Aerospace Technology Development of Three Types of Solid State Remote Power Controllers for 120VDC With Current Ratings of Five and Thirty Amperes, One Type Having Current Limiting

摘要

Three types of transistor remote power controllers (RPC) for 120VDC spacecraft distribution systems have been developed, built, and fully tested. Simple, efficient (99%), reliable and relatively low cost RPC designs are described with test results. Two generations of RPC's were developed. The first generation consists of a 5 ampere design (Type I) capable of limiting maximum overload current to 15 amperes for .1 second; a 5 ampere noncurrent limiting design (Type II); and a 30 ampere noncurrent limiting design (Type in). Each design provides overcorrect protection through an inverse I2T trip out function with an automatic reset option. The non current limiting designs have selectable instant trip levels for high current overload protection. All designs have demonstrated step applied fault capability with a 4000 ampere surge, fast rise time (low inductance) power source. They have also been demonstrated to meet MIL - STD - 461A specification for Electromagnetic Interference. The second generation RPC's traded off specification compliance for reduction in cost and complexity for the Type I & II designs. These designs gave comparable performance in most areas and improved performance in other areas relative to the original designs with substantial improvements in cost and complexity. Improved areas of performance include; extended operating voltage range of 25 Volts dc to 132 Volts dc, no magnetic components are required, and superior partial load electrical efficiency was demonstrated. In both generations It was determined that the non current limiting type of RPC is not only feasible but is a more economical method of overload protection for certain load types.