Testing and validating SCADA (Supervisory Control and Data Acquisition) systems in substations is a critical but challenging task. It becomes exponentially more complex when hundreds of substations need to be tested over a limited time frame. This post explores a real-world case of automating SCADA testing and the incredible efficiency gains achieved through automation and interdisciplinary collaboration.
The Challenge of Manual Substation Testing
Testing a single substation involves several steps, from checking that relays are executing protection logic correctly to verifying that data flows between the station and the control center are accurate. Each point of data must be meticulously checked to ensure that all values and controls are properly communicated and match on both ends.
To illustrate the challenge of manual testing, imagine a field technician or engineer in the field, whom we’ll call Chris, and a SCADA control center operator named Emma. During testing, Chris would force a value on a point, and Emma would confirm what she sees on her end. For example, Chris might say, “Hey Emma, I just forced a point of 20. What are you seeing?” If Emma responds, “I’m seeing 2, not 20,” the issue would need to be noted, and adjustments would have to be made. This labor-intensive process is repeated point by point, making manual testing highly time-consuming and prone to error.
Additionally, each station requires a detailed test plan before testing can begin. This plan must outline the specific types of work to be done, the values that will be forced, and the expected results. Without automation, this planning process alone can take several hours.
Enter Automation: A Game-Changer
The challenges of manual testing highlight the need for a more efficient and accurate approach. This is where automation steps in. By bringing together an interdisciplinary team of power system engineers, cybersecurity experts, and software developers, an automated solution was created to streamline both the creation and execution of the test plans.
The automation process involved writing software scripts that could handle various tasks, from digesting migration files (used for data upgrades from legacy SCADA systems to new Advanced Distribution Management Systems, or ADMS) to creating comprehensive test plans. These scripts could identify errors in the migration data and send them back to the migration team for resolution, making the process more efficient and less error-prone.
The autogenerated code for the test plan could also ingest the Remote Terminal Unit (RTU) configuration file for each substation and quickly produce a station-specific test plan. A second script was created for test execution, which could run on a laptop in the field, connect to the RTU, and facilitate bidirectional communication. This allowed the software to simulate force operations to the RTU safely, ensuring all testing switches remained open for safety.
Automated Testing Execution and Results
Traditionally, a technician in the field, like the hypothetical Chris, would be manually forcing values and communicating with a control center operator like Emma to confirm results. With automation, the process changed dramatically. The software running on a laptop could now automatically take in historian data, force all points, and, once complete, load the historian file to automatically produce results. These results would indicate whether each point passed, failed, or required scaling adjustments.
The time savings from this approach were significant. For example, creating a test plan manually could take approximately 2.4 hours, requiring a point-by-point comparison of the RTU configuration to the migration file—a painstakingly slow process. With automation, the same task could be completed in just 15 seconds, with an additional 10 minutes for a quality control (QC) review by an engineer.
The execution of the test was also vastly improved. Manual testing took about 40 seconds per point, with the hypothetical technician Chris on the phone with Emma confirming each value. The automated script, however, could accomplish this in just 5 seconds per point. The result? A task that would typically take a day or a day and a half to complete for 300 points per substation was reduced to half a day or even a quarter of a day.
The Impact of Automation on Efficiency
When calculating the overall savings, the results were impressive. The automated approach saved approximately 3,000 hours of work, translating to around 363 person-days of labor. For large substations, this meant significant reductions in time, cost, and effort, allowing teams to focus on more critical tasks and reducing the risk of errors in the testing process.
Key Takeaways
This case study illustrates the power of automation in tackling complex engineering challenges. When faced with testing hundreds of substations, the solution was to bring together an interdisciplinary team, ensure safety and engineering oversight, and leverage automation to achieve remarkable efficiency gains. Proper documentation was also essential, not only for delivering the project but for ensuring that all processes were conducted safely.
For any engineering project facing similar challenges, the lesson is clear: leverage automation where possible, maintain rigorous documentation and oversight, and involve experts from various disciplines to achieve the best results.
About the Author:
Dr Nathan Wallace, PE has BS degrees in Electrical Engineering, and Physics, a MS in Engineering, and a Ph.D. in Engineering from Louisiana Tech University. Nathan is a CoFounder and Director of GridIntel. Nathan is actively involved in the IEEE-PES PSRC and PSCC technical committees and currently chairs two IEEE standards development working groups. Nathan is a licensed PE in AL, LA, MS, OH, and TN.