What is meant by Subtransient reactance?
Subtransient reactance is the reactance of the motor during the first cycle of the short-circuit. Transient reactance is the reactance of the motor during the remainder of the short-circuit. The computer program supplies typical values of subtransient and transient reactance for motors.
What is generator Subtransient?
The subtransient reactance, X”d, is the generator internal impedance element that is effective in the first cycles of a transient load event and determines the magnitude of the instantaneous fault current from the generator. The magnitudes of the fault currents need to be calculated so that breakers, etc.
What is Subtransient?
First, “subtransient” refers to the fact that this quantity operates extremely fast—faster than even “transient.” In technical terms, the subtransient time period lasts from about one to three cycles, which is from 16.7 milliseconds to 50 milliseconds (assuming a power frequency of 60 Hz).
What do you understand by Subtransient and transient reactance?
Subtransient Reactance, usually denoted as X”d, is the reactance used to determine the current during the first cycle after the occurance of the fault. In about 0.1 second this reactance increases to the level known. A transient is a short-lived burst of energy in a system caused by a sudden change of state.
What is transient Subtransient and steady state?
Sub-transient period: first cycle or so after the fault – AC current is very large and falls rapidly. Transient period: current falls at a slower rate. Steady-state period: current reaches its steady value.
What is Subtransient period?
What is direct axis Subtransient reactance?
The reactance during these first two or three cycle is least and the short circuit current is high. This reactance is called subtransient reactance and is denoted by X”. Since the short circuit current of the alternator lags behind the voltage by 90 degree, the reactance involved are direct axis reactance.
What is Subtransient transient and steady state?
What is Subtransient transient and steady state fault analysis?
This stage is called subtransient reactance. This reactance is denoted by X”. After first few cycles decrement in RMS value of short circuit current is less. This state is called transient reactance and is denoted by X’. Finally transient dies out and current reaches the steady sinusoidal state.
What is meant by transient and Subtransient reactance?
During first few cycles reactance of system/synchronous machine is least and short circuit current is highest. This stage is called subtransient reactance. After first few cycles decrement in RMS value of short circuit current is less. This state is called transient reactance and is denoted by X’.
What is Subtransient transient and steady state reactance?
The reactance during these first two or three cycle is least and the short circuit current is high. This reactance is called subtransient reactance and is denoted by X”. Finally the transient dies out and the current reaches a steady sinusoidal state called the Steady State.