UCAIUG 2017 IEC 61850 IOP Integrated Application
Integrated System Application and Testing Platform 3
Objectives and General Use Cases 3
Application System Diagrams 5
Protection and Control Functions and Related Applications 7
HV Transmission Line Protection and Control 8
HV-side Bus Protection 9
Transformer Protection and Control 9
LV Distribution protection and Control 9
Feeder Protection and Control 10
Transfer Breaker IED 10
Incomer Protection 11
LV Bus protection (Fast Bus Reverse Blocking scheme) 12
Bus Tie IED 13
Custom Logic for Edition 1 Testing 15
Matrix of Published Signals and Subscribing Functions 16
Protection Settings 17
Operation and Control 17
HMI and Client 17
Reports 18
Application Testing Use Cases 18
Objectives: 18
Testing of LV-side IEDs 18
Operational functional test of the protection system (Normal service conditions) 18
Isolated testing of IEDs or protection schemes 22
Testing of Transformer Protection 22
Operational test of the protection system (Normal service conditions) 22
Isolated testing of IEDs or protection schemes 22
Testing of HV-side IEDs 22
Operational test of the protection system (Normal service conditions) 22
Isolated testing of IEDs or protection schemes 22
Integrated System Application and Testing Platform
Objectives and General Use Cases
· To test the interoperability of IEC 61850 tools and devices in an integrated application platform using a realistic and typical power substation with HV transmission lines, step-down transformers feeding LV-buses and distribution feeders. Realistic settings will be applied.
· To test and verify interoperability of devices of various models from different vendors.
· To test and verify that the testing features of the IEDs work, and to show and verify the testing approaches to be performed during commissioning and during maintenance.
o Commissioning
§ This includes testing of individual IEDs and schemes with distributed functional elements that are located in different IEDs.
§ All IEDs are in a mode that presumes that they are in normal operation
§ Tests include the following:
· Injecting analog voltages and currents into merging units; or, if IED does not use sampled values, injecting directly into IED
· Simulating breaker/switch position contacts by energizing optical inputs of IED
· Observing, recording and assessing the response of the device(s) under test by monitoring and measuring the resulting GOOSE messages and their specific data members
o Maintenance
§ Testing of an IED or scheme with distributed functional elements and “isolate” it together with the test system from the rest of the PACS that are in normal operation.
§ The IED under test or IEDs that are part of a distributed scheme under test are placed in a mode that allows them to be isolated. All other IEDs are in normal operation.
§ Tests include the following:
· Simulating sampled values that replicate identical SV messages from the real merging units that supply SV messages to the IED under test; or, if IED does not use sampled values, injecting directly into IED
· Simulating GOOSE messages that replicate identical GOOSE messages that are published by real IEDs
· Observing, recording and assessing the response of the device(s) under test by monitoring and measuring the resulting GOOSE messages and their specific data members
· Only IEDs under test respond to the simulated GOOSE and SV messages; the rest of the PACS that are in normal operation do not process nor respond to the simulated messages as well as the resulting responses (GOOSE messages) of the IEDs under test.
· To identify any interoperability and testing issues and record them for future discussion and resolution.
Application System Diagrams
The integrated testing platform is based on a realistic power system application. It is based on the single line diagram that was supplied by Entergy. This was modified and redrawn using international symbols as shown in Figure 1 to make it more suitable for the general audience. The CT and VT ratios have been added. The CT secondary is 5A but can be changed to 1 A for some IEDs as needed.
Figure 1 Reference Single Line Diagram (without IEDs)
Figure 2 shows a partial single line diagram with additional details for typical objects, devices and protection and control functions. The flow of key analog and status signals is shown but without the communication network. P&C functions are shown in a single box but they may be implemented in a single device or multiple devices.
Figure 2 Partial Single Line Diagram showing typical objects, devices and signals
Protection and Control Functions and Related Applications
Assumptions:
· All HV-side currents and voltages will use 9-2 LE sampled values from merging units.
o IEDs that use conventional analog sources should come with wired test blocks where test injection currents can be easily connected to, using standard banana plugs. Or preferably come with a wiring harness with banana plugs at the ends to connect to test sets.
· All LV-side Incomers, Bus Tie breaker, and Transfer breaker will use 9-2 LE sampled values
· Feeder currents sources may use 9-2 LE sampled values or conventional current sources.
o IEDs that use conventional analog sources should come with wired test blocks where test injection currents can be easily connected to, using standard banana plugs. Or preferably come with a wiring harness with banana plugs at the ends to connect to test sets.
· All HV-side IEDs will be IEC 61850 edition 2 of parts 7 and 8-1.
· All Transformer IEDs will be edition 2.
· IEDs connected to Zone A (includes all objects connected to LV Bus A) will be edition 2. This includes the incomer breaker, the distribution feeders, the bus tie breaker, and the transfer bus breaker.
· Zone B includes all objects connected to Bus B. The incomer B and feeder IEDs will be edition 1. Edition 1 IEDs will need a custom logic to deal with testing and maintenance to indicate that an IED is in normal service or is in a mode for testing. The proposed logic is described in Custom Logic for Edition 1 Testing.
· All edition 2 IEDs that communicate with edition 1 IEDs will also implement the edition 1 custom logic for maintenance testing.
· The Bus Tie IED and the Transfer Breaker IED will be Edition 2 compliant but will also implement the custom logic to interface with Edition 1 IEDs
· Realistic setting values will be used in order to prove that the test methodologies work.
· Test cases will be based on these settings. They will include tests to verify settings as well as tests to verify protection scheme functions involving multiple IEDs that make up the scheme.
Possible issues and workarounds during the integrated application testing
· Will there be enough merging units if there are many IEDs that need them.
· Will there be a sufficient number of test systems for conventional voltages/ currents and sampled values as well as conventional logic inputs and GOOSE data to the IEDs?
· However, it is a lot easier to set up testing using sampled values directly into the network compared to wiring multiple currents and voltages into merging units.
· So some testing can be done without the merging unit but instead simulated by the test sets. Such testing scenario will also be needed to prove maintenance testing features.
· Breaker simulators?
o Breaker simulators with a/b contacts and close/open coils can be used, if available.
o Breaker simulators can be implemented internally in the IEDs with programmable logic
o These can also be simulated by test sets (logic output contacts to inject dc voltage into optical inputs of IEDs), but is too complicated for an integrated system and with so many hard-wired connections.
Communication Network architecture …..
Time Synchronization of IEDs and Test tools ….
HV Transmission Line Protection and Control
· Line1_P1_IED
o Line current differential protection
o Subscribes to L1_MU
o Exchange of current values
§ Conventional, over direct fiber between terminals?
§ Or R-SV over IP communication network?
· Line1_P2_IED
o Phase and Ground distance elements
o Subscribes to L1_MU and Bus230_MU
o Step distance (3 forward zones)
o POTT teleprotection scheme (Zone 2 elements). Permissive trip signals exchanged between terminals using
§ GOOSE/R-GOOSE messages over IP communication network.
o Auto-reclose and voltage/synch check – RREC1, RSYN1
· Line1_BC_IED
o Bay Controller
o All bay controllers shall implement interlocking
o All 230 kV side bay controllers shall check voltage and synchronization
o Implement SBO mode
o Control of CB_L1, DS_L11 and DS_L12
o Standalone IED or Implemented as part of Line1_P1_IED
· Line1_BF_IED
o Breaker Fail protection
o Based on current and breaker position
o Initiated by operation of Line1_P1_IED, Line1_P2_IED and Bus230_IED
o Trips all breakers connected to the 230 kV bus
o Direct Transfer Trip to opposite terminal of the line
o May be implemented as part either Line1_P1_IED or Bay Controller
Similar IEDs (P&C) for Line 2 and for the opposite terminals
HV-side Bus Protection
· Bus230_P1_IED
o Current differential
o Subscribes to merging units L1_MU, L2_MU, TXA_MU01 and TXB_MU01
o Trips all bus breakers
o Initiates all breaker fail protection for breakers connected to the bus
Transformer Protection and Control
· TxA_P1_IED
o Transformer Current differential
o Currents from merging units TXA_MU01 and TXA_MU02
o Trips breakers CB_TXA and CB_INC_A
o Initiates breaker fail of both breakers
· TxA_P2
o HV-side back-up overcurrent protection - phase and ground
§ PTOC1 (Inverse time)
§ High-set PTOC2 (no delay)
o Subscribes to TXA_MU01
o Trips breaker CB_TXA
o Initiates breaker fail
o May be implemented in bay controller
· TXA_P3_IED Breaker Fail
o Based on current and breaker position
o Subscribes to TXA_MU01
o May be implemented in bay controller
· TXA_BC_IED
o Bay controller
o All bay controllers shall implement interlocking
o Implement SBO mode for switch control
o Control of CB_TXA, DS_TXA1, and CB_TXA2
o Subscribes to TXA_MU01
Transformer TXB will have similar IEDs.
LV Distribution protection and Control
- Power distribution system
- Two LV incomers feed from the two transformers supply LV feeders and form two zones. (Zone A includes all objects connected to Bus A; and Zone B includes all objects connected to Bus B.
- Bus Tie breaker
- Common Transfer Bus fed from Bus A only, but Feeders in Zone B can connect toe this transfer bus.
- LV-side protection
NOTES:
· All IEDs in zone A will be edition 2
· All IEDs in zone B will be edition 1 (Custom logic for testing isolation will be implemented)
· The Bus Tie IED will be edition 2. (It will have the same custom logic used in edition 1 for communication with IEDs in zone B).
· The Transfer breaker IED will be edition 2
Feeder Protection and Control
· FdrA1_IED
o Includes both protection and bay control in a single IED. Separate IEDs are allowed
o Overcurrent – Phase and ground
§ PTOC1 (IEC Very Inverse time )
§ PTOC2 (no delay)
§ Trips its own feeder breaker
§ Initiates breaker fail
o Breaker failure RBRF1
§ Based on current and/or breaker position.
§ Trips all breakers connected to the bus that the feeder is connected to
§ Feeder IEDs connected to Bus A also trip the Transfer breaker, but feeder IEDs connected to Bus B do not.
o Bay controller controls CB_A1, DS_A11, DS_A11, DS_A12 and DS_A13
· Other feeders are similar
o FdrA2_IED, FdrA3_IED, etc. connected to Bus A
o FdrB1_IED, FdrB2_IED, etc. connected to Bus B
o Note: for the purpose of this integrated application testing, all the feeder IEDs will have identical settings.
Transfer Breaker IED
· XF_IED
o Includes both protection and bay control in a single IED. Separate IEDs are allowed
o Overcurrent – Phase and ground (similar to transfer breaker IED)
§ PTOC1 (IEC Very Inverse time )
§ PTOC2 (Instantaneous)
§ Trips the transfer breaker
§ For this integrated application testing the transfer breaker IED will have the same settings as the Feeder IEDs. Setting group change will not be implemented.
o Breaker failure RBRF1
§ Based on current and/or breaker position
§ Trips all breakers connected to Bus A
o Bay control function controls CB_XF, DS_XF1, DS_XF2 and XF3
o Bay control function shall implement interlocking and SBO mode
Incomer Protection
· INC_A_IED
o Includes both protection and bay control in a single IED. Separate IEDs are allowed
o Overcurrent backup (PTOC1 and PTOC2) for feeder faults, in case of failure of feeder IED.
§ PTOC1 (IEC Standard Inverse time). Coordinate with feeder PTOC1 and with Bus Tie PTOC1 when Incomer is suppling power to the other bus.
§ PTOC2 (Definite time). Coordinate with Bus Tie PTOC2 when bus tie breaker is closed. Coordinate with feeder when bus tie is open. Set to avoid operation on feeder line-end faults and maximum load conditions. Must detect all bus faults with minimum current.
§ When the Bus Tie breaker is closed, it will switch to a setting group (group 2) with higher pickup settings to be able to carry the additional load from the other feeders. Opening of the Bus Tie breaker will switch back to setting group 1.
o Fast reverse blocking bus protection to use same Overcurrent start (PTOC2.Str) with a separate timer (small definite time delay) as described below.
o Breaker Fail RBRF1
§ Based on current and/or breaker position
§ Trips HV-side breaker and all LV-side breakers connected to the Bus A zone.
o Bay control function controls CB_INC_A, DS_INC_A1, DS_INC_A2 and DS_INC_A3
Figure 3 Incomer Protection and Input/Output Signals
· INC_B_IED will have the same functions and INC_A_IED. Since it is based on Edition 1, it will have the custom logic for maintenance testing isolation.
LV Bus protection (Fast Bus Reverse Blocking scheme)
· Uses Incomer IED for fault detection, and uses the feeder IEDs connected to the bus and the bus tie to reverse block for external faults/