Research And Development Of Synchronized Phasor Measurement Unit Based On GPS

With the development of modern power systerm, the transient stability problem becomes more and more serious. Phasor including phasor of generators and phasor of bus voltage are most important state variables that reflect stability of power systerm . If it can be measured at real time, dispatcher adopts in effect controlling step based on phasor such that all generators can still be synchronously operated To do this, it is necessary to messure the phasor of generators and to send them to the power system control center. However, these phasor of generators should be messured at the same time and with the same reference. These urge us to research phasor measurement unit.After investigating the relationship between generator measuring speed pulse and its on-load voltage at phase A, it is proposed in the thesis that we can obtained phasor of generators through messuring dividing frequency signal of generator measuring speed pulse.Zero-crossing detecting approach is used to detect the phasor of generators. And the 1PPS of the GPS receiver is used as the synchronous signal and reference to ensure that the messured phasor of generator is the same reference. Also the phasors of generators are labeled with the corresponding standard time.A new bus voltage and currents measurements sheme based on Digital Signal Prosessor (DSP) is proposed. And Adopted Discrete Fourier Transform to compute electrical parameters and analyze harmonics. The hardware and the software of PMU are designed and implemented based on those.