The order of the sub-harmonic during SSR for 50 Hz normal frequency is
The order of the sub-harmonic during SSR for 50 Hz normal frequency is
Right Answer is:
50/3 HZ
SOLUTION
Sub-synchronous resonance
- The transient currents at the sub-harmonic frequency resulted in a series-compensated network due to a switching operation or a fault.
- These sub-harmonic frequency currents assume dangerously high values and even become unstable.
- The unstable operation is exhibited in the form of negative resistance in the equivalent circuit of synchronous and induction motors.
- Sub-synchronous resonance (SSR) is a phenomenon in which electrical energy is exchanged between generators and transmission systems below the nominal power frequency (50/60Hz).
- Synchronous Resonance (SSR) is a phenomenon in which electrical energy is exchanged between generators and transmission systems below power frequency.
- It can be caused due to interaction of a series compensated transmission line with a generator; in addition, results in oscillation in the shaft and power swing.
- The subsynchronous frequency is typically 1/3 of the fundamental frequency. So for 50 Hz fundamental frequency, the subsynchronous frequency is 50/3 Hz.