Magnetic Sensors with No Remanence for Aircraft Application
The objective of this project was to leverage on a breakthrough nanotechnology invented by a French SME, Neelogy, for high performance isolated magnetic sensors with no remanence, and adapt it for harsh environmental avionics constraints (high amplitude variation of operating temperature -60° to +125°C, depression, humidity, vibration and EMI/EMC constraints).
The same technology was used for both current and voltage sensors.
Neelogy was the only participant to this project, but they are supported by subcontractors, who are experts in avionics standards and recommendations, especially for the electronics parts.
The project duration was 42 months. The goal was to have 5 prototypes of current sensors and 5 prototypes of voltage sensors at the end of the project, as requested in the Call for Proposal. With regard to commercial products, the objective was to have them available 1 to 2 years after the end of the project.
The project was organised in 16 Work Packages (in summary: simulation tools, test benches, design of measurement heads for Current and for Voltage, design of discrete analog and digital electronics, design of mechanical parts, test of mock-ups and prototypes, design of PCB, specification of ASIC).
It represents an effort of 62 Person-Months for Neelogy (internal resources). A scientific project manager, as well as a project coordinator was assigned.
The total budget was €600k (€515k for Research & Technology Development, €55k for Demonstration, and €30k for Management). It was spread as follows: 55% to Neelogy and 45% to Neelogy’s subcontractors.
The current and voltage sensors for aerospace applications are conventionally shunt or resistive dividers, Hall sensors (open loop or closed loop) and transformers (VT and CT). Increasing onboard electrical power in aircrafts requires additional numerus and novel power équipements which implies a large increase in the number of sensors. These sensors are used for power control, for protection (overcurrent and overvoltage detection or leakage current), and for the management of energy storage means. The evolution of loads, sources and storage means requires the use of mixed networks DC and AC. Thus, sensor must allow measurement for DC and AC.
Existing solutions have certain drawbacks, in general size and weight when the sensors are accurate. The required accuracy is of the order of 1% over a temperature range from -60 °C to + 125 °C.