transmission lines and the anti ice ability of power grids in China and internationally. He wishes his Chinese counterparts to soon obtain the foundation of ice cover on transmission lines in natural environments. Data fills the gap in international research in this field, Overcome the world-class challenge of power grid icing mechanism and anti icing technology as soon as possible.
Zhang Jiwu, President of the Design Institute of Huaihua Electric Power Bureau, stated that with the strong support of Secretary Liang Liqing of the Huaihua Electric Power Bureau Party Committee, the Xuefengshan Natural Ice Cover Test Station has been built in cooperation with Chongqing University. On the one hand, it can make its own contribution to the research on improving the ice resistance of the power grid and reflect the company's sense of social responsibility; On the other hand, it can also enhance its own technological strength and corporate reputation through cooperation and exchange, improve its external competitiveness, and achieve a win-win situation. It is a model of "industry university research" cooperation between enterprises and higher education institutions. (Shu Daisong and Zhang Deming)
Information source: Hunan Electric Power Company
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Reliability Test for Light-emitting Diodes for Communication
Communication light-emitting diode failure determination:
Provide a fixed current to compare the optical output power, and determine failure if the error is greater than 10%
Mechanical stability test:
Impact test: 5tims/axis, 1500G, 0.5ms
Vibration test: 20G, 20 ~ 2000Hz, 4min/cycle, 4cycle/axis
Liquid thermal shock test: 100℃(15sec)←→0℃(5sec)/5cycle
Solder heat resistance: 260℃/10 seconds /1 time
Solder adhesion: 250℃/5 seconds
Durability test:
Accelerated aging test: 85℃/ power (maximum rated power)/5000 hours, 10000 hours
High temperature storage: maximum rated storage temperature /2000 hours
Low temperature storage test: maximum rated storage temperature /2000 hours
Temperature cycle test: -40℃(30min)←85℃(30min), RAMP: 10/min, 500cycle
Moisture resistance test: 40℃/95%/56 days, 85℃/85%/2000 hours, sealing time
Communication diode element screening test:
Temperature screening test: 85℃/ power (maximum rated power)/96 hours screening failure determination: Compare the optical output power with the fixed current, and determine failure if the error is larger than 10%
Communication diode module screening test:
Step 1: Temperature cycle screening: -40℃(30min)←→85℃(30min), RAMP: 10/min, 20cycle, no power supply
Step 2: Temperature screening test: 85℃/ power (maximum rated power)/96 hours
Road LED Text Reliability Test
Environmental resistance test:
Vibration test, transportation package drop test, temperature cycle test, temperature and humidity test, impact test, waterproof test
Durability test:
High and low temperature preservation test, continuous switch operation test, continuous action test
LED display reliability test conditions finishing:
Vibration test: three-axis (XYZ) vibration, 10 minutes each, 10 ~ 35 ~ 10Hz sine wave, 300 ~ 1200 times/min, 3 minutes per cycle, vibration Fu 2mm
Vibration tightening test: vibration + temperature (-10 ~ 60℃)+ voltage + load
Drop test for transport packaging: Drop material slurry (at least 12mm thick), height depends on the purpose of use
Temperature cycle:
a. No boot test: 60℃/6 hours ← Rising and cooling for 30 minutes →-10℃/6 hours, 2cycle
b. Boot test: 60℃/4 hours ← Rising and cooling 30 minutes →0℃/6 hours, 2cycle, power supply without packaging and load
Temperature and humidity test:
No power test: 60℃/95%R.H./48 hours
Boot test: 60℃/95%R.H./24 hours/no packaging power supply load
Impact test: impact distance 3m, slope 15 degrees, six sides
Waterproof test: height 30 cm, 10 liters /min spray Angle 60 degrees, spraying position: front and back up, spraying range 1 square meter, spraying time 1 minute
Humidity test: 40℃/90%R.H./8 hours ←→25℃/65%R.H./16 hours, 10cycle)
High and low temperature preservation test: 60℃/95%R.H./72 hours →10℃/72 hours
Continuous switch action test:
Complete the switch within one second, shut down for at least three seconds, 2000 times, 45℃/80%R.H.
Continuous action test: 40℃/85%R.H./72 hours/power on
Ac Solar Modules & Microinverters 1
The overall output power of the solar cell panel is greatly reduced, mainly because of some module damage (hail, wind pressure, wind vibration, snow pressure, lightning strike), local shadows, dirt, tilt Angle, orientation, different degrees of aging, small cracks... These problems will cause system configuration misalignment, resulting in reduced output efficiency defects, which are difficult to overcome traditional centralized inverters. Solar power generation cost ratio: module (40 ~ 50%), construction (20 ~ 30%), inverter (<10%), from the point of view of the cost proportion, the construction cost is as high as 1/3, if the inverter is directly installed on the module in production, the overall power generation cost can be greatly reduced.
In order to overcome such problems, in 2008 developed a microinverter (microinverter) applied to the solar module, that is, each DC solar module is equipped with a direct conversion of direct current (DC) to AC (AC) small inverter, it can be directly installed behind the module or fixed frame, Through the micro inverter tracking, each module can operate at more than 95% of the highest power point (system more than 99.5% of the time is normal operation), such an advantage is for each module to optimize the output power, so that the entire solar power system output power to obtain the highest, for the design architecture, Even if some modules are covered by shadows, heat, dust... In addition, its power transmission value is connected to AC power supply, do not need complex and professional series and parallel, direct parallel output, can also reduce the attenuation between power transmission, recent research shows that the module assembly micro-inverter can increase the energy collection by 20%, a single module provides standard AC frequency power supply, Each module has arc protection, which can reduce the probability of arc occurrence. It can be seen that the failure rate of the centralized inverter is high, it must be replaced often, and its life is only about half of the module, if we use the micro inverter its output power is lower, it can improve the service life of the inverter.
Since each module is behind the small inverter, the module does not need to configure another communication wire, can directly through the output wire of the AC Power supply, direct network communication, only need to install a power line network Bridge (Power line Ethernet Bridge) on the socket, do not need to set up another communication line, Users can directly access the web, iPhone, blackberry, tablet... Etc., watch the operation status of each module (power output, module temperature, fault message, module identification code), if there is an anomaly, it can be repaired or replaced immediately, so that the entire solar power system can operate smoothly.
Output terminal of AC module:
AC output, DC output, Control Interface
Ac solar module English name:
AC solar PV module ac pv module AC photovoltaic module AC Module PV systems composed of AC modules AC module-composed PVAC Module
Proprietary abbreviation:
CVCF: constant voltage, constant frequency
EIA(Energy Information Administration) The United States Energy Information Administration
EMC: includes EMI(Electromagnetic interference) and EMS(electromagnetic tolerance) two parts
EMI(Electromagnetic interference) : The electromagnetic noise generated by the machine itself in the process of performing the intended function is not conducive to other systems
ETL: Electronic Testing Laboratory
MFGR: Manufacturer
HALT: Highly Accelerated Life Test. Halt: highly accelerated life test
HAST(Highly Accelerated Stress Test) : Accelerated stress test
HFRE: high frequency rectifier
HFTR: high frequency transformer
MEOST[Multiple Environment Over Stress Tests] : MEOST[multiple environment over stress tests]
MIC(microinverter) : A microinverter
Micro-inverters: indicates micro-inverters
MPPT[Maximum Power Point Tracking] : indicates maximum power point tracking
MTBF: mean time between failures
NEC: National Electrical Code
PVAC Module: AC solar module
VVVF: Change voltage, change frequency
Ac Solar Modules & Microinverters 2
Ac module test specification:
ETL Certification: UL 1741, CSA Standard 22.2, CSA Standard 22.2 No. 107.1-1, IEEE 1547, IEEE 929
PV Module: UL1703
Newsletter: 47CFR, Part 15, Class B
Voltage Surge rating: IEEE 62.41 Class B
National Electrical Code: NEC 1999-2008
Arc protection devices: IEEE 1547
Electromagnetic waves: BS EN 55022, FCC Class B per CISPR 22B, EMC 89/336/EEG, EN 50081-1, EN 61000-3-2, EN 50082-2, EN 60950
Micro-Inverter (Micro-inverter) : UL1741-calss A
Typical component failure rate: MIL HB-217F
Other specifications:
IEC 503, IEC 62380 IEEE1547, IEEE929, IEEE-P929, IEEE SCC21, ANSI/NFPA-70 NEC690.2, NEC690.5, NEC690.6, NEC690.10, NEC690.11, NEC690.14, NEC690.17, NEC690.18, NEC690.64
Main specifications of AC solar module:
Operating temperature: -20℃ ~ 46℃, -40℃ ~ 60℃, -40℃ ~ 65℃, -40℃ ~ 85℃, -20 ~ 90℃
Output voltage: 120/240V, 117V, 120/208V
Output power frequency: 60Hz
Advantages of AC modules:
1. Try to increase the power generation of each inverter power module and track the maximum power, because the maximum power point of a single component is tracked, the power generation of the photovoltaic system can be greatly improved, which can be increased by 25%.
2. By adjusting the voltage and current of each row of solar panels until all are balanced, so as to avoid system mismatch.
3. Each module has monitoring function to reduce the maintenance cost of the system and make the operation more stable and reliable.
4. The configuration is flexible, and the solar cell size can be installed in the household market according to the user's financial resources.
5. No high voltage, safer to use, easy to install, faster, low maintenance and installation cost, reduce the dependence on installation service providers, so that the solar power system can be installed by users themselves.
6. The cost is similar or even lower than that of centralized inverters.
7. Easy installation (installation time reduced by half).
8. Reduce procurement and installation costs.
9. Reduce the overall cost of solar power generation.
10. No special wiring and installation program.
11. The failure of a single AC module does not affect other modules or systems.
12. If the module is abnormal, the power switch can be automatically cut off.
13. Only a simple interrupt procedure is required for maintenance.
14. Can be installed in any direction and will not affect other modules in the system.
15. It can fill the entire setting space, as long as it is placed under it.
16. Reduce the bridge between DC line and cable.
17. Reduce DC connectors (DC connectors).
18. Reduce DC ground fault detection and set protection devices.
19. Reduce DC junction boxes.
20. Reduce the bypass diode of the solar module.
21. There is no need to purchase, install and maintain large inverters.
22. No need to buy batteries.
23. Each module is installed with anti-arc device, which meets the requirements of UL1741 specification.
24. The module communicates directly through the AC power output wire without setting up another communication line.
25. 40% less components.
Ac Solar Modules & Microinverters 3
Ac module test method:
1. Output performance test: The existing module test equipment, for the non-inverter module related testing
2. Electrical stress test: Perform temperature cycle test under different conditions to evaluate the inverter's characteristics under operating temperature and standby temperature conditions
3. Mechanical stress test: find out the micro inverter with weak adhesion and the capacitor welded on the PCB board
4. Use a solar simulator for overall testing: a steady-state pulse solar simulator with large size and good uniformity is required
5. Outdoor test: Record module output I-V curve and inverter efficiency conversion curve in outdoor environment
6. Individual test: Each component of the module is tested separately in the room, and the comprehensive benefit is calculated by the formula
7. Electromagnetic interference test: Because the module has the inverter component, it is necessary to evaluate the impact on EMC&EMI when the module is running under the sunlight simulator.
Common failure causes of AC modules:
1. The resistance value is incorrect
2. The diode is inverted
3. Inverter failure causes: electrolytic capacitor failure, moisture, dust
Ac module test conditions:
HAST test: 110℃/85%R.H./206h(Sandia National Laboratory)
High temperature test (UL1741) : 50℃, 60℃
Temperature cycle: -40℃←→90℃/200cycle
Wet freezing: 85℃/85%R.H.←→-40℃/10cycles, 110 cycles(Enphase-ALT test)
Wet heat test: 85℃/85%R.H/1000h
Multiple environmental pressure tests (MEOST) : -50℃ ~ 120℃, 30G ~ 50G vibration
Waterproof: NEMA 6/24 hours
Lightning test: Tolerated surge voltage up to 6000V
Others (please refer to UL1703) : water spray test, tensile strength test, anti-arc test
Solar related Modules MTBF:
Traditional inverter 10 ~ 15years, micro inverter 331years, PV module 600years, micro inverter 600years[future]
Introduction of microinverter:
Instructions: Micro inverter (microinverter) applied to the solar module, each DC solar module is equipped with a, can reduce the probability of arc occurrence, microinverter can directly through the AC power output wire, direct network communication, Only need to install a power line Ethernet Bridge (Powerline Ethernet Bridge) on the socket, do not need to set up another communication line, users can through the computer web page, iPhone, blackberry, tablet computer... Etc., directly watch the operating state of each module (power output, module temperature, fault message, module identification code), if there is an anomaly, it can be repaired or replaced immediately, so that the entire solar power system can operate smoothly, because the micro inverter is installed behind the module, so the aging effect of ultraviolet on the micro inverter is also low.
Microinverter specifications:
UL 1741 CSA 22.2, CSA 22.2, No. 107.1-1 IEEE 1547 IEEE 929 FCC 47CFR, Part 15, Class B Compliant with the National Electric Code (NEC 1999-2008) EIA-IS-749(Corrected major application life test, specification for capacitor use)
Micro inverter test:
1. Microinverter reliability test: microinverter weight +65 pounds *4 times
2. Waterproof test of micro-inverter: NEMA 6[1 meter continuous operation in water for 24 hours]
3. Wet freezing according to IEC61215 test method: 85℃/85%R.H.←→-45℃/110 days
4. Accelerated life test of micro-inverter [110 days in total, dynamic test at rated power, has ensured that micro-inverter can last more than 20 years] :
Step 1: Wet freezing: 85℃/85%R.H.←→-45℃/10 days
Step 2: Temperature cycle: -45℃←→85℃/50 days
Step 3: Humid heat: 85℃/85%R.H./50 days
IEC 61646 Test Standard for Thin-film Solar Photoelectric Modules
Through the diagnostic measurement, electrical measurement, irradiation test, environmental test, mechanical test five types of test and inspection mode, confirm the design confirmation and form approval requirements of thin film solar energy, and confirm that the module can operate in the general climate environment required by the specification for a long time.
IEC 61646-10.1 Visual inspection procedure
Objective: To check for any visual defects in the module.
Performance at STC under IEC 61646-10.2 Standard test conditions
Objective: Using natural light or A class simulator, under standard test conditions (battery temperature: 25±2℃, irradiance: 1000wm^-2, standard solar spectrum irradiation distribution in accordance with IEC891), test the electrical performance of the module with load change.
IEC 61646-10.3 Insulation test
Objective: To test whether there is good insulation between the current carrying parts and the frame of the module
IEC 61646-10.4 Measurement of temperature coefficients
Objective: To test the current temperature coefficient and voltage temperature coefficient in the module test. The temperature coefficient measured is valid only for the irradiation used in the test. For linear modules, it is valid within ±30% of this irradiation. This procedure is in addition to IEC891, which specifies the measurement of these coefficients from individual cells in a representative batch. The temperature coefficient of the thin-film solar cell module depends on the heat treatment process of the module involved. When the temperature coefficient is involved, the conditions of the thermal test and the irradiation results of the process should be indicated.
IEC 61646-10.5 Measurement of nominal operating cell temperature (NOCT)
Objective: To test the NOCT of the module
IEC 61646-10.6 Performance at NOCT
Objective: When the nominal operating battery temperature and irradiance are 800Wm^-2, under the standard solar spectrum irradiance distribution condition, the electrical performance of the module varies with the load.
IEC 61646-10.7 Performance at low irradiance
Objective: To determine the electrical performance of modules under load under natural light or A class A simulator at 25℃ and 200Wm^-2(measured with appropriate reference cell).
IEC 61646-10.8 Outdoor exposure Testing
Objective: To make an unknown assessment of the resistance of the module to exposure to outdoor conditions and to show any effects of degradation that could not be detected by the experiment or test.
IEC 61646-10.9 Hot spot test
Objective: To determine the ability of the module to withstand thermal effects, such as packaging material aging, battery cracking, internal connection failure, local shading or stained edges can cause such defects.
IEC 61646-10.10 UV test (UV test)
Objective: To confirm the ability of the module to withstand ultraviolet (UV) radiation, the new UV test is described in IEC1345, and if necessary, the module should be exposed to light before performing this test.
IEC61646-10.11 Thermal cycling Test (Thermal cycling)
Objective: To confirm the ability of the module to resist thermal inhomogeneity, fatigue and other stresses due to repeated temperature changes. The module should be annealed before receiving this test. [Pre-I-V test] refers to the test after annealing, be careful not to expose the module to light before the final I-V test.
Test requirements:
a. Instruments to monitor the electrical continuity within each module throughout the test process
b. Monitor the insulation integrity between one of the recessed ends of each module and the frame or support frame
c. Record module temperature throughout the test and monitor any open circuit or ground failure that may occur (no intermittent open circuit or ground failure during the test).
d.The insulation resistance shall meet the same requirements as the initial measurement
IEC 61646-10.12 Humidity freeze cycle test
Purpose: To test the module's resistance to the influence of the subsequent sub-zero temperature under high temperature and humidity, this is not a thermal shock test, before receiving the test, the module should be annealed and subjected to a thermal cycle test, [[Pre-I-V test] refers to the thermal cycle after the test, be careful not to expose the module to light before the final I-V test.
Test requirements:
a. Instruments to monitor the electrical continuity within each module throughout the test process
b. Monitor the insulation integrity between one of the recessed ends of each module and the frame or support frame
c. Record module temperature throughout the test and monitor any open circuit or ground failure that may occur (no intermittent open circuit or ground failure during the test).
d. The insulation resistance shall meet the same requirements as the initial measurement
IEC 61646-10.13 Damp heat Test (Damp heat)
Objective: To test the ability of the module to resist long-term infiltration of moisture
Test requirements: The insulation resistance shall meet the same requirements as the initial measurement
IEC 61646-10.14 Robustness of terminations
Objective: To determine whether the attachment between the lead end and the lead end to the module body can withstand the force during normal installation and operation.
IEC 61646-10.15 Twist Test
Objective: To detect possible problems caused by module installation on an imperfect structure
IEC 61646-10.16 Mechanical load test
Purpose: The purpose of this test is to determine the ability of the module to withstand wind, snow, ice, or static loads
IEC 61646-10.17 Hail test
Objective: To verify the impact resistance of the module to hail
IEC 61646-10.18 Light soaking Test
Objective: To stabilize the electrical properties of thin film modules by simulating solar irradiation
IEC 61646-10.19 Annealing Tests (Annealing)
Objective: The film module is annealed before the verification test. If not annealed, the heating during the subsequent test procedure may mask the attenuation caused by other causes.
IEC 61646-10.20 Wet leakage current Test
Purpose: To evaluate the insulation of the module under wet operating conditions and to verify that moisture from rain, fog, dew or melting snow does not enter the live parts of the module circuit, which may cause corrosion, ground failure or safety hazards.
IEEE1513 Temperature Cycle Test , Humidity Freezing Test and Thermal-humidity Test 1
Among the environmental reliability test requirements of Cells, Receiver, and Module of concentrated solar cells have their own test methods and test conditions in temperature cycle test, humidity freezing test, and thermal-humidity test, and there are also differences in the quality confirmation after the test. Therefore, IEEE1513 has three tests on temperature cycle test, humidity freezing test and thermal-humidity test in the specification, and its differences and test methods are sorted out for everyone's reference.
Reference source: IEEE Std 1513-2001
IEEE1513-5.7 Thermal cycle test IEEE1513-5.7 thermal cycle test
Objective: To determine whether the receiving end can properly withstand the failure caused by the thermal expansion difference between the parts and the joint material, especially the solder joint and package quality. Background: Temperature cycling tests of concentrated solar cells reveal welding fatigue of copper heat sinks and require complete ultrasonic transmission to detect crack growth in the cells (SAND92-0958 [B5]).
Crack propagation is a function of the temperature cycle number, the initial complete solder joint, solder joint type, between the battery and the radiator due to the thermal expansion coefficient and temperature cycle parameters, after the thermal cycle test to check the receiver structure of the packaging and insulation material quality. There are two test plans for the program, tested as follows:
Program A and Program B
Procedure A: Test receiver resistance at thermal stress caused by thermal expansion difference
Procedure B: Temperature cycle before humidity freezing test
Before pretreatment, it is emphasized that the initial defects of the receiving material are caused by actual wet freezing. In order to adapt to different concentrated solar energy designs, temperature cycle tests of program A and Program B can be checked, which are listed in Table 1 and Table 2.
1. These receivers are designed with solar cells directly connected to copper radiators, and the conditions required are listed in the first row table
2. This will ensure that potential failure mechanisms, which may lead to defects occurring during the development process, are discovered. These designs adopt different methods and can use alternative conditions as shown in the table to debond the radiator of the battery.
Table 3 shows that the receiving portion performs a program B temperature cycle prior to the alternative.
Since program B mainly tests other materials on the receiving end, alternatives are offered to all designs
Table 1 - Temperature cycle procedure test for receivers
Program A- Thermal cycle
Option
Maximum temperature
Total number of cycles
Application current
Required design
TCR-A
110℃
250
No
The battery is welded directly to the copper radiator
TCR-B
90℃
500
No
Other design records
TCR-C
90℃
250
I(applied) = Isc
Other design records
Table 2 - Temperature cycle procedure test of the receiver
Procedure B- Temperature cycle before wet freezing test
Option
Maximum temperature
Total number of cycles
Application current
Required design
HFR-A
110℃
100
No
Documentation of all designs
HFR-B
90℃
200
No
Documentation of all designs
HFR-C
90℃
100
I(applied) = Isc
Documentation of all designs
Procedure: The receiving end will be subjected to a temperature cycle between -40 °C and the maximum temperature (following the test procedure in Table 1 and Table 2), the cycle test can be put into a single or two boxes of gas temperature shock test chamber, the liquid shock cycle should not be used, the dwell time is at least 10 minutes, and the high and low temperature should be within the requirement of ±5 °C. The cycle frequency should not be greater than 24 cycles a day and not less than 4 cycles a day, the recommended frequency is 18 times a day.
The number of thermal cycles and the maximum temperature required for the two samples, refer to Table 3 (Procedure B of Figure 1), after which a visual inspection and electrical characteristics test will be carried out (refer to 5.1 and 5.2). These samples will be subjected to a wet freezing test, according to 5.8, and a larger receiver will refer to 4.1.1(this procedure is illustrated in Figure 2).
Background: The purpose of the temperature cycle test is to accelerate the test that will appear in the short term failure mechanism, prior to the detection of concentrating solar hardware failure, therefore, the test includes the possibility of seeing a wide temperature difference beyond the module range, the upper limit of the temperature cycle of 60 ° C is based on the softening temperature of many module acrylic lenses, for other designs, the temperature of the module. The upper limit of the temperature cycle is 90 ° C (see Table 3)
Table 3- List of test conditions for module temperature cycles
Procedure B Temperature cycle pretreatment before wet freezing test
Option
Maximum temperature
Total number of cycles
Application current
Required design
TCM-A
90℃
50
No
Documentation of all designs
TEM-B
60℃
200
No
Plastic lens module design may be required
IEEE1513 Temperature Cycle Test and Humidity Freezing Test, Thermal-humidity Test 2
Steps:
Both modules will perform 200 cycle temperature cycles between -40 °C and 60 °C or 50 cycle temperature cycles between -40 °C and 90 °C, as specified in ASTM E1171-99.
Note:
ASTM E1171-01: Test method for photoelectric modulus at Loop Temperature and humidity
Relative humidity does not need to be controlled.
The temperature variation should not exceed 100℃/ hour.
The residence time should be at least 10 minutes and the high and low temperature should be within the requirement of ±5℃
Requirements:
a. The module will be inspected for any obvious damage or degradation after the cycle test.
b. The module should not show any cracks or warps, and the sealing material should not delaminate.
c. If there is a selective electrical function test, the output power should be 90% or more under the same conditions of many original basic parameters
Added:
IEEE1513-4.1.1 Module representative or receiver test sample, if a complete module or receiver size is too large to fit into an existing environmental test chamber, the module representative or receiver test sample may be substituted for a full-size module or receiver.
These test samples should be specially assembled with a replacement receiver, as if containing a string of cells connected to a full-size receiver, the battery string should be long and include at least two bypass diodes, but in any case three cells are relatively few, which summarizes the inclusion of links with the replacement receiver terminal should be the same as the full module.
The replacement receiver shall include components representative of the other modules, including lens/lens housing, receiver/receiver housing, rear segment/rear segment lens, case and receiver connector, procedures A, B, and C will be tested.
Two full-size modules should be used for outdoor exposure test procedure D.
IEEE1513-5.8 Humidity freeze cycle test Humidity freeze cycle test
Receiver
Purpose:
To determine whether the receiving part is sufficient to resist corrosion damage and the ability of moisture expansion to expand the material molecules. In addition, frozen water vapor is the stress for determining the cause of failure
Procedure:
The samples after temperature cycling will be tested according to Table 3, and will be subjected to wet freezing test at 85 ℃ and -40 ℃, humidity 85%, and 20 cycles. According to ASTM E1171-99, the receiving end with large volume shall refer to 4.1.1
Requirements:
The receiving part shall meet the requirements of 5.7. Move out of the environment tank within 2 to 4 hours, and the receiving part should meet the requirements of the high-voltage insulation leakage test (see 5.4).
module
Purpose:
Determine whether the module has sufficient capacity to resist harmful corrosion or widening of material bonding differences
Procedure: Both modules will be subjected to wet freezing tests for 20 cycles, 4 or 10 cycles to 85 ° C as shown in ASTM E1171-99.
Please note that the maximum temperature of 60 ° C is lower than the wet freezing test section at the receiving end.
A complete high voltage insulation test (see 5.4) will be completed after a two to four hour cycle. Following the high voltage insulation test, the electrical performance test as described in 5.2 will be carried out. In large modules may also be completed, see 4.1.1.
Requirements:
a. The module will check for any obvious damage or degradation after the test, and record any.
b. The module should exhibit no cracking, warping, or severe corrosion. There should be no layers of sealing material.
c. The module shall pass the high voltage insulation test as described in IEEE1513-5.4.
If there is a selective electrical function test, the output power can reach 90% or more under the same conditions of many original basic parameters
IEEE1513-5.10 Damp heat test IEEE1513-5.10 Damp heat test
Objective: To evaluate the effect and ability of receiving end to withstand long-term moisture infiltration.
Procedure: The test receiver is tested in an environmental test chamber with 85%±5% relative humidity and 85 ° C ±2 ° C as described in ASTM E1171-99. This test should be completed in 1000 hours, but an additional 60 hours can be added to perform a high voltage insulation leakage test. The receiving part can be used for testing.
Requirements: The receiving end needs to leave the damp heat test chamber for 2 ~ 4 hours to pass the high voltage insulation leakage test (see 5.4) and pass the visual inspection (see 5.1). If there is a selective electrical function test, the output power should be 90% or more under the same conditions of many original basic parameters.
IEEE1513 Module test and inspection procedures
IEEE1513-5.1 Visual inspection procedure
Purpose: To establish the current visual status so that the receiving end can compare whether they pass each test and guarantee that they meet the requirements for further testing.
IEEE1513-5.2 Electrical performance test
Objective: To describe the electrical characteristics of the test module and the receiver and to determine their peak output power.
IEEE1513-5.3 Ground continuity test
Purpose: To verify electrical continuity between all exposed conductive components and the grounding module.
IEEE1513-5.4 Electrical isolation test (dry hi-po)
Purpose: To ensure that the electrical insulation between the circuit module and any external contact conductive part is sufficient to prevent corrosion and safeguard the safety of workers.
IEEE1513-5.5 Wet insulation resistance test
Purpose: To verify that moisture cannot penetrate the electronically active part of the receiving end, where it could cause corrosion, ground failure, or identify hazards for human safety.
IEEE1513-5.6 Water spray test
Objective: The field wet resistance test (FWRT) evaluates the electrical insulation of solar cell modules based on humidity operating conditions. This test simulates heavy rain or dew on its configuration and wiring to verify that moisture does not enter the array circuit used, which can increase corrosiveness, cause ground failures, and create electrical safety hazards for personnel or equipment.
IEEE1513-5.7 Thermal cycle test (Thermal cycle test)
Objective: To determine whether the receiving end can properly withstand the failure caused by the difference in thermal expansion of parts and joint materials.
IEEE1513-5.8 Humidity freeze cycle test
Objective: To determine whether the receiving part is sufficiently resistant to corrosion damage and the ability of moisture expansion to expand the material molecules. In addition, frozen water vapor is the stress for determining the cause of failure.
IEEE1513-5.9 Robustness of terminations test
Purpose: To ensure the wires and connectors, apply external forces on each part to confirm that they are strong enough to maintain normal handling procedures.
IEEE1513-5.10 Damp heat test (Damp heat test)
Objective: To evaluate the effect and ability of receiving end to withstand long-term moisture infiltration. I
EEE1513-5.11 Hail impact test
Objective: To determine whether any component, especially the condenser, can survive hail. IE
EE1513-5.12 Bypass diode thermal test (Bypass diode thermal test)
Objective: To evaluate the availability of sufficient thermal design and use of bypass diodes with relative long-term reliability to limit the adverse effects of module thermal shift diffusion.
IEEE1513-5.13 Hot-spot endurance test (Hot-Spot endurance test)
Objective: To assess the ability of modules to withstand periodic heat shifts over time, commonly associated with failure scenarios such as severely cracked or mismatched cell chips, single point open circuit failures, or uneven shadows (shaded portions). I
EEE1513-5.14 Outdoor exposure test (Outdoor exposure test)
Purpose: In order to preliminarily assess the capability of the module to withstand exposure to outdoor environments (including ultraviolet radiation), the reduced effectiveness of the product may not be detected by laboratory testing.
IEEE1513-5.15 Off-axis beam damage test
Purpose: To ensure that any part of the module is destroyed due to module deviation of the concentrated solar radiation beam.
Solar Module EVA Film Introduction 1
In order to improve the power generation efficiency of solar cell modules, provide protection against the loss caused by environmental climate change, and ensure the service life of solar modules, EVA plays a very important role. EVA is non-adhesive and anti-adhesive at room temperature. After hot pressing under certain conditions during the solar cell packaging process, EVA will produce melt bonding and adhesive curing. The cured EVA film becomes completely transparent and has quite high light transmittance. The cured EVA can withstand atmospheric changes and has elasticity. The solar cell wafer is wrapped and bonded with the upper glass and lower TPT by vacuum lamination technology.
Basic functions of EVA film:
1. Secure the solar Cell and connecting circuit wires to provide cell insulation protection
2. Perform optical coupling
3. Provide moderate mechanical strength
4. Provide a heat transfer pathway
EVA Main features:
1. Heat resistance, low temperature resistance, moisture resistance and weather resistance
2. Good followability to metal glass and plastic
3. Flexibility & Elasticity
4. High light transmission
5. Impact resistance
6. Low temperature winding
Thermal conductivity of solar cell related materials: (K value of thermal conductivity at 27 ° C (300'K))
Description: EVA is used for the combination of solar cells as a follow-up agent, because of its strong follow-up ability, softness and elongation, it is suitable for joining two different expansion coefficient materials.
Aluminum: 229 ~ 237 W/(m·K)
Coated aluminum alloy: 144 W/(m·K)
Silicon wafer: 80 ~ 148 W/(m·K)
Glass: 0.76 ~ 1.38 W/(m·K)
EVA: 0.35W /(m·K)
TPT: 0.614 W/(m·K)
EVA appearance inspection: no crease, no stain, smooth, translucent, no stain edge, clear embossing
EVA material performance parameters:
Melting index: affects the enrichment rate of EVA
Softening point: The temperature point at which EVA begins to soften
Transmittance: There are different transmittance for different spectral distributions, which mainly refers to the transmittance under the spectral distribution of AM1.5
Density: density after bonding
Specific heat: the specific heat after bonding, reflecting the size of the temperature increase value when the EVA after bonding absorbs the same heat
Thermal conductivity: thermal conductivity after bonding, reflecting the thermal conductivity of EVA after bonding
Glass transition temperature: reflects the low temperature resistance of EVA
Breaking tension strength: The breaking tension strength of EVA after bonding reflects the mechanical strength of EVA after bonding
Elongation at break: the elongation at break at EVA after bonding reflects the tension of EVA after bonding
Water absorption: It directly affects the sealing performance of battery cells
Binding rate: The binding rate of EVA directly affects his impermeability
Peel strength: reflects the bond strength between EVA and peel
EVA reliability test purpose: to confirm the weather resistance, light transmission, bonding force, ability to absorb deformation, ability to absorb physical impact, damage rate of pressing process of EVA... Let's wait.
EVA aging test equipment and projects: constant temperature and humidity test chamber (high temperature, low temperature, high temperature and high humidity), high and low temperature chamber (temperature cycle), ultraviolet testing machine (UV)
VA Model 2: Glass /EVA/ conductive copper sheet /EVA/ glass composite
Description: Through the on-resistance electrical measurement system, the low resistance in EVA is measured. Through the change of the on-resistance value during the test, the water and gas penetration of EVA is determined, and the oxidation corrosion of copper sheet is observed.
After three tests of temperature cycle, wet freezing and wet heat, the characteristics of EVA and Backsheet change:
(↑ : up, ↓ : down)
After three tests of temperature cycle, wet freezing and wet heat, the characteristics of EVA and Backsheet change:
(↑ : up, ↓ : down)
EVA：
Backsheet：
Yellow↑
Inner layer yellow ↑
Cracking ↑
Cracks in the inner layer and PET layer ↑
Atomization ↑
Reflectivity ↓
Transparency ↓
Solar Module EVA Film Introduction 2
EVA-UV test:
Description: Test the attenuation ability of EVA to withstand ultraviolet (UV) irradiation, after a long time of UV irradiation, EVA film will appear brown, penetration rate decreased... And so on.
EVA environmental test project and test conditions:
Humid heat: 85℃ / RH 85%; 1,000 hrs
Thermal cycle: -40℃ ~ 85℃; 50 cycles
Wet freezing test: -40℃ ~ 85℃ / RH 85%; 10 times UV: 280~385nm/ 1000w/200hrs (no cracking and no discoloration)
EVA Test Conditions (NREL) :
High temperature test: 95℃ ~ 105℃/1000h
Humidity and heat: 85℃/85%R.H./>1000h[1500h]
Temperature cycle: -40℃←→85℃/>200Cycles
(No bubbles, no cracking, no desticking, no discoloration, no thermal expansion and contraction)
UV aging: 0.72W/m2, 1000 hrs, 60℃(no cracking, no discoloration) Outdoor: > California sunshine for 6 months
Example of EVA characteristics change under Damp heat test:
Discoloration, atomization, Browning, delamination
Comparison of EVA bond strength at high temperature and humidity:
Description: EVA film at 65℃/85%R.H and 85℃/85%R.H. The degradation of the bond strength was compared at 65℃/85%R.H under two different wet and hot conditions. After 5000 hours of testing, the degradation benefit is not high, but EVA at 85℃/85%R.H. In the test environment, the adhesion is quickly lost, and there is a significant reduction in bond strength in 250 hours.
EVA-HAST unsaturated pressurized vapor test:
Objective: Since EVA film needs to be tested for more than 1000 hours at 85℃/85%R.H., which is equal to at least 42 days, in order to shorten the test time and accelerate the test speed, it is necessary to increase the environmental stress (temperature & humidity & pressure) and speed up the test process in the environment of unsaturated humidity (85%R.H.).
Test conditions: 110℃/85%R.H./264h
EVA-PCT pressure digester test:
Objective: The PCT test of EVA is to increase the environmental stress (temperature & humidity) and expose EVA to wetting vapor pressure exceeding one atmosphere, which is used to evaluate the sealing effect of EVA and the moisture absorption status of EVA.
Test condition: 121℃/100%R.H.
Test time: 80h(COVEME) / 200h(toyal Solar)
EVA and CELL bond tensile force test:
EVA: 3 ~ 6Mpa Non-EVA material: 15Mpa
Additional information from EVA:
1. The water absorption of EVA will directly affect its sealing performance of the battery
2.WVTR < 1×10-6g/m2/day(NREL recommended PV WVTR)
3. The adhesive degree of EVA directly affects its impermeability. It is recommended that the adhesive degree of EVA and cell should be greater than 60%
4. When the bonding degree reaches more than 60%, thermal expansion and contraction will no longer occur
5. The bonding degree of EVA directly affects the performance and service life of the component
6. Unmodified EVA has low cohesion strength and is prone to thermal expansion and contraction leading to chip fragmentation
7.EVA peeling strength: longitudinal ≧20N/cm, horizontal ≧20N/cm
8. The initial light transmittance of the packaging film is not less than 90%, and the internal decline rate of 30 years is not less than 5%
Reliability - Environment
Reliability analysis is based on quantitative data as the basis of product quality, through the experimental simulation, the product in a given time, specific use of environmental conditions, the implementation of specific specifications, the probability of successful completion of work objectives, to quantitative data as the basis for product quality assurance. Among them, environmental testing is a common analysis item in reliability analysis.
Environmental reliability testing is a test performed to ensure that the functional reliability of a product is maintained during the specified life period, under all circumstances in which it is intended to be used, transported or stored. The specific test method is to expose the product to natural or artificial environmental conditions, to evaluate the performance of the product under the environmental conditions of actual use, transportation and storage, and to analyze the impact of environmental factors and their mechanism of action.
Sembcorp's Nanoreliability Analysis laboratory mainly evaluates IC reliability by increasing temperature, humidity, bias, analog IO and other conditions, and selecting conditions to accelerate aging according to IC design requirements. The main test methods are as follows:
TC temperature cycle test
Experimental standard: JESD22-A104
Objective: To accelerate the effect of temperature change on the sample
Test procedure: The sample is placed in a test chamber, which cycles between specified temperatures and is held at each temperature for at least ten minutes. The temperature extremes depend on the conditions selected in the test method. The total stress corresponds to the number of cycles completed at the specified temperature.
capacity of equipment
Temperature Range
-70℃—+180℃
Temperature Change Rate
15℃/min linear
Internal Volume
160L
Internal Dimension
W800*H500 * D400mm
External Dimension
W1000 * H1808 * D1915mm
Quantity of sample
25 / 3lot
Time/pass
700 cycles / 0 Fail2300 cycles / 0 Fail
BLT high temperature bias test
Experimental standard: JESD22-A108
Objective: The influence of high temperature bias on samples
Test process: Put the sample into the experimental chamber, set the specified voltage and current limit value in power supply, try run at room temperature, observe whether the limited current occurs in power supply, measure whether the input chip terminal voltage meets the expectation, record the current value at room temperature, and set the specified temperature in chamber. When the temperature is stable at the set value, power on at high temperature and record the high temperature current value
Equipment capacity:
Temperature Range
+20℃—+300℃
Internal Volume
448L
Internal Dimension
W800*H800 * D700mm
External Dimension
W1450 * H1215 * D980mm
Quantity of sample
25 / 3lot
Time/pass
Case Temperature 125℃ ,1000hrs/ 0 Fail
HAST highly accelerated stress test
Experimental standard: JESD22-A110/A118 (EHS-431ML, EHS-222MD)
Objective: HAST provides constant multiple stress conditions, including temperature, humidity, pressure, and bias. Carried out to assess the reliability of non-enclosed packaged equipment operating in humid environments. Multiple stress conditions can accelerate the infiltration of moisture through the encapsulation mold compound or along the interface between the external protective material and the metal conductor passing through the encapsulation. When water reaches the surface of the bare piece, the applied potential sets up an electrolytic condition that corrodes the aluminum conductor and affects the DC parameters of the device. Contaminants present on the chip surface, such as chlorine, can greatly accelerate the corrosion process. In addition, too much phosphorus in the passivation layer can also react under these conditions.
Device 1 and device 2
Equipment capacity:
Quantity of sample
25 / 3lot
Time/pass
130℃，85%RH ,96hrs/ 0 Fail
110℃，85%RH ,264hrs/ 0 Fail
Device 1
Temperature Range
-105℃—+142.9℃
Humidity Range
75%RH—100%RH
Pressure Range
0.02—0.196MPa
Internal Volume
51L
Internal Dimension
W355*H355 * D426mm
External Dimension
W860 * H1796 * D1000mm
Device 2
Temperature Range
-105℃—+142.9℃
Humidity Range
75%RH—100%RH
Pressure Range
0.02—0.392MPa
Internal Volume
180L
Internal Dimension
W569*H560 * D760mm
External Dimension
W800 * H1575 * D1460mm
THB temperature and humidity cycle test
Experimental standard: JESD22-A101
Objective: The influence of temperature and humidity change on the sample
Experimental process: Put the sample into the experimental chamber, set the specified voltage and current limit value in power supply, try run at room temperature, observe whether the limited current occurs in power supply, measure whether the input chip terminal voltage meets the expectation, record the current value at room temperature, and set the specified temperature in chamber. When the temperature is stable at the set value, power on at high temperature and record the high temperature current value
Equipment capacity:
Temperature Range
-40℃—+180℃
Humidity Range
10%RH—98%RH
Temperature Conversion Rate
3℃/min
Internal Volume
784L
Internal Dimension
W1000*H980 * D800mm
External Dimension
W1200 * H1840 * D1625mm
Quantity of sample
25 / 3lot
Time/pass
85℃，85%RH ,1000hrs/ 0 Fail
Procedure temperature and humidity cycle, there has no humidity when temperature over 100℃
TSA&TSB temperature shock test
Experimental standard: JESD22-A106
Objective: To accelerate the effect of temperature change on the sample
Test process: The sample is put into the test chamber, and the specified temperature is set inside the chamber. Before heating up, it is confirmed that the sample has been fixed on the mold, which has prevented damage due to the sample falling into the chamber during the experiment.
Equipment capacity:
TSA
TSB
Temperature Range
-70℃—+200℃
-65℃—+200℃
Temperature Change Rate
≤5min
＜20S
Internal Volume
70L
4.5L
Internal Dimension
W410*H460 * D3700mm
W150*H150 * D200mm
External Dimension
W1310 * H1900 * D1770mm
W1200 * H1785 * D1320mm
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