Pacific Power Source UPC-32, Руководство по эксплуатации

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SECTION 4 OPERATION
44
4.5.2 TRANSIENT EDITING
Before beginning to create a transient, the sequence of the voltage, frequency, and waveform changes
should be fully determined. The UPC allows transient events to be defined in two ways: Time-based
transients and Cycle-based transients.
Transient event timing always begins at 0 degrees of
Ф
A (the rising 0 volt crossing), and will proceed based
on defined Segments. Each Segment has 5 editable values:
a) SEGMENT # defines the order of segment execution
b) Time defines the duration of the segment
c) Voltage(s) defines the Voltage at the end of the segment
d) Frequency defines the frequency at the end of the segment
e) Waveform(s) defines the waveform used for the duration of the segment
Time-based transients use absolute time to sequence through the defined segments. Each segment has a
duration, defined by
T= <0.0002 to 300 sec>. Up to 99 segments can be defined in a transient event. The
total transient duration will be the sum of the defined segment times.
Cycle-based transient segments substitute a single cycle of a specified waveform. Up to 99 segments can
be defined in a transient event. Each segment may use any waveform. The transient duration is counted in
number of cycles and is therefore dependent on frequency. Custom waveforms can be created (
4.6.2 ) or
the existing waveform table ( 2.1.4 ) may be used.
Transient sequences can be repeated, from single events to endless-looping terminated by the operator.
The UPC can store up to 1000 transient segments, total. It is not possible to have 99 Programs with each
having a 99 segment transient.
Transient voltage amplitudes will be calculated based on the RMS voltage of the transient waveform, or
based on the amplitude factor of the Program that contains the Transient. The calculation method is defined
by the TRANSIENT AUTO RMS setting in the STORE TRANSIENT screen.
AUTO RMS=ENABLED, causes all transient voltages to be calculated as true RMS voltage of the
waveforms used in any Segment of the Transient.
AUTO RMS=DISABLED, RMS calculation of substituted waveforms does not occur. The amplitude
of all waveforms used in the transient will be based on the system gain factor for each
phase, as calculated for the waveforms of the Program which contains the transient.
For transients using waveform substitution, enabling the RMS calculation may cause the waveform
peak voltages to vary. For example, a sine wave which has been modified to create a ¼ cycle
dropout is substituted for one cycle at 120 Vrms. Since it is missing a portion of the waveform, the
RMS calculation will determine that the voltage peak must be higher than a normal sine wave in
order to maintain the specified 120 Vrms. Disabling AUTO RMS, facilitates constant-amplitude
transients, such as partial cycle dropouts or sub-cycle spike transients. To have the transient
waveforms track the amplitude of the Program steady-state values, the base waveforms used in all
segments must be consistent.
EXAMPLE: If a 10% spike transient waveform is desired, the base sinewave was copied at 90% to
allow margin for the spike (4.6.2.2). The TRANSIENT WFs setting should be RMS=DISABLED and
the Program must use a sinewave copied at 90% but without the spike. The Program will calculate
the system gain to create the programmed voltage using the 90% waveform and the transient will
then be executed using that gain, thereby maintaining sine wave continuity.