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The power and signal dual modulation (PSDM) method can drastically reduce system complexity since it can eliminate the communication lines between the power converters in the systems. It introduces the perturbation of the operating point of the power converters according to the transmitting data signal. Besides, the online battery impedance measuring technique calculates the ac impedance of the battery by injecting sinusoidal perturbation into the batteries. Using this correlation, this article proposes a multisinusoidal perturbation strategy of power converters to integrate the communication capability and the online battery impedance measurement. The binary phase shift keying (BPSK) has one communication frequency to transfer the binary data. The other frequencies are utilized to measure the ac impedance of the battery. The operational principles of the proposed modulation are analyzed to obtain the design methodology. Therefore, it can simultaneously communicate with the neighbor circuits and detect the ac impedance of the batteries at several frequencies. The proposed method has validated its communication and impedance measuring performance using a bidirectional buck–boost converter.

Photovoltaic (PV) power generation has become widespread owing to the global need to achieve carbon neutrality. With the increase in the number of PV systems, a broken connector in the PV panel induces a dc series arc fault condition. Therefore, arc fault detection technology becomes significant to guarantee the safety and reliability of PV systems. However, the series arc fault condition is similar to that of the normal operation with a small current variation, which makes it difficult to classify the normal and arc fault conditions. In this article, the resonant filter is proposed to improve the dc series arc fault detection capability. The characteristics of arc fault current are analyzed with the considerations of PV and converter impedance. The operational principle and design methodology of the proposed resonant filter are analyzed to clarify the arc fault signal through decoupling with the converter impedance. In addition, the algorithm for arc fault detection is designed with the proposed resonant filter. The experiment setups are designed with a dc optimizer and two commercial inverters, which can verify the arc fault detection performance with the proposed resonant filter.