i) Design appropriate CT ratios for CTA, CTB, and CTC. (ii) Estimate time of Operation for all three relays for maximum value of fault current to maintain the selectivity. (iii) Determine TSM for relays at bus A and B for maximum fault current. (Use the standard formula for IDMT relays for these calculations.) (iv) Also use the standard curves for IDMT relays shown in Figure 2 to select TSM for relays at bus A and B for maximum fault current. Compare results obtained in (ii) and (iv). Verify the design to ensure that selectivity is maintained at minimum fault current for the fault in the same zone
Protection System
A system that protects electrical systems from faults by isolating the problematic part from the remainder of the system, preventing power from being cut from healthy elements, improving system dependability and efficiency is the protection system. Protection devices are the equipment that are utilized to implement the protection system.
Predictive Maintenance System
Predictive maintenance technologies are designed to assist in determining the state of in-service equipment so that maintenance can be scheduled. Predictive maintenance is the application of information; proactive maintenance approaches examine the condition of equipment and anticipate when it should maintain. The purpose of predictive maintenance is to forecast when equipment will fail (depending on a variety of parameters), then prevent the failure through routine and corrective maintenance.Condition monitoring is the continual monitoring of machines during process conditions to maintain optimal machine use, which is necessary for predictive maintenance. There are three types of condition monitoring: online, periodic, and remote. Finally, remote condition monitoring allows the equipment observed from a small place and data supplied for analysis.
Preventive Maintenance System
To maintain the equipment and materials on a regular basis in order to maintain those running conditions and reduce unnecessary shutdowns due to unexpected equipment failure is called Preventive Maintenance (PM).
asnwers:
1) relay at C (CT ratio) = 40 : 1
relay at B (CT ratio) = 60 : 1
relay at A (CT ratio) = 40 : 1
2) TMS/A = 0.711
3) top = 1.48 sec ( relay will operate as per the fault current level.)
- i) Design appropriate CT ratios for CTA, CTB, and CTC.
- (ii) Estimate time of Operation for all three relays for maximum value of fault current to maintain the selectivity.
- (iii) Determine TSM for relays at bus A and B for maximum fault current. (Use the standard formula for IDMT relays for these calculations.)
- (iv) Also use the standard curves for IDMT relays shown in Figure 2 to select TSM for relays at bus A and B for maximum fault current. Compare results obtained in (ii) and (iv).
- Verify the design to ensure that selectivity is maintained at minimum fault current for the fault in the same zone
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