Research And Development Of Hardware For PMU

Following the shaped huge interconnected power grid and the impeling power market reform, it needs the system to monitor the status of wide area power network. As a result of this situation, a wide area measurement system becomes ture. As the fundamental external measurement unit, the performance of PMU based on GPS takes a direct effect on the precision of the system.A phasor measurement unit with free scaled synchronized time mark (Novel PMU) has been developed. The novel PMU is composed of frequency auto-adapted equal interval sampling module, synchronized time-mark generating module, core module based microprocessor, and resolved the problem of uncoupling treatment to "time-synchronized" and "frequency-synchronized" sampling. There by the synchronized time-mark and its synchronization model can be marked freely, the full circle sampling data can be automatically orientated and intercepted (no frequency spectrum leak out) to make high precision DFT calculation. The calculation phasor offset caused by synchronized time-mark offset can be precisely corrected with simple linear method. The precision of phasor measurement under three modes (the first, middle and last sampling point) of time-mark synchronization has also been simulated. The hardware of the novel PMU is investigated in depth, the corresponding circuit is worked out, all functions are tested and debugged, all functions that need to be realized are partially tested in the laboratory. In the paper, HPI interface for the communications between DSP and MMI in the phasor measurement unit is designed through which DSP and embedded x86 systems can communicate and renew data in the DSP memory quickly, reliable with low power while DSP works without being interrupted.