Resistive Reach Calculation of Distance Relay

Resistive Reach of Distance Relay Characteristics is defined by the fault resistance for which the distance relay characteristics is defined. In MHO type distance relay the major drawback is that resistive reach is defined by the impedance reach and line angle and hence it is not independently settable in the relay. However, it is independently … Read more

Reactance and MHO Relay

Reactance Relay: In Reactance Relay the operating torque is obtained from the current and the restraining torque by the current and voltage of the directional element. This implies that Reactance Relay is an over-current Relay with directional Restraint. The directional element is so designed to give Maximum Torque Angle (MTA/RCA) of 90 degree.  Therefore from … Read more

Impedance Relay

Distance Relays are of three types: ·         Impedance Relay ·         Reactance Relay ·         MHO Relay. Impedance Relay: As from Universal Relay Torque Equation, T = K1I2+K2V2+K3VICos(Ɵ-Ƭ)+K4 Where K1 = Constant             K2 = Constant             K3 = Constant             K4 = Spring Torque             V = Voltage fed to the Relay             I = Current … Read more