BFP WITH VFD

G. ROZARIO

6.6 KV Breaker

6.6 KV Breaker

VFDVFD

BFP-1BFP-1 BFP-2BFP-2

QS-1

QS-2

QS-3

QS-4

QS-5

QS-6

BFP-1 VFD MODEBFP-1 DOL MODE

0 – 100%

BFP-2 VFD MODEBFP-2 DOL MODE

VFD READY TO START

VFD TRIP FEEDBACKSEVERE FAULT

VFD FAULT ALARM

SPEEDSPEED

AMPSAMPS

LOADLOAD

BFP - VFD

BFP-1 AMPS BFP-2 AMPS

BFP DISCH PRESSURE 125 KSC BFP FEEDWATER FLOW 172 TPH

BFP-1 READY TO START PERMISSIVE INTERLOCK TO VFDLube oil pressure healthy >1KSC.

De-aerator level normal (Individual Transmitter)+ 200 mmwc (60%).

Suction pressure is healthy > 1.85 (LOW 1.5KSC)

Vibration / temperature normal.

Discharge MOV closed or if it is auto standbythen Auto & Standby mode should be selected.

&

BFP-1 Ready to Start Permissive interlock to VFD

&

VFD Ready to Start Available

VFD Fault / Trip is not present

QS1 & 2 Close Feedback present

BFP-1 Ready to start Permissive

ON Command

BFP-1 VFD START PERMISSIVE TO START FROM DCS

BFP-1 READY TO START PERMISSIVE DCSLube oil pressure healthy >1KSC.

De-aerator level normal (Individual Transmitter)+ 200 mmwc (60%).

Suction pressure is healthy > 1.85 (LOW 1.5KSC)

Remote selection.

Vibration / temperature normal.

Discharge MOV closed or if it is auto standbythen Auto & Standby mode should be selected.

&

BFP-1 Ready to Start Permissive

&

BFP -1 START PERMISSIVE AVAILABLE

BFP -1 DOL MODE

DOL START FROM DCS

START PERMISSIVE ENABLE(QS-1 & 2 OPEN ) & QS-3

(CLOSED)

BFP PROTECTION WITH VFD

PRESENT BFP-1 PROCESS PROTECTION

1. BALANCE LEAK OF PRESSURE HIGH =7 KSC.

2. SUCTION PRESSURE LOW =1.5KSC.

3. DEAERATOR LEVEL LOLO ( 40%)

4. LUBE OIL PRESSURE LOLO = 0.4 KSC.

5. TEMP OR VIBRATION HIGH.

ORBFP PROTECTION ACTED

BFP PROTECTION = ADDING VFD

& VFD OFF

BFP1 VFD MODE (QS1 CLOSED)

BFP -1 PROTECTION ACTED

AUTO STANDBY

&

OR

BFP 2 START REQBFP-1 PROTECTION ACTEDBFP-2 DOL MODE(QS4 OPEN & QS6 CLOSED)

BFP2 AUTO SELEC

BFP2 REMOTE

BFP2 START CMD

&

PRESENT AUTO STANDBYBFP 1 RUNNING / BFP2 STANDBY

BFP1 ELEC TRIP FB

BFP2 STANDBY SELECTED

BFP1 RUNNING FB

DISCH HDR PR LOW <120 BARBFP2 STANDBY SELECTED

&

OR& BFP2

START REQ

BFP-1 DOL MODE (QS1 OPEN)

OR BFP2 START REQ&

BFP 1 STOP FB

BFP2 STOP FB

BFP2 RUN SELECTION

QUESTION :

1.AT PRESETN IN CASE OF BFP PROTECTION ACTED BREAKER IS OPENED BY DCS, BUT AFTER VFD INSTALLATION EITHER DCS WILL OPEN THE BREAKER OR IT GIVES OFF COMMAND TO VFD ? 2.WHAT ABOUT RUN OUT PROTECTION? 3.AS VFD IS NOT AN INTELLIGENT DEVICE LIKE DCS AND IT GIVES ON (6.6KV BREAKER) / OFF COMMAND BASED ON ISOLATOR FEEDBACKS, BUT HOW WE CAN ENSURE PROTECTION ?4.IF OPERATOR GIVES LOW FREQUENCY SETPOINT THAN OPERATING FREQUENCY ,WHAT IS THE BEHAVIOUR OF VFD / WHICH ONE IT WILL TAKE?

THANK YOU