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
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