Objective:The objective is to study, develop and test new thermal architectures for power units to maximise the heat transfer, minimise the unit's volume and to allow the unit to operate at a higher temperature.
Description:The design concepts and methods currently used to integrate power units, both at unit level and at satellite level, considerably constrain the thermal performance of high dissipative units such as Power Conditioning and Distribution Units (PCDUs) or the Propulsion Processing Units (PPUs). As a consequence, some low level electronics end up operating at unnecessarily high temperatures, thus impacting the mass and the volume of the unit. The high temperature rating also limits the choice of available components for the design, such as power bus capacitors for example. It leadsto demanding thermal control requirements and it limits the platform areas where the units can be accommodated. Power units have been using the same internal configuration for decades. This configuration is based on a vertical module approach, which considerably limits the access to the coolest part of the unit: the baseplate. Low dissipating modules, with such configuration, currently occupyspace on the baseplate that is so valuable for the high power consumers. This becomes a limiting factor in high dissipation units. Power units like PCDUs and PPUs dissipate more than 300W and at satellite level a dedicated radiator of 1 square metre is typically needed.
In this activity thermal and mechanical concepts that allow to maximise the space allocated at spacecraft level to the high dissipative modules shall be developed. A modularity approach changing from purely vertical architecture to a combination of vertical and horizontal architectures can be a solution to have ample space for power dissipative components to be mounted close to the radiators but also to thermally decouple the low level electronics. Emerging materials and latest heat spreader technology have a greatpotential to lead to simplification of the satellite thermal control system on the order of 20% to 30%. Concepts such as baseplate with heat-pipe monoblock systems could exceed 20% mass-savings.
At unit level a thermal architecture for power units shall be developed with a 25% reduction of volume.
Spin in from the automotive industry, new packaging techniques, new materials shall be studied and a scaled engineering model of a power unit shall be designed, manufactured and tested. The experimental testing shall evaluate the concepts developed at unit level and at spacecraft level.