15KW General Purpose Power Conditioner (Frequency Changer). AC-DC Section.
GENERAL MOTORS CORP GOLETA CALIF DELCO ELECTRONICS DIV
This report covers effort under Contract DAAK70-77-C-0035 to further develop the ac-to-dc section or converter portion of a 15 kW general purpose power conditioner or frequency changer. Previous Delco effort under Contract DAAK02-72-C-0210 had provided a breadboard system which established the feasibility of using resonant converter concepts coupled with Delcos power center inverter for the 15 kW general purpose frequency changer. MERADCOM testing of the breadboard frequency changer revealed performance deficiencies relative to transient loading and input power line harmonic current generation. The equipment shortcomings were traced to the ac-to-dc section and led, through competitive bid, to the award of the subject contract. In implementing a new ac-to-dc converter, Delco has again relied upon resonant converters similar to the low frequency, 4-SCR resonant converter used in the early breadboard. To overcome transient performance deficiencies, the new approach uses multiple 4-SCR resonant converters operating at much higher frequencies along with more sophisticated sensing, feedback, and control circuits. In order to achieve the newly specified low levels of input power line harmonic current distortion without resorting to conventional, excessively heavy methods, Delco has relied upon a new resonant converter configuration which evolved through past internal research and development IR and D programs. The present concept was demonstrated and reported as part of the Delco 1977 IR and D activity and has resulted in submission of the concept for GMC patent.