Overview
The “Power swing detect” element provides both power swing blocking and out-of-step tripping functions. The element measures the positive-sequence apparent impedance and traces its locus with respect to either two or three user selectable operating characteristic boundaries.
For more detailed information on “Power swing detect” element, refer to GE, Universal Relay (UR) family of products, Version 8.0x manuals.
To view other supported elements, click here.
Setting Parameters
Modbus memory map for Setting parameters
| Products | Hex address | Register name | Range | Units | Step | Format | Default |
| D30, D60, G60, L60, L90, N60, T60 | 40D9 | Power Swing Detect Function | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 40DA | Power Swing Detect Source | 0 to 5 | — | 1 | F167 | 0 (SRC 1) |
| " | 40DB | Power Swing Detect Mode | 0 to 1 | — | 1 | F513 | 0 (Two Step) |
| " | 40DC | Power Swing Detect Supervision | 0.05 to 30 | pu | 0.001 | F001 | 600 |
| " | 40DD | Power Swing Detect Forward Reach | 0.1 to 500 | ohms | 0.01 | F001 | 5000 |
| " | 40DE | Power Swing Detect Forward RCA | 40 to 90 | degrees | 1 | F001 | 75 |
| " | 40DF | Power Swing Detect Reverse Reach | 0.1 to 500 | ohms | 0.01 | F001 | 5000 |
| " | 40E0 | Power Swing Detect Reverse RCA | 40 to 90 | degrees | 1 | F001 | 75 |
| " | 40E1 | Power Swing Detect Outer Limit Angle | 40 to 140 | degrees | 1 | F001 | 120 |
| " | 40E2 | Power Swing Detect Middle Limit Angle | 40 to 140 | degrees | 1 | F001 | 90 |
| " | 40E3 | Power Swing Detect Inner Limit Angle | 40 to 140 | degrees | 1 | F001 | 60 |
| " | 40E4 | Power Swing Detect Delay 1 Pickup | 0 to 65.535 | s | 0.001 | F001 | 30 |
| " | 40E5 | Power Swing Detect Delay 1 Reset | 0 to 65.535 | s | 0.001 | F001 | 50 |
| " | 40E6 | Power Swing Detect Delay 2 Pickup | 0 to 65.535 | s | 0.001 | F001 | 17 |
| " | 40E7 | Power Swing Detect Delay 3 Pickup | 0 to 65.535 | s | 0.001 | F001 | 9 |
| " | 40E8 | Power Swing Detect Delay 4 Pickup | 0 to 65.535 | s | 0.001 | F001 | 17 |
| " | 40E9 | Power Swing Detect Seal In Delay | 0 to 65.535 | s | 0.001 | F001 | 400 |
| " | 40EA | Power Swing Detect Trip Mode | 0 to 1 | — | 1 | F514 | 0 (Delayed) |
| " | 40EB | Power Swing Detect Block | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | 40ED | Power Swing Detect Target | 0 to 2 | — | 1 | F109 | 0 (Self-reset) |
| " | 40EE | Power Swing Detect Event | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 40EF | Power Swing Detect Shape | 0 to 1 | — | 1 | F085 | 0 (Mho Shape) |
| " | 40F0 | Power Swing Detect Quad Forward Middle | 0.1 to 500 | ohms | 0.01 | F001 | 6000 |
| " | 40F1 | Power Swing Detect Quad Forward Outer | 0.1 to 500 | ohms | 0.01 | F001 | 7000 |
| " | 40F2 | Power Swing Detect Quad Reverse Middle | 0.1 to 500 | ohms | 0.01 | F001 | 6000 |
| " | 40F3 | Power Swing Detect Quad Reverse Outer | 0.1 to 500 | ohms | 0.01 | F001 | 7000 |
| " | 40F4 | Power Swing Detect Outer Right Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40F5 | Power Swing Detect Outer Left Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40F6 | Power Swing Detect Middle Right Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40F7 | Power Swing Detect Middle Left Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40F8 | Power Swing Detect Inner Right Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40F9 | Power Swing Detect Inner Left Blinder | 0.1 to 500 | ohms | 0.01 | F001 | 10000 |
| " | 40FA | Power Swing I2 Supervision Enable | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | 40FC | Power Swing I2 Supervision | 0.05 to 30 | pu | 0.001 | F001 | 200 |
| F085 | 0 = Mho Shape, 1 = Quad Shape | ||||||
| F102 | 0 = Disabled, 1 = Enabled | ||||||
| F109 | 0 = Self-reset, 1 = Latched, 2 = Disabled | ||||||
| F167 | 0 = SRC 1, 1 = SRC 2, 2 = SRC 3, 3 = SRC 4, 4 = SRC 5, 5 = SRC 6 | ||||||
| F300 | 0 : Off (This is boolean FALSE value), 1 : On (This is boolean TRUE value) | ||||||
| F513 | 0 = Two Step, 1 = Three Step | ||||||
| F514 | 0 = Delayed, 1 = Early | ||||||
Logics & highlights
Power swing detect mho operating characteristics
Effects of blinders on the mho characteristics
Power swing detect quadrilateral operating characteristics
Power swing detect logic (Sheet 1 of 3)
Power swing detect logic (Sheet 2 of 3)
Power swing detect logic (Sheet 3 of 3)
Definition of Setting Parameters
POWER SWING FUNCTION — This setting enables and disables the power swing detection element. The setting applies to both power swing blocking and out-of-step tripping functions.
POWER SWING SOURCE — The source setting identifies the signal source for both blocking and tripping functions.
POWER SWING SHAPE — This setting selects the shapes (either “Mho” or “Quad”) of the outer, middle, and inner characteristics of the power swing detect element. The operating principle is not affected. The “Mho” characteristics use the left and right blinders.
POWER SWING MODE — This setting selects between the two-step and three-step operating modes and applies it to both power swing blocking and out-of-step tripping functions. The three-step mode applies if there is enough space between the maximum load impedances and distance characteristics of the relay that all three (outer, middle, and inner) characteristics can be placed between the load and the distance characteristics. Whether the spans between the outer and middle as well as the middle and inner characteristics are sufficient is determined by analysis of the fastest power swings expected in correlation with settings of the power swing timers.
The two-step mode uses only the outer and inner characteristics for both blocking and tripping functions. This leaves more space in heavily loaded systems to place two power swing characteristics between the distance characteristics and the maximum load, but allows for only one determination of the impedance trajectory.
POWER SWING SUPV — A common overcurrent pickup level supervises all three power swing characteristics. The supervision responds to the positive-sequence current.
POWER SW I2 SUPV ENAB — This setting is to enable I2 supervision logic through a FlexLogic operand, which is used to detect the presence of significant unbalance in current signals, such as during fault conditions. Under these conditions, the POWER SWING BLOCK operand is not asserted.
POWER SWING I2 SUPV — This setting specifies the threshold of the I2 supervision logic.
POWER SWING FWD REACH — This setting specifies the forward reach of all three mho characteristics and the inner quadrilateral characteristic. For a simple system consisting of a line and two equivalent sources, this reach needs to be higher than the sum of the line and remote source positive-sequence impedances. Detailed transient stability studies can be needed for complex systems in order to determine this setting. The angle of this reach impedance is specified by the POWER SWING FWD RCA setting.
POWER SWING QUAD FWD REACH MID — This setting specifies the forward reach of the middle quadrilateral characteristic.
The angle of this reach impedance is specified by the POWER SWING FWD RCA setting. The setting is not used if the shape setting is “Mho.”
POWER SWING QUAD FWD REACH OUT — This setting specifies the forward reach of the outer quadrilateral characteristic.
The angle of this reach impedance is specified by the POWER SWING FWD RCA setting. The setting is not used if the shape setting is “Mho.”
POWER SWING FWD RCA — This setting specifies the angle of the forward reach impedance for the mho characteristics, angles of all blinders, and both forward and reverse reach impedances of the quadrilateral characteristics.
POWER SWING REV REACH — This setting specifies the reverse reach of all three mho characteristics and the inner quadrilateral characteristic. For a simple system of a line and two equivalent sources, this reach needs to be higher than the positive-sequence impedance of the local source. Detailed transient stability studies can be needed for complex systems to determine this setting. The angle of this reach impedance is specified by the POWER SWING REV RCA setting for “Mho,” and the POWER SWING FWD RCA setting for inner “Quad.”
POWER SWING QUAD REV REACH MID — This setting specifies the reverse reach of the middle quadrilateral characteristic.
The angle of this reach impedance is specified by the POWER SWING FWD RCA setting. The setting is not used if the shape setting is “Mho.”
POWER SWING QUAD REV REACH OUT — This setting specifies the reverse reach of the outer quadrilateral characteristic. The angle of this reach impedance is specified by the POWER SWING FWD RCA setting. The setting is not used if the shape setting is “Mho.”
POWER SWING REV RCA — This setting specifies the angle of the reverse reach impedance for the mho characteristics. This setting applies to mho shapes only.
POWER SWING OUTER LIMIT ANGLE — This setting defines the outer power swing characteristic. The convention depicted in the power swing detect mho operating characteristic diagram are to be observed: values greater than 90° result in an apple-shaped characteristic; values less than 90° result in a lens-shaped characteristic. This angle must be selected in consideration of the maximum expected load. If the maximum load angle is known, coordinate the outer limit angle with a 20° security margin. Detailed studies can be needed for complex systems to determine this setting. This setting applies to mho shapes only.
POWER SWING MIDDLE LIMIT ANGLE — This setting defines the middle power swing detect characteristic. It is relevant only for the three-step mode. A typical value is close to the average of the outer and inner limit angles. This setting applies to mho shapes only.
POWER SWING INNER LIMIT ANGLE — This setting defines the inner power swing detect characteristic. The inner characteristic is used by the out-of-step tripping function: beyond the inner characteristic out-of-step trip action is definite (the actual trip can be delayed as per the TRIP MODE setting). Therefore, this angle must be selected in consideration to the power swing angle beyond which the system becomes unstable and cannot recover.
The inner characteristic is also used by the power swing blocking function in the two-step mode. In this case, set this angle large enough so that the characteristics of the distance elements are safely enclosed by the inner characteristic. This setting applies to mho shapes only.
POWER SWING OUTER, MIDDLE, and INNER RGT BLD — These settings specify the resistive reach of the right blinder. The blinder applies to both “Mho” and “Quad” characteristics. Set these value high if no blinder is required for the “Mho” characteristic.
POWER SWING OUTER, MIDDLE, and INNER LFT BLD — These settings specify the resistive reach of the left blinder. Enter a positive value; the relay automatically uses a negative value. The blinder applies to both “Mho” and “Quad” characteristics.
Set this value high if no blinder is required for the “Mho” characteristic.
POWER SWING PICKUP DELAY 1 — All the coordinating timers are related to each other and need to be set to detect the fastest expected power swing and produce out-of-step tripping in a secure manner. Set the timers in relation to the power swing detect characteristics, mode of power swing detect operation, and mode of out-of-step tripping. This timer defines the interval that the impedance locus must spend between the outer and inner characteristics (two-step operating mode), or between the outer and middle characteristics (three-step operating mode) before the power swing blocking signal is established. This time delay must be set shorter than the time required for the impedance locus to travel between the two selected characteristics during the fastest expected power swing. This setting is relevant for both power swing blocking and out-of-step tripping.
POWER SWING RESET DELAY 1 — This setting defines the dropout delay for the power swing blocking signal. Detection of a condition requiring a block output sets latch 1 after PICKUP DELAY 1 time. When the impedance locus leaves the outer characteristic, timer POWER SWING RESET DELAY 1 is started. When the timer times-out, the latch is reset. Select this setting to give extra security for the power swing blocking action.
POWER SWING PICKUP DELAY 2 — Controls the out-of-step tripping function in the three-step mode only. This timer defines the interval the impedance locus must spend between the middle and inner characteristics before the second step of the out-of-step tripping sequence is completed. This time delay must be set shorter than the time required for the impedance locus to travel between the two characteristics during the fastest expected power swing.
POWER SWING PICKUP DELAY 3 — Controls the out-of-step tripping function only. It defines the interval the impedance locus must spend within the inner characteristic before the last step of the out-of-step tripping sequence is completed and the element is armed to trip. The actual moment of tripping is controlled by the TRIP MODE setting. This time delay is provided for extra security before the out-of-step trip action is executed.
POWER SWING PICKUP DELAY 4 — Controls the out-of-step tripping function in “Delayed” trip mode only. This timer defines the interval the impedance locus must spend outside the inner characteristic but within the outer characteristic before the element is armed for the delayed trip. The delayed trip occurs when the impedance leaves the outer characteristic. This time delay is provided for extra security. Set it considering the fastest expected power swing.
POWER SWING SEAL-IN DELAY — The out-of-step trip FlexLogic operand (POWER SWING TRIP) is sealed-in for the specified period of time. The sealing-in is crucial in the delayed trip mode, as the original trip signal is a very short pulse occurring when the impedance locus leaves the outer characteristic after the out-of-step sequence is completed.
POWER SWING TRIP MODE — Selection of the “Early” trip mode results in an instantaneous trip after the last step in the out-of-step tripping sequence is completed. The early trip mode stresses the circuit breakers as the currents at that moment are high (the electromotive forces of the two equivalent systems are approximately 180° apart). Selection of the “Delayed” trip mode results in a trip at the moment when the impedance locus leaves the outer characteristic. Delayed trip mode relaxes the operating conditions for the breakers as the currents at that moment are low. Make the selection considering the capability of the breakers in the system.
POWER SWING BLK — This setting specifies the FlexLogic operand used for blocking the out-of-step function only. The power swing blocking function is operational all the time as long as the element is enabled. The blocking signal resets the output POWER SWING TRIP operand but does not stop the out-of-step tripping sequence.
POWER SWING EVENTS — Enables and disables the logging of power swing detect events in the sequence of events recorder.