Dynamic hosting capacity control lets electric vehicle (EV) charging stations use the voltage headroom of distribution feeders. Because charging power is set from voltage measurements, a false data injection attack (FDIA) that inflates the reported voltage makes the controller over-allocate power and drives the real voltage below its limit. This paper models the closed loop of measurement, estimation, control and feeder for a 0.6 MW station on the IEEE 33-bus system and proposes a physics-informed defense: a consistency test between the controller’s voltage and a reconstruction built only from protected substation measurements, the station’s revenue meter and load forecasts. For attacks independent of the measurement noise, its detection probability depends only on the injected shift. With the chi-square bad-data detector at a 1% false-alarm rate, it detects 70–95% of stealthy 0.0075 p.u. attacks, against 34–66% for residual-based detectors, and over 30 simulated days cuts daily under-voltage time from about 180 min to 2–8 min for injections of 0.01 p.u. or more. A supervised neural classifier matches it only on attacks it was trained on and is fully evaded by a model-aware attacker. An adaptive safety margin counters detector-aware attackers for 5.5–7.2% of EV energy. Model bias must be removed by offset re-estimation; noisier protected meters reduce detection power.

This study investigates the isolated-port response of a four-port parallel coupled-line microstrip structure as a nondestructive microwave indicator for storage-related changes in Nakhon Phanom Lychee (NP.1). Unlike conventional one-port or two-port microwave sensors that mainly rely on reflection, forward transmission, resonant-frequency shift, or quality factor, the present approach monitors the nominally isolated port, where the measured signal is affected by perturbation of the coupled-line field balance. Ten fruits were stored under refrigerated conditions and evaluated at 7-day intervals over three storage periods. Each fruit was measured ten times during each period at room temperature using a two-port vector network analyzer over 0.3–0.8 GHz. In the adopted connection, the measured VNA $S_{21}$ corresponded to the sensor isolated-port parameter $S_{31}$. The mean resonant frequency decreased from 487 MHz in Week 1 to 478 MHz in Weeks 2 and 3. The $S_{31}$ magnitude at the resonant dip became progressively less negative, changing from $-59.59$ dB to $-53.95$ dB and $-48.27$ dB, corresponding to a total change of 11.32 dB. Although the resonant frequency did not distinguish Weeks 2 and 3, the isolation magnitude remained different between these periods. The measured response is consistent with storage-related changes in the effective electromagnetic properties of the fruit. These preliminary results support the feasibility of using isolated-port magnitude as an additional microwave feature for nondestructive lychee monitoring. Further validation using direct physicochemical, dielectric, and metrological measurements is required before quantitative quality assessment can be established.