Residential U.S. Solar PV Inverter with Advanced Features Test Report

This report will provide the dynamic performance of a UL1741 approved residential solar PV inverter pre-programmed with advanced features that are normally disabled, but will be turned on for this test. Grid Advancement had previously tested various U.S. standard inverters as well as German inverters with advanced features. The testing for this inverter will be using a similar test methodology.

The incentive for testing this inverter is to enable and evaluate its advanced features (voltage ride through, power curtailment, ramp rate, watts/over-frequency, voltage support, and communications) which are not currently supported by U.S. interconnection standards. Additionally, the inverter has an emergency power supply to be used during off-grid conditions that will also be evaluated.

The following steady-state, transient, and harmonic test results will be used to support SCE Field Engineering's assessment of the advanced inverter characteristics and uncover any potential negative impacts. As with the previous testing, the data will be used to:

• Influence the standards revisions such as UL1741, IEEE 1547, and California Rule 21, in order to ensure that these devices support the reliability of the grid
• Develop and/or validate solar PV models for distribution system impact studies
• Review and revise, if necessary, SCE internal standards (interconnection or working practices)