Power line carrier interference from HVDC converter terminals

Power line carrier (PLC) equipment typically operates in the frequency range from 25 kHz to 300 kHz. Interference studies indicate that PLC equipment is susceptible to interference from sources of power system harmonics below the PLC frequency range. Extensive field testing and analytical studies show that each PLC circuit has a resonant frequency below the operating frequency. If excited at this resonant frequency, high voltages may exist within the PLC circuit. The resulting saturation of PLC components leads to local generation of radio frequency (RF) noise that interferes with proper operation of PLC circuits. Sources of power system harmonics in the 3-10 kHz range, such as line commutated DC power converters, are potential sources of this type of interference. >