Electronic controller with off-load and anti-stall capability for Ram air turbine variable displacement hydraulic pump

An hydraulic control system included in an aircraft, the hydraulic control system comprising:

• a pump system including a hydraulic pump and a ram air turbine assembly, the ram air turbine assembly comprising a permanent magnet generator (PMG) rotatably coupled to the ram air turbine, the PMG configured to generate a voltage signal in response to the rotation of the ram air turbine;
• a fluid circuit configured to deliver hydraulic fluid to the hydraulic pump and to receive the hydraulic fluid output from the hydraulic pump;
• and
• a controller in signal communication with the hydraulic pump, the controller configured to determine a rotational frequency of a ram air turbine included in the ram air assembly, and to control the hydraulic pump so as to control the flow of hydraulic fluid in the fluid circuit,
• wherein the flow of hydraulic fluid in the fluid circuit controls a fluid pressure of the aircraft, and
• wherein the controller is in signal communication with the PMG and is powered in response to receiving the voltage signal output from the PMG, and wherein the controller determines a rotation signal based on the voltage signal generated in response to rotating the PMG.