Simulation error, what next?

I'm trying to model a medium concentration PV system and get the following dump. What am I doing wrong (or, which parameters are making SAM unhappy)?

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SAMSIM MESSAGES

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MSG[0]:
CEC 6 parameter model: Could not solve for normalized coefficients. Please check your inputs.

MSG[1]: Vmp: 11 Imp: 16 Voc: 14.7 Isc: 17.5 beta: -0.11 alpha: 0.004 gamma: -0.38 Nser: 60 Tech: 1

MSG[2]: Invalid Results a: 0.555758 Io: 5.43834e-011 Il: 18.7234 Rs: 0.130617 Rsh: 7.26446 Adj: -60.214

MSG[3]: MISSING OUTPUT system.hourly.glob_horiz_rad
MSG[4]: MISSING OUTPUT system.hourly.beam
MSG[5]: MISSING OUTPUT system.hourly.diff
MSG[6]: MISSING OUTPUT system.hourly.inc_beam
MSG[7]: MISSING OUTPUT system.hourly.inc_diff
MSG[8]: MISSING OUTPUT system.hourly.inc_total
MSG[9]: MISSING OUTPUT system.hourly.input_radiation
MSG[10]: MISSING OUTPUT system.hourly.modeff
MSG[11]: MISSING OUTPUT system.hourly.surf_tilt
MSG[12]: MISSING OUTPUT system.hourly.surf_azi
MSG[13]: MISSING OUTPUT system.hourly.soiling_derate
MSG[14]: MISSING OUTPUT system.hourly.sol_zen
MSG[15]: MISSING OUTPUT system.hourly.sol_azi
MSG[16]: MISSING OUTPUT system.hourly.windspd
MSG[17]: MISSING OUTPUT system.hourly.ambtemp
MSG[18]: MISSING OUTPUT system.hourly.celltemp
MSG[19]: MISSING OUTPUT system.hourly.axisrot
MSG[20]: MISSING OUTPUT system.hourly.idealrot
MSG[21]: MISSING OUTPUT system.hourly.ss_area
MSG[22]: MISSING OUTPUT system.hourly.ss_derate
MSG[23]: MISSING OUTPUT system.hourly.vmp
MSG[24]: MISSING OUTPUT system.hourly.dcgross
MSG[25]: MISSING OUTPUT system.hourly.dcpower
MSG[26]: MISSING OUTPUT system.hourly.acgross
MSG[27]: MISSING OUTPUT system.hourly.e_net
MSG[28]: MISSING OUTPUT system.monthly.e_net
MSG[29]: MISSING OUTPUT system.monthly.dcpower
MSG[30]: MISSING OUTPUT system.monthly.inc_total
MSG[31]: MISSING OUTPUT system.monthly.inc_beam
MSG[32]: MISSING OUTPUT system.annual.incident_beam
MSG[33]: MISSING OUTPUT system.annual.input_radiation
MSG[34]: MISSING OUTPUT system.annual.dc_nominal
MSG[35]: MISSING OUTPUT system.annual.dc_gross
MSG[36]: MISSING OUTPUT system.annual.dc_derated
MSG[37]: MISSING OUTPUT system.annual.ac_gross
MSG[38]: MISSING OUTPUT system.annual.ac_derated
MSG[39]: MISSING OUTPUT system.annual.e_net
MSG[40]: MISSING OUTPUT system.annual.fuel_usage
MSG[41]: MISSING OUTPUT system.annual.water_usage
MSG[42]: MISSING OUTPUT system.performance_factor
MSG[43]: MISSING OUTPUT system.use_lifetime_output
MSG[44]: MISSING OUTPUT system.heat_rate
MSG[45]: MISSING OUTPUT system.use_recapitalization
MSG[46]: MISSING OUTPUT 6par.a
MSG[47]: MISSING OUTPUT 6par.Io
MSG[48]: MISSING OUTPUT 6par.Il
MSG[49]: MISSING OUTPUT 6par.Rs
MSG[50]: MISSING OUTPUT 6par.Rsh
MSG[51]: MISSING OUTPUT 6par.Adj

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TRNSYS LOG FILE

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Please send me a copy of your SAM file (.zsam extension), either by attaching it to a reply to this post, or by emailing sam dot support at nrel dot gov.

Best regards,
Paul.

Hi Paul,

I've attached the ZSAM file that's causing the error. (The same error in the official May release as in the March beta.) I'd love to know what's causing the problem.

Cheers,
Bruce

Thank you for sending the file. SAM can't calculate module parameters based on the electrical specifications you entered on the Module page for the CEC model with user-entered specifications. SAM uses a numerical method to generate the parameters that may fail under certain circumstances. We tested the method with all of the modules in the CEC library, so it should work with most commercially available modules.

Are the specifications you entered from a real module's data sheet? If so, could you either reply with a copy of the data sheet or tell me the manufacturer and model name so that I can look it up?

Best regards,
Paul.

Hi Paul, I will be reviewing the parameters with our technical team to make sure that I have accurately captured them and will circle back to you afterwards. The product is one of our own (Skyline Solar) 1-axis tracked Medium CPV systems.

Ah ha! That might explain the error. The CEC model is designed for flat-plate, non-concentrating modules. You may be providing parameters that accurately describe your CPV module, but are causing calculation errors for the flat-plate model.

Please let me know what you learn from the technical team. I'm also having our programming team look into this.

Best regards,
Paul.