Cost Reduction and Manufacture of the SunSine{reg_sign} ac Module: Final Subcontract Report, 11 June 2001

Abstract

This project was a two-phase effort consisting of technical research and manufacturing development to improve and reduce the costs of the SunSine{reg_sign} inverter. Research addressed packaging, soft switching, circuit optimization, manufacturing process improvements, and pilot production manufacturing. Significant cost reductions were achieved. The main goal of this project was to reduce cost and improve the manufacturability and reliability of the SunSine{reg_sign} ac module, which consists of a SunSine{reg_sign} inverter mounted on an ASE Americas PV laminate. This work has also boosted the performance and enhanced marketability by adding customer-valued features. Ascension Technology has accomplished these advancements by cost reductions or design modifications in the following areas: Die-cast aluminum enclosure and base plate; soft switching for cost reduction and efficiency gains; circuit board and component optimization for performance gains and size reduction; streamlined inverter assembly and production testing; and streamlined inverter/module assembly. As a result of the effort in these areas, Ascension Technology's objectives were to achieve the following: 40%-50% reduction in inverter manufacturing costs; 40% reduction in inverter size from 169 to 100 square inches; 4% increase in peak inverter efficiency from 87% to 91% at full power; UL listing, FCC certification; establish a production capability of 5000 SunSine{reg_sign} inverters/year through manufacturing improvements and production-line design improvements; less than 1 failure per 1000 units at time of installation/turn-on; a 5-year warranty; and a rating of 250 Wac at PTC for the SunSine{reg_sign} ac Module. Accomplishments during this project include: Inverter production costs were reduced 32% in the pilot production run; inverter production costs anticipated to be reduced a total of 36% in future production runs; 45% reduction in inverter footprint (in contact with module) from 169 to 93 square inches; and a 2.3% increase in inverter efficiency from 85.7% to 88.0% at full power. In addition, the SunSine{reg_sign} ac module is UL listed, meets IEEE Std. 929-2000, IEEE-C62.41-1991, IEEE-C62.45-1992, and NY State SIR requirements, and was verified to comply with FCC Class B EMI limits. There were 4 failures per 214 units at time of installation/turn-on; a 5-year inverter warranty is offered; and a rating of 235 Wac at PTC for the SunSine{reg_sign} ac module was achieved.