Studies On Phasor Measurement Unit

Power system changes great with the development of economics. Traditional protection and control method cannot satisfy the requirement of system oscillation and dynamic security defense. It is urgent to develop new technologies and methods.Phasor Measurement Unit (PMU) measures voltage and current qualities from the key junction of the grid with the synchronized high-resolution time source. The phase data with time stamp is packed and sent to the data analysis center through the high-speed communication network. The phase information is applied to the real-time monitor,protection and control. The early of PMU technologies developed slowly because of the restriction of communication speed,network technologies and accurate synchronized time signal. However, the deadlock is break into with the successful application of GPS technologiesThis paper first introduces the research underground and the state-of-the-art of PMU technologies. Then the theory and application of PMU technologies are described. The paper analysis the error of phasor measurement method, which comes from frequency offset. In the next, the paper presents a simple, precise, and low calculation burden instantaneous frequency tracking method based on derivate.The paper reviews the sources of synchronization technologies, and completes the program for the GPS time signal receiving. LabVIEW and industry PC are the development platform. The data acquisition is based on advantech PCI-1716 DAQ. The data processing,phasor measurement,display and storage are implement in the LabVIEW environment.