Probabilistic power bus loading analysis for Space Station Freedom

The Space Station Freedom´s electrical power system is an isolated electric power generation and distribution network with limited generation capability to meet the demands of various housekeeping and experiment loads. A statistical method is developed to determine the power bus loading under normal operating conditions to ensure the supply meets the demand at each bus. The load probability density functions and probability distribution functions were calculated based on the probability of load operation. The probability that a particular load is operating is based on the load´s duty cycle. The probability density function is defined as the probability that the power demand at a bus is at a specific power level. The probability distribution function is defined as the probability that the power demand at a bus is below a specific power level. The results indicate that the 12.5 kW power bus is adequate for Lab-A power loads and the 3 kW power bus to the pressurized logistics module is adequate