Tablet Reliability Test
A Tablet Computer, also known as a Tablet Personal Computer (Tablet PC), is a small, portable personal computer that uses a touch screen as its basic input device. It is an electronic product with strong mobility, and it can be seen everywhere in life (such as waiting stations, trains, high-speed trains, cafes, restaurants, meeting rooms, suburbs, etc.). People carry only simple coat protection or even no, in order to facilitate use, the design reduces the size, so that it can be directly placed in the pocket or handbag, backpack, but the tablet computer in the process of moving will also experience many environmental physical changes (such as temperature, humidity, vibration, impact, extrusion, etc.). Etc.) and natural damage (such as ultraviolet light, sunlight, dust, salt spray, water droplets... It will also cause artificial unintentional injury or abnormal operation and misoperation, and even cause failure and damage (such as: household chemicals, hand sweating, falling, terminal insertion and removal too much, pocket friction, crystal nails... These will shorten the life of the tablet computer, in order to ensure the reliability of the product and extend the service life to improve, we must carry out a number of environmental reliability test projects on the tablet computer, the following relevant tests for your reference.
Environmental test project description:
Simulate various harsh environments and reliability assessments used by tablet computers to test whether their performance meets the requirements; It mainly includes high and low temperature operation and high and low temperature storage, temperature and condensation, temperature cycle and shock, wet and heat combination test, ultraviolet, sunlight, drip, dust, salt spray and other tests.
Operating temperature range: 0℃ ~ 35℃/5% ~ 95%RH
Storage temperature range: -10℃ ~ 50℃/10% ~ 90%RH
Operating low temperature test: -10℃/2h/ power operation
Operating high temperature test: 40℃/8h/ all running
Storage low temperature test: -20℃/96h/ shutdown
Storage high temperature test: 60℃/96h/ shutdown
High temperature test of vehicle storage: 85℃/96h/ shutdown
Temperature shock: -40℃(30min)←→80℃(30min)/10cycle
Wet heat test: 40℃/95%R.H./48h/ power standby
Hot and humid cycle test: 40℃/95%R.H./1h→ramp:1℃/min→-10℃/1h, 20cycles, power standby
Wet heat test: 40℃/95%R.H./48h/ power standby
Hot and humid cycle test: 40℃/95%R.H./1h→ramp:1℃/min→-10℃/1h, 20cycles, power standby
Weather resistance test:
Simulation of the most severe natural conditions, solar thermal effect test, each cycle of 24 hours, 8 hours of continuous exposure, 16 hours to keep dark, each cycle radiation amount of 8.96 kWh/m2, a total of 10cycles.
Salt spray test:
5% sodium chloride solution/Water temperature 35°C/PH 6.5~7.2/24h/ Shutdown → Pure water wipe shell →55°C/0.5h→ Function test: after 2 hours, after 40/80%R.H./168h.
Dripping test: According to IEC60529, in line with IPX2 waterproof rating, can prevent water droplets falling at an Angle of less than 15 degrees from entering the tablet computer and causing damage. Test conditions: water flow rate 3mm/min, 2.5min at each position, checkpoint: after test, 24 hours later, standby for 1 week.
Dust Test:
According to IEC60529, in line with the IP5X dust class, can not completely prevent the entry of dust but does not affect the device should be the action and anquan, in addition to tablet computers are currently many personal mobile portable 3C products commonly used dust standards, such as: mobile phones, digital cameras, MP3, MP4... Let's wait.
Conditions:
Dust sample 110mm/3 ~ 8h/ test for dynamic operation
After the test, a microscope is used to detect whether dust particles will enter the interior space of the tablet.
Chemical staining test:
Confirm the external components related to the tablet, confirm the chemical resistance of household chemicals, chemicals: sunscreen, lipstick, hand cream, mosquito repellent, cooking oil (salad oil, sunflower oil, olive oil... Etc.), the test time is 24 hours, check the color, gloss, surface smoothness... Etc., and confirm whether there are bubbles or cracks.
Mechanical test:
Test the strength of the mechanical structure of the tablet computer and the wear resistance of the key components; Mainly includes vibration test, drop test, impact test, plug test, and wear test... Etc.
Fall test: The height of 130cm, free fall on the smooth soil surface, each side fell 7 times, 2 sides a total of 14 times, tablet computer in standby state, each fall, the function of the test product is checked.
Repeated drop test: the height of 30cm, free drop on the smooth dense surface of 2cm thickness, each side fell 100 times, each interval of 2s, 7 sides a total of 700 times, every 20 times, check the function of the experimental product, tablet computer is in the state of power.
Random vibration test: frequency 30 ~ 100Hz, 2G, axial: three axial. Time: 1 hour in each direction, for a total of three hours, the tablet is in standby mode.
Screen impact resistance test: 11φ/5.5g copper ball fell on the center surface of 1m object at 1.8m height and 3ψ/9g stainless steel ball fell at 30cm height
Screen writing durability: more than 100,000 words (width R0.8mm, pressure 250g)
Screen touch durability: 1 million, 10 million, 160 million, 200 million times or more (width R8mm, hardness 60°, pressure 250g, 2 times per second)
Screen flat press test: the diameter of the rubber block is 8mm, the pressure speed is 1.2mm/min, the vertical direction is 5kg force flat press the window 3 times, each time for 5 seconds, the screen should display normally.
Screen front flat press test: The entire contact area, the direction of the vertical 25kg force front flat press each side of the tablet computer, for 10 seconds, flat press 3 times, there should be no abnormal.
Earphone plug and remove test: Insert the earphone vertically into the earphone hole, and then pull it out vertically. Repeat this for more than 5000 times
I/O plug and pull test: The tablet is in standby state, and the plug terminal connector is pulled out, a total of more than 5000 times
Pocket friction test: Simulate various materials pocket or backpack, the tablet is repeatedly rubbed in the pocket 2,000 times (friction test will also add some mixed dust particles, including dust particles, yan grass particles, fluff and paper particles for mixing test).
Screen hardness test: hardness greater than class 7 (ASTM D 3363, JIS 5400)
Screen impact test: hit the most vulnerable sides and center of the panel with a force of more than 5㎏
Laptop Test Conditions
Notebook computer from the early 12-inch screen evolution to the current LED backlit screen, its computing efficiency and 3D processing, will not be lost to the general desktop computer, and the weight is becoming less and less burden, the relative reliability test requirements for the entire notebook computer is becoming more and more stringent, from the early packaging to the current boot down, the traditional high temperature and high humidity to the current condensation test. From the temperature and humidity range of the general environment to the desert test as a common condition, these are the parts that need to be considered in the production of notebook computer related components and design, the test conditions of the relevant environmental tests collected so far are organized and shared with you.
Keyboard tapping test:
Test one:
GB:1 million times
Key pressure :0.3~0.8(N)
Button stroke :0.3~1.5(mm)
Test 2: Key pressure: 75g(±10g) Test 10 keys for 14 days, 240 times per minute, a total of about 4.83 million times, once every 1 million times
Japanese manufacturers :2 to 5 million times
Taiwan manufacturer 1: more than 8 million times
Taiwan Manufacturer 2:10 million times
Power switch and connector plug pull test:
This test model simulates the lateral forces that each connector can withstand under abnormal usage. General laptop test items: USB, 1394, PS2, RJ45, Modem, VGA... Equal application force 5kg(50 times), up and down left and right pull and plug.
Power switch and connector plug test:
4000 times (Power supply)
Screen cover opening and closing test:
Taiwanese manufacturers: open and close 20,000 times
Japanese manufacturer 1: opening and closing test 85,000 times
Japanese manufacturer 2: opening and closing 30,000 times
System standby and recovery switch test:
General note type: interval 10sec, 1000cycles
Japanese manufacturer: System standby and recovery switch test 2000 times
Common causes of laptop failure:
☆ Foreign objects fall on the notebook
☆ Falls off the table while in use
☆ Tuck the notebook in a handbag or trolley case
☆ Extremely high temperature or low temperature ☆ Normal use (overuse)
☆ Wrong use in tourist destinations
☆PCMCIA inserted incorrectly
☆ Place foreign objects on the keyboard
Shutdown drop test:
General notebook type :76 cm
GB package drop: 100cm
Us Army and Japanese notebook computers: The height of the computer is 90 cm from all sides, sides, corners, a total of 26 sides
Platform :74 cm (packing required)
Land: 90cm (packing required)
TOSHIBA&BENQ 100 cm
Boot drop test:
Japanese :10 cm boot fall
Taiwan :74 cm boot fall
Laptop main board temperature shock:
Slope 20℃/min
Number of cycles 50cycles(no operation during impact)
The U.S. military's technical standards and test conditions for laptop procurement are as follows:
Impact test: Drop the computer 26 times from all sides, sides and corners at a height of 90 cm
Earthquake resistance test :20Hz~1000Hz, 1000Hz~2000Hz frequency once an hour X, Y and Z axis continuous vibration
Temperature test :0℃~60℃ 72 hours of aging oven
Waterproof test: Spray water on the computer for 10 minutes in all directions, and the water spray rate is 1mm per minute
Dust test: Spray the concentration of 60,000 mg/ per cubic meter of dust for 2 seconds (interval of 10 minutes, 10 consecutive times, time 1 hour)
Meets MIL-STD-810 military specifications
Waterproof test:
Us Army notebook :protection class:IP54(dust & rain) Sprayed the computer with water in all directions for 10 minutes at a rate of 1mm per minute.
Dust proof test:
Us Army notebook: Spray a concentration of 60,000 mg/ m3 of dust for 2 seconds (10 minute intervals, 10 consecutive times, time 1 hour)
Temperature Cyclic Stress Screening (1)
Environmental Stress Screening (ESS)
Stress screening is the use of acceleration techniques and environmental stress under the design strength limit, such as: burn in, temperature cycling, random vibration, power cycle... By accelerating the stress, the potential defects in the product emerge [potential parts material defects, design defects, process defects, process defects], and eliminate electronic or mechanical residual stress, as well as eliminate stray capacitors between multi-layer circuit boards, the early death stage of the product in the bath curve is removed and repaired in advance, so that the product through moderate screening, Save the normal period and decline period of the bathtub curve to avoid the product in the process of use, the test of environmental stress sometimes lead to failure, resulting in unnecessary losses. Although the use of ESS stress screening will increase the cost and time, for improving the product delivery yield and reduce the number of repairs, there is a significant effect, but for the total cost will be reduced. In addition, customer trust will also be improved, generally for electronic parts of the stress screening methods are pre-burning, temperature cycle, high temperature, low temperature, PCB printed circuit board stress screening method is temperature cycle, for the electronic cost of the stress screening is: Power pre-burning, temperature cycling, random vibration, in addition to the stress screen itself is a process stage, rather than a test, screening is 100% of the product procedure.
Stress screening applicable product stage: R & D stage, mass production stage, before delivery (screening test can be carried out in components, devices, connectors and other products or the whole machine system, according to different requirements can have different screening stress)
Stress screening comparison:
a. Constant high temperature pre-burning (Burn in) stress screening, is the current electronic IT industry commonly used method to precipitate electronic components defects, but this method is not suitable for screening parts (PCB, IC, resistor, capacitor), According to statistics, the number of companies in the United States that use temperature cycling to screen parts is five times more than the number of companies that use constant high temperature prefiring to screen components.
B. GJB/DZ34 indicates the proportion of temperature cycle and random vibrating screen selection defects, temperature accounted for about 80%, vibration accounted for about 20% of the defects in various products.
c. The United States has conducted a survey of 42 enterprises, random vibration stress can screen out 15 to 25% of the defects, while the temperature cycle can screen out 75 to 85%, if the combination of the two can reach 90%.
d. The proportion of product defect types detected by temperature cycling: insufficient design margin: 5%, production and workmanship errors: 33%, defective parts: 62%
Description of fault induction of temperature cyclic stress screening:
The cause of product failure induced by temperature cycling is: when the temperature is cycled within the upper and lower extremal temperatures, the product produces alternating expansion and contraction, resulting in thermal stress and strain in the product. If there is a transient thermal ladder (temperature non-uniformity) within the product, or the thermal expansion coefficients of adjacent materials within the product do not match each other, these thermal stresses and strains will be more drastic. This stress and strain is greatest at the defect, and this cycle causes the defect to grow so large that it can eventually cause structural failure and generate electrical failure. For example, a cracked electroplated through-hole eventually cracks completely around it, causing an open circuit. Thermal cycling enables soldering and plating through holes on printed circuit boards... Temperature cyclic stress screening is especially suitable for electronic products with printed circuit board structure.
The fault mode triggered by the temperature cycle or the impact on the product is as follows:
a. The expansion of various microscopic cracks in the coating, material or wire
b. Loosen poorly bonded joints
c. Loosen improperly connected or riveted joints
d. Relax the pressed fittings with insufficient mechanical tension
e. Increase the contact resistance of poor quality solder joints or cause an open circuit
f. Particle, chemical pollution
g. Seal failure
h. Packaging issues, such as bonding of protective coatings
i. Short circuit or open circuit of the transformer and coil
j. The potentiometer is defective
k. Poor connection of welding and welding points
l. Cold welding contact
m. Multi-layer board due to improper handling of open circuit, short circuit
n. Short circuit of power transistor
o. Capacitor, transistor bad
p. Dual row integrated circuit failure
q. A box or cable that is nearly short-circuited due to damage or improper assembly
r. Breakage, breakage, scoring of material due to improper handling... Etc.
s. out-of-tolerance parts and materials
t. resistor ruptured due to lack of synthetic rubber buffer coating
u. The transistor hair is involved in the grounding of the metal strip
v. Mica insulation gasket rupture, resulting in short circuit transistor
w. Improper fixing of the metal plate of the regulating coil leads to irregular output
x. The bipolar vacuum tube is open internally at low temperature
y. Coil indirect short circuit
z. Ungrounded terminals
a1. Component parameter drift
a2. Components are improperly installed
a3. Misused components
a4. Seal failure
Introduction of stress parameters for temperature cyclic stress screening:
The stress parameters of temperature cyclic stress screening mainly include the following: high and low temperature extremum range, dwell time, temperature variability, cycle number
High and low temperature extremal range: the larger the range of high and low temperature extremal, the fewer cycles required, the lower the cost, but can not exceed the product can withstand the limit, do not cause new fault principle, the difference between the upper and lower limits of temperature change is not less than 88°C, the typical range of change is -54°C to 55°C.
Dwell time: In addition, the dwell time can not be too short, otherwise it is too late to make the product under test produce thermal expansion and contraction stress changes, as for the dwell time, the dwell time of different products is different, you can refer to the relevant specification requirements.
Number of cycles: As for the number of cycles of temperature cyclic stress screening, it is also determined by considering product characteristics, complexity, upper and lower limits of temperature and screening rate, and the screening number should not be exceeded, otherwise it will cause unnecessary harm to the product and cannot improve the screening rate. The number of temperature cycles ranges from 1 to 10 cycles [ordinary screening, primary screening] to 20 to 60 cycles [precision screening, secondary screening], for the removal of the most likely workmanship defects, about 6 to 10 cycles can be effectively removed, in addition to the effectiveness of the temperature cycle, Mainly depends on the temperature variation of the product surface, rather than the temperature variation inside the test box.
There are seven main influencing parameters of temperature cycle:
(1) Temperature Range
(2) Number of Cycles
(3) Temperature Rate of Chang
(4) Dwell Time
(5) Airflow Velocities
(6) Uniformity of Stress
(7) Function test or not (Product Operating Condition)
Temperature Cyclic Stress Screening (2)
Introduction of stress parameters for temperature cyclic stress screening:
The stress parameters of temperature cyclic stress screening mainly include the following: high and low temperature extremum range, dwell time, temperature variability, cycle number
High and low temperature extremal range: the larger the range of high and low temperature extremal, the fewer cycles required, the lower the cost, but can not exceed the product can withstand the limit, do not cause new fault principle, the difference between the upper and lower limits of temperature change is not less than 88°C, the typical range of change is -54°C to 55°C.
Dwell time: In addition, the dwell time can not be too short, otherwise it is too late to make the product under test produce thermal expansion and contraction stress changes, as for the dwell time, the dwell time of different products is different, you can refer to the relevant specification requirements.
Number of cycles: As for the number of cycles of temperature cyclic stress screening, it is also determined by considering product characteristics, complexity, upper and lower limits of temperature and screening rate, and the screening number should not be exceeded, otherwise it will cause unnecessary harm to the product and cannot improve the screening rate. The number of temperature cycles ranges from 1 to 10 cycles [ordinary screening, primary screening] to 20 to 60 cycles [precision screening, secondary screening], for the removal of the most likely workmanship defects, about 6 to 10 cycles can be effectively removed, in addition to the effectiveness of the temperature cycle, Mainly depends on the temperature variation of the product surface, rather than the temperature variation inside the test box.
There are seven main influencing parameters of temperature cycle:
(1) Temperature Range
(2) Number of Cycles
(3) Temperature Rate of Chang
(4) Dwell Time
(5) Airflow Velocities
(6) Uniformity of Stress
(7) Function test or not (Product Operating Condition)
Stress screening fatigue classification:
The general classification of Fatigue research can be divided into High-cycle Fatigue, Low-cycle Fatigue and Fatigue Crack Growth. In the aspect of low cycle Fatigue, it can be subdivided into Thermal Fatigue and Isothermal Fatigue.
Stress screening acronyms:
ESS: Environmental stress screening
FBT: Function board tester
ICA: Circuit analyzer
ICT: Circuit tester
LBS: load board short-circuit tester
MTBF: mean time between failures
Time of temperature cycles:
a.MIL-STD-2164(GJB 1302-90) : In the defect removal test, the number of temperature cycles is 10, 12 times, and in the trouble-free detection it is 10 ~ 20 times or 12 ~ 24 times. In order to remove the most likely workmanship defects, about 6 ~ 10 cycles are needed to effectively remove them. 1 ~ 10 cycles [general screening, primary screening], 20 ~ 60 cycles [precision screening, secondary screening].
B.od-hdbk-344 (GJB/DZ34) Initial screening equipment and unit level uses 10 to 20 loops (usually ≧10), component level uses 20 to 40 loops (usually ≧25).
Temperature variability:
a.MIL-STD-2164(GJB1032) clearly states: [Temperature change rate of temperature cycle 5℃/min]
B.od-hdbk-344 (GJB/DZ34) Component level 15 ° C /min, system 5 ° C /min
c. Temperature cyclic stress screening is generally not specified temperature variability, and its commonly used degree variation rate is usually 5°C/min
VMR- plate Temperature Cycle Transient Break Test
Temperature cycle test is one of the most commonly used methods for reliability and life test of lead-free welding materials and SMD parts. It evaluates the adhesive parts and solder joints on the surface of SMD, and causes plastic deformation and mechanical fatigue of solder joints materials under the fatigue effect of cold and hot temperature cycle with controlled temperature variability, so as to understand the potential hazards and failure factors of solder joints and SMD. The Daisy chain diagram is connected between the parts and the solder joints. The test process detects the on-off and on-off between the lines, parts and solder joints through the high-speed instantaneous break measuring system, which meets the demand for the reliability test of electrical connections to evaluate whether the solder joints, tin balls and parts fail. This test is not really simulated. Its purpose is to apply severe stress and accelerate the aging factor on the object to be tested to confirm whether the product is designed or manufactured correctly, and then evaluate the thermal fatigue life of the component solder joints. The reliability test of the electrical high-speed instantaneous break connection has become a key link to ensure the normal operation of the electronic system and avoid the failure of the electrical connection caused by the failure of the immature system. The resistance changes over a short period of time were observed under accelerated temperature changes and vibration tests.
Purpose:
1. Ensure that products designed, manufactured and assembled meet predetermined requirements
2. Relaxation of solder joint creep stress and SMD fracture failure caused by thermal expansion difference
3. The maximum test temperature of the temperature cycle should be 25℃ lower than the Tg temperature of the PCB material, so as to avoid more than one damage mechanism of the substitute test product
4. Temperature variability at 20℃/min is a temperature cycle, and temperature variability above 20℃/min is a temperature shock
5. The welding joint dynamic measurement interval does not exceed 1min
6. The high temperature and low temperature residence time for failure determination needs to be measured in 5 strokes
Requirements:
1. The total temperature time of the test product is within the range of the rated maximum temperature and the minimum temperature, and the length of the residence time is very important for the accelerated test, because the residence time is not enough during the accelerated test, which will make the creep process incomplete
2. The resident temperature must be higher than Tmax temperature and lower than Tmin temperature
Refer to the list of specifications:
IPC-9701, IPC650-2.6.26, IPC-SM-785, IPCD-279, J-STD-001, J-STD-002, J-STD-003, JESD22-A104, JESD22-B111, JESD22-B113, JESD22-B117 , SJR-01
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
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