What is significance of short circuit ratio?

Short circuit ratio or SCR is a measure of the stability of an electromechanical generator. It is the ratio of field current required to produce rated armature voltage at open circuit to the field current required to produce the rated armature current at short circuit.

What is the importance of SCR?

SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded. Their operation makes them suitable for use in medium- to high-voltage AC power control applications, such as lamp dimming, power regulators and motor control.

What does the short circuit ratio of a synchronous machine yield?

The short circuit ratio (SCR) of a synchronous machine is defined as the ratio of the field current required to generate rated voltage on an open circuit to the field current required to circulate rated armature current on a short circuit.

What is short circuit ratio in HVDC system?

A short circuit ratio (SCR) is used to determine the strength of the HVDC transmission line as well as the strength of the AC transmission line. A short circuit ratio (SCR) is determined by the ratio between short circuit MVA at the bus bar and equivalent DC rating to that busbar.

What is the effect of low value of short circuit ratio on machine?

For the small value of the short circuit ratio (SCR), the synchronizing power is small. As the synchronizing power keeps the machine in synchronism, a lower value of the SCR has a low stability limit. Thus, a machine with a low SCR is less stable when operating in parallel with the other generators.

Why SCR is known as latch device?

Silicon Controlled Rectifier ( SCR) is a semiconductor device used in switching applications. Unlike Transistors, SCR latches once triggered and remain on even if the triggering voltage at the gate is removed.

What is short circuit withstand?

Short-circuit current rating (SCCR) is the maximum short-circuit current a component or assembly can safely withstand when protected by a specific overcurrent protective device(s) or for a specified time.

What is the short circuit withstand rating?

The short circuit current withstand capability is a measure of the short circuit current a device can tolerate without being damaged when a fault occurs on the output of the device. It is usually defined in terms of the short circuit current capability of the source or system.