Power Electronics

Power Electronics in Space Systems




The difficulties of generating and storing power in space provide a fertile ground for power electronics research. Design constraints such as weight, efficiency, and reliability consistently push power electronics research efforts to the limits of today's technology.

 

The primary sources of power and energy storage for satellites and space probes have included solar cells, fuel cells, thermoelectric nuclear power, batteries, and flywheels. In most cases these power sources provide low power with uncertain electrical behavior. The energy must be converted into a useable form with the lowest possible loss.

 

Modern space systems have very large power systems. A typical communications satellite, for example, might operate with hundreds of independent dc sources for maximum reliability at every network node. The International Space Station has sophisticated redundant power feeds and sources to maintain science operations and life support systems. In the space power context, thermal management is extremely important, since all lost energy must be dissipated into outer space by radiation cooling. Reliability, especially under exposure to large temperature swings and intense radiation, is a difficult challenge.

 

Many of today's fundamental power electronics designs derive originally for space power systems. Early dc-dc converters and fuel cell systems were developed for 1960s space projects, including the Apollo moon missions. Today, NASA, the European Space Agency (ESA), and their major technology suppliers are the international leaders in advanced power electronics.

 

Processing power from current sources such as solar cells, thermoelectric generators, and fuel cells requires a boost converter to transform input current at low voltage to a voltage appropriate for charging the on-board battery or flywheel storage system.