The objective of the activity is to identify, design, manufacture and test critical technology and hardware elements needed for a high voltage electric power system (EPS) for high power telecom applications. This shall include typical primary and secondary DCDC converters and protection circuits (e.g. latching current limiters). Targeted Improvements:- Increase bus voltage up to > 300V, enabling direct drive for electric propulsion;- Reduce mass of the EPS (excl. solar panels/generator) > 20% and power losses >50%;- Reduce complexity for a platform power bus greater than tens of kW.Description: Today the typical bus voltage for telecommunications spacecraft is 100 V. As spacecraft power is scaled up to tens of kW, a 100 V power bus leads to high mass and losses in the DC harness, connectors and equipment components. A bus voltage increase to 300 V or more for high power spacecraft would reduce power lossesand the mass of conducting components, and would increase the electrical efficiency. Latest developments in the domain of solar arrays indicate that a bus voltage of around 300 V could be realistic. It is an enabling technology for a direct drive approach in electric propulsion systems. Hence, bus converters (primary and secondary) for such a high voltage power subsystem in telecommunication applications are required. This activity shall identify the critical items of a high voltage power system, address the main technical challenges and provide solutions for implementation of latching current limiters, power converters (PPUs and EPCs), solar array, components, etc. The optimum bus voltage on the power subsystem side shall be evaluated and potential limiting factors, such as components, shall be identified. A scaled engineering model shall be produced and tested for each of the critical elements and verified by vacuum test. Footnote: On Delegation Request activities will only be initiated on the explicit request of at least one National Delegation.