DC power supply systems are attracting attention. If a power line communication is introduced into a dc system, the power supply and the communication can be concentrated on the power line. In this reseach, a power line communication method is applied which provides zero voltage section periodically and applies negative or zero voltage is applied during the section to send a bit signal. In this method, when the dc voltage is increased, surge voltage across switching devices due to the line inductance becomes a problem. To solve this, we propose that a diode in the conventional circuit is substituted into a MOSFET. Experimental results show the surge voltage is sufficiently reduced with the proposed circuit.
