Agilent 5990-5915EN Solving the Challenges of Solar Array Simulation - Application Note c20140828 [14] free download

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Keysight Technologies Solving the Challenges of Solar Array Simulation Helping you select the optimal power solution for satellite ground testing Application Note The goal of this note is to help you deine the optimal power solution for satellite ground testing. We do this in four parts: a brief overview of solar cell behavior; a review of operational conditions in orbit; an outline of the need for a purpose-built SAS; and the key attributes of the optimal solution. For additional information, a list of related literature is included at the end of the note. Introduction Satellites are some of the world's most delicate and expensive electronic devices. Because most take a one-way trip into space, they are thoroughly tested on the ground before launch. Within the complement of electronic ground support equipment (EGSE), a typical test system contains two major elements: The instrumentation that tests the various electronic subsystems; and one or more power sources for the subsystems. The power sources must accurately simulate the behavior of solar arrays that face widely varied operating conditions in space. During testing, it's seldom possible to use actual solar arrays to provide power. Two of the reasons for this are obvious: There is no direct sunlight in a test bay, and it isn't practical to test outside. Two additional reasons are crucial to accurate testing: repeatability and controllability. These attributes make it possible to simulate the effects of varying operating conditions--light intensity, temperature, shadow, eclipse--at multiple operating points and achieve consistent results. The recommended solution is to simulate a solar array with electronic test equipment, but it isn't easy to accurately mimic the behavior of solar cells and solar arrays. Fortunately, purpose-built solar array simulator (SAS) instrumentation is commercially available. Compared to "homebrew" simulators, an SAS offers the advantages of standard, commercial off-the-shelf equipment: