LE1 Flashcards
(25 cards)
True or False. No immediate damage will be caused by permitting the alternator to run without a field for a short period
True
What is the protective device used for over speeding in alternators?
Centrifugal devices
True or False. Over voltage results to over voltage.
True
What is the protection against the phase to phase and phase to ground faults in alternators?
Differential Protection
It is used for multi-turn generators such as hydro-electric generators which have double winding armatures
Inter-turn fault protection
It is classified as areas where heavy congestion in electric network is frequent.
Zonal markets
It is classified as areas where congestion in electric network is less frequent.
Nodal market
True or False. Nodal markets are viewed as superior to zonal markets because they have the ability to reduce costs associated with congestion in heavily populated areas
True
True or False. Zones are transparent in pricing.
False
True or False. Nodal markets provide a better pricing system that strives for complete transparency
True
True or False. For zonal markets residents of predominately industrious zones are forced to pay higher electrical bills even though the majority of energy used is from commercial businesses.
True
True or False. In a nodal market, communities are priced individually, which means that a residential community will not have to pay additional fees for companies that use large amounts of electricity.
True
True or False. Nodal markets essentially offer lower rates than zonal markets because they do not group several neighbourhoods together when analysing usage.
True
What is the transmission line capacity for 230kV?
300MW
What is the transmission line capacity for 500kV?
2650MW
It is the process of making the production, transmission, and consumption of electrical energy as safe as possible from the effects of failures and events that may place the power system at risk.
Power system protection
The main objective is to make the power system ______ safe and ______ reliable.
100% ; 100%
It is any condition that causes abnormal operation for the power system or equipment serving the power system.
Faults
What are the 6 common faults?
Short circuits, open circuits, power swings, over voltage, elevated temperature, and off-nominal frequency operation
It is an electrical circuit that allows a current to travel along an unintended path, often where essentially no (or very low) electrical impedance is encountered.
Short circuit
It lacks a complete path between the terminals of its power source.
Open circuit
It is basically caused by the large disturbances in the power system which if not blocked could cause wrong operation of the distance relay and can generate wrong or undesired tripping of the transmission line breaker.
Power swing
What are the two classification of over voltage?
External over voltage, and internal over voltage
This originates from atmospheric disturbances, mainly due to lightning. This takes the form of surge and has no direct relationship with the operating voltage of the line.
External over voltage
