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L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
SYSTEM SETUP
CHAPTER 5: SETTINGS
5
This section contains basic Phasor Measurement Unit (PMU) data, such as functions, source settings, and names.
PMU 1 FUNCTION
— This setting enables the LOGICAL Device PMU 1 functionality. Use this setting to permanently enable or
disable the feature.
PMU 1 IDCODE
— This setting assigns a numerical ID to the PMU. It corresponds to the IDCODE field of the data,
configuration, header, and command frames of the IEEE C37.118 protocol. The PMU uses this value when sending data,
configuration, and header frames; and it responds to this value when receiving the command frame. This is used when
only data from one PMU is present.
PMU 1 STN
— This setting assigns an alphanumeric ID to the PMU station. It corresponds to the STN field of the
configuration frame of the IEEE C37.118 protocol. This value is a 16-character ASCII string as per the IEEE C37.118
standard.
PMU 1 SIGNAL SOURCE
— This setting specifies one of the available L90 signal sources for processing in the PMU. Any
combination of voltages and currents can be configured as a source. The current channels can be configured as sums of
physically connected currents. This facilitates PMU applications in breaker-and-a-half, ring-bus, and similar arrangements.
The PMU feature calculates voltage phasors for actual voltage (A, B, C, and auxiliary) and current (A, B, C, and ground)
channels of the source, as well as symmetrical components (0, 1, and 2) of both voltages and currents. When configuring
communication and recording features of the PMU, the user can select, from the above superset, the content to be sent
out or recorded. When one source is selected by one PMU, it cannot be selected by another PMU.
PMU 1 CLASS (Range P, M, None)
— This setting selects the synchrophasor class. A reporting rate of 100 or 120 can only be
selected for class P synchrophasors and if the system frequency is 50 or 60 Hz, respectively.
PMU 1 NETWORK REPORTING FORMAT
— This setting selects between reporting synchrophasors as 16-bit integer or 32-bit
IEEE floating point numbers. This setting complies with bit-1 of the FORMAT field of the C37.118 configuration frame. Note
that this setting applies to synchrophasors only; the user-selectable FlexAnalog channels are always transmitted as 16-bit
integer values.
PMU 1 NETWORK REPORTING STYLE
— This setting selects between reporting synchrophasors in rectangular (real and
imaginary) or in polar (magnitude and angle) coordinates. This setting complies with bit-0 of the FORMAT field of the
C37.118 configuration frame.
PMU 1 RATE
— This setting specifies the reporting rate for the network (Ethernet) port. This value applies to all PMU streams
of the device that are assigned to transmit over this aggregator. For a system frequency of 60 Hz (50 Hz), the L90 generates
a reporting mismatch message if the selected rate is not set as 10 Hz, 12 Hz, 15 Hz, 20 Hz, 30 Hz, 60 Hz, or 120 Hz (or 10 Hz,
25 Hz, 50 Hz, or 100 Hz when the system frequency is 50 Hz) when entered via the keypad or software; and the L90 stops
the transmission of reports. Note that 4 Hz is not allowed for an M-class 50 Hz system.
PMU 1 f & df/dt FILTER
— This setting allows applying post-filtering to the frequency and rate-of-change of-frequency to
avoid reporting erroneous values, which can possibly happen during fault, switching, and other system disturbances. For
example, choosing 20Hz/s <10Hz setting ensures that if rate-of-change of-frequency between current reporting instance
and previous one exceeds 20Hz/s or frequency deviation from the nominal frequency exceeds 10Hz, then new frequency
and rate-of-change of-frequency value are invalidated. If this happens, the previous valid value of the frequency is
maintained and rate-of-change of-frequency value is forced to 0 at this reporting instance.
PMU 1 PHS-1
to
PMU 1 PHS-14
— These settings specify synchrophasors to be transmitted from the superset of all
synchronized measurements. The table outlines available synchrophasor values.
Table 5-19: Synchrophaser settings
90-5 PMU 1
CONFIGURATION
See below
Selection
Meaning
Va
First voltage channel, either Va or Vab
Vb
Second voltage channel, either Vb or Vbc
Vc
Third voltage channel, either Vc or Vca
Vx
Fourth voltage channel
Ia
Phase A current, physical channel or summation as per the source settings
Ib
Phase B current, physical channel or summation as per the source settings