macrodyne, inc.

 4 Chelsea Place  s  PO Box 376  s  Clifton Park, New York  12065  USA

Phasor Measurement Systems for Real-Time Data Acquisition and Control

 Model 1690 Phasor Measurement Unit

Phasor representations of voltages and currents at key locations throughout the power system define the state of the network.  The Model 1690 Phasor Measurement Unit (PMU) provides instant access to this information providing new opportunities to understand and improve the performance of today's power systems.

Capable of both recording long duration electrical disturbances in phasor format and providing continuous phasor measurements in support of real time applications,  the PMU adds a new dimension to power system monitoring.

Performance

Through the use of integral GPS (Global Positioning System) satellite receiver-clocks, PMUs sample synchronously at selected locations throughout the power system.  Sequence phasors are continuously calculated and made available for system operators.  Phasor values are also forwarded to a central master station where the phasor at several busses can be monitored with respect to a selected reference phasor or absolute time.

An extensive selection of flexible software triggers enables the PMU to capture disturbances on the power system in phasor format to support system studies and post disturbance analysis.

Remote triggering capability between units allows for the capture of disturbances on selected units or all units for a system level overview of an event.

Operation

Voltage and current inputs to the PMU are derived from standard CT and PT secondaries.  Input signals are isolated, filtered and sampled at an effective rate of 48 samples per cycle of the fundamental frequency.  The internal GPS satellite receiver-clock coordinates the sampling process to ensure that data is sampled at the same instant in time by PMUs installed at remote locations throughout the power system.

A recursive DFT algorithm is used to calculate the local positive sequence, fundamental frequency and, voltage and current phasors from the sampled data.  The resultant time tagged phasors are immediately available for local and / or remote applications via the standard RS-232 serial communications ports.

Convenience outputs from the PMU's integral GPS receiver-clock, including the one pulse / second GPS synchronizing signal, PMU sampling clock, an IRIG-B time code, fiber-optic time code and a one pulse / minute signal are readily accessible to support other substation applications requiring precise time coordination.

  Macrodyne,Inc.    Model 1690 Phasor Measurement Unit     Model 1698 Satellite Timing Unit  Model 1698E Satellite Timing Unit Model 1692 Integrated Recording Unit    Model 1692C Integrated Recording Unit   FOM100 Fiber Optic Modem            Corporate History   Customer Service    Request Info