Power Management

Scenario Power Load Analysis Tool (SPLAT) MagicDraw Plug-in

The SPLAT tool could be applied to any project that needs to track time-dependent power consumption; it computes power usage profiles based on modeled component information and scenarios. NASA’s Jet Propulsion Laboratory, Pasadena, California Power consumption during all phases of spacecraft flight is of great interest to the aerospace community. As a result, significant analysis effort is exerted by both system and electrical-domain engineers to understand the rates of electrical energy generation and consumption under many operational scenarios of the system. Previously, no standard tool existed for creating and maintaining a Power Equipment List (PEL) of spacecraft components that consume power, and no standard tool existed for generating power load profiles based on this PEL information during mission design phases. Projects have traditionally either developed ad-hoc spreadsheet-based tools, or adapted complex simulation tools to compute such resource predictions; both of these approaches have significant limitations.

Posted in: Briefs, Power Management

Read More >>

Wideband, GaN MMIC, Distributed Amplifier-Based Microwave Power Module

The solid-state module operates as a radar, communication, or navigation system. John H. Glenn Research Center, Cleveland, Ohio Historically, the term microwave power module (MPM) has been associated with a small, fully integrated, self-contained radio frequency (RF) amplifier that combines both solid-state and microwave vacuum electronics technologies. Typically, the output power of these MPMs is on the order of about 100 Watts CW over an octave bandwidth. The MPMs require both a solid-state amplifier at the front end and a microwave vacuum electronics amplifier at the back end. However, such MPMs cannot be utilized for communications because the MPMs are not optimized for linearity or efficiency. Also, the MPMs can be very expensive to manufacture, particularly when modules are produced in very small quantities for space applications. Also, a kilovolt (kV) class power supply is required to power the traveling-wave tube amplifier, which is a part of the microwave vacuum electronics.

Posted in: Briefs, Power Management

Read More >>

Integrated Solar Array Power Management System

Marshall Space Flight Center, Alabama When solar cells are electrically connected to form solar arrays, they are organized into strings. Each string represents a specific number of cells connected in series to produce a specific voltage. The strings are then connected in parallel to add their currents to meet the array power requirement. This requires that the strings have the same voltage. Blocking diodes are used to take out strings with voltage that is too low, resulting in loss of power. When the arrays are mounted to a non-coplanar surface such as a spacecraft body or inflatable structure, many strings will have voltages lower than the rated voltage. This regulator manages the voltage of each string individually so that its power may be used, regardless of its voltage. It does this by converting each string’s energy into a series of high-voltage pulses that charges a reservoir capacitor to one of a set of common voltages used by the spacecraft bus. This allows for use of all of the illuminated strings in producing well-regulated power at pre-programmed voltages.

Posted in: Briefs, Power Management

Read More >>

Fault Recovery for Multi-Phase Power Converters

This method has application in power converters for thin film deposition to prevent loss of expensive silicon wafer products. John H. Glenn Research Center, Cleveland, Ohio A fault recovery method for multiphase power converters enables delivery of reduced output power of as much as 66% of normal power in the event of a shorted power switch component. The need for redundant power converters in conventional multi-phase space power systems is reduced, if not eliminated. Fault recovery includes detecting a shorted power switch fault, providing short circuit current protection, providing isolation of the shorted power switch, and reconfiguring the remaining undamaged power switches.

Posted in: Briefs, TSP, Electronics & Computers, Power Management

Read More >>

Isolated Bidirectional DC Converters for Distributed Battery Energy Applications

This development is applicable to electric propulsion systems of vehicles. John H. Glenn Research Center, Cleveland, Ohio Power systems are the core heartbeat of any advanced vehicle. Reliability and flexibility of these systems are of the highest priority. This innovation is a highly efficient and modular isolated bidirectional DC converter for battery energy applications that has been translated into high-priority NASA power system applications, demonstrating transferability, robustness, and scalability.

Posted in: Briefs, TSP, Electronics & Computers, Power Management

Read More >>

Device Accommodating Volume Expansion and Contraction for Water-Ice Phase Change Material Heat Sinks

This innovation enables the use of water as a phase change material for thermal energy storage. Lyndon B. Johnson Space Center, Houston, Texas This invention accommodates the volume expansion and contraction of water ice as it freezes and thaws, thus enabling the use of water as a phase change material (PCM) for thermal energy storage. Due to the relatively large volume expansion of water upon freezing, and the relatively large bulk modulus of elasticity of ice, it is imperative to accommodate the volume expansion in order to prevent rupture of the containment vessel. In addition to accommodating the volume expansion associated with the phase change from liquid water to solid ice, this invention is usable at temperatures as low as –150 °C, thus enabling the ice to be super-cooled for additional sensible thermal storage capacity. Finally, this invention operates independent of gravity, enabling its use in space applications.

Posted in: Briefs, TSP, Electronics & Computers, Power Management

Read More >>

High-Power, Solid-State Power Amplifier System

Marshall Space Flight Center, Alabama The purpose of the invention was to increase the operational power levels of solid-state power amplifiers using state-ofthe- art power amplifier design and combining methodology. Using 1-kW RF modules and proper RF combining techniques, a system was built that generated 16 kW of RF power for use in electric plasma propulsion. The 1-kW units were fault-protected against excessive power, excessive current, and high VSWR, since the RF power devices are extremely sensitive to variations in their operating conditions.

Posted in: Briefs, Electronics & Computers, Power Management

Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.