# Why should we maintain a constant frequency in the supply system?

#### tapan

• Aug 4th, 2011

because , FOR THE GRID-: if the frequency of grid is increase by some another generator , at that time the power flows from that generator to all the other generators connected to the grid. means all the generators will act as a motor in their opposite direction which will be very dangerous. vice a versa for low frequency.

FOR THE SUPPLY-: we know that when we design any electrical equipment , we consider all the standard ratings on which we are use that equipment. so if we change the frequency , that affects losses(xmer ,power electronic ckt) , affects the speed of induction motor , also losses and torque of the induction motor.

#### harshita

• Aug 7th, 2011

because when we do not maintain constant frequency ,transformer windings will be overheated and total transformer will be damaged

#### Stalin

• Dec 2nd, 2011

We want to maintain the synchronisation and also to avoide phase imbalance so only we maintain frequency should be constant

#### Rockhy

• Dec 2nd, 2011

Frequency means Cycles Per Second ...So to Maintain Phase Difference of 120 degree between three phase to achieve Perfect Sine Wave Frequency Should Remain Constant ..if we dont Maintain the Constant Frequency then there will Be Fluctuation in Voltage as Voltage Is Directly proportional to frequecy

#### anass mugdam

• Apr 29th, 2018

The frequency of a system is dependent on the active power balance. As frequency is a common factor throughout the system, a change in active power demand at one point is reflected throughout the system. There are four reasons need to maintain constant frequency:

(1) Loads and other electrical equipment are usually designed to operate at a particular frequency, The speed of ac motors are directly related to the frequency.

(2) If the normal operating frequency is 50 Hz and the turbines run at speeds corresponding to frequencies less than 47.5 Hz or above 52.5 Hz, then the blades of the turbines may get damaged.

(3) The operation of a transformer below the rated frequency is not desirable, When frequency goes below rated frequency at constant system voltage, then the flux in the core increases and the transformer core goes into the saturation region.

(4) With reduced frequency, the output of power plant auxiliaries like pumps or fans may reduce, causing the reduction in power plant output, and so the generation decreases and thus it becomes a multiplying effect and may result in shut down of the plant.