A Digital-Model-Based Approach for Defining HIRF Immunity Design Requirements of Commercial Aircraft Engine Control Systems

Commercial aircraft engine control systems must be immune to high-intensity radiated field (HIRF) effects to operate reliably and function stably under electromagnetic (EM) disturbances. However, there is a lack of effective methods to clearly define the HIRF immunity design requirements for engine control system development in engineering practice. This paper proposes a digital-model-based approach to define the HIRF immunity design requirements for commercial aircraft engine control systems. The approach starts with digitally modeling the airborne control system integrated from system topology models, signal transmission models, electric loading models, and cable harness models, and then sets cable probes at measurement points to measure the control system EM responses. The control system model is then exposed to EM excitations generated by unit-magnitude plane waves, and the transfer functions of induced EM responses and electric field intensity at different frequencies are obtained. The transfer functions are then multiplied by the HIRF environments of interest to obtain the induced EM responses under HIRF excitations. After confirming that there is no further optimization of the control system, the proposed approach defines the HIRF immunity design requirements, which are higher than the HIRF induced EM responses. The results of numerical experiments conducted on an engine control system that has an interface with the aircraft confirm the effectiveness of the proposed digital-model-based approach in capturing induced EM responses, defining HIRF immunity design requirements specifically tailored to engine control system configurations, and avoiding under-design defects caused by document-based designs.