Basler Electric BE1-25A - Manual (Page 42)

FREQUENCY MATCHING MODULE F5
Frequency Correction
A proportional correction pulse train is issued when the slip frequency is greater than 50 percent of the
maximum slip frequency setting. The pulses are steered (as appropriate) to operate one of the two speed-
adjust output relays. The contacts of one relay are used to signal the generator to raise speed, while the
contacts of the other relay are used to signal the generator to lower the speed. The period of the
correction pulses is determined by the settings loaded into the microprocessor. That is, the period is equal
to the sum of the correction pulse interval plus the correction pulse width. The period remains constant
once the correction pulse width and correction pulse interval are set. The proportional correction pulse is
determined by the percent of correction required. If the slip frequency is greater than four times the
maximum slip allowed, the proportional correction pulse train is at 100 percent of the setting (correction
pulse interval setting plus correction pulse width setting). If the slip frequency is equal to the maximum
slip setting, the proportional correction pulse width is at 25 percent of the original setting. The correction
pulse interval (wait time) will increase to maintain a consistent correction pulse period (total of the pulse
interval and pulse width).
Proportional correction is linear between 100 percent (four times maximum slip frequency setting) and
12.5 percent (equal to one-half maximum slip frequency setting). Synchronization is enabled at slip
frequencies less than the maximum slip setting. Although synchronization is enabled at slip frequencies
below 50 percent of the maximum slip allowed, no correction pulses are issued. The pulses issued by this
option (to direct the output relays) may be monitored at the SIG and COM jacks. (+5 Vdc = raise pulse;
−5 Vdc = lower pulse.)
Phase Correction
A target pulse is issued to the correction pulse train when the bus and generator are frequency matched
(within approximately six percent of the maximum slip setting) but not phase matched. The pulses are
steered to induce a slip frequency that may be adjusted to fall within the allowable limits of the correction
pulse train. The contacts of one relay are used to signal the generator to raise speed, while the contacts
of the other relay are used to signal the generator to lower the speed. The target pulses issued may be
monitored at the SIG and COM jacks and are additional pulses to the correction pulse train. (+5 Vdc =
raise pulse;
−5 Vdc = lower pulse.) See Figure 3-6.
Figure 3-6. Frequency Matching Module F5 Block Diagram
3-8 BE1-25A Functional Description 9146600990 Rev S