A Novel Three-Phase Software Phase-Locked Loop

This paper describes the development of a novel three-phase phase-locked loop (PLL) used to compensate for mains variations by being incorporated as part of a feedforward loop in a three-phase telecommunications power converter. A telecommunications converter must comply with industry standards, in particular the psophometric noise standard CCIF-1951; this is achieved by controlling the output voltage ripple from the dc-dc converter. It is required that psophometric compliance is maintained under expected mains variations documented in the EN50160 power quality standard. The software PLL is simulated and performance characteristics show a high degree of noise rejection while also maintaining good dynamic performance.