High-speed Single-Phase PLL Control by Quasi dq Transformation Using FPGA

Abstract

In this paper, we propose a high-speed frequency detection method for a single phase utility interactive inverter. Distributed power systems are considered to be a solution to environmental problems. As the use of distributed power systems spreads, the stability and reliability of utility interactive systems become important. In a utility interactive system, it is necessary to synchronize an internal phase of controller to a utility voltage. In the case of a single phase system, it is difficult to detect the instantaneous phase angle of the utility voltage.In this paper, we describe a new high-speed frequency detection method. In this method, a quasi dq transformation is applied by using an FPGA-based hardware controller. The quasi dq transformation is applied to develop PLL control. In this PLL control method, multiple samples can be processed in parallel by adopting an FPGA implementation. The hardware implementations are demonstrated by performing simulations and experiments.