Grid Standards Regulations, 2010-I: CEA makes frequency profile norms more stringent

In a bid to maintain stability and robustness of power transmission lines, the Central Electricity Authority (CEA) has stipulated a more stringent frequency profile to be maintained by operators, in the just-released Grid Standards Regulations, 2010, which replaces the 2006 version. 

Thereby, all Load Despatch Centres, Regional Power Committees and concerned entities are required to operate at a frequency close to 50 Hz, and not exceed the range 49.2 to 50.3 Hz. This supersedes the 49 Hz to 50.5 Hz range specified in the previous .

 On the other hand, the permissible voltage fluctuation-limit that may occur repetitively during step changes has now been fixed at 1.5 % against 1% in 2006 Regulations. 

 In case of occasional fluctuations, that apply to situations other than step changes, the limit is 3 %, as compared to 2% in the 2006 Regulations. 

 Besides, the following voltage limits have been specified in 2010 Regulations during steady state operations:

 --Nominal System Voltage (kV rms): 765; maximum (kV rms): 800; minimum (kV rms): 728.

 --Nominal System Voltage (kV rms): 400; maximum (kV rms):  420; minimum (kV rms):  380.

 --Nominal System Voltage (kV rms): 220; maximum (kV rms):  245; minimum (kV rms):  198.

 --Nominal System Voltage (kV rms): 132; maximum (kV rms):  145; minimum (kV rms):  122.

 --Nominal System Voltage (kV rms): 110; maximum (kV rms):  121; minimum (kV rms):  99.

 --Nominal System Voltage (kV rms): 66; maximum (kV rms):  72; minimum (kV rms):  60.

 --Nominal System Voltage (kV rms): 33; maximum (kV rms):  36; minimum (kV rms):  30.