electricpy.fault.tdradial¶

electricpy.fault.tdradial(I, CTI, Ipu_up, Ipu_dn=0, TDdn=0, curve='U1', scale=2, freq=60, CTR_up=1, CTR_dn=1, tfixed=None)[source]¶

Radial Time Dial Coordination Function.

Function to evaluate the Time-Dial (TD) setting in radial schemes where the Coordinating Time Interval (CTI) and the up/downstream pickup settings are known along with the TD setting for the downstream protection.

Parameters:¶

I : float¶

Measured fault current in Amps, typically set using the maximum fault current available.

CTI : float¶

Coordinating Time Interval in cycles.

Ipu_up : float¶

Pickup setting for upstream protection, specified in amps

Ipu_dn : float, optional¶

Pickup setting for downstream protection, specified in amps, default=0

TDdn : float, optional¶

Time-Dial setting for downstream protection, specified in seconds, default=0

curve : string, optional¶

Name of specified TOC curve, may be entry from set: {U1,U2,U3,U4,U5,C1,C2,C3,C4,C5}, default=U1

scale : int, optional¶

Scaling value used to evaluate a practical TD setting, default=2

freq : float, optional¶

System operating frequency, default=60

CTR_up : float, optional¶

Current Transformer Ratio for upstream relay. default=1

CTR_dn : float, optional¶

Current Transformer Ratio for downstream relay. default=1

tfixed : float, optional¶

Used to specify a fixed time delay for coordinated protection elements, primarily used for coordinating TOC elements (51) with OC elements (50) with a fixed tripping time. Overrides downstream TOC arguments including Ipu_dn and TDdn.

Returns:¶

TD – Calculated Time-Dial setting according to radial scheme logical analysis.

Return type:¶

float