The Aircraft industry is moving very quickly towards what it known as More Electric Aircraft (MEA). In a modern aircraft power technology system instead of using a fixed 400 Hz supply, a variable frequency supply (360 to 800 Hz) is used, which is dependent on the aircraft speed. In MEA electrical energy feeds the aircraft subsystems such as the flight control actuation, environmental control system, and utility function instead of mechanical, hydraulic and pneumatic energy. Although the new technology of MEA goes towards variable frequency supply, one of the essential parts of the power distribution systems require DC power sources to feed different DC loads, and a portion of load may require a fixed 400 Hz supply. This chapter simulation model of 12-pulse active rectifier for More Electric Aircraft applications.