Fundamental Concepts for Real-time Spacecraft Power Distribution Control G. B. SHEBLE’, R. M. NELMS & L. L. GRIGSBY Summary A conceptual framework for computer-directed monitoring, assessment and control of a spacecraft power system is presented. The five principal operating modes are defined. The basic structure is divided into the functions that will monitor and assess the power system, the functions that will control the power system and the functions that will diagnose the power system both before and after equipment failures. The basis for these functions is the extensive experience with monitoring, assessment and control of terrestrial power systems with energy management systems. All applications are computer-based. However, some manual intervention may be required for degraded operation. A statement of the function methodology, the expected computer requirements, the expected periodicities and the operating restrictions are provided. The difference between power management for spacecraft power systems and energy management for terrestrial power systems are compared for each major function. The initial software development status of a power management system (PMS) for spacecraft power systems is presented for each major subsystem. Introduction The data acquisition, monitoring and control of terrestrial power systems has significantly changed during the last 15 years. Several blackouts in major cities caused a focusing of the entire electric utility industry on the control systems that protect equipment and that control the everyday operation of power systems. Experience gained from such research and development is very appropriate for spacecraft power systems, especially since a blackout of a space station is potentially more disastrous than for terrestrial power systems. There are significant differences between the two types of power systems which will cause significant changes to the approaches that have been implemented for terrestrial power systems. The intent of this paper is to outline some of these differences and the expected changes required for spacecraft power systems. The first section defines the operating modes for a spacecraft power system. The major assumptions necessary to segment the control systems based on required response speeds and on computer resource requirements are also outlined. The second section outlines the basic structure of an energy management system G. B. Sheble’, R. M. Nelms & L. L. Grigsby, Electrical Engineering Department, Auburn University, AL 36849, USA.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==