LF Radio Receiver For Substation Intrusion Deterrent and Measurement Validation

In this paper, we implement non-contact, low frequency radio measurements of the local magnetic field within an electric substation to infer power grid parameters like current, frequency, and harmonic distortion. In particular, our receiver measures the 60 Hz emission and its harmonics with time resolution <1 second. The goal is to independently verify the state of the power grid to guard against certain types of attacks. Using a linear regression model, we can estimate the power grid parameters using our radio observations. Initial results indicate a correlation coefficient as high as 70% in estimating the three-phase current, and that the estimation accuracy is significantly improved by including higher harmonics.