TOPIC 2 - Photovoltaic & Generator

ASSIGNMENT - POWER SYSTEMANALYSIS AND PROTECTION BEF43303TOPIC 2: PREVENTION AND CONTROL OF SYSTEM FAILURE

GROUPNAME: PHOTOVOLTAIC1. MOHAMMAD SHAMIR MOHAMMAD FUAD CE1301402. NUR HAZWANI NADIAWAHAB CE1301603. NURULAINA FARAHIN ISMAIL CE1301644. NURUL 'AIN SHUHADAMAZLAN CE1301695. NURUL SYAHIRAH RAHAYU CE1301676. AINATULADILLADAHRI CE130120

GROUPNAME: GENERATOR1. NURUL JANNAH MOHD RAMLAN CE1301662. NUR FATIN FATIHA SALEH CE1301593. KOH CHUN CHEN CE1301304. AZLIN HAZWANI ROSLEE CE1301255. SHARINI P. JANASEKARAN CE130108

Scoring Rubric for Presentation

BEF43303 Power System Analysis and Protection

Topic: Introduction to Power System Protection

GROUP:_______________________

PRESENCE 5 4 3 2 1 0 -body language & eye contact

-contact with the public

-poise

-physical organization

LANGUAGE SKILLS 5 4 3 2 1 0 -correct usage

-appropriate vocabulary and grammar

-understandable (rhythm, intonation, accent)

-spoken loud enough to hear easily

ORGANIZATION 5 4 3 2 1 0 -clear objectives

-logical structure

-signposting

MASTERY OF THE SUBJECT 5 4 3 2 1 0 -pertinence

-depth of commentary

-spoken, not read

-able to answer questions

VISUAL AIDS 5 4 3 2 1 0

-transparencies, slides

-handouts

-audio, video, etc.

OVERALL IMPRESSION 5 4 3 2 1 0 -very interesting / very boring

-pleasant / unpleasant to listen to

-very good / poor communication

TOTAL SCORE _______ / 30

POWER SYSTEM ANALYSIS AND PROTECTIONSESSION 20152016

Group name: GeneratorPrevention and Control of System Failure

Most of failure mode in power system can be controlled.• To limit damage.• Enhance reliability.• Minimise the total transport cost of energy. (Balance between initial

cost and maintenance)• Insulation design is not economical to design a system to withstand all

possible system failure.• Design a protective system that can quickly detect abnormal condition

and take appropriate action.

INTRODUCTIONPrevention and Control of System Failure

Two basic types of protective system1. Reactionary devices:

• Designed to recognise certain hazard in the power system environment.• Take predetermined action to remove hazard.• To isolate that portion of the system experiencing the hazard and the

rest of the system can operate normally.2. Safeguard devices:

• Designed to recognise certain hazard in the power system environment.• Take predetermined action to change that environment to a less

hazardous condition.

cont. INTRODUCTIONPrevention and Control of System Failure

HAZARD

MATERIAL

EQUIPMENT

ENVIRONMENT

PROCESS

PEOPLE

M

E

E

P

P

Design to protect specific hazard: a short circuit on system component to remove the hazard

• The protective system action restore the system to best possible operating system under circumstance.

• The protection of the system against total failure must be adaptive in sense that must be operate in acceptable manner for any kind of abnormal occur in reliable manner.

REACTIONARY DEVICE

Abnormal State

Action State

Outrage State

Restorative State

Normal State

x > Xm x < Xm

t < Tm t > Tm

t > 0

Inequality Constraint

Time Constraint

Abnormal State

Action State

Outrage State

Restorative State

NORMAL STATEAll item of equipment should be in operation actually working and operate within normal design.

When an event occur that cause the operation of any system component to exceed normal operating limit, the system has entered abnormal state which mean something must be done to relieve abnormality before serious failure occurs.

Normal StateNormal State

ABNORMAL STATEAbnormalities can be charge in nature depends on nature condition.

It might be wise to wait a bit before taking action to see if the abnormality clear itself.

ACTION STATECertain prescribed action must be taken,

usually without further intentional delay.

OUTRAGE STATEThe faulted device is remove from

service.Since this state not desired operating

condition, the system usually caused to enter restorative state.

RESTORATIVE STATEAny required inspection or other repair

action are taken in order to reach the normal state.

Abnormal State

Action State

Outrage State

Restorative State

Normal State

Abnormal State

Action State

Outrage State

Restorative State

Violate the time constraint, t > Tm

To trip the device?!

Violate the inequality constraint, x > Xm

FLOW CHARTtripping decision process

FLOW CHARTNormal State

Increment Time

Trip Circuit Outage State

Time Delay

Restore Circuitx > Xm

?

Restore?

t > Tm?

YES

YES

NO

NO

NO

YES

tripping decision process

Normal State

Increment Time

Trip Circuit

x > xm?

t > Tm?

NO

Usually system in the normal state

The protective device is set:to assume that the normal state prevails at startup.

The protective device checks the observed system variables, x to determine if any variable exceeds its threshold value

Time is incremented to observe the next measured value

YES If the threshold is exceeded,the time threshold is checked and tripping action is with held until the time threshold expires.

When both the quantity and time thresholds are exceeded, the circuit is tripped.

This type of logic is designed to prevent tripping for short, temporary disturbances that might be observed. Such disturbances are often a part ofthenormal operating

condition of the network, and tripping should not be initiated for such events.

Outage State

Time Delay

Restore Circuit

Restore?Automatic restoration is begun following a preset time delay.

This concept has proven valuable since most power system disturbances are temporary, including short circuits.

Once the circuitis de-energized, the abnormal condition clears itself, and the circuit can be successfully restored.

If this is not a part of the programmed response of the device,the circuit is "locked-out" and remains in the outage state until repair personnel can determine the

cause of the outage and take appropriate action.

This state is shown at the bottom of the flow chart, where the system is in the outage state with no automatic escape.

• Designed to recognize a certain hazard in the power system environment

• To take predetermined action to change that environment to a less hazardous condition

SAFEGUARD DEVICES

SAFEGUARD that are the cause of the emergency

Removing of equipment from service if other remedial actions not effective

Shut down facility experiencing a hazardous condition

Design to change the environmental conditions

Design to alarm the operator

Design to take action

• Fire sprinkler system • Apparatus supplementary cooling system• Detector: monitor unbalance current/volt equipment• Emergency core cooling system of a nuclear reactor: preventing core meltdown

EXAMPLE

SAFEGUARD

Protective sensor detect specified hazardous condition - change operating environmental

OPERATION

Safeguard must be carefully designed for very high reliability and security because of the high cost of failure.

• System condition• Make decisions regarding the normality of observed variables• Take action

PROTECTIVE DEVICE operation

Protective device functional elements

ELEMENTS:

Threshold Quantity

Metered Quantity Comparison Element Decision Element Action Element

• Measured certain system quantities – Volt/Current• Compare system quantities or combination quantities• Threshold setting (by protection engineer) – Set into device• Comparison indicates – alert condition• Decision element is trigged

– All check satisfied : Action element release to operate– Timing element : Determine permanence of the condition

that require other check system other point in network

cont. PROTECTIVE DEVICE operation

• Clearing time, Tc = Tp + Td + Ta－Tp, comparison time－Td, decision time－Ta, action time

cont. PROTECTIVE DEVICE operation

cont. PROTECTIVE DEVICE operation

IMPORTANT

Clearing time is also important because some disturbances, such as short circuits, must be cleared promptly in order to preserve system stability.

The clearing time is very important since other protective systems in the network maybe time-coordinated with this protective device in order to ensure that only the necessary portions of the network are interrupted.

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