Surround_the_Inverter”_test_system2010年电源技术研讨会讲义.ppt

solar array,house loads,off -grid batteries,“surround the inverter” test system,regenerative ac/dc power,located in san diego, california power, digital, software and systems engrg 120,000 ft2 (11,100m2) manufacturing facility smt & through hole pcba manufacturing sub and final assembly and test systems integration and test iso 9000 compliant quality system,solutions and resources,customer focused solutions turn-key systems power subsystems modified standard products custom products,market focused solutions low to high power ac sources low to high power dc supplies ac and dc loads modular ate power products laboratory and bench supplies,ppd products & markets,primary products ac power sources dc power supplies engineered solutions primary markets commercial & industrial government & defense energy & utilities aerospace,bench-top dc supplies,programmable dc supplies,programmable ac sources,modular ate power systems,complete engineered solutions,clear vision sound strategies solid performance,clear vision sound strategies solid performance,5,terrasas terrestrial solar array simulator,ametek solar array simulation history,number one world-wide provider application: testing satellites for development & production function: simulates satellite solar panels behavior in both static and dynamic modes like eclipse and spin benefits: flexible and modular from 1 channel to144-channels fully integrated fully warranted world-wide support,from solar cells to installations,solar cells operate like a battery when illuminated from the sun combining cells into panels generates higher voltage and power very similar to batteries,7,pv cell (2.3vdc),pv module (60vdc 250w),pv array (600vdc 20,000w),solar cell characteristics,there is a difference in output voltage and current characteristics for a standard dc power supply and a solar panel. a power supply is a “stiff” source meaning that the voltage is constant regardless of the load. the solar cell is a “soft” source in that the voltage drops off as you load it the output power characteristic for a solar panel is important because the pv inverter needs to operate at the peak power point to return the most power back to the utility grid,8,typical dc power supply,solar cell,solar cell,solar cell characteristics,a grid connected pv inverter must operate on the maximum peak power point (mppt) to efficiently convert this energy it must also pick the correct maximum power point even when the pv panel is shaded,9,power supply comparison,just creating an iv curve does not assure a power supply will track a pv inverter response time to load changes and mppt algorithms are critical modifications must be made to the power supplys control loops and output capacitance to provide a realistic simulation if the power supply is too slow it will not track the iv and the inverter will not be tested properly and can become unstable.,10,terrasas system,available in three versions: micro inverter for 300-600w, low voltage non-isolated up to 600v per channel isolated up to 1000v per channel statically simulates: various solar cell material curves different panel configurations multiple power points dynamically simulates the change in array output based upon fluctuations in light energy and temperature simulates test protocols and events that any solar installation will be subjected to working with sandia nl and arsenal to establish to provide best possible product,11,sandia national lab relationship,this fully-integrated pv simulator from ametek has performed well in preliminary evaluations and has shown the flexibility necessary to exercise the variations in mppt algorithms,multiple configuration examples,completely independent channels three power modules available 1200w/ch for micro-inverters 600v15kw/ch for isolated inverters 1000v10kw/ch for non-isolated inverters can be programmed independently or paralleled to provide high-power channels can simulate shadowed panels and moving shadows panel configurations at installation sites are easily created and managed independently,300kw terrasas system (artist rendering),high-performance capability,programmable irradiance levels from 0-2,000/m2 programmable temperature from -100 to +100 c programmable fill factor from 0.5 - 0.95 dsp samples at 3khz 4096 data points the terrasas generates a more accurate iv curve, with no “flat spots” in the iv curve,14,competitors flat top iv curve,terrasas smooth iv curve,from formula,io as a function of vo: io=isc (1-c1 (exp (v/(c2 x voc)-1) eeff c1=(1-(imp/isc) (exp(-vmp/(c2 x voc) c2=(vmp/voc)-1)/(ln(1-imp/isc) where: eeff=ginc/gstc; gstc=1000 w/m2 (standard test condition) ginc=incident irradiation (actual irradiation),programmable parallel and series string configurations,16,programmable fill factor,17,single string scenario,18,the terrasas also allows the user to select the desired iv curve and fill factor cells, strings, and panels can be selected at any time to contribute to the test scenarios,multiple string, series and parallel,19,the terrasas also allows the user to program parameters to create multiple power points by combining several different solar panels with different output characteristics. this is used to test the inverters mppt algorithm reaction to change,unique dynamic simulation,20,the terrasas simulates irradiance level, temperature level, and simulation time to ramp the voltage, temperature or irradiance level over time uses any iv curve previously defined this ability allows the unit to simulate dynamic irradiance and temperature going from night to day or from a clear day to cloud cover,morning,21,afternoon,22,graphic display of mppt,23,24,real life solar panel database,the software includes a database of more than 1000 solar panels to choose from or a custom panel can be imported via excel,measurement data logging,25,optional: high-current relay chassis for polarity reversal test of pv-inverter dc input,terrasas in the news!,terrasas press release story ran by 216 newspapers, business journals and news reporting organizations nationwide! picked up by16 online trade journals electronic design magazine offered a “feature article“ spot for its july 2010 print edition first of several magazines to publish an article about ameteks terrasas and pv inverter test solutions!,27,problem solved!,high voltage output floating capability: the output dc terminals of the unit can float up to 1000vrms. this is necessary for testing non-isolated inverters. the unit has a common mode voltage protection circuit. ultra-low common-mode output capacitors: the output dc terminals have very little capacitance to earth ground. this is necessary to prevent the inverter gfi from tripping because of common mode current. maximum common mode current is in the order of 3ma with 1kvrms and 50hz. fast transient capability: it can control the output current (it measures the true output current) with high speed, because the output current loop bandwidth is 3khz. this is necessary to track fast mppt algorithms. low output ripple and noise (both differential and common mode). this is necessary because high-frequency noise can affect inverter measurements and may affect its operation.,28,clear vision sound strategies solid performance,clear vision sound strategies solid performance,29,mx series ac and dc programmable power source bi-directional and regenerative!,solar array,house loads,off -grid batteries,“surround the inverter” test system,regenerative ac/dc power,mx series,programmable ac, dc and ac+dc power source regenerative sink option returns 100% of power back to the utility line 15kva 270kva harmonic waveform generation fund-50th harmonic analyzer measuring fundamental to 50th simulate utility disturbances,31,mx-snk option,the snk or current sink option enables the mx to feed energy back onto the grid when testing grid-tied products. the ability of the mx to simulate the grid provides unique opportunities to test the eut for immunity to commonly occurring line anomalies like voltage and/or frequency fluctuations. the snk option requires special amplifiers that have a different control loop from the standard mx amplifiers. this different control loop ensures greater stability under regenerative load conditions.,32,sink mode,relationship during the transition between automatic source and sink mode while under constant load,33,utility simulation mx series,anti-islanding utility disturbances phase loss voltage dips and interruptions frequency disturbances dc injection harmonically enriched waveforms test inverter tracking capability test against interharmonic susceptibility,34,voltage variations,source voltage varied from 240v 195v. the result is that the inverter detects the low voltage and shuts down at 205v,35,frequency fluctuations,the inverter must disconnect itself in the event of a frequency variation that is out of tolerance. in this example, the inverter being tested has a default setting with a “low” trip limit of 59.3 hz, and a high limit of 60.50 hz. the mx was programmed to start at 60 hz, and then successively go to 59.80 - 60.20 59.60 60.40 60.60hz,36,frequency variations to test inverter immunity,voltage distortion test,inverter behavior when the unit is subjected to significant distortion of the public supply (i.e. the immunity and emission of the inverter are both tested in this case),37,inverter compliance test system,iec 61000-3-15 (in draft) 2010 emissions (harmonics and flicker) compliance test for grid- tie inverters similar to iec 61000-3-2/3 and 3-11/12 cts release scheduled for dec., 2010 requires ac mains simulation, i.e. regenerative capability interharmonic susceptibility test country defined dc injection requires ac + dc source ametek cts is numb