1. KD Relay
Application:
Compensator distance relay that provides a single zone of phase protection for all three phases.
It provides tripping for phase to phase, two phase to ground and three phase faults within the reach setting and sensitivity level of the relay

2. KD Relay Construction Cylinder Unit:
Main function is to operate when the angle between two signal applied is within certain range.
Widely used as a directional unit and in impedance relays.

3. KD Relay Construction Cylinder Unit: T=KI1I2SIN(Ø12-Ø)-KS
Where K and Ø are design constants.
Different combinations of input quantities can be used for different applications, system voltages or currents or network voltages.

4. KD Relay Construction Compensator: Designated as T
Current to Voltage air gap transformer.
Voltage side has a tap which divides the winding in two sections.
The output voltage angle can be changed by connecting a resistor across one of the voltage winding sections

5. KD Relay Construction
Compensator:

6. KD Relay

7. KD Relay
Operation:

8. KD Relay

9. KD Relay
C3C Capacitor

10. KD Relay
Impedance Circle

11. KD Relay
Impedance Curve

12. KD Relay

13. KD RELAY Equations needed for testing
Relay Setting
Impedance measured by 3 phase unit
Used to find required test current
Impedance measured by 2 phase unit
Used to find required test current

14. Tests Required
Main tests required are the compensator check, maximum torque angle and the impedance test for 3 phase unit and phase to phase units.