Photovoltaic system test facility electromagnetic interference measurements

Early (spring of 1976) EMI tests were conducted on several solar cell panels of the ERDA Photovoltaic System Test Facility without power conditioning to determine the characteristic radiated interference frequencies. This test was conducted using a manually switched resistive load of approximately 360 W at a 1 Hz rate. Later (early summer) tests were conducted at an array output of approximately 1.5 kW while interfacing with an availaable line commutated type of inverter. The ERDA Photovoltaic System Test Facility as configured appears to present very few problems associated with common everyday appliances such as radio and television sets with regard to both radiated and conducted interference. Further, field strength measurements on a single row of panels indicates that the operational mode of the array as configured presents no radiated EMI problems. Only one relatively significant frequency band near 200 kHz showed any degree of intensity (9 ..mu..V/m including a background level of 5 ..mu..V/m). However, the level was measured very near the array (at 20 ft distance) while Federal Communications Commission (FCC) regulations call for these measurements at 1000 ft. FCC regulations limit spurious emissions to 15 ..mu..V/m at 1000 ft. No field strength readings could be obtained even atmore » 35 ft distant.« less