Testing the performance of IEC 61850 substation automation designs

Test facility for IEC 61850 designs

The objective of this project is to construct a test facility for assessing the performance of IEC 61850 substation automation designs. This project will focus more closely at the protection and control side of the IEC 61850 standard. This test facility will be used by zone substation designers, engineers, protection and commissioning office and field staff to understand the IEC 61850 standard.

It is then the intention that this test facility will aid ActewAGL Distribution’s goal of an IEC 61850 compliant substation automation system that can be implemented as part of the impending distribution zone substation modernization project, over the next five to ten years.

Another reason that this configuration has been chosen is due to the probability that the next 132/11 kV distribution zone substation, which is due to commence construction in 2016, will be constructed with this two transformer configuration.

The test facility will be constructed as a one 132/11 kV power transformer distribution zone substation. This has been decided because of both time and space limitations.

As a result, the remaining part of the test facility will be simulated by using IED configurator / simulator software to mimic both control and protection functions.

Once this test facility is operational, it will be extensively evaluated and its overall performance benchmarked to both the IEC 61850 standard and ActewAGL Distribution’s own internal regulations to determine if the substation automation systems should be implemented in ActewAGL Distributions electrical network.

Upon completion of this testing, cost and performance comparisons will be carried out to determine if the implementation of this standard can be justified over the current designs in service.

Design and implementation

Discussed in detail are the reasons for the hardware selection, the guidelines that the test facility is to be built to and its pre-commissioning checks prior to it being used to assess IEC 61850 compliant substation automation system designs.

The substation automation designs developed with the use of the test facility will be implemented into ActewAGL Distributions electrical network.

Hardware Selection

The system hardware installed in the test facility comprises of the following devices:

1. Protection and Control relays, or IEDs;
2. Industrial Ethernet switches;
3. GPS clock;
4. 125V DC Power Supply;
5. Remote Terminal Unit; and
6. Optic Fibre Cabling.

It has been decided that only devices that can be installed in a common 19 inch rack arrangement will be evaluated.

Protection and Control IEDs

ActewAGL Distribution’s protection philosophy is based on the provision of duplicate redundant systems operating simultaneously to mitigate failure and ensure availability under all normal and abnormal system conditions. These duplicate redundant systems are driven by a risk based philosophy of providing an “n – 1” contingency. This implies ‘A’ and ‘B’ protection schemes for each zone of protection with separate DC power supplies to mitigate the risk of any system failure.

Also due to the project’s time constraints it was decided that using familiar IEDs rather than introducing new devices would allow more time to use the test facility, rather than also needing to learn a new device and its quirks.

In order to assess each different device vendor equally and fairly, a selection criteria was utilised. The selection criteria is designed to be simple. The fundamentals of power system protection are not being rewritten throughout this evaluation process.

The criteria allowed ActewAGL Distribution to identify the strengths and weaknesses in each IED in order to suit the needs of both the test facility and the future implementation of the final substation automation system design.