Siemens SIPROTEC 5 Replacement and Upgrade Guide

Part 3: Using DIGSI 5 for Engineering Configuration and Parameter Migration

3.1 Offline Engineering and Online Synchronization of DIGSI 5

DIGSI 5 is a unified engineering tool for SIPROTEC 5, supporting the entire process from single line diagram design to equipment parameterization. When replacing old equipment, the following steps are recommended:

Generate product code using SIPROTEC 5 configurator

Select the device type, standard variant, and communication module on the Siemens website, and the system will automatically generate a unique product code. This code can be directly imported into DIGSI 5.

Create a project in DIGSI 5

After importing all SIPROTEC 5 devices, use the "Single Line Editor" to draw a system topology and graphically associate the protection function group with the actual primary devices (circuit breakers, CTs, VTs).

Migration protection setting

Although SIPROTEC 4 and SIPROTEC 5 have different fixed value formats, DIGSI 5 supports exporting CSV files from old projects, converting them, and then re inputting them. For distance protection, attention should be paid to the correspondence between the quadrilateral characteristic (Polygon) and the MHO characteristic.

3.2 Application Templates Acceleration Configuration

DIGSI 5 provides pre configured application templates for each device, such as:

Distance Protection Basic Template (Basic)

Distance protection of resonant grounding/arc suppression coil grounding system (including automatic reclosing)

Reactive distance protection (RMD) for overhead lines in grounding systems

RMD distance protection applicable to 1.5 circuit breaker wiring

After selecting the template, the system will automatically create the required functional groups (such as distance protection group, circuit breaker management group, fault recording group) and complete internal signal routing. Engineers only need to modify the fixed value and CT/VT ratio.

3.3 Configuration of Protection Communication

For differential protection or directional comparison protection, a protection interface needs to be configured. In DIGSI 5:

Add communication modules (such as USART-AE-2FO) to the device hardware tree

Select the "Protection Interface" application and set the communication type (Type 1 for differential protection, Type 2 for general data transmission)

Assign binary signals (such as trip permits and direction information) that need to be transmitted to the protection interface channel through the "Communication Mapping" editor

When performing mixed operations, the original communication converter settings remain unchanged on the SIPROTEC 4 side, while the corresponding fiber module and baud rate (64 kbit/s to 2 Mbit/s) are selected on the SIPROTEC 5 side.

Part Four: Testing and Troubleshooting

4.1 Offline verification using DIGSI 5 test suite

DIGSI 5 integrates a powerful testing suite that can verify protection functions without connecting a secondary tester:

Test sequence generator: It can create multi-step test sequences (such as simulating A-phase ground faults, three-phase short circuits), load them into the built-in test actuators of the device, and simulate analog and binary inputs in real time. This allows offline verification of all protection logic and automatic reclosing sequences before replacing the device.

Protection function test view: In distance protection testing, the position of the impedance trajectory falling in the characteristic circle or quadrilateral can be displayed in real time, and the start/trip signal can be recorded.

4.2 Necessary tests after on-site replacement

Hardware wiring test: Force close a relay output through DIGSI 5, observe the displacement of the binary input of the remote device, and verify the correct wiring of the inter interval interlock.

Loop Test for Protection Interface: Select the communication module interface, send the test message, receive it after remote loopback, and calculate the bit error rate and transmission delay. This test can diagnose the quality of fiber optic links.

Differential protection stability test: After a load operation of the equipment, use the phasor diagram of DIGSI 5 to compare the amplitude and phase of the current on this side and the opposite side, ensuring that the differential current is close to zero and the braking current is normal.

Circuit breaker failure protection transmission: Simulate protection startup and verify whether the circuit breaker failure protection (50BF) issues a re trip or bus trip command according to the set delay.

4.3 Common Troubleshooting

Possible causes and solutions for the fault phenomenon

New and old devices cannot establish protection communication module type mismatch (Type1 vs Type2) or communication parameter inconsistency. Check the interface types of both parties (USART-AE-2FO and SIPROTEC 4-side converter compatibility) and confirm that the baud rate and CRC check are consistent

Differential protection misoperation or refusal CT ratio setting error, incorrect vector group calibration in DIGSI 5 differential protection function group, input primary side rated current and wiring group (such as Yyn0), equipment automatically calculates compensation