Recently hydraulic and mechanical-based aircraft systems are replaced by electrical-based ’on board aircraft systems’ because of their various advantages like less volume and weight, and reliability. So electrical power system architecture needs to be modified. In spacecraft, a major volume is utilised for the electrical subsystem. The main requirements of the electrical power system of spacecraft are better reliability, less volume and weight, and improved power efficiency. Separate power-generating sources are used for propulsion and various auxiliary systems. Solar-based generation, nuclear-based generation, and fuel cells are some electrical energy sources used in aircraft. More reliable power generation techniques are required for long-duration space missions. The multiphase alternator is a better choice for reliable power generation. Another constraining factor for space power systems is volume and weight because of less space availability in the aircraft. Considering these constraining factors very high power density alternators are suitable for space power systems. Hence, High-Speed Homo Polar Inductor Alternator (HSHIA) is the most suitable candidate. High-speed operation up to 1 lakh RPM is possible with this machine due to its better power density and the special structure of the rotor. This machine already finds application in pulse charging as well as for energy storage by NASA and certain defense organizations. For studying its suitability for auxiliary power generation, a performance analysis is to be carried out. In HSHIA the performance is classified into three levels such as magnetic, electrical, and thermal. This paper presents the electrical performance analysis of HSHIA with different load conditions using the 3 -D Finite Element Method.