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Relay#

( Circuit Element, Control Element )

EPRI’s OpenDSS Documentation for this component: https://opendss.epri.com/Relay.html

#

Name

Type

Default

Units

Description

1

MonitoredObj

string
(CktElement name)

Full object name of the circuit element, typically a line, transformer, load, or generator, to which the relay’s PT and/or CT are connected. This is the “monitored” element. There is no default; must be specified.

2

MonitoredTerm

integer

1

Number of the terminal of the circuit element to which the Relay is connected. 1 or 2, typically.

3

SwitchedObj

string
(CktElement name)

Name of circuit element switch that the Relay controls. Specify the full object name. Defaults to the same as the Monitored element. This is the “controlled” element.

4

SwitchedTerm

integer

1

Number of the terminal of the controlled element in which the switch is controlled by the Relay. 1 or 2, typically.

5

Type

string
(from enum. Type)

Current

One of a legal relay type:
Current
Voltage
Reversepower
46 (neg seq current)
47 (neg seq voltage)
Generic (generic over/under relay)
Distance
TD21
DOC (directional overcurrent)

Default is overcurrent relay (Current) Specify the curve and pickup settings appropriate for each type. Generic relays monitor PC Element Control variables and trip on out of over/under range in definite time.

6

PhaseCurve

string
(TCC_Curve name)

Name of the TCC Curve object that determines the phase trip. Must have been previously defined as a TCC_Curve object. Default is none (ignored). For overcurrent relay, multiplying the current values in the curve by the “phasetrip” value gives the actual current.

7

GroundCurve

string
(TCC_Curve name)

Name of the TCC Curve object that determines the ground trip. Must have been previously defined as a TCC_Curve object. Default is none (ignored).For overcurrent relay, multiplying the current values in the curve by the “groundtrip” valuw gives the actual current.

8

PhaseTrip

real

1.0

Multiplier or actual phase amps for the phase TCC curve.

9

GroundTrip

real

1.0

Multiplier or actual ground amps (3I0) for the ground TCC curve.

10

TDPhase

real

1.0

Time dial for Phase trip curve. Multiplier on time axis of specified curve.

11

TDGround

real

1.0

Time dial for Ground trip curve. Multiplier on time axis of specified curve.

12

PhaseInst

real

0.0

Actual amps (Current relay) or kW (reverse power relay) for instantaneous phase trip which is assumed to happen in 0.01 sec + Delay Time. Default is 0.0, which signifies no inst trip. Use this value for specifying the Reverse Power threshold (kW) for reverse power relays.

13

GroundInst

real

0.0

A

Actual amps for instantaneous ground trip which is assumed to happen in 0.01 sec + Delay Time. Default is 0, which signifies no inst trip.

14

Reset

real

15.0

s

Reset time for relay. If this much time passes between the last pickup event, and the relay has not locked out, the operation counter resets.

15

Shots

integer

4

Number of shots to lockout. This is one more than the number of reclose intervals.

16

RecloseIntervals

array of reals

[0.5, 2.0, 2.0]

Array of reclose intervals. If none, specify “NONE”. Default for overcurrent relay is (0.5, 2.0, 2.0) seconds. Default for a voltage relay is (5.0). In a voltage relay, this is seconds after restoration of voltage that the reclose occurs. Reverse power relay is one shot to lockout, so this is ignored. A locked out relay must be closed manually (set action=close).

17

Delay

real

Trip time delay (sec) for DEFINITE TIME relays. Default is 0 for current, voltage and DOC relays. If >0 then this value is used instead of curves. Used by Generic, RevPower, 46 and 47 relays. Defaults to 0.1 s for these relays.

18

OvervoltCurve

string
(TCC_Curve name)

TCC Curve object to use for overvoltage relay. Curve is assumed to be defined with per unit voltage values. Voltage base should be defined for the relay. Default is none (ignored).

19

UndervoltCurve

string
(TCC_Curve name)

TCC Curve object to use for undervoltage relay. Curve is assumed to be defined with per unit voltage values. Voltage base should be defined for the relay. Default is none (ignored).

20

kVBase

real

0.0

Voltage base (kV) for the relay. Specify line-line for 3 phase devices); line-neutral for 1-phase devices. Relay assumes the number of phases of the monitored element. Default is 0.0, which results in assuming the voltage values in the “TCC” curve are specified in actual line-to-neutral volts.

21

47%Pickup

real

Percent voltage pickup for 47 relay (Neg seq voltage). Default is 2. Specify also base voltage (kvbase) and delay time value.

22

46BaseAmps

real

Base current, Amps, for 46 relay (neg seq current). Used for establishing pickup and per unit I-squared-t.

23

46%Pickup

real

Percent pickup current for 46 relay (neg seq current). Default is 20. When current exceeds this value × BaseAmps, I-squared-t calc starts.

24

46isqt

real

Negative Sequence I-squared-t trip value for 46 relay (neg seq current). Default is 1 (trips in 1 sec for 1 per unit neg seq current). Should be 1 to 99.

25

Variable

string

Name of variable in PC Elements being monitored. Only applies to Generic relay.

26

Overtrip

real

1.2

Trip setting (high value) for Generic relay variable. Relay trips in definite time if value of variable exceeds this value.

27

Undertrip

real

0.8

Trip setting (low value) for Generic relay variable. Relay trips in definite time if value of variable is less than this value.

28

BreakerTime

real

0.0

Fixed delay time (sec) added to relay time. Designed to represent breaker time or some other delay after a trip decision is made.Use Delay property for setting a fixed trip time delay.Added to trip time of current and voltage relays. Could use in combination with inst trip value to obtain a definite time overcurrent relay.

29

Action

string
(from enum. Action)

DEPRECATED. See “State” property
Redundant with State

30

Z1Mag

real

0.7

Positive sequence reach impedance in primary ohms for Distance and TD21 functions.

31

Z1Ang

real

64.0

Positive sequence reach impedance angle in degrees for Distance and TD21 functions.

32

Z0Mag

real

2.1

Zero sequence reach impedance in primary ohms for Distance and TD21 functions.

33

Z0Ang

real

68.0

Zero sequence reach impedance angle in degrees for Distance and TD21 functions.

34

MPhase

real

0.7

Phase reach multiplier in per-unit for Distance and TD21 functions.

35

MGround

real

0.7

Ground reach multiplier in per-unit for Distance and TD21 functions.

36

EventLog

boolean

False

Write trips, reclose and reset events to EventLog.

37

DebugTrace

boolean

False

Write extra details to Eventlog.

38

DistReverse

boolean

False

Reverse direction for distance and td21 types.

39

Normal

string
(from enum. State)

closed

{Open | Closed} Normal state of the relay. The relay reverts to this state for reset, change of mode, etc. Defaults to “State” if not specifically declared.

40

State

string
(from enum. State)

closed

{Open | Closed} Actual state of the relay. Upon setting, immediately forces state of the relay, overriding the Relay control. Simulates manual control on relay. Defaults to Closed. “Open” causes the controlled element to open and lock out. “Closed” causes the controlled element to close and the relay to reset to its first operation.

41

DOC_TiltAngleLow

real

90.0

Tilt angle for low-current trip line.

42

DOC_TiltAngleHigh

real

90.0

Tilt angle for high-current trip line.

43

DOC_TripSettingLow

real

0.0

Resistive trip setting for low-current line.

44

DOC_TripSettingHigh

real

-1.0

Resistive trip setting for high-current line. Default is -1 (deactivated). To activate, set a positive value. Must be greater than “DOC_TripSettingLow”.

45

DOC_TripSettingMag

real

-1.0

Trip setting for current magnitude (defines a circle in the relay characteristics). Default is -1 (deactivated). To activate, set a positive value.

46

DOC_DelayInner

real

-1.0

Trip time delay (sec) for operation in inner region for DOC relay, defined when “DOC_TripSettingMag” or “DOC_TripSettingHigh” are activate. Default is -1.0 (deactivated), meaning that the relay characteristic is insensitive in the inner region (no trip). Set to 0 for instantaneous trip and >0 for a definite time delay. If “DOC_PhaseCurveInner” is specified, time delay from curve is utilized instead.

47

DOC_PhaseCurveInner

string
(TCC_Curve name)

Name of the TCC Curve object that determines the phase trip for operation in inner region for DOC relay. Must have been previously defined as a TCC_Curve object. Default is none (ignored). Multiplying the current values in the curve by the “DOC_PhaseTripInner” value gives the actual current.

48

DOC_PhaseTripInner

real

1.0

Multiplier for the “DOC_PhaseCurveInner” TCC curve.

49

DOC_TDPhaseInner

real

1.0

Time dial for “DOC_PhaseCurveInner” TCC curve. Multiplier on time axis of specified curve.

50

DOC_P1Blocking

boolean

True

Blocking element that impedes relay from tripping if balanced net three-phase active power is in the forward direction (i.e., flowing into the monitored terminal). For a delayed trip, if at any given time the reverse power flow condition stops, the tripping is reset. Default=True.

51

BaseFreq

real

Hz

Base Frequency for ratings.

52

Enabled

boolean

True

Indicates whether this element is enabled.

53

Like

string
(Relay name)
deprecated

Make like another object, e.g.:

New Capacitor.C2 like=c1 …

Enumerations#

Relay: Action#

Value

close

open

trip

Relay: State#

Value

closed

open

trip

Relay: Type#

Value

Current

Voltage

ReversePower

46

47

Generic

Distance

TD21

DOC