Simulation of large scale, spacecraft power systems using sparse-matrix solution techniques

Abstract

A program for simulating dynamic, coupled electrical power and thermal-hydraulic systems utilizes a single method to solve for both system electrical currents and fluid flow-rates. The simulation has been applied to large spacecraft, aircraft, and terrestrial power systems. The core of the program is a network solver that combines Newton's method with techniques for solving large, linear systems. The solution of nodal equations for both the electrical and fluid networks enables a common representation of the networks that easily translates into an object-oriented design. The speed and efficiency of the method enables large, real-time simulations with hardware-in-the-loop and software-in-the-loop as well as faster-than-real-time simulations. An example of the method is presented for the energy-coupled electrical power system (420×420 matrix) and thermal control system (200×200 matrix) on the International Space Station.