A very low-cost low-frequency PLC system based on DS-CDMA for DC power lines

We propose a very low-cost low-frequency PLC (LF-PLC) system for DC power lines. The proposed LF-PLC system has three features: baseband transmission, unidirectional connection from a slave unit to a master unit, and multiplexing with Direct Spread Code Division Multiple Access (DS-CDMA). These features make it possible to implement multiplex communication with high tolerance for noise using very low-cost slave units. The effectiveness of the proposed method is demonstrated with a prototype system for monitoring separate thirty photovoltaic (PV) panels with the DC line within the PV system. The estimated mass-production cost of one transmitter is about 2 US Dollars. Thus, it is possible to dramatically reduce the maintenance costs because faulty panels can be detected quickly.