ABB MDAR Instruction Manual page 100

- Initialization
POWER
- Self-Checks
ON
Figure 7 Overall Flowchart for Microprocessor Software in MDAR (REL-300) Relay
Mode =
Background
START
Sample V and I
dc Offset
Correction
Compute V and I
Phasors Using
fourier Algorithm
Mode?
Background
Y
Disturbance
in ∆V or ∆I?
N
− Operate Panel Interface
- Hardware Self-Checks
Relaying Calculations
- Zone 2
- Zone 3
- Out-of-Step Blinders
- Inst. Overcurrent
- Ground Backup
- Phase Selector
Checks and Logic
- Non-Pilot Trip Logic
- Loss-of-Potential and Loss of Current
- Data Communications
- Contact Inputs
Fault
Relaying Calculations
Zone 1 and Pilot Zone
Pilot Logic and
Channel Control
Mode =
Fault
I.L. 40-385.5 I.L. 40-385.5 I.L. 40-385.5
Y
No Fault for
Mode =
3 Cycles?
Background
N
sub 2
9654A12
A-28 A-28 A-28