Multisinusoidal Perturbation Strategy for BPSK Power Line Communication and Online Battery Impedance Measurement

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.