Seminar: Graduate Seminar
Electronic Driver for Electrically Operated Propellant Thrusters
Date:
January,08,2025
Start Time:
14:30 - 15:30
Location:
1061, Meyer Building
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Lecturer:
Asaf Malka
Research Areas:
| Most maneuvering, orbit correction, and station keeping of satellites to-date use liquid hydrazine rocket thrusters. Hydrazine motors require pressurized tanks, liquid pumps and metering valves, and are relatively heavy and cumbersome. In addition, hydrazine is toxic and carcinogenic. Significant efforts have been made to find more effective and eco-friendly alternatives, especially for low earth orbiting vehicles. One such alternative is Electric Solid Propellants (ESP), which have emerged as a promising and environmentally friendly substitute to traditional chemical propellants in space propulsion systems. These fall into two distinct categories. First, hydroxyl ammonium nitrate (HAN) propellants. HAN is electrically conductive, and HAN propellants are ablated by application of periodic high voltage electric pulses, generating high-frequency thrust pulses, in the range 0.001 – 0.1 Newtons. These are considered for micro thruster applications, and on board micro- or nanosatellites. Second, ammonium nitrate (AN) based propellants. AN is dielectric and develops a thin ionic melt layer on its burning surface, used to electrically drive its steady-state burn rate, which depends linearly on the applied voltage. This method can be used to develop thrusts in the range of 1-1,000 Newtons. The focus of the proposed work is the development of flight-capable electrical power supplies for AN-propellant thrusters, capable of the high voltage and high power required for a typical mission. The proposed system will be optimized to deliver high voltage and power in short periodic pulses. The primary source of electrical energy chosen is a supercapacitor array, where state of the art power density levels is 27 kW/kg, while energy density and voltage are relatively low, 6.8 Wh/kg, and 2.85 volts, respectively. This design is scalable to meet different power and operational needs. Each discharge power module can handle up to 600 W and deliver up to 250 VDC. It uses a full-bridge topology with a switching frequency of 50 kHz, featuring a lightweight, low leakage step-up transformer and supercapacitors as the main power source. Multiple modules of the proposed design can be connected in parallel to increase the discharge power as needed.
M.Sc. student under the supervision of Prof. Yoash Levron.
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